xref: /linux/tools/testing/selftests/landlock/fs_test.c (revision 316d06b011300ece31f90febb432385636f3d00e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Landlock tests - Filesystem
4  *
5  * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
6  * Copyright © 2020 ANSSI
7  * Copyright © 2020-2022 Microsoft Corporation
8  */
9 
10 #define _GNU_SOURCE
11 #include <asm/termbits.h>
12 #include <fcntl.h>
13 #include <libgen.h>
14 #include <linux/fiemap.h>
15 #include <linux/landlock.h>
16 #include <linux/magic.h>
17 #include <sched.h>
18 #include <stddef.h>
19 #include <stdio.h>
20 #include <string.h>
21 #include <sys/capability.h>
22 #include <sys/ioctl.h>
23 #include <sys/mount.h>
24 #include <sys/prctl.h>
25 #include <sys/sendfile.h>
26 #include <sys/socket.h>
27 #include <sys/stat.h>
28 #include <sys/sysmacros.h>
29 #include <sys/un.h>
30 #include <sys/vfs.h>
31 #include <unistd.h>
32 
33 /*
34  * Intentionally included last to work around header conflict.
35  * See https://sourceware.org/glibc/wiki/Synchronizing_Headers.
36  */
37 #include <linux/fs.h>
38 #include <linux/mount.h>
39 
40 /* Defines AT_EXECVE_CHECK without type conflicts. */
41 #define _ASM_GENERIC_FCNTL_H
42 #include <linux/fcntl.h>
43 
44 #include "audit.h"
45 #include "common.h"
46 
47 #ifndef renameat2
48 int renameat2(int olddirfd, const char *oldpath, int newdirfd,
49 	      const char *newpath, unsigned int flags)
50 {
51 	return syscall(__NR_renameat2, olddirfd, oldpath, newdirfd, newpath,
52 		       flags);
53 }
54 #endif
55 
56 #ifndef open_tree
57 int open_tree(int dfd, const char *filename, unsigned int flags)
58 {
59 	return syscall(__NR_open_tree, dfd, filename, flags);
60 }
61 #endif
62 
63 static int sys_execveat(int dirfd, const char *pathname, char *const argv[],
64 			char *const envp[], int flags)
65 {
66 	return syscall(__NR_execveat, dirfd, pathname, argv, envp, flags);
67 }
68 
69 #ifndef RENAME_EXCHANGE
70 #define RENAME_EXCHANGE (1 << 1)
71 #endif
72 
73 static const char bin_true[] = "./true";
74 
75 /* Paths (sibling number and depth) */
76 static const char dir_s1d1[] = TMP_DIR "/s1d1";
77 static const char file1_s1d1[] = TMP_DIR "/s1d1/f1";
78 static const char file2_s1d1[] = TMP_DIR "/s1d1/f2";
79 static const char dir_s1d2[] = TMP_DIR "/s1d1/s1d2";
80 static const char file1_s1d2[] = TMP_DIR "/s1d1/s1d2/f1";
81 static const char file2_s1d2[] = TMP_DIR "/s1d1/s1d2/f2";
82 static const char dir_s1d3[] = TMP_DIR "/s1d1/s1d2/s1d3";
83 static const char file1_s1d3[] = TMP_DIR "/s1d1/s1d2/s1d3/f1";
84 static const char file2_s1d3[] = TMP_DIR "/s1d1/s1d2/s1d3/f2";
85 
86 static const char dir_s2d1[] = TMP_DIR "/s2d1";
87 static const char file1_s2d1[] = TMP_DIR "/s2d1/f1";
88 static const char dir_s2d2[] = TMP_DIR "/s2d1/s2d2";
89 static const char file1_s2d2[] = TMP_DIR "/s2d1/s2d2/f1";
90 static const char dir_s2d3[] = TMP_DIR "/s2d1/s2d2/s2d3";
91 static const char file1_s2d3[] = TMP_DIR "/s2d1/s2d2/s2d3/f1";
92 static const char file2_s2d3[] = TMP_DIR "/s2d1/s2d2/s2d3/f2";
93 
94 static const char dir_s3d1[] = TMP_DIR "/s3d1";
95 static const char file1_s3d1[] = TMP_DIR "/s3d1/f1";
96 /* dir_s3d2 is a mount point. */
97 static const char dir_s3d2[] = TMP_DIR "/s3d1/s3d2";
98 static const char dir_s3d3[] = TMP_DIR "/s3d1/s3d2/s3d3";
99 static const char file1_s3d3[] = TMP_DIR "/s3d1/s3d2/s3d3/f1";
100 static const char dir_s3d4[] = TMP_DIR "/s3d1/s3d2/s3d4";
101 static const char file1_s3d4[] = TMP_DIR "/s3d1/s3d2/s3d4/f1";
102 
103 /*
104  * layout1 hierarchy:
105  *
106  * tmp
107  * ├── s1d1
108  * │   ├── f1
109  * │   ├── f2
110  * │   └── s1d2
111  * │       ├── f1
112  * │       ├── f2
113  * │       └── s1d3
114  * │           ├── f1
115  * │           └── f2
116  * ├── s2d1
117  * │   ├── f1
118  * │   └── s2d2
119  * │       ├── f1
120  * │       └── s2d3
121  * │           ├── f1
122  * │           └── f2
123  * └── s3d1
124  *     ├── f1
125  *     └── s3d2 [mount point]
126  *         ├── s3d3
127  *         │   └── f1
128  *         └── s3d4
129  *             └── f1
130  */
131 
132 static bool fgrep(FILE *const inf, const char *const str)
133 {
134 	char line[32];
135 	const int slen = strlen(str);
136 
137 	while (!feof(inf)) {
138 		if (!fgets(line, sizeof(line), inf))
139 			break;
140 		if (strncmp(line, str, slen))
141 			continue;
142 
143 		return true;
144 	}
145 
146 	return false;
147 }
148 
149 static bool supports_filesystem(const char *const filesystem)
150 {
151 	char str[32];
152 	int len;
153 	bool res = true;
154 	FILE *const inf = fopen("/proc/filesystems", "r");
155 
156 	/*
157 	 * Consider that the filesystem is supported if we cannot get the
158 	 * supported ones.
159 	 */
160 	if (!inf)
161 		return true;
162 
163 	/* filesystem can be null for bind mounts. */
164 	if (!filesystem)
165 		goto out;
166 
167 	len = snprintf(str, sizeof(str), "nodev\t%s\n", filesystem);
168 	if (len >= sizeof(str))
169 		/* Ignores too-long filesystem names. */
170 		goto out;
171 
172 	res = fgrep(inf, str);
173 
174 out:
175 	fclose(inf);
176 	return res;
177 }
178 
179 static bool cwd_matches_fs(unsigned int fs_magic)
180 {
181 	struct statfs statfs_buf;
182 
183 	if (!fs_magic)
184 		return true;
185 
186 	if (statfs(".", &statfs_buf))
187 		return true;
188 
189 	return statfs_buf.f_type == fs_magic;
190 }
191 
192 static void mkdir_parents(struct __test_metadata *const _metadata,
193 			  const char *const path)
194 {
195 	char *walker;
196 	const char *parent;
197 	int i, err;
198 
199 	ASSERT_NE(path[0], '\0');
200 	walker = strdup(path);
201 	ASSERT_NE(NULL, walker);
202 	parent = walker;
203 	for (i = 1; walker[i]; i++) {
204 		if (walker[i] != '/')
205 			continue;
206 		walker[i] = '\0';
207 		err = mkdir(parent, 0700);
208 		ASSERT_FALSE(err && errno != EEXIST)
209 		{
210 			TH_LOG("Failed to create directory \"%s\": %s", parent,
211 			       strerror(errno));
212 		}
213 		walker[i] = '/';
214 	}
215 	free(walker);
216 }
217 
218 static void create_directory(struct __test_metadata *const _metadata,
219 			     const char *const path)
220 {
221 	mkdir_parents(_metadata, path);
222 	ASSERT_EQ(0, mkdir(path, 0700))
223 	{
224 		TH_LOG("Failed to create directory \"%s\": %s", path,
225 		       strerror(errno));
226 	}
227 }
228 
229 static void create_file(struct __test_metadata *const _metadata,
230 			const char *const path)
231 {
232 	mkdir_parents(_metadata, path);
233 	ASSERT_EQ(0, mknod(path, S_IFREG | 0700, 0))
234 	{
235 		TH_LOG("Failed to create file \"%s\": %s", path,
236 		       strerror(errno));
237 	}
238 }
239 
240 static int remove_path(const char *const path)
241 {
242 	char *walker;
243 	int i, ret, err = 0;
244 
245 	walker = strdup(path);
246 	if (!walker) {
247 		err = ENOMEM;
248 		goto out;
249 	}
250 	if (unlink(path) && rmdir(path)) {
251 		if (errno != ENOENT && errno != ENOTDIR)
252 			err = errno;
253 		goto out;
254 	}
255 	for (i = strlen(walker); i > 0; i--) {
256 		if (walker[i] != '/')
257 			continue;
258 		walker[i] = '\0';
259 		ret = rmdir(walker);
260 		if (ret) {
261 			if (errno != ENOTEMPTY && errno != EBUSY)
262 				err = errno;
263 			goto out;
264 		}
265 		if (strcmp(walker, TMP_DIR) == 0)
266 			goto out;
267 	}
268 
269 out:
270 	free(walker);
271 	return err;
272 }
273 
274 struct mnt_opt {
275 	const char *const source;
276 	const char *const type;
277 	const unsigned long flags;
278 	const char *const data;
279 };
280 
281 #define MNT_TMP_DATA "size=4m,mode=700"
282 
283 static const struct mnt_opt mnt_tmp = {
284 	.type = "tmpfs",
285 	.data = MNT_TMP_DATA,
286 };
287 
288 static int mount_opt(const struct mnt_opt *const mnt, const char *const target)
289 {
290 	return mount(mnt->source ?: mnt->type, target, mnt->type, mnt->flags,
291 		     mnt->data);
292 }
293 
294 static void prepare_layout_opt(struct __test_metadata *const _metadata,
295 			       const struct mnt_opt *const mnt)
296 {
297 	disable_caps(_metadata);
298 	umask(0077);
299 	create_directory(_metadata, TMP_DIR);
300 
301 	/*
302 	 * Do not pollute the rest of the system: creates a private mount point
303 	 * for tests relying on pivot_root(2) and move_mount(2).
304 	 */
305 	set_cap(_metadata, CAP_SYS_ADMIN);
306 	ASSERT_EQ(0, unshare(CLONE_NEWNS | CLONE_NEWCGROUP));
307 	ASSERT_EQ(0, mount_opt(mnt, TMP_DIR))
308 	{
309 		TH_LOG("Failed to mount the %s filesystem: %s", mnt->type,
310 		       strerror(errno));
311 		/*
312 		 * FIXTURE_TEARDOWN() is not called when FIXTURE_SETUP()
313 		 * failed, so we need to explicitly do a minimal cleanup to
314 		 * avoid cascading errors with other tests that don't depend on
315 		 * the same filesystem.
316 		 */
317 		remove_path(TMP_DIR);
318 	}
319 	ASSERT_EQ(0, mount(NULL, TMP_DIR, NULL, MS_PRIVATE | MS_REC, NULL));
320 	clear_cap(_metadata, CAP_SYS_ADMIN);
321 }
322 
323 static void prepare_layout(struct __test_metadata *const _metadata)
324 {
325 	prepare_layout_opt(_metadata, &mnt_tmp);
326 }
327 
328 static void cleanup_layout(struct __test_metadata *const _metadata)
329 {
330 	set_cap(_metadata, CAP_SYS_ADMIN);
331 	if (umount(TMP_DIR)) {
332 		/*
333 		 * According to the test environment, the mount point of the
334 		 * current directory may be shared or not, which changes the
335 		 * visibility of the nested TMP_DIR mount point for the test's
336 		 * parent process doing this cleanup.
337 		 */
338 		ASSERT_EQ(EINVAL, errno);
339 	}
340 	clear_cap(_metadata, CAP_SYS_ADMIN);
341 	EXPECT_EQ(0, remove_path(TMP_DIR));
342 }
343 
344 /* clang-format off */
345 FIXTURE(layout0) {};
346 /* clang-format on */
347 
348 FIXTURE_SETUP(layout0)
349 {
350 	prepare_layout(_metadata);
351 }
352 
353 FIXTURE_TEARDOWN_PARENT(layout0)
354 {
355 	cleanup_layout(_metadata);
356 }
357 
358 static void create_layout1(struct __test_metadata *const _metadata)
359 {
360 	create_file(_metadata, file1_s1d1);
361 	create_file(_metadata, file1_s1d2);
362 	create_file(_metadata, file1_s1d3);
363 	create_file(_metadata, file2_s1d1);
364 	create_file(_metadata, file2_s1d2);
365 	create_file(_metadata, file2_s1d3);
366 
367 	create_file(_metadata, file1_s2d1);
368 	create_file(_metadata, file1_s2d2);
369 	create_file(_metadata, file1_s2d3);
370 	create_file(_metadata, file2_s2d3);
371 
372 	create_file(_metadata, file1_s3d1);
373 	create_directory(_metadata, dir_s3d2);
374 	set_cap(_metadata, CAP_SYS_ADMIN);
375 	ASSERT_EQ(0, mount_opt(&mnt_tmp, dir_s3d2));
376 	clear_cap(_metadata, CAP_SYS_ADMIN);
377 
378 	create_file(_metadata, file1_s3d3);
379 	create_file(_metadata, file1_s3d4);
380 }
381 
382 static void remove_layout1(struct __test_metadata *const _metadata)
383 {
384 	EXPECT_EQ(0, remove_path(file2_s1d3));
385 	EXPECT_EQ(0, remove_path(file2_s1d2));
386 	EXPECT_EQ(0, remove_path(file2_s1d1));
387 	EXPECT_EQ(0, remove_path(file1_s1d3));
388 	EXPECT_EQ(0, remove_path(file1_s1d2));
389 	EXPECT_EQ(0, remove_path(file1_s1d1));
390 	EXPECT_EQ(0, remove_path(dir_s1d3));
391 
392 	EXPECT_EQ(0, remove_path(file2_s2d3));
393 	EXPECT_EQ(0, remove_path(file1_s2d3));
394 	EXPECT_EQ(0, remove_path(file1_s2d2));
395 	EXPECT_EQ(0, remove_path(file1_s2d1));
396 	EXPECT_EQ(0, remove_path(dir_s2d2));
397 
398 	EXPECT_EQ(0, remove_path(file1_s3d1));
399 	EXPECT_EQ(0, remove_path(file1_s3d3));
400 	EXPECT_EQ(0, remove_path(file1_s3d4));
401 	set_cap(_metadata, CAP_SYS_ADMIN);
402 	umount(dir_s3d2);
403 	clear_cap(_metadata, CAP_SYS_ADMIN);
404 	EXPECT_EQ(0, remove_path(dir_s3d2));
405 }
406 
407 /* clang-format off */
408 FIXTURE(layout1) {};
409 /* clang-format on */
410 
411 FIXTURE_SETUP(layout1)
412 {
413 	prepare_layout(_metadata);
414 
415 	create_layout1(_metadata);
416 }
417 
418 FIXTURE_TEARDOWN_PARENT(layout1)
419 {
420 	remove_layout1(_metadata);
421 
422 	cleanup_layout(_metadata);
423 }
424 
425 /*
426  * This helper enables to use the ASSERT_* macros and print the line number
427  * pointing to the test caller.
428  */
429 static int test_open_rel(const int dirfd, const char *const path,
430 			 const int flags)
431 {
432 	int fd;
433 
434 	/* Works with file and directories. */
435 	fd = openat(dirfd, path, flags | O_CLOEXEC);
436 	if (fd < 0)
437 		return errno;
438 	/*
439 	 * Mixing error codes from close(2) and open(2) should not lead to any
440 	 * (access type) confusion for this test.
441 	 */
442 	if (close(fd) != 0)
443 		return errno;
444 	return 0;
445 }
446 
447 static int test_open(const char *const path, const int flags)
448 {
449 	return test_open_rel(AT_FDCWD, path, flags);
450 }
451 
452 TEST_F_FORK(layout1, no_restriction)
453 {
454 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
455 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
456 	ASSERT_EQ(0, test_open(file2_s1d1, O_RDONLY));
457 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
458 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
459 	ASSERT_EQ(0, test_open(file2_s1d2, O_RDONLY));
460 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
461 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
462 
463 	ASSERT_EQ(0, test_open(dir_s2d1, O_RDONLY));
464 	ASSERT_EQ(0, test_open(file1_s2d1, O_RDONLY));
465 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY));
466 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDONLY));
467 	ASSERT_EQ(0, test_open(dir_s2d3, O_RDONLY));
468 	ASSERT_EQ(0, test_open(file1_s2d3, O_RDONLY));
469 
470 	ASSERT_EQ(0, test_open(dir_s3d1, O_RDONLY));
471 	ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY));
472 	ASSERT_EQ(0, test_open(dir_s3d3, O_RDONLY));
473 }
474 
475 TEST_F_FORK(layout1, inval)
476 {
477 	struct landlock_path_beneath_attr path_beneath = {
478 		.allowed_access = LANDLOCK_ACCESS_FS_READ_FILE |
479 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
480 		.parent_fd = -1,
481 	};
482 	struct landlock_ruleset_attr ruleset_attr = {
483 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE |
484 				     LANDLOCK_ACCESS_FS_WRITE_FILE,
485 	};
486 	int ruleset_fd;
487 
488 	path_beneath.parent_fd =
489 		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
490 	ASSERT_LE(0, path_beneath.parent_fd);
491 
492 	ruleset_fd = open(dir_s1d1, O_PATH | O_DIRECTORY | O_CLOEXEC);
493 	ASSERT_LE(0, ruleset_fd);
494 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
495 					&path_beneath, 0));
496 	/* Returns EBADF because ruleset_fd is not a landlock-ruleset FD. */
497 	ASSERT_EQ(EBADF, errno);
498 	ASSERT_EQ(0, close(ruleset_fd));
499 
500 	ruleset_fd = open(dir_s1d1, O_DIRECTORY | O_CLOEXEC);
501 	ASSERT_LE(0, ruleset_fd);
502 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
503 					&path_beneath, 0));
504 	/* Returns EBADFD because ruleset_fd is not a valid ruleset. */
505 	ASSERT_EQ(EBADFD, errno);
506 	ASSERT_EQ(0, close(ruleset_fd));
507 
508 	/* Gets a real ruleset. */
509 	ruleset_fd =
510 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
511 	ASSERT_LE(0, ruleset_fd);
512 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
513 				       &path_beneath, 0));
514 	ASSERT_EQ(0, close(path_beneath.parent_fd));
515 
516 	/* Tests without O_PATH. */
517 	path_beneath.parent_fd = open(dir_s1d2, O_DIRECTORY | O_CLOEXEC);
518 	ASSERT_LE(0, path_beneath.parent_fd);
519 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
520 				       &path_beneath, 0));
521 	ASSERT_EQ(0, close(path_beneath.parent_fd));
522 
523 	/* Tests with a ruleset FD. */
524 	path_beneath.parent_fd = ruleset_fd;
525 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
526 					&path_beneath, 0));
527 	ASSERT_EQ(EBADFD, errno);
528 
529 	/* Checks unhandled allowed_access. */
530 	path_beneath.parent_fd =
531 		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
532 	ASSERT_LE(0, path_beneath.parent_fd);
533 
534 	/* Test with legitimate values. */
535 	path_beneath.allowed_access |= LANDLOCK_ACCESS_FS_EXECUTE;
536 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
537 					&path_beneath, 0));
538 	ASSERT_EQ(EINVAL, errno);
539 	path_beneath.allowed_access &= ~LANDLOCK_ACCESS_FS_EXECUTE;
540 
541 	/* Tests with denied-by-default access right. */
542 	path_beneath.allowed_access |= LANDLOCK_ACCESS_FS_REFER;
543 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
544 					&path_beneath, 0));
545 	ASSERT_EQ(EINVAL, errno);
546 	path_beneath.allowed_access &= ~LANDLOCK_ACCESS_FS_REFER;
547 
548 	/* Test with unknown (64-bits) value. */
549 	path_beneath.allowed_access |= (1ULL << 60);
550 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
551 					&path_beneath, 0));
552 	ASSERT_EQ(EINVAL, errno);
553 	path_beneath.allowed_access &= ~(1ULL << 60);
554 
555 	/* Test with no access. */
556 	path_beneath.allowed_access = 0;
557 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
558 					&path_beneath, 0));
559 	ASSERT_EQ(ENOMSG, errno);
560 	path_beneath.allowed_access &= ~(1ULL << 60);
561 
562 	ASSERT_EQ(0, close(path_beneath.parent_fd));
563 
564 	/* Enforces the ruleset. */
565 	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
566 	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
567 
568 	ASSERT_EQ(0, close(ruleset_fd));
569 }
570 
571 /* clang-format off */
572 
573 #define ACCESS_FILE ( \
574 	LANDLOCK_ACCESS_FS_EXECUTE | \
575 	LANDLOCK_ACCESS_FS_WRITE_FILE | \
576 	LANDLOCK_ACCESS_FS_READ_FILE | \
577 	LANDLOCK_ACCESS_FS_TRUNCATE | \
578 	LANDLOCK_ACCESS_FS_IOCTL_DEV)
579 
580 #define ACCESS_LAST LANDLOCK_ACCESS_FS_IOCTL_DEV
581 
582 #define ACCESS_ALL ( \
583 	ACCESS_FILE | \
584 	LANDLOCK_ACCESS_FS_READ_DIR | \
585 	LANDLOCK_ACCESS_FS_REMOVE_DIR | \
586 	LANDLOCK_ACCESS_FS_REMOVE_FILE | \
587 	LANDLOCK_ACCESS_FS_MAKE_CHAR | \
588 	LANDLOCK_ACCESS_FS_MAKE_DIR | \
589 	LANDLOCK_ACCESS_FS_MAKE_REG | \
590 	LANDLOCK_ACCESS_FS_MAKE_SOCK | \
591 	LANDLOCK_ACCESS_FS_MAKE_FIFO | \
592 	LANDLOCK_ACCESS_FS_MAKE_BLOCK | \
593 	LANDLOCK_ACCESS_FS_MAKE_SYM | \
594 	LANDLOCK_ACCESS_FS_REFER)
595 
596 /* clang-format on */
597 
598 TEST_F_FORK(layout1, file_and_dir_access_rights)
599 {
600 	__u64 access;
601 	int err;
602 	struct landlock_path_beneath_attr path_beneath_file = {},
603 					  path_beneath_dir = {};
604 	struct landlock_ruleset_attr ruleset_attr = {
605 		.handled_access_fs = ACCESS_ALL,
606 	};
607 	const int ruleset_fd =
608 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
609 
610 	ASSERT_LE(0, ruleset_fd);
611 
612 	/* Tests access rights for files. */
613 	path_beneath_file.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
614 	ASSERT_LE(0, path_beneath_file.parent_fd);
615 
616 	/* Tests access rights for directories. */
617 	path_beneath_dir.parent_fd =
618 		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
619 	ASSERT_LE(0, path_beneath_dir.parent_fd);
620 
621 	for (access = 1; access <= ACCESS_LAST; access <<= 1) {
622 		path_beneath_dir.allowed_access = access;
623 		ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
624 					       LANDLOCK_RULE_PATH_BENEATH,
625 					       &path_beneath_dir, 0));
626 
627 		path_beneath_file.allowed_access = access;
628 		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
629 					&path_beneath_file, 0);
630 		if (access & ACCESS_FILE) {
631 			ASSERT_EQ(0, err);
632 		} else {
633 			ASSERT_EQ(-1, err);
634 			ASSERT_EQ(EINVAL, errno);
635 		}
636 	}
637 	ASSERT_EQ(0, close(path_beneath_file.parent_fd));
638 	ASSERT_EQ(0, close(path_beneath_dir.parent_fd));
639 	ASSERT_EQ(0, close(ruleset_fd));
640 }
641 
642 TEST_F_FORK(layout0, ruleset_with_unknown_access)
643 {
644 	__u64 access_mask;
645 
646 	for (access_mask = 1ULL << 63; access_mask != ACCESS_LAST;
647 	     access_mask >>= 1) {
648 		struct landlock_ruleset_attr ruleset_attr = {
649 			.handled_access_fs = access_mask,
650 		};
651 
652 		ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr,
653 						      sizeof(ruleset_attr), 0));
654 		ASSERT_EQ(EINVAL, errno);
655 	}
656 }
657 
658 TEST_F_FORK(layout0, rule_with_unknown_access)
659 {
660 	__u64 access;
661 	struct landlock_path_beneath_attr path_beneath = {};
662 	const struct landlock_ruleset_attr ruleset_attr = {
663 		.handled_access_fs = ACCESS_ALL,
664 	};
665 	const int ruleset_fd =
666 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
667 
668 	ASSERT_LE(0, ruleset_fd);
669 
670 	path_beneath.parent_fd =
671 		open(TMP_DIR, O_PATH | O_DIRECTORY | O_CLOEXEC);
672 	ASSERT_LE(0, path_beneath.parent_fd);
673 
674 	for (access = 1ULL << 63; access != ACCESS_LAST; access >>= 1) {
675 		path_beneath.allowed_access = access;
676 		EXPECT_EQ(-1, landlock_add_rule(ruleset_fd,
677 						LANDLOCK_RULE_PATH_BENEATH,
678 						&path_beneath, 0));
679 		EXPECT_EQ(EINVAL, errno);
680 	}
681 	ASSERT_EQ(0, close(path_beneath.parent_fd));
682 	ASSERT_EQ(0, close(ruleset_fd));
683 }
684 
685 TEST_F_FORK(layout1, rule_with_unhandled_access)
686 {
687 	struct landlock_ruleset_attr ruleset_attr = {
688 		.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
689 	};
690 	struct landlock_path_beneath_attr path_beneath = {};
691 	int ruleset_fd;
692 	__u64 access;
693 
694 	ruleset_fd =
695 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
696 	ASSERT_LE(0, ruleset_fd);
697 
698 	path_beneath.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
699 	ASSERT_LE(0, path_beneath.parent_fd);
700 
701 	for (access = 1; access > 0; access <<= 1) {
702 		int err;
703 
704 		path_beneath.allowed_access = access;
705 		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
706 					&path_beneath, 0);
707 		if (access == ruleset_attr.handled_access_fs) {
708 			EXPECT_EQ(0, err);
709 		} else {
710 			EXPECT_EQ(-1, err);
711 			EXPECT_EQ(EINVAL, errno);
712 		}
713 	}
714 
715 	EXPECT_EQ(0, close(path_beneath.parent_fd));
716 	EXPECT_EQ(0, close(ruleset_fd));
717 }
718 
719 static void add_path_beneath(struct __test_metadata *const _metadata,
720 			     const int ruleset_fd, const __u64 allowed_access,
721 			     const char *const path)
722 {
723 	struct landlock_path_beneath_attr path_beneath = {
724 		.allowed_access = allowed_access,
725 	};
726 
727 	path_beneath.parent_fd = open(path, O_PATH | O_CLOEXEC);
728 	ASSERT_LE(0, path_beneath.parent_fd)
729 	{
730 		TH_LOG("Failed to open directory \"%s\": %s", path,
731 		       strerror(errno));
732 	}
733 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
734 				       &path_beneath, 0))
735 	{
736 		TH_LOG("Failed to update the ruleset with \"%s\": %s", path,
737 		       strerror(errno));
738 	}
739 	ASSERT_EQ(0, close(path_beneath.parent_fd));
740 }
741 
742 struct rule {
743 	const char *path;
744 	__u64 access;
745 };
746 
747 /* clang-format off */
748 
749 #define ACCESS_RO ( \
750 	LANDLOCK_ACCESS_FS_READ_FILE | \
751 	LANDLOCK_ACCESS_FS_READ_DIR)
752 
753 #define ACCESS_RW ( \
754 	ACCESS_RO | \
755 	LANDLOCK_ACCESS_FS_WRITE_FILE)
756 
757 /* clang-format on */
758 
759 static int create_ruleset(struct __test_metadata *const _metadata,
760 			  const __u64 handled_access_fs,
761 			  const struct rule rules[])
762 {
763 	int ruleset_fd, i;
764 	struct landlock_ruleset_attr ruleset_attr = {
765 		.handled_access_fs = handled_access_fs,
766 	};
767 
768 	ASSERT_NE(NULL, rules)
769 	{
770 		TH_LOG("No rule list");
771 	}
772 	ASSERT_NE(NULL, rules[0].path)
773 	{
774 		TH_LOG("Empty rule list");
775 	}
776 
777 	ruleset_fd =
778 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
779 	ASSERT_LE(0, ruleset_fd)
780 	{
781 		TH_LOG("Failed to create a ruleset: %s", strerror(errno));
782 	}
783 
784 	for (i = 0; rules[i].path; i++) {
785 		if (!rules[i].access)
786 			continue;
787 
788 		add_path_beneath(_metadata, ruleset_fd, rules[i].access,
789 				 rules[i].path);
790 	}
791 	return ruleset_fd;
792 }
793 
794 TEST_F_FORK(layout0, proc_nsfs)
795 {
796 	const struct rule rules[] = {
797 		{
798 			.path = "/dev/null",
799 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
800 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
801 		},
802 		{},
803 	};
804 	struct landlock_path_beneath_attr path_beneath;
805 	const int ruleset_fd = create_ruleset(
806 		_metadata, rules[0].access | LANDLOCK_ACCESS_FS_READ_DIR,
807 		rules);
808 
809 	ASSERT_LE(0, ruleset_fd);
810 	ASSERT_EQ(0, test_open("/proc/self/ns/mnt", O_RDONLY));
811 
812 	enforce_ruleset(_metadata, ruleset_fd);
813 
814 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
815 	ASSERT_EQ(EACCES, test_open("/dev", O_RDONLY));
816 	ASSERT_EQ(0, test_open("/dev/null", O_RDONLY));
817 	ASSERT_EQ(EACCES, test_open("/dev/full", O_RDONLY));
818 
819 	ASSERT_EQ(EACCES, test_open("/proc", O_RDONLY));
820 	ASSERT_EQ(EACCES, test_open("/proc/self", O_RDONLY));
821 	ASSERT_EQ(EACCES, test_open("/proc/self/ns", O_RDONLY));
822 	/*
823 	 * Because nsfs is an internal filesystem, /proc/self/ns/mnt is a
824 	 * disconnected path.  Such path cannot be identified and must then be
825 	 * allowed.
826 	 */
827 	ASSERT_EQ(0, test_open("/proc/self/ns/mnt", O_RDONLY));
828 
829 	/*
830 	 * Checks that it is not possible to add nsfs-like filesystem
831 	 * references to a ruleset.
832 	 */
833 	path_beneath.allowed_access = LANDLOCK_ACCESS_FS_READ_FILE |
834 				      LANDLOCK_ACCESS_FS_WRITE_FILE,
835 	path_beneath.parent_fd = open("/proc/self/ns/mnt", O_PATH | O_CLOEXEC);
836 	ASSERT_LE(0, path_beneath.parent_fd);
837 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
838 					&path_beneath, 0));
839 	ASSERT_EQ(EBADFD, errno);
840 	ASSERT_EQ(0, close(path_beneath.parent_fd));
841 }
842 
843 TEST_F_FORK(layout0, unpriv)
844 {
845 	const struct rule rules[] = {
846 		{
847 			.path = TMP_DIR,
848 			.access = ACCESS_RO,
849 		},
850 		{},
851 	};
852 	int ruleset_fd;
853 
854 	drop_caps(_metadata);
855 
856 	ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules);
857 	ASSERT_LE(0, ruleset_fd);
858 	ASSERT_EQ(-1, landlock_restrict_self(ruleset_fd, 0));
859 	ASSERT_EQ(EPERM, errno);
860 
861 	/* enforce_ruleset() calls prctl(no_new_privs). */
862 	enforce_ruleset(_metadata, ruleset_fd);
863 	ASSERT_EQ(0, close(ruleset_fd));
864 }
865 
866 TEST_F_FORK(layout1, effective_access)
867 {
868 	const struct rule rules[] = {
869 		{
870 			.path = dir_s1d2,
871 			.access = ACCESS_RO,
872 		},
873 		{
874 			.path = file1_s2d2,
875 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
876 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
877 		},
878 		{},
879 	};
880 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
881 	char buf;
882 	int reg_fd;
883 
884 	ASSERT_LE(0, ruleset_fd);
885 	enforce_ruleset(_metadata, ruleset_fd);
886 	ASSERT_EQ(0, close(ruleset_fd));
887 
888 	/* Tests on a directory (with or without O_PATH). */
889 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
890 	ASSERT_EQ(0, test_open("/", O_RDONLY | O_PATH));
891 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
892 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY | O_PATH));
893 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
894 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY | O_PATH));
895 
896 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
897 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
898 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
899 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
900 
901 	/* Tests on a file (with or without O_PATH). */
902 	ASSERT_EQ(EACCES, test_open(dir_s2d2, O_RDONLY));
903 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY | O_PATH));
904 
905 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDONLY));
906 
907 	/* Checks effective read and write actions. */
908 	reg_fd = open(file1_s2d2, O_RDWR | O_CLOEXEC);
909 	ASSERT_LE(0, reg_fd);
910 	ASSERT_EQ(1, write(reg_fd, ".", 1));
911 	ASSERT_LE(0, lseek(reg_fd, 0, SEEK_SET));
912 	ASSERT_EQ(1, read(reg_fd, &buf, 1));
913 	ASSERT_EQ('.', buf);
914 	ASSERT_EQ(0, close(reg_fd));
915 
916 	/* Just in case, double-checks effective actions. */
917 	reg_fd = open(file1_s2d2, O_RDONLY | O_CLOEXEC);
918 	ASSERT_LE(0, reg_fd);
919 	ASSERT_EQ(-1, write(reg_fd, &buf, 1));
920 	ASSERT_EQ(EBADF, errno);
921 	ASSERT_EQ(0, close(reg_fd));
922 }
923 
924 TEST_F_FORK(layout1, unhandled_access)
925 {
926 	const struct rule rules[] = {
927 		{
928 			.path = dir_s1d2,
929 			.access = ACCESS_RO,
930 		},
931 		{},
932 	};
933 	/* Here, we only handle read accesses, not write accesses. */
934 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules);
935 
936 	ASSERT_LE(0, ruleset_fd);
937 	enforce_ruleset(_metadata, ruleset_fd);
938 	ASSERT_EQ(0, close(ruleset_fd));
939 
940 	/*
941 	 * Because the policy does not handle LANDLOCK_ACCESS_FS_WRITE_FILE,
942 	 * opening for write-only should be allowed, but not read-write.
943 	 */
944 	ASSERT_EQ(0, test_open(file1_s1d1, O_WRONLY));
945 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
946 
947 	ASSERT_EQ(0, test_open(file1_s1d2, O_WRONLY));
948 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDWR));
949 }
950 
951 TEST_F_FORK(layout1, ruleset_overlap)
952 {
953 	const struct rule rules[] = {
954 		/* These rules should be ORed among them. */
955 		{
956 			.path = dir_s1d2,
957 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
958 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
959 		},
960 		{
961 			.path = dir_s1d2,
962 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
963 				  LANDLOCK_ACCESS_FS_READ_DIR,
964 		},
965 		{},
966 	};
967 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
968 
969 	ASSERT_LE(0, ruleset_fd);
970 	enforce_ruleset(_metadata, ruleset_fd);
971 	ASSERT_EQ(0, close(ruleset_fd));
972 
973 	/* Checks s1d1 hierarchy. */
974 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
975 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
976 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
977 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
978 
979 	/* Checks s1d2 hierarchy. */
980 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
981 	ASSERT_EQ(0, test_open(file1_s1d2, O_WRONLY));
982 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDWR));
983 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
984 
985 	/* Checks s1d3 hierarchy. */
986 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
987 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
988 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
989 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
990 }
991 
992 TEST_F_FORK(layout1, layer_rule_unions)
993 {
994 	const struct rule layer1[] = {
995 		{
996 			.path = dir_s1d2,
997 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
998 		},
999 		/* dir_s1d3 should allow READ_FILE and WRITE_FILE (O_RDWR). */
1000 		{
1001 			.path = dir_s1d3,
1002 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1003 		},
1004 		{},
1005 	};
1006 	const struct rule layer2[] = {
1007 		/* Doesn't change anything from layer1. */
1008 		{
1009 			.path = dir_s1d2,
1010 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
1011 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
1012 		},
1013 		{},
1014 	};
1015 	const struct rule layer3[] = {
1016 		/* Only allows write (but not read) to dir_s1d3. */
1017 		{
1018 			.path = dir_s1d2,
1019 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1020 		},
1021 		{},
1022 	};
1023 	int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1);
1024 
1025 	ASSERT_LE(0, ruleset_fd);
1026 	enforce_ruleset(_metadata, ruleset_fd);
1027 	ASSERT_EQ(0, close(ruleset_fd));
1028 
1029 	/* Checks s1d1 hierarchy with layer1. */
1030 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1031 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1032 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
1033 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1034 
1035 	/* Checks s1d2 hierarchy with layer1. */
1036 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
1037 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1038 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
1039 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1040 
1041 	/* Checks s1d3 hierarchy with layer1. */
1042 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1043 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
1044 	/* dir_s1d3 should allow READ_FILE and WRITE_FILE (O_RDWR). */
1045 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1046 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1047 
1048 	/* Doesn't change anything from layer1. */
1049 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2);
1050 	ASSERT_LE(0, ruleset_fd);
1051 	enforce_ruleset(_metadata, ruleset_fd);
1052 	ASSERT_EQ(0, close(ruleset_fd));
1053 
1054 	/* Checks s1d1 hierarchy with layer2. */
1055 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1056 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1057 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
1058 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1059 
1060 	/* Checks s1d2 hierarchy with layer2. */
1061 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
1062 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1063 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
1064 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1065 
1066 	/* Checks s1d3 hierarchy with layer2. */
1067 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1068 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
1069 	/* dir_s1d3 should allow READ_FILE and WRITE_FILE (O_RDWR). */
1070 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1071 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1072 
1073 	/* Only allows write (but not read) to dir_s1d3. */
1074 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer3);
1075 	ASSERT_LE(0, ruleset_fd);
1076 	enforce_ruleset(_metadata, ruleset_fd);
1077 	ASSERT_EQ(0, close(ruleset_fd));
1078 
1079 	/* Checks s1d1 hierarchy with layer3. */
1080 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1081 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1082 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
1083 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1084 
1085 	/* Checks s1d2 hierarchy with layer3. */
1086 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDONLY));
1087 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1088 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
1089 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1090 
1091 	/* Checks s1d3 hierarchy with layer3. */
1092 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDONLY));
1093 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
1094 	/* dir_s1d3 should now deny READ_FILE and WRITE_FILE (O_RDWR). */
1095 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDWR));
1096 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1097 }
1098 
1099 TEST_F_FORK(layout1, non_overlapping_accesses)
1100 {
1101 	const struct rule layer1[] = {
1102 		{
1103 			.path = dir_s1d2,
1104 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
1105 		},
1106 		{},
1107 	};
1108 	const struct rule layer2[] = {
1109 		{
1110 			.path = dir_s1d3,
1111 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
1112 		},
1113 		{},
1114 	};
1115 	int ruleset_fd;
1116 
1117 	ASSERT_EQ(0, unlink(file1_s1d1));
1118 	ASSERT_EQ(0, unlink(file1_s1d2));
1119 
1120 	ruleset_fd =
1121 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, layer1);
1122 	ASSERT_LE(0, ruleset_fd);
1123 	enforce_ruleset(_metadata, ruleset_fd);
1124 	ASSERT_EQ(0, close(ruleset_fd));
1125 
1126 	ASSERT_EQ(-1, mknod(file1_s1d1, S_IFREG | 0700, 0));
1127 	ASSERT_EQ(EACCES, errno);
1128 	ASSERT_EQ(0, mknod(file1_s1d2, S_IFREG | 0700, 0));
1129 	ASSERT_EQ(0, unlink(file1_s1d2));
1130 
1131 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_REMOVE_FILE,
1132 				    layer2);
1133 	ASSERT_LE(0, ruleset_fd);
1134 	enforce_ruleset(_metadata, ruleset_fd);
1135 	ASSERT_EQ(0, close(ruleset_fd));
1136 
1137 	/* Unchanged accesses for file creation. */
1138 	ASSERT_EQ(-1, mknod(file1_s1d1, S_IFREG | 0700, 0));
1139 	ASSERT_EQ(EACCES, errno);
1140 	ASSERT_EQ(0, mknod(file1_s1d2, S_IFREG | 0700, 0));
1141 
1142 	/* Checks file removing. */
1143 	ASSERT_EQ(-1, unlink(file1_s1d2));
1144 	ASSERT_EQ(EACCES, errno);
1145 	ASSERT_EQ(0, unlink(file1_s1d3));
1146 }
1147 
1148 TEST_F_FORK(layout1, interleaved_masked_accesses)
1149 {
1150 	/*
1151 	 * Checks overly restrictive rules:
1152 	 * layer 1: allows R   s1d1/s1d2/s1d3/file1
1153 	 * layer 2: allows RW  s1d1/s1d2/s1d3
1154 	 *          allows  W  s1d1/s1d2
1155 	 *          denies R   s1d1/s1d2
1156 	 * layer 3: allows R   s1d1
1157 	 * layer 4: allows R   s1d1/s1d2
1158 	 *          denies  W  s1d1/s1d2
1159 	 * layer 5: allows R   s1d1/s1d2
1160 	 * layer 6: allows   X ----
1161 	 * layer 7: allows  W  s1d1/s1d2
1162 	 *          denies R   s1d1/s1d2
1163 	 */
1164 	const struct rule layer1_read[] = {
1165 		/* Allows read access to file1_s1d3 with the first layer. */
1166 		{
1167 			.path = file1_s1d3,
1168 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1169 		},
1170 		{},
1171 	};
1172 	/* First rule with write restrictions. */
1173 	const struct rule layer2_read_write[] = {
1174 		/* Start by granting read-write access via its parent directory... */
1175 		{
1176 			.path = dir_s1d3,
1177 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
1178 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
1179 		},
1180 		/* ...but also denies read access via its grandparent directory. */
1181 		{
1182 			.path = dir_s1d2,
1183 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1184 		},
1185 		{},
1186 	};
1187 	const struct rule layer3_read[] = {
1188 		/* Allows read access via its great-grandparent directory. */
1189 		{
1190 			.path = dir_s1d1,
1191 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1192 		},
1193 		{},
1194 	};
1195 	const struct rule layer4_read_write[] = {
1196 		/*
1197 		 * Try to confuse the deny access by denying write (but not
1198 		 * read) access via its grandparent directory.
1199 		 */
1200 		{
1201 			.path = dir_s1d2,
1202 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1203 		},
1204 		{},
1205 	};
1206 	const struct rule layer5_read[] = {
1207 		/*
1208 		 * Try to override layer2's deny read access by explicitly
1209 		 * allowing read access via file1_s1d3's grandparent.
1210 		 */
1211 		{
1212 			.path = dir_s1d2,
1213 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1214 		},
1215 		{},
1216 	};
1217 	const struct rule layer6_execute[] = {
1218 		/*
1219 		 * Restricts an unrelated file hierarchy with a new access
1220 		 * (non-overlapping) type.
1221 		 */
1222 		{
1223 			.path = dir_s2d1,
1224 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
1225 		},
1226 		{},
1227 	};
1228 	const struct rule layer7_read_write[] = {
1229 		/*
1230 		 * Finally, denies read access to file1_s1d3 via its
1231 		 * grandparent.
1232 		 */
1233 		{
1234 			.path = dir_s1d2,
1235 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1236 		},
1237 		{},
1238 	};
1239 	int ruleset_fd;
1240 
1241 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
1242 				    layer1_read);
1243 	ASSERT_LE(0, ruleset_fd);
1244 	enforce_ruleset(_metadata, ruleset_fd);
1245 	ASSERT_EQ(0, close(ruleset_fd));
1246 
1247 	/* Checks that read access is granted for file1_s1d3 with layer 1. */
1248 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1249 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1250 	ASSERT_EQ(0, test_open(file2_s1d3, O_WRONLY));
1251 
1252 	ruleset_fd = create_ruleset(_metadata,
1253 				    LANDLOCK_ACCESS_FS_READ_FILE |
1254 					    LANDLOCK_ACCESS_FS_WRITE_FILE,
1255 				    layer2_read_write);
1256 	ASSERT_LE(0, ruleset_fd);
1257 	enforce_ruleset(_metadata, ruleset_fd);
1258 	ASSERT_EQ(0, close(ruleset_fd));
1259 
1260 	/* Checks that previous access rights are unchanged with layer 2. */
1261 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1262 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1263 	ASSERT_EQ(0, test_open(file2_s1d3, O_WRONLY));
1264 
1265 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
1266 				    layer3_read);
1267 	ASSERT_LE(0, ruleset_fd);
1268 	enforce_ruleset(_metadata, ruleset_fd);
1269 	ASSERT_EQ(0, close(ruleset_fd));
1270 
1271 	/* Checks that previous access rights are unchanged with layer 3. */
1272 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1273 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1274 	ASSERT_EQ(0, test_open(file2_s1d3, O_WRONLY));
1275 
1276 	/* This time, denies write access for the file hierarchy. */
1277 	ruleset_fd = create_ruleset(_metadata,
1278 				    LANDLOCK_ACCESS_FS_READ_FILE |
1279 					    LANDLOCK_ACCESS_FS_WRITE_FILE,
1280 				    layer4_read_write);
1281 	ASSERT_LE(0, ruleset_fd);
1282 	enforce_ruleset(_metadata, ruleset_fd);
1283 	ASSERT_EQ(0, close(ruleset_fd));
1284 
1285 	/*
1286 	 * Checks that the only change with layer 4 is that write access is
1287 	 * denied.
1288 	 */
1289 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1290 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1291 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1292 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1293 
1294 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
1295 				    layer5_read);
1296 	ASSERT_LE(0, ruleset_fd);
1297 	enforce_ruleset(_metadata, ruleset_fd);
1298 	ASSERT_EQ(0, close(ruleset_fd));
1299 
1300 	/* Checks that previous access rights are unchanged with layer 5. */
1301 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1302 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1303 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1304 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1305 
1306 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_EXECUTE,
1307 				    layer6_execute);
1308 	ASSERT_LE(0, ruleset_fd);
1309 	enforce_ruleset(_metadata, ruleset_fd);
1310 	ASSERT_EQ(0, close(ruleset_fd));
1311 
1312 	/* Checks that previous access rights are unchanged with layer 6. */
1313 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1314 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1315 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1316 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1317 
1318 	ruleset_fd = create_ruleset(_metadata,
1319 				    LANDLOCK_ACCESS_FS_READ_FILE |
1320 					    LANDLOCK_ACCESS_FS_WRITE_FILE,
1321 				    layer7_read_write);
1322 	ASSERT_LE(0, ruleset_fd);
1323 	enforce_ruleset(_metadata, ruleset_fd);
1324 	ASSERT_EQ(0, close(ruleset_fd));
1325 
1326 	/* Checks read access is now denied with layer 7. */
1327 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDONLY));
1328 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1329 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1330 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1331 }
1332 
1333 TEST_F_FORK(layout1, inherit_subset)
1334 {
1335 	const struct rule rules[] = {
1336 		{
1337 			.path = dir_s1d2,
1338 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
1339 				  LANDLOCK_ACCESS_FS_READ_DIR,
1340 		},
1341 		{},
1342 	};
1343 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1344 
1345 	ASSERT_LE(0, ruleset_fd);
1346 	enforce_ruleset(_metadata, ruleset_fd);
1347 
1348 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1349 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1350 
1351 	/* Write access is forbidden. */
1352 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1353 	/* Readdir access is allowed. */
1354 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1355 
1356 	/* Write access is forbidden. */
1357 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1358 	/* Readdir access is allowed. */
1359 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1360 
1361 	/*
1362 	 * Tests shared rule extension: the following rules should not grant
1363 	 * any new access, only remove some.  Once enforced, these rules are
1364 	 * ANDed with the previous ones.
1365 	 */
1366 	add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_WRITE_FILE,
1367 			 dir_s1d2);
1368 	/*
1369 	 * According to ruleset_fd, dir_s1d2 should now have the
1370 	 * LANDLOCK_ACCESS_FS_READ_FILE and LANDLOCK_ACCESS_FS_WRITE_FILE
1371 	 * access rights (even if this directory is opened a second time).
1372 	 * However, when enforcing this updated ruleset, the ruleset tied to
1373 	 * the current process (i.e. its domain) will still only have the
1374 	 * dir_s1d2 with LANDLOCK_ACCESS_FS_READ_FILE and
1375 	 * LANDLOCK_ACCESS_FS_READ_DIR accesses, but
1376 	 * LANDLOCK_ACCESS_FS_WRITE_FILE must not be allowed because it would
1377 	 * be a privilege escalation.
1378 	 */
1379 	enforce_ruleset(_metadata, ruleset_fd);
1380 
1381 	/* Same tests and results as above. */
1382 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1383 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1384 
1385 	/* It is still forbidden to write in file1_s1d2. */
1386 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1387 	/* Readdir access is still allowed. */
1388 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1389 
1390 	/* It is still forbidden to write in file1_s1d3. */
1391 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1392 	/* Readdir access is still allowed. */
1393 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1394 
1395 	/*
1396 	 * Try to get more privileges by adding new access rights to the parent
1397 	 * directory: dir_s1d1.
1398 	 */
1399 	add_path_beneath(_metadata, ruleset_fd, ACCESS_RW, dir_s1d1);
1400 	enforce_ruleset(_metadata, ruleset_fd);
1401 
1402 	/* Same tests and results as above. */
1403 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1404 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1405 
1406 	/* It is still forbidden to write in file1_s1d2. */
1407 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1408 	/* Readdir access is still allowed. */
1409 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1410 
1411 	/* It is still forbidden to write in file1_s1d3. */
1412 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1413 	/* Readdir access is still allowed. */
1414 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1415 
1416 	/*
1417 	 * Now, dir_s1d3 get a new rule tied to it, only allowing
1418 	 * LANDLOCK_ACCESS_FS_WRITE_FILE.  The (kernel internal) difference is
1419 	 * that there was no rule tied to it before.
1420 	 */
1421 	add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_WRITE_FILE,
1422 			 dir_s1d3);
1423 	enforce_ruleset(_metadata, ruleset_fd);
1424 	ASSERT_EQ(0, close(ruleset_fd));
1425 
1426 	/*
1427 	 * Same tests and results as above, except for open(dir_s1d3) which is
1428 	 * now denied because the new rule mask the rule previously inherited
1429 	 * from dir_s1d2.
1430 	 */
1431 
1432 	/* Same tests and results as above. */
1433 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1434 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1435 
1436 	/* It is still forbidden to write in file1_s1d2. */
1437 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1438 	/* Readdir access is still allowed. */
1439 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1440 
1441 	/* It is still forbidden to write in file1_s1d3. */
1442 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1443 	/*
1444 	 * Readdir of dir_s1d3 is still allowed because of the OR policy inside
1445 	 * the same layer.
1446 	 */
1447 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1448 }
1449 
1450 TEST_F_FORK(layout1, inherit_superset)
1451 {
1452 	const struct rule rules[] = {
1453 		{
1454 			.path = dir_s1d3,
1455 			.access = ACCESS_RO,
1456 		},
1457 		{},
1458 	};
1459 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1460 
1461 	ASSERT_LE(0, ruleset_fd);
1462 	enforce_ruleset(_metadata, ruleset_fd);
1463 
1464 	/* Readdir access is denied for dir_s1d2. */
1465 	ASSERT_EQ(EACCES, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1466 	/* Readdir access is allowed for dir_s1d3. */
1467 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1468 	/* File access is allowed for file1_s1d3. */
1469 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1470 
1471 	/* Now dir_s1d2, parent of dir_s1d3, gets a new rule tied to it. */
1472 	add_path_beneath(_metadata, ruleset_fd,
1473 			 LANDLOCK_ACCESS_FS_READ_FILE |
1474 				 LANDLOCK_ACCESS_FS_READ_DIR,
1475 			 dir_s1d2);
1476 	enforce_ruleset(_metadata, ruleset_fd);
1477 	ASSERT_EQ(0, close(ruleset_fd));
1478 
1479 	/* Readdir access is still denied for dir_s1d2. */
1480 	ASSERT_EQ(EACCES, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1481 	/* Readdir access is still allowed for dir_s1d3. */
1482 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1483 	/* File access is still allowed for file1_s1d3. */
1484 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1485 }
1486 
1487 TEST_F_FORK(layout0, max_layers)
1488 {
1489 	int i, err;
1490 	const struct rule rules[] = {
1491 		{
1492 			.path = TMP_DIR,
1493 			.access = ACCESS_RO,
1494 		},
1495 		{},
1496 	};
1497 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1498 
1499 	ASSERT_LE(0, ruleset_fd);
1500 	for (i = 0; i < 16; i++)
1501 		enforce_ruleset(_metadata, ruleset_fd);
1502 
1503 	for (i = 0; i < 2; i++) {
1504 		err = landlock_restrict_self(ruleset_fd, 0);
1505 		ASSERT_EQ(-1, err);
1506 		ASSERT_EQ(E2BIG, errno);
1507 	}
1508 	ASSERT_EQ(0, close(ruleset_fd));
1509 }
1510 
1511 TEST_F_FORK(layout1, empty_or_same_ruleset)
1512 {
1513 	struct landlock_ruleset_attr ruleset_attr = {};
1514 	int ruleset_fd;
1515 
1516 	/* Tests empty handled_access_fs. */
1517 	ruleset_fd =
1518 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
1519 	ASSERT_LE(-1, ruleset_fd);
1520 	ASSERT_EQ(ENOMSG, errno);
1521 
1522 	/* Enforces policy which deny read access to all files. */
1523 	ruleset_attr.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE;
1524 	ruleset_fd =
1525 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
1526 	ASSERT_LE(0, ruleset_fd);
1527 	enforce_ruleset(_metadata, ruleset_fd);
1528 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1529 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1530 
1531 	/* Nests a policy which deny read access to all directories. */
1532 	ruleset_attr.handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR;
1533 	ruleset_fd =
1534 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
1535 	ASSERT_LE(0, ruleset_fd);
1536 	enforce_ruleset(_metadata, ruleset_fd);
1537 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1538 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
1539 
1540 	/* Enforces a second time with the same ruleset. */
1541 	enforce_ruleset(_metadata, ruleset_fd);
1542 	ASSERT_EQ(0, close(ruleset_fd));
1543 }
1544 
1545 TEST_F_FORK(layout1, rule_on_mountpoint)
1546 {
1547 	const struct rule rules[] = {
1548 		{
1549 			.path = dir_s1d1,
1550 			.access = ACCESS_RO,
1551 		},
1552 		{
1553 			/* dir_s3d2 is a mount point. */
1554 			.path = dir_s3d2,
1555 			.access = ACCESS_RO,
1556 		},
1557 		{},
1558 	};
1559 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1560 
1561 	ASSERT_LE(0, ruleset_fd);
1562 	enforce_ruleset(_metadata, ruleset_fd);
1563 	ASSERT_EQ(0, close(ruleset_fd));
1564 
1565 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1566 
1567 	ASSERT_EQ(EACCES, test_open(dir_s2d1, O_RDONLY));
1568 
1569 	ASSERT_EQ(EACCES, test_open(dir_s3d1, O_RDONLY));
1570 	ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY));
1571 	ASSERT_EQ(0, test_open(dir_s3d3, O_RDONLY));
1572 }
1573 
1574 TEST_F_FORK(layout1, rule_over_mountpoint)
1575 {
1576 	const struct rule rules[] = {
1577 		{
1578 			.path = dir_s1d1,
1579 			.access = ACCESS_RO,
1580 		},
1581 		{
1582 			/* dir_s3d2 is a mount point. */
1583 			.path = dir_s3d1,
1584 			.access = ACCESS_RO,
1585 		},
1586 		{},
1587 	};
1588 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1589 
1590 	ASSERT_LE(0, ruleset_fd);
1591 	enforce_ruleset(_metadata, ruleset_fd);
1592 	ASSERT_EQ(0, close(ruleset_fd));
1593 
1594 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1595 
1596 	ASSERT_EQ(EACCES, test_open(dir_s2d1, O_RDONLY));
1597 
1598 	ASSERT_EQ(0, test_open(dir_s3d1, O_RDONLY));
1599 	ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY));
1600 	ASSERT_EQ(0, test_open(dir_s3d3, O_RDONLY));
1601 }
1602 
1603 /*
1604  * This test verifies that we can apply a landlock rule on the root directory
1605  * (which might require special handling).
1606  */
1607 TEST_F_FORK(layout1, rule_over_root_allow_then_deny)
1608 {
1609 	struct rule rules[] = {
1610 		{
1611 			.path = "/",
1612 			.access = ACCESS_RO,
1613 		},
1614 		{},
1615 	};
1616 	int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1617 
1618 	ASSERT_LE(0, ruleset_fd);
1619 	enforce_ruleset(_metadata, ruleset_fd);
1620 	ASSERT_EQ(0, close(ruleset_fd));
1621 
1622 	/* Checks allowed access. */
1623 	ASSERT_EQ(0, test_open("/", O_RDONLY));
1624 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1625 
1626 	rules[0].access = LANDLOCK_ACCESS_FS_READ_FILE;
1627 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1628 	ASSERT_LE(0, ruleset_fd);
1629 	enforce_ruleset(_metadata, ruleset_fd);
1630 	ASSERT_EQ(0, close(ruleset_fd));
1631 
1632 	/* Checks denied access (on a directory). */
1633 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
1634 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
1635 }
1636 
1637 TEST_F_FORK(layout1, rule_over_root_deny)
1638 {
1639 	const struct rule rules[] = {
1640 		{
1641 			.path = "/",
1642 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1643 		},
1644 		{},
1645 	};
1646 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1647 
1648 	ASSERT_LE(0, ruleset_fd);
1649 	enforce_ruleset(_metadata, ruleset_fd);
1650 	ASSERT_EQ(0, close(ruleset_fd));
1651 
1652 	/* Checks denied access (on a directory). */
1653 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
1654 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
1655 }
1656 
1657 TEST_F_FORK(layout1, rule_inside_mount_ns)
1658 {
1659 	const struct rule rules[] = {
1660 		{
1661 			.path = "s3d3",
1662 			.access = ACCESS_RO,
1663 		},
1664 		{},
1665 	};
1666 	int ruleset_fd;
1667 
1668 	set_cap(_metadata, CAP_SYS_ADMIN);
1669 	ASSERT_EQ(0, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3))
1670 	{
1671 		TH_LOG("Failed to pivot root: %s", strerror(errno));
1672 	};
1673 	ASSERT_EQ(0, chdir("/"));
1674 	clear_cap(_metadata, CAP_SYS_ADMIN);
1675 
1676 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1677 	ASSERT_LE(0, ruleset_fd);
1678 	enforce_ruleset(_metadata, ruleset_fd);
1679 	ASSERT_EQ(0, close(ruleset_fd));
1680 
1681 	ASSERT_EQ(0, test_open("s3d3", O_RDONLY));
1682 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
1683 }
1684 
1685 TEST_F_FORK(layout1, mount_and_pivot)
1686 {
1687 	const struct rule rules[] = {
1688 		{
1689 			.path = dir_s3d2,
1690 			.access = ACCESS_RO,
1691 		},
1692 		{},
1693 	};
1694 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1695 
1696 	ASSERT_LE(0, ruleset_fd);
1697 	enforce_ruleset(_metadata, ruleset_fd);
1698 	ASSERT_EQ(0, close(ruleset_fd));
1699 
1700 	set_cap(_metadata, CAP_SYS_ADMIN);
1701 	ASSERT_EQ(-1, mount(NULL, dir_s3d2, NULL, MS_RDONLY, NULL));
1702 	ASSERT_EQ(EPERM, errno);
1703 	ASSERT_EQ(-1, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3));
1704 	ASSERT_EQ(EPERM, errno);
1705 	clear_cap(_metadata, CAP_SYS_ADMIN);
1706 }
1707 
1708 TEST_F_FORK(layout1, move_mount)
1709 {
1710 	const struct rule rules[] = {
1711 		{
1712 			.path = dir_s3d2,
1713 			.access = ACCESS_RO,
1714 		},
1715 		{},
1716 	};
1717 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1718 
1719 	ASSERT_LE(0, ruleset_fd);
1720 
1721 	set_cap(_metadata, CAP_SYS_ADMIN);
1722 	ASSERT_EQ(0, syscall(__NR_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
1723 			     dir_s1d2, 0))
1724 	{
1725 		TH_LOG("Failed to move mount: %s", strerror(errno));
1726 	}
1727 
1728 	ASSERT_EQ(0, syscall(__NR_move_mount, AT_FDCWD, dir_s1d2, AT_FDCWD,
1729 			     dir_s3d2, 0));
1730 	clear_cap(_metadata, CAP_SYS_ADMIN);
1731 
1732 	enforce_ruleset(_metadata, ruleset_fd);
1733 	ASSERT_EQ(0, close(ruleset_fd));
1734 
1735 	set_cap(_metadata, CAP_SYS_ADMIN);
1736 	ASSERT_EQ(-1, syscall(__NR_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
1737 			      dir_s1d2, 0));
1738 	ASSERT_EQ(EPERM, errno);
1739 	clear_cap(_metadata, CAP_SYS_ADMIN);
1740 }
1741 
1742 TEST_F_FORK(layout1, topology_changes_with_net_only)
1743 {
1744 	const struct landlock_ruleset_attr ruleset_net = {
1745 		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
1746 				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
1747 	};
1748 	int ruleset_fd;
1749 
1750 	/* Add network restrictions. */
1751 	ruleset_fd =
1752 		landlock_create_ruleset(&ruleset_net, sizeof(ruleset_net), 0);
1753 	ASSERT_LE(0, ruleset_fd);
1754 	enforce_ruleset(_metadata, ruleset_fd);
1755 	ASSERT_EQ(0, close(ruleset_fd));
1756 
1757 	/* Mount, remount, move_mount, umount, and pivot_root checks. */
1758 	set_cap(_metadata, CAP_SYS_ADMIN);
1759 	ASSERT_EQ(0, mount_opt(&mnt_tmp, dir_s1d2));
1760 	ASSERT_EQ(0, mount(NULL, dir_s1d2, NULL, MS_PRIVATE | MS_REC, NULL));
1761 	ASSERT_EQ(0, syscall(__NR_move_mount, AT_FDCWD, dir_s1d2, AT_FDCWD,
1762 			     dir_s2d2, 0));
1763 	ASSERT_EQ(0, umount(dir_s2d2));
1764 	ASSERT_EQ(0, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3));
1765 	ASSERT_EQ(0, chdir("/"));
1766 	clear_cap(_metadata, CAP_SYS_ADMIN);
1767 }
1768 
1769 TEST_F_FORK(layout1, topology_changes_with_net_and_fs)
1770 {
1771 	const struct landlock_ruleset_attr ruleset_net_fs = {
1772 		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
1773 				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
1774 		.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
1775 	};
1776 	int ruleset_fd;
1777 
1778 	/* Add network and filesystem restrictions. */
1779 	ruleset_fd = landlock_create_ruleset(&ruleset_net_fs,
1780 					     sizeof(ruleset_net_fs), 0);
1781 	ASSERT_LE(0, ruleset_fd);
1782 	enforce_ruleset(_metadata, ruleset_fd);
1783 	ASSERT_EQ(0, close(ruleset_fd));
1784 
1785 	/* Mount, remount, move_mount, umount, and pivot_root checks. */
1786 	set_cap(_metadata, CAP_SYS_ADMIN);
1787 	ASSERT_EQ(-1, mount_opt(&mnt_tmp, dir_s1d2));
1788 	ASSERT_EQ(EPERM, errno);
1789 	ASSERT_EQ(-1, mount(NULL, dir_s3d2, NULL, MS_PRIVATE | MS_REC, NULL));
1790 	ASSERT_EQ(EPERM, errno);
1791 	ASSERT_EQ(-1, syscall(__NR_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
1792 			      dir_s2d2, 0));
1793 	ASSERT_EQ(EPERM, errno);
1794 	ASSERT_EQ(-1, umount(dir_s3d2));
1795 	ASSERT_EQ(EPERM, errno);
1796 	ASSERT_EQ(-1, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3));
1797 	ASSERT_EQ(EPERM, errno);
1798 	clear_cap(_metadata, CAP_SYS_ADMIN);
1799 }
1800 
1801 TEST_F_FORK(layout1, release_inodes)
1802 {
1803 	const struct rule rules[] = {
1804 		{
1805 			.path = dir_s1d1,
1806 			.access = ACCESS_RO,
1807 		},
1808 		{
1809 			.path = dir_s3d2,
1810 			.access = ACCESS_RO,
1811 		},
1812 		{
1813 			.path = dir_s3d3,
1814 			.access = ACCESS_RO,
1815 		},
1816 		{},
1817 	};
1818 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1819 
1820 	ASSERT_LE(0, ruleset_fd);
1821 	/* Unmount a file hierarchy while it is being used by a ruleset. */
1822 	set_cap(_metadata, CAP_SYS_ADMIN);
1823 	ASSERT_EQ(0, umount(dir_s3d2));
1824 	clear_cap(_metadata, CAP_SYS_ADMIN);
1825 
1826 	enforce_ruleset(_metadata, ruleset_fd);
1827 	ASSERT_EQ(0, close(ruleset_fd));
1828 
1829 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
1830 	ASSERT_EQ(EACCES, test_open(dir_s3d2, O_RDONLY));
1831 	/* This dir_s3d3 would not be allowed and does not exist anyway. */
1832 	ASSERT_EQ(ENOENT, test_open(dir_s3d3, O_RDONLY));
1833 }
1834 
1835 enum relative_access {
1836 	REL_OPEN,
1837 	REL_CHDIR,
1838 	REL_CHROOT_ONLY,
1839 	REL_CHROOT_CHDIR,
1840 };
1841 
1842 static void test_relative_path(struct __test_metadata *const _metadata,
1843 			       const enum relative_access rel)
1844 {
1845 	/*
1846 	 * Common layer to check that chroot doesn't ignore it (i.e. a chroot
1847 	 * is not a disconnected root directory).
1848 	 */
1849 	const struct rule layer1_base[] = {
1850 		{
1851 			.path = TMP_DIR,
1852 			.access = ACCESS_RO,
1853 		},
1854 		{},
1855 	};
1856 	const struct rule layer2_subs[] = {
1857 		{
1858 			.path = dir_s1d2,
1859 			.access = ACCESS_RO,
1860 		},
1861 		{
1862 			.path = dir_s2d2,
1863 			.access = ACCESS_RO,
1864 		},
1865 		{},
1866 	};
1867 	int dirfd, ruleset_fd;
1868 
1869 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_base);
1870 	ASSERT_LE(0, ruleset_fd);
1871 	enforce_ruleset(_metadata, ruleset_fd);
1872 	ASSERT_EQ(0, close(ruleset_fd));
1873 
1874 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2_subs);
1875 
1876 	ASSERT_LE(0, ruleset_fd);
1877 	switch (rel) {
1878 	case REL_OPEN:
1879 	case REL_CHDIR:
1880 		break;
1881 	case REL_CHROOT_ONLY:
1882 		ASSERT_EQ(0, chdir(dir_s2d2));
1883 		break;
1884 	case REL_CHROOT_CHDIR:
1885 		ASSERT_EQ(0, chdir(dir_s1d2));
1886 		break;
1887 	default:
1888 		ASSERT_TRUE(false);
1889 		return;
1890 	}
1891 
1892 	set_cap(_metadata, CAP_SYS_CHROOT);
1893 	enforce_ruleset(_metadata, ruleset_fd);
1894 
1895 	switch (rel) {
1896 	case REL_OPEN:
1897 		dirfd = open(dir_s1d2, O_DIRECTORY);
1898 		ASSERT_LE(0, dirfd);
1899 		break;
1900 	case REL_CHDIR:
1901 		ASSERT_EQ(0, chdir(dir_s1d2));
1902 		dirfd = AT_FDCWD;
1903 		break;
1904 	case REL_CHROOT_ONLY:
1905 		/* Do chroot into dir_s1d2 (relative to dir_s2d2). */
1906 		ASSERT_EQ(0, chroot("../../s1d1/s1d2"))
1907 		{
1908 			TH_LOG("Failed to chroot: %s", strerror(errno));
1909 		}
1910 		dirfd = AT_FDCWD;
1911 		break;
1912 	case REL_CHROOT_CHDIR:
1913 		/* Do chroot into dir_s1d2. */
1914 		ASSERT_EQ(0, chroot("."))
1915 		{
1916 			TH_LOG("Failed to chroot: %s", strerror(errno));
1917 		}
1918 		dirfd = AT_FDCWD;
1919 		break;
1920 	}
1921 
1922 	ASSERT_EQ((rel == REL_CHROOT_CHDIR) ? 0 : EACCES,
1923 		  test_open_rel(dirfd, "..", O_RDONLY));
1924 	ASSERT_EQ(0, test_open_rel(dirfd, ".", O_RDONLY));
1925 
1926 	if (rel == REL_CHROOT_ONLY) {
1927 		/* The current directory is dir_s2d2. */
1928 		ASSERT_EQ(0, test_open_rel(dirfd, "./s2d3", O_RDONLY));
1929 	} else {
1930 		/* The current directory is dir_s1d2. */
1931 		ASSERT_EQ(0, test_open_rel(dirfd, "./s1d3", O_RDONLY));
1932 	}
1933 
1934 	if (rel == REL_CHROOT_ONLY || rel == REL_CHROOT_CHDIR) {
1935 		/* Checks the root dir_s1d2. */
1936 		ASSERT_EQ(0, test_open_rel(dirfd, "/..", O_RDONLY));
1937 		ASSERT_EQ(0, test_open_rel(dirfd, "/", O_RDONLY));
1938 		ASSERT_EQ(0, test_open_rel(dirfd, "/f1", O_RDONLY));
1939 		ASSERT_EQ(0, test_open_rel(dirfd, "/s1d3", O_RDONLY));
1940 	}
1941 
1942 	if (rel != REL_CHROOT_CHDIR) {
1943 		ASSERT_EQ(EACCES, test_open_rel(dirfd, "../../s1d1", O_RDONLY));
1944 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s1d1/s1d2", O_RDONLY));
1945 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s1d1/s1d2/s1d3",
1946 					   O_RDONLY));
1947 
1948 		ASSERT_EQ(EACCES, test_open_rel(dirfd, "../../s2d1", O_RDONLY));
1949 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s2d1/s2d2", O_RDONLY));
1950 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s2d1/s2d2/s2d3",
1951 					   O_RDONLY));
1952 	}
1953 
1954 	if (rel == REL_OPEN)
1955 		ASSERT_EQ(0, close(dirfd));
1956 	ASSERT_EQ(0, close(ruleset_fd));
1957 }
1958 
1959 TEST_F_FORK(layout1, relative_open)
1960 {
1961 	test_relative_path(_metadata, REL_OPEN);
1962 }
1963 
1964 TEST_F_FORK(layout1, relative_chdir)
1965 {
1966 	test_relative_path(_metadata, REL_CHDIR);
1967 }
1968 
1969 TEST_F_FORK(layout1, relative_chroot_only)
1970 {
1971 	test_relative_path(_metadata, REL_CHROOT_ONLY);
1972 }
1973 
1974 TEST_F_FORK(layout1, relative_chroot_chdir)
1975 {
1976 	test_relative_path(_metadata, REL_CHROOT_CHDIR);
1977 }
1978 
1979 static void copy_file(struct __test_metadata *const _metadata,
1980 		      const char *const src_path, const char *const dst_path)
1981 {
1982 	int dst_fd, src_fd;
1983 	struct stat statbuf;
1984 
1985 	dst_fd = open(dst_path, O_WRONLY | O_TRUNC | O_CLOEXEC);
1986 	ASSERT_LE(0, dst_fd)
1987 	{
1988 		TH_LOG("Failed to open \"%s\": %s", dst_path, strerror(errno));
1989 	}
1990 	src_fd = open(src_path, O_RDONLY | O_CLOEXEC);
1991 	ASSERT_LE(0, src_fd)
1992 	{
1993 		TH_LOG("Failed to open \"%s\": %s", src_path, strerror(errno));
1994 	}
1995 	ASSERT_EQ(0, fstat(src_fd, &statbuf));
1996 	ASSERT_EQ(statbuf.st_size,
1997 		  sendfile(dst_fd, src_fd, 0, statbuf.st_size));
1998 	ASSERT_EQ(0, close(src_fd));
1999 	ASSERT_EQ(0, close(dst_fd));
2000 }
2001 
2002 static void test_execute(struct __test_metadata *const _metadata, const int err,
2003 			 const char *const path)
2004 {
2005 	int status;
2006 	char *const argv[] = { (char *)path, NULL };
2007 	const pid_t child = fork();
2008 
2009 	ASSERT_LE(0, child);
2010 	if (child == 0) {
2011 		ASSERT_EQ(err ? -1 : 0, execve(path, argv, NULL))
2012 		{
2013 			TH_LOG("Failed to execute \"%s\": %s", path,
2014 			       strerror(errno));
2015 		};
2016 		ASSERT_EQ(err, errno);
2017 		_exit(__test_passed(_metadata) ? 2 : 1);
2018 		return;
2019 	}
2020 	ASSERT_EQ(child, waitpid(child, &status, 0));
2021 	ASSERT_EQ(1, WIFEXITED(status));
2022 	ASSERT_EQ(err ? 2 : 0, WEXITSTATUS(status))
2023 	{
2024 		TH_LOG("Unexpected return code for \"%s\"", path);
2025 	};
2026 }
2027 
2028 static void test_check_exec(struct __test_metadata *const _metadata,
2029 			    const int err, const char *const path)
2030 {
2031 	int ret;
2032 	char *const argv[] = { (char *)path, NULL };
2033 
2034 	ret = sys_execveat(AT_FDCWD, path, argv, NULL,
2035 			   AT_EMPTY_PATH | AT_EXECVE_CHECK);
2036 	if (err) {
2037 		EXPECT_EQ(-1, ret);
2038 		EXPECT_EQ(errno, err);
2039 	} else {
2040 		EXPECT_EQ(0, ret);
2041 	}
2042 }
2043 
2044 TEST_F_FORK(layout1, execute)
2045 {
2046 	const struct rule rules[] = {
2047 		{
2048 			.path = dir_s1d2,
2049 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
2050 		},
2051 		{},
2052 	};
2053 	const int ruleset_fd =
2054 		create_ruleset(_metadata, rules[0].access, rules);
2055 
2056 	ASSERT_LE(0, ruleset_fd);
2057 	copy_file(_metadata, bin_true, file1_s1d1);
2058 	copy_file(_metadata, bin_true, file1_s1d2);
2059 	copy_file(_metadata, bin_true, file1_s1d3);
2060 
2061 	/* Checks before file1_s1d1 being denied. */
2062 	test_execute(_metadata, 0, file1_s1d1);
2063 	test_check_exec(_metadata, 0, file1_s1d1);
2064 
2065 	enforce_ruleset(_metadata, ruleset_fd);
2066 	ASSERT_EQ(0, close(ruleset_fd));
2067 
2068 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
2069 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
2070 	test_execute(_metadata, EACCES, file1_s1d1);
2071 	test_check_exec(_metadata, EACCES, file1_s1d1);
2072 
2073 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
2074 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
2075 	test_execute(_metadata, 0, file1_s1d2);
2076 	test_check_exec(_metadata, 0, file1_s1d2);
2077 
2078 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
2079 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
2080 	test_execute(_metadata, 0, file1_s1d3);
2081 	test_check_exec(_metadata, 0, file1_s1d3);
2082 }
2083 
2084 TEST_F_FORK(layout1, umount_sandboxer)
2085 {
2086 	int pipe_child[2], pipe_parent[2];
2087 	char buf_parent;
2088 	pid_t child;
2089 	int status;
2090 
2091 	copy_file(_metadata, bin_sandbox_and_launch, file1_s3d3);
2092 	ASSERT_EQ(0, pipe2(pipe_child, 0));
2093 	ASSERT_EQ(0, pipe2(pipe_parent, 0));
2094 
2095 	child = fork();
2096 	ASSERT_LE(0, child);
2097 	if (child == 0) {
2098 		char pipe_child_str[12], pipe_parent_str[12];
2099 		char *const argv[] = { (char *)file1_s3d3,
2100 				       (char *)bin_wait_pipe, pipe_child_str,
2101 				       pipe_parent_str, NULL };
2102 
2103 		/* Passes the pipe FDs to the executed binary and its child. */
2104 		EXPECT_EQ(0, close(pipe_child[0]));
2105 		EXPECT_EQ(0, close(pipe_parent[1]));
2106 		snprintf(pipe_child_str, sizeof(pipe_child_str), "%d",
2107 			 pipe_child[1]);
2108 		snprintf(pipe_parent_str, sizeof(pipe_parent_str), "%d",
2109 			 pipe_parent[0]);
2110 
2111 		/*
2112 		 * We need bin_sandbox_and_launch (copied inside the mount as
2113 		 * file1_s3d3) to execute bin_wait_pipe (outside the mount) to
2114 		 * make sure the mount point will not be EBUSY because of
2115 		 * file1_s3d3 being in use.  This avoids a potential race
2116 		 * condition between the following read() and umount() calls.
2117 		 */
2118 		ASSERT_EQ(0, execve(argv[0], argv, NULL))
2119 		{
2120 			TH_LOG("Failed to execute \"%s\": %s", argv[0],
2121 			       strerror(errno));
2122 		};
2123 		_exit(1);
2124 		return;
2125 	}
2126 
2127 	EXPECT_EQ(0, close(pipe_child[1]));
2128 	EXPECT_EQ(0, close(pipe_parent[0]));
2129 
2130 	/* Waits for the child to sandbox itself. */
2131 	EXPECT_EQ(1, read(pipe_child[0], &buf_parent, 1));
2132 
2133 	/* Tests that the sandboxer is tied to its mount point. */
2134 	set_cap(_metadata, CAP_SYS_ADMIN);
2135 	EXPECT_EQ(-1, umount(dir_s3d2));
2136 	EXPECT_EQ(EBUSY, errno);
2137 	clear_cap(_metadata, CAP_SYS_ADMIN);
2138 
2139 	/* Signals the child to launch a grandchild. */
2140 	EXPECT_EQ(1, write(pipe_parent[1], ".", 1));
2141 
2142 	/* Waits for the grandchild. */
2143 	EXPECT_EQ(1, read(pipe_child[0], &buf_parent, 1));
2144 
2145 	/* Tests that the domain's sandboxer is not tied to its mount point. */
2146 	set_cap(_metadata, CAP_SYS_ADMIN);
2147 	EXPECT_EQ(0, umount(dir_s3d2))
2148 	{
2149 		TH_LOG("Failed to umount \"%s\": %s", dir_s3d2,
2150 		       strerror(errno));
2151 	};
2152 	clear_cap(_metadata, CAP_SYS_ADMIN);
2153 
2154 	/* Signals the grandchild to terminate. */
2155 	EXPECT_EQ(1, write(pipe_parent[1], ".", 1));
2156 	ASSERT_EQ(child, waitpid(child, &status, 0));
2157 	ASSERT_EQ(1, WIFEXITED(status));
2158 	ASSERT_EQ(0, WEXITSTATUS(status));
2159 }
2160 
2161 TEST_F_FORK(layout1, link)
2162 {
2163 	const struct rule layer1[] = {
2164 		{
2165 			.path = dir_s1d2,
2166 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2167 		},
2168 		{},
2169 	};
2170 	const struct rule layer2[] = {
2171 		{
2172 			.path = dir_s1d3,
2173 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2174 		},
2175 		{},
2176 	};
2177 	int ruleset_fd = create_ruleset(_metadata, layer1[0].access, layer1);
2178 
2179 	ASSERT_LE(0, ruleset_fd);
2180 
2181 	ASSERT_EQ(0, unlink(file1_s1d1));
2182 	ASSERT_EQ(0, unlink(file1_s1d2));
2183 	ASSERT_EQ(0, unlink(file1_s1d3));
2184 
2185 	enforce_ruleset(_metadata, ruleset_fd);
2186 	ASSERT_EQ(0, close(ruleset_fd));
2187 
2188 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
2189 	ASSERT_EQ(EACCES, errno);
2190 
2191 	/* Denies linking because of reparenting. */
2192 	ASSERT_EQ(-1, link(file1_s2d1, file1_s1d2));
2193 	ASSERT_EQ(EXDEV, errno);
2194 	ASSERT_EQ(-1, link(file2_s1d2, file1_s1d3));
2195 	ASSERT_EQ(EXDEV, errno);
2196 	ASSERT_EQ(-1, link(file2_s1d3, file1_s1d2));
2197 	ASSERT_EQ(EXDEV, errno);
2198 
2199 	ASSERT_EQ(0, link(file2_s1d2, file1_s1d2));
2200 	ASSERT_EQ(0, link(file2_s1d3, file1_s1d3));
2201 
2202 	/* Prepares for next unlinks. */
2203 	ASSERT_EQ(0, unlink(file2_s1d2));
2204 	ASSERT_EQ(0, unlink(file2_s1d3));
2205 
2206 	ruleset_fd = create_ruleset(_metadata, layer2[0].access, layer2);
2207 	ASSERT_LE(0, ruleset_fd);
2208 	enforce_ruleset(_metadata, ruleset_fd);
2209 	ASSERT_EQ(0, close(ruleset_fd));
2210 
2211 	/* Checks that linkind doesn't require the ability to delete a file. */
2212 	ASSERT_EQ(0, link(file1_s1d2, file2_s1d2));
2213 	ASSERT_EQ(0, link(file1_s1d3, file2_s1d3));
2214 }
2215 
2216 static int test_rename(const char *const oldpath, const char *const newpath)
2217 {
2218 	if (rename(oldpath, newpath))
2219 		return errno;
2220 	return 0;
2221 }
2222 
2223 static int test_exchange(const char *const oldpath, const char *const newpath)
2224 {
2225 	if (renameat2(AT_FDCWD, oldpath, AT_FDCWD, newpath, RENAME_EXCHANGE))
2226 		return errno;
2227 	return 0;
2228 }
2229 
2230 TEST_F_FORK(layout1, rename_file)
2231 {
2232 	const struct rule rules[] = {
2233 		{
2234 			.path = dir_s1d3,
2235 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2236 		},
2237 		{
2238 			.path = dir_s2d2,
2239 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2240 		},
2241 		{},
2242 	};
2243 	const int ruleset_fd =
2244 		create_ruleset(_metadata, rules[0].access, rules);
2245 
2246 	ASSERT_LE(0, ruleset_fd);
2247 
2248 	ASSERT_EQ(0, unlink(file1_s1d2));
2249 
2250 	enforce_ruleset(_metadata, ruleset_fd);
2251 	ASSERT_EQ(0, close(ruleset_fd));
2252 
2253 	/*
2254 	 * Tries to replace a file, from a directory that allows file removal,
2255 	 * but to a different directory (which also allows file removal).
2256 	 */
2257 	ASSERT_EQ(-1, rename(file1_s2d3, file1_s1d3));
2258 	ASSERT_EQ(EXDEV, errno);
2259 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, file1_s1d3,
2260 				RENAME_EXCHANGE));
2261 	ASSERT_EQ(EXDEV, errno);
2262 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, dir_s1d3,
2263 				RENAME_EXCHANGE));
2264 	ASSERT_EQ(EXDEV, errno);
2265 
2266 	/*
2267 	 * Tries to replace a file, from a directory that denies file removal,
2268 	 * to a different directory (which allows file removal).
2269 	 */
2270 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
2271 	ASSERT_EQ(EACCES, errno);
2272 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, file1_s1d3,
2273 				RENAME_EXCHANGE));
2274 	ASSERT_EQ(EACCES, errno);
2275 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d2, AT_FDCWD, file1_s1d3,
2276 				RENAME_EXCHANGE));
2277 	ASSERT_EQ(EXDEV, errno);
2278 
2279 	/* Exchanges files and directories that partially allow removal. */
2280 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d2, AT_FDCWD, file1_s2d1,
2281 				RENAME_EXCHANGE));
2282 	ASSERT_EQ(EACCES, errno);
2283 	/* Checks that file1_s2d1 cannot be removed (instead of ENOTDIR). */
2284 	ASSERT_EQ(-1, rename(dir_s2d2, file1_s2d1));
2285 	ASSERT_EQ(EACCES, errno);
2286 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, dir_s2d2,
2287 				RENAME_EXCHANGE));
2288 	ASSERT_EQ(EACCES, errno);
2289 	/* Checks that file1_s1d1 cannot be removed (instead of EISDIR). */
2290 	ASSERT_EQ(-1, rename(file1_s1d1, dir_s1d2));
2291 	ASSERT_EQ(EACCES, errno);
2292 
2293 	/* Renames files with different parents. */
2294 	ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d2));
2295 	ASSERT_EQ(EXDEV, errno);
2296 	ASSERT_EQ(0, unlink(file1_s1d3));
2297 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
2298 	ASSERT_EQ(EACCES, errno);
2299 
2300 	/* Exchanges and renames files with same parent. */
2301 	ASSERT_EQ(0, renameat2(AT_FDCWD, file2_s2d3, AT_FDCWD, file1_s2d3,
2302 			       RENAME_EXCHANGE));
2303 	ASSERT_EQ(0, rename(file2_s2d3, file1_s2d3));
2304 
2305 	/* Exchanges files and directories with same parent, twice. */
2306 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s2d3,
2307 			       RENAME_EXCHANGE));
2308 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s2d3,
2309 			       RENAME_EXCHANGE));
2310 }
2311 
2312 TEST_F_FORK(layout1, rename_dir)
2313 {
2314 	const struct rule rules[] = {
2315 		{
2316 			.path = dir_s1d2,
2317 			.access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
2318 		},
2319 		{
2320 			.path = dir_s2d1,
2321 			.access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
2322 		},
2323 		{},
2324 	};
2325 	const int ruleset_fd =
2326 		create_ruleset(_metadata, rules[0].access, rules);
2327 
2328 	ASSERT_LE(0, ruleset_fd);
2329 
2330 	/* Empties dir_s1d3 to allow renaming. */
2331 	ASSERT_EQ(0, unlink(file1_s1d3));
2332 	ASSERT_EQ(0, unlink(file2_s1d3));
2333 
2334 	enforce_ruleset(_metadata, ruleset_fd);
2335 	ASSERT_EQ(0, close(ruleset_fd));
2336 
2337 	/* Exchanges and renames directory to a different parent. */
2338 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_s1d3,
2339 				RENAME_EXCHANGE));
2340 	ASSERT_EQ(EXDEV, errno);
2341 	ASSERT_EQ(-1, rename(dir_s2d3, dir_s1d3));
2342 	ASSERT_EQ(EXDEV, errno);
2343 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s1d3,
2344 				RENAME_EXCHANGE));
2345 	ASSERT_EQ(EXDEV, errno);
2346 
2347 	/*
2348 	 * Exchanges directory to the same parent, which doesn't allow
2349 	 * directory removal.
2350 	 */
2351 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s1d1, AT_FDCWD, dir_s2d1,
2352 				RENAME_EXCHANGE));
2353 	ASSERT_EQ(EACCES, errno);
2354 	/* Checks that dir_s1d2 cannot be removed (instead of ENOTDIR). */
2355 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s1d1));
2356 	ASSERT_EQ(EACCES, errno);
2357 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, dir_s1d2,
2358 				RENAME_EXCHANGE));
2359 	ASSERT_EQ(EACCES, errno);
2360 	/* Checks that dir_s1d2 cannot be removed (instead of EISDIR). */
2361 	ASSERT_EQ(-1, rename(file1_s1d1, dir_s1d2));
2362 	ASSERT_EQ(EACCES, errno);
2363 
2364 	/*
2365 	 * Exchanges and renames directory to the same parent, which allows
2366 	 * directory removal.
2367 	 */
2368 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, file1_s1d2,
2369 			       RENAME_EXCHANGE));
2370 	ASSERT_EQ(0, unlink(dir_s1d3));
2371 	ASSERT_EQ(0, mkdir(dir_s1d3, 0700));
2372 	ASSERT_EQ(0, rename(file1_s1d2, dir_s1d3));
2373 	ASSERT_EQ(0, rmdir(dir_s1d3));
2374 }
2375 
2376 TEST_F_FORK(layout1, reparent_refer)
2377 {
2378 	const struct rule layer1[] = {
2379 		{
2380 			.path = dir_s1d2,
2381 			.access = LANDLOCK_ACCESS_FS_REFER,
2382 		},
2383 		{
2384 			.path = dir_s2d2,
2385 			.access = LANDLOCK_ACCESS_FS_REFER,
2386 		},
2387 		{},
2388 	};
2389 	int ruleset_fd =
2390 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_REFER, layer1);
2391 
2392 	ASSERT_LE(0, ruleset_fd);
2393 	enforce_ruleset(_metadata, ruleset_fd);
2394 	ASSERT_EQ(0, close(ruleset_fd));
2395 
2396 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d1));
2397 	ASSERT_EQ(EXDEV, errno);
2398 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d2));
2399 	ASSERT_EQ(EXDEV, errno);
2400 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d3));
2401 	ASSERT_EQ(EXDEV, errno);
2402 
2403 	ASSERT_EQ(-1, rename(dir_s1d3, dir_s2d1));
2404 	ASSERT_EQ(EXDEV, errno);
2405 	ASSERT_EQ(-1, rename(dir_s1d3, dir_s2d2));
2406 	ASSERT_EQ(EXDEV, errno);
2407 	/*
2408 	 * Moving should only be allowed when the source and the destination
2409 	 * parent directory have REFER.
2410 	 */
2411 	ASSERT_EQ(-1, rename(dir_s1d3, dir_s2d3));
2412 	ASSERT_EQ(ENOTEMPTY, errno);
2413 	ASSERT_EQ(0, unlink(file1_s2d3));
2414 	ASSERT_EQ(0, unlink(file2_s2d3));
2415 	ASSERT_EQ(0, rename(dir_s1d3, dir_s2d3));
2416 }
2417 
2418 /* Checks renames beneath dir_s1d1. */
2419 static void refer_denied_by_default(struct __test_metadata *const _metadata,
2420 				    const struct rule layer1[],
2421 				    const int layer1_err,
2422 				    const struct rule layer2[])
2423 {
2424 	int ruleset_fd;
2425 
2426 	ASSERT_EQ(0, unlink(file1_s1d2));
2427 
2428 	ruleset_fd = create_ruleset(_metadata, layer1[0].access, layer1);
2429 	ASSERT_LE(0, ruleset_fd);
2430 	enforce_ruleset(_metadata, ruleset_fd);
2431 	ASSERT_EQ(0, close(ruleset_fd));
2432 
2433 	/*
2434 	 * If the first layer handles LANDLOCK_ACCESS_FS_REFER (according to
2435 	 * layer1_err), then it allows some different-parent renames and links.
2436 	 */
2437 	ASSERT_EQ(layer1_err, test_rename(file1_s1d1, file1_s1d2));
2438 	if (layer1_err == 0)
2439 		ASSERT_EQ(layer1_err, test_rename(file1_s1d2, file1_s1d1));
2440 	ASSERT_EQ(layer1_err, test_exchange(file2_s1d1, file2_s1d2));
2441 	ASSERT_EQ(layer1_err, test_exchange(file2_s1d2, file2_s1d1));
2442 
2443 	ruleset_fd = create_ruleset(_metadata, layer2[0].access, layer2);
2444 	ASSERT_LE(0, ruleset_fd);
2445 	enforce_ruleset(_metadata, ruleset_fd);
2446 	ASSERT_EQ(0, close(ruleset_fd));
2447 
2448 	/*
2449 	 * Now, either the first or the second layer does not handle
2450 	 * LANDLOCK_ACCESS_FS_REFER, which means that any different-parent
2451 	 * renames and links are denied, thus making the layer handling
2452 	 * LANDLOCK_ACCESS_FS_REFER null and void.
2453 	 */
2454 	ASSERT_EQ(EXDEV, test_rename(file1_s1d1, file1_s1d2));
2455 	ASSERT_EQ(EXDEV, test_exchange(file2_s1d1, file2_s1d2));
2456 	ASSERT_EQ(EXDEV, test_exchange(file2_s1d2, file2_s1d1));
2457 }
2458 
2459 const struct rule layer_dir_s1d1_refer[] = {
2460 	{
2461 		.path = dir_s1d1,
2462 		.access = LANDLOCK_ACCESS_FS_REFER,
2463 	},
2464 	{},
2465 };
2466 
2467 const struct rule layer_dir_s1d1_execute[] = {
2468 	{
2469 		/* Matches a parent directory. */
2470 		.path = dir_s1d1,
2471 		.access = LANDLOCK_ACCESS_FS_EXECUTE,
2472 	},
2473 	{},
2474 };
2475 
2476 const struct rule layer_dir_s2d1_execute[] = {
2477 	{
2478 		/* Does not match a parent directory. */
2479 		.path = dir_s2d1,
2480 		.access = LANDLOCK_ACCESS_FS_EXECUTE,
2481 	},
2482 	{},
2483 };
2484 
2485 /*
2486  * Tests precedence over renames: denied by default for different parent
2487  * directories, *with* a rule matching a parent directory, but not directly
2488  * denying access (with MAKE_REG nor REMOVE).
2489  */
2490 TEST_F_FORK(layout1, refer_denied_by_default1)
2491 {
2492 	refer_denied_by_default(_metadata, layer_dir_s1d1_refer, 0,
2493 				layer_dir_s1d1_execute);
2494 }
2495 
2496 /*
2497  * Same test but this time turning around the ABI version order: the first
2498  * layer does not handle LANDLOCK_ACCESS_FS_REFER.
2499  */
2500 TEST_F_FORK(layout1, refer_denied_by_default2)
2501 {
2502 	refer_denied_by_default(_metadata, layer_dir_s1d1_execute, EXDEV,
2503 				layer_dir_s1d1_refer);
2504 }
2505 
2506 /*
2507  * Tests precedence over renames: denied by default for different parent
2508  * directories, *without* a rule matching a parent directory, but not directly
2509  * denying access (with MAKE_REG nor REMOVE).
2510  */
2511 TEST_F_FORK(layout1, refer_denied_by_default3)
2512 {
2513 	refer_denied_by_default(_metadata, layer_dir_s1d1_refer, 0,
2514 				layer_dir_s2d1_execute);
2515 }
2516 
2517 /*
2518  * Same test but this time turning around the ABI version order: the first
2519  * layer does not handle LANDLOCK_ACCESS_FS_REFER.
2520  */
2521 TEST_F_FORK(layout1, refer_denied_by_default4)
2522 {
2523 	refer_denied_by_default(_metadata, layer_dir_s2d1_execute, EXDEV,
2524 				layer_dir_s1d1_refer);
2525 }
2526 
2527 /*
2528  * Tests walking through a denied root mount.
2529  */
2530 TEST_F_FORK(layout1, refer_mount_root_deny)
2531 {
2532 	const struct landlock_ruleset_attr ruleset_attr = {
2533 		.handled_access_fs = LANDLOCK_ACCESS_FS_MAKE_DIR,
2534 	};
2535 	int root_fd, ruleset_fd;
2536 
2537 	/* Creates a mount object from a non-mount point. */
2538 	set_cap(_metadata, CAP_SYS_ADMIN);
2539 	root_fd =
2540 		open_tree(AT_FDCWD, dir_s1d1,
2541 			  AT_EMPTY_PATH | OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC);
2542 	clear_cap(_metadata, CAP_SYS_ADMIN);
2543 	ASSERT_LE(0, root_fd);
2544 
2545 	ruleset_fd =
2546 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
2547 	ASSERT_LE(0, ruleset_fd);
2548 
2549 	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
2550 	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
2551 	EXPECT_EQ(0, close(ruleset_fd));
2552 
2553 	/* Link denied by Landlock: EACCES. */
2554 	EXPECT_EQ(-1, linkat(root_fd, ".", root_fd, "does_not_exist", 0));
2555 	EXPECT_EQ(EACCES, errno);
2556 
2557 	/* renameat2() always returns EBUSY. */
2558 	EXPECT_EQ(-1, renameat2(root_fd, ".", root_fd, "does_not_exist", 0));
2559 	EXPECT_EQ(EBUSY, errno);
2560 
2561 	EXPECT_EQ(0, close(root_fd));
2562 }
2563 
2564 TEST_F_FORK(layout1, refer_part_mount_tree_is_allowed)
2565 {
2566 	const struct rule layer1[] = {
2567 		{
2568 			/* Parent mount point. */
2569 			.path = dir_s3d1,
2570 			.access = LANDLOCK_ACCESS_FS_REFER |
2571 				  LANDLOCK_ACCESS_FS_MAKE_REG,
2572 		},
2573 		{
2574 			/*
2575 			 * Removing the source file is allowed because its
2576 			 * access rights are already a superset of the
2577 			 * destination.
2578 			 */
2579 			.path = dir_s3d4,
2580 			.access = LANDLOCK_ACCESS_FS_REFER |
2581 				  LANDLOCK_ACCESS_FS_MAKE_REG |
2582 				  LANDLOCK_ACCESS_FS_REMOVE_FILE,
2583 		},
2584 		{},
2585 	};
2586 	int ruleset_fd;
2587 
2588 	ASSERT_EQ(0, unlink(file1_s3d3));
2589 	ruleset_fd = create_ruleset(_metadata,
2590 				    LANDLOCK_ACCESS_FS_REFER |
2591 					    LANDLOCK_ACCESS_FS_MAKE_REG |
2592 					    LANDLOCK_ACCESS_FS_REMOVE_FILE,
2593 				    layer1);
2594 
2595 	ASSERT_LE(0, ruleset_fd);
2596 	enforce_ruleset(_metadata, ruleset_fd);
2597 	ASSERT_EQ(0, close(ruleset_fd));
2598 
2599 	ASSERT_EQ(0, rename(file1_s3d4, file1_s3d3));
2600 }
2601 
2602 TEST_F_FORK(layout1, reparent_link)
2603 {
2604 	const struct rule layer1[] = {
2605 		{
2606 			.path = dir_s1d2,
2607 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2608 		},
2609 		{
2610 			.path = dir_s1d3,
2611 			.access = LANDLOCK_ACCESS_FS_REFER,
2612 		},
2613 		{
2614 			.path = dir_s2d2,
2615 			.access = LANDLOCK_ACCESS_FS_REFER,
2616 		},
2617 		{
2618 			.path = dir_s2d3,
2619 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2620 		},
2621 		{},
2622 	};
2623 	const int ruleset_fd = create_ruleset(
2624 		_metadata,
2625 		LANDLOCK_ACCESS_FS_MAKE_REG | LANDLOCK_ACCESS_FS_REFER, layer1);
2626 
2627 	ASSERT_LE(0, ruleset_fd);
2628 	enforce_ruleset(_metadata, ruleset_fd);
2629 	ASSERT_EQ(0, close(ruleset_fd));
2630 
2631 	ASSERT_EQ(0, unlink(file1_s1d1));
2632 	ASSERT_EQ(0, unlink(file1_s1d2));
2633 	ASSERT_EQ(0, unlink(file1_s1d3));
2634 
2635 	/* Denies linking because of missing MAKE_REG. */
2636 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
2637 	ASSERT_EQ(EACCES, errno);
2638 	/* Denies linking because of missing source and destination REFER. */
2639 	ASSERT_EQ(-1, link(file1_s2d1, file1_s1d2));
2640 	ASSERT_EQ(EXDEV, errno);
2641 	/* Denies linking because of missing source REFER. */
2642 	ASSERT_EQ(-1, link(file1_s2d1, file1_s1d3));
2643 	ASSERT_EQ(EXDEV, errno);
2644 
2645 	/* Denies linking because of missing MAKE_REG. */
2646 	ASSERT_EQ(-1, link(file1_s2d2, file1_s1d1));
2647 	ASSERT_EQ(EACCES, errno);
2648 	/* Denies linking because of missing destination REFER. */
2649 	ASSERT_EQ(-1, link(file1_s2d2, file1_s1d2));
2650 	ASSERT_EQ(EXDEV, errno);
2651 
2652 	/* Allows linking because of REFER and MAKE_REG. */
2653 	ASSERT_EQ(0, link(file1_s2d2, file1_s1d3));
2654 	ASSERT_EQ(0, unlink(file1_s2d2));
2655 	/* Reverse linking denied because of missing MAKE_REG. */
2656 	ASSERT_EQ(-1, link(file1_s1d3, file1_s2d2));
2657 	ASSERT_EQ(EACCES, errno);
2658 	ASSERT_EQ(0, unlink(file1_s2d3));
2659 	/* Checks reverse linking. */
2660 	ASSERT_EQ(0, link(file1_s1d3, file1_s2d3));
2661 	ASSERT_EQ(0, unlink(file1_s1d3));
2662 
2663 	/*
2664 	 * This is OK for a file link, but it should not be allowed for a
2665 	 * directory rename (because of the superset of access rights.
2666 	 */
2667 	ASSERT_EQ(0, link(file1_s2d3, file1_s1d3));
2668 	ASSERT_EQ(0, unlink(file1_s1d3));
2669 
2670 	ASSERT_EQ(-1, link(file2_s1d2, file1_s1d3));
2671 	ASSERT_EQ(EXDEV, errno);
2672 	ASSERT_EQ(-1, link(file2_s1d3, file1_s1d2));
2673 	ASSERT_EQ(EXDEV, errno);
2674 
2675 	ASSERT_EQ(0, link(file2_s1d2, file1_s1d2));
2676 	ASSERT_EQ(0, link(file2_s1d3, file1_s1d3));
2677 }
2678 
2679 TEST_F_FORK(layout1, reparent_rename)
2680 {
2681 	/* Same rules as for reparent_link. */
2682 	const struct rule layer1[] = {
2683 		{
2684 			.path = dir_s1d2,
2685 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2686 		},
2687 		{
2688 			.path = dir_s1d3,
2689 			.access = LANDLOCK_ACCESS_FS_REFER,
2690 		},
2691 		{
2692 			.path = dir_s2d2,
2693 			.access = LANDLOCK_ACCESS_FS_REFER,
2694 		},
2695 		{
2696 			.path = dir_s2d3,
2697 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2698 		},
2699 		{},
2700 	};
2701 	const int ruleset_fd = create_ruleset(
2702 		_metadata,
2703 		LANDLOCK_ACCESS_FS_MAKE_REG | LANDLOCK_ACCESS_FS_REFER, layer1);
2704 
2705 	ASSERT_LE(0, ruleset_fd);
2706 	enforce_ruleset(_metadata, ruleset_fd);
2707 	ASSERT_EQ(0, close(ruleset_fd));
2708 
2709 	ASSERT_EQ(0, unlink(file1_s1d2));
2710 	ASSERT_EQ(0, unlink(file1_s1d3));
2711 
2712 	/* Denies renaming because of missing MAKE_REG. */
2713 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file2_s1d1, AT_FDCWD, file1_s1d1,
2714 				RENAME_EXCHANGE));
2715 	ASSERT_EQ(EACCES, errno);
2716 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, file2_s1d1,
2717 				RENAME_EXCHANGE));
2718 	ASSERT_EQ(EACCES, errno);
2719 	ASSERT_EQ(0, unlink(file1_s1d1));
2720 	ASSERT_EQ(-1, rename(file2_s1d1, file1_s1d1));
2721 	ASSERT_EQ(EACCES, errno);
2722 	/* Even denies same file exchange. */
2723 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file2_s1d1, AT_FDCWD, file2_s1d1,
2724 				RENAME_EXCHANGE));
2725 	ASSERT_EQ(EACCES, errno);
2726 
2727 	/* Denies renaming because of missing source and destination REFER. */
2728 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d2));
2729 	ASSERT_EQ(EXDEV, errno);
2730 	/*
2731 	 * Denies renaming because of missing MAKE_REG, source and destination
2732 	 * REFER.
2733 	 */
2734 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, file2_s1d1,
2735 				RENAME_EXCHANGE));
2736 	ASSERT_EQ(EACCES, errno);
2737 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file2_s1d1, AT_FDCWD, file1_s2d1,
2738 				RENAME_EXCHANGE));
2739 	ASSERT_EQ(EACCES, errno);
2740 
2741 	/* Denies renaming because of missing source REFER. */
2742 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
2743 	ASSERT_EQ(EXDEV, errno);
2744 	/* Denies renaming because of missing MAKE_REG. */
2745 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, file2_s1d3,
2746 				RENAME_EXCHANGE));
2747 	ASSERT_EQ(EACCES, errno);
2748 
2749 	/* Denies renaming because of missing MAKE_REG. */
2750 	ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d1));
2751 	ASSERT_EQ(EACCES, errno);
2752 	/* Denies renaming because of missing destination REFER*/
2753 	ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d2));
2754 	ASSERT_EQ(EXDEV, errno);
2755 
2756 	/* Denies exchange because of one missing MAKE_REG. */
2757 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, file2_s1d3,
2758 				RENAME_EXCHANGE));
2759 	ASSERT_EQ(EACCES, errno);
2760 	/* Allows renaming because of REFER and MAKE_REG. */
2761 	ASSERT_EQ(0, rename(file1_s2d2, file1_s1d3));
2762 
2763 	/* Reverse renaming denied because of missing MAKE_REG. */
2764 	ASSERT_EQ(-1, rename(file1_s1d3, file1_s2d2));
2765 	ASSERT_EQ(EACCES, errno);
2766 	ASSERT_EQ(0, unlink(file1_s2d3));
2767 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2768 
2769 	/* Tests reverse renaming. */
2770 	ASSERT_EQ(0, rename(file1_s2d3, file1_s1d3));
2771 	ASSERT_EQ(0, renameat2(AT_FDCWD, file2_s2d3, AT_FDCWD, file1_s1d3,
2772 			       RENAME_EXCHANGE));
2773 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2774 
2775 	/*
2776 	 * This is OK for a file rename, but it should not be allowed for a
2777 	 * directory rename (because of the superset of access rights).
2778 	 */
2779 	ASSERT_EQ(0, rename(file1_s2d3, file1_s1d3));
2780 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2781 
2782 	/*
2783 	 * Tests superset restrictions applied to directories.  Not only the
2784 	 * dir_s2d3's parent (dir_s2d2) should be taken into account but also
2785 	 * access rights tied to dir_s2d3. dir_s2d2 is missing one access right
2786 	 * compared to dir_s1d3/file1_s1d3 (MAKE_REG) but it is provided
2787 	 * directly by the moved dir_s2d3.
2788 	 */
2789 	ASSERT_EQ(0, rename(dir_s2d3, file1_s1d3));
2790 	ASSERT_EQ(0, rename(file1_s1d3, dir_s2d3));
2791 	/*
2792 	 * The first rename is allowed but not the exchange because dir_s1d3's
2793 	 * parent (dir_s1d2) doesn't have REFER.
2794 	 */
2795 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, dir_s1d3,
2796 				RENAME_EXCHANGE));
2797 	ASSERT_EQ(EXDEV, errno);
2798 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, file1_s2d3,
2799 				RENAME_EXCHANGE));
2800 	ASSERT_EQ(EXDEV, errno);
2801 	ASSERT_EQ(-1, rename(file1_s2d3, dir_s1d3));
2802 	ASSERT_EQ(EXDEV, errno);
2803 
2804 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s1d3));
2805 	ASSERT_EQ(EXDEV, errno);
2806 	ASSERT_EQ(-1, rename(file2_s1d3, file1_s1d2));
2807 	ASSERT_EQ(EXDEV, errno);
2808 
2809 	/* Renaming in the same directory is always allowed. */
2810 	ASSERT_EQ(0, rename(file2_s1d2, file1_s1d2));
2811 	ASSERT_EQ(0, rename(file2_s1d3, file1_s1d3));
2812 
2813 	ASSERT_EQ(0, unlink(file1_s1d2));
2814 	/* Denies because of missing source MAKE_REG and destination REFER. */
2815 	ASSERT_EQ(-1, rename(dir_s2d3, file1_s1d2));
2816 	ASSERT_EQ(EXDEV, errno);
2817 
2818 	ASSERT_EQ(0, unlink(file1_s1d3));
2819 	/* Denies because of missing source MAKE_REG and REFER. */
2820 	ASSERT_EQ(-1, rename(dir_s2d2, file1_s1d3));
2821 	ASSERT_EQ(EXDEV, errno);
2822 }
2823 
2824 static void
2825 reparent_exdev_layers_enforce1(struct __test_metadata *const _metadata)
2826 {
2827 	const struct rule layer1[] = {
2828 		{
2829 			.path = dir_s1d2,
2830 			.access = LANDLOCK_ACCESS_FS_REFER,
2831 		},
2832 		{
2833 			/* Interesting for the layer2 tests. */
2834 			.path = dir_s1d3,
2835 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2836 		},
2837 		{
2838 			.path = dir_s2d2,
2839 			.access = LANDLOCK_ACCESS_FS_REFER,
2840 		},
2841 		{
2842 			.path = dir_s2d3,
2843 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2844 		},
2845 		{},
2846 	};
2847 	const int ruleset_fd = create_ruleset(
2848 		_metadata,
2849 		LANDLOCK_ACCESS_FS_MAKE_REG | LANDLOCK_ACCESS_FS_REFER, layer1);
2850 
2851 	ASSERT_LE(0, ruleset_fd);
2852 	enforce_ruleset(_metadata, ruleset_fd);
2853 	ASSERT_EQ(0, close(ruleset_fd));
2854 }
2855 
2856 static void
2857 reparent_exdev_layers_enforce2(struct __test_metadata *const _metadata)
2858 {
2859 	const struct rule layer2[] = {
2860 		{
2861 			.path = dir_s2d3,
2862 			.access = LANDLOCK_ACCESS_FS_MAKE_DIR,
2863 		},
2864 		{},
2865 	};
2866 	/*
2867 	 * Same checks as before but with a second layer and a new MAKE_DIR
2868 	 * rule (and no explicit handling of REFER).
2869 	 */
2870 	const int ruleset_fd =
2871 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_MAKE_DIR, layer2);
2872 
2873 	ASSERT_LE(0, ruleset_fd);
2874 	enforce_ruleset(_metadata, ruleset_fd);
2875 	ASSERT_EQ(0, close(ruleset_fd));
2876 }
2877 
2878 TEST_F_FORK(layout1, reparent_exdev_layers_rename1)
2879 {
2880 	ASSERT_EQ(0, unlink(file1_s2d2));
2881 	ASSERT_EQ(0, unlink(file1_s2d3));
2882 
2883 	reparent_exdev_layers_enforce1(_metadata);
2884 
2885 	/*
2886 	 * Moving the dir_s1d3 directory below dir_s2d2 is allowed by Landlock
2887 	 * because it doesn't inherit new access rights.
2888 	 */
2889 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d2));
2890 	ASSERT_EQ(0, rename(file1_s2d2, dir_s1d3));
2891 
2892 	/*
2893 	 * Moving the dir_s1d3 directory below dir_s2d3 is allowed, even if it
2894 	 * gets a new inherited access rights (MAKE_REG), because MAKE_REG is
2895 	 * already allowed for dir_s1d3.
2896 	 */
2897 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d3));
2898 	ASSERT_EQ(0, rename(file1_s2d3, dir_s1d3));
2899 
2900 	/*
2901 	 * However, moving the file1_s1d3 file below dir_s2d3 is allowed
2902 	 * because it cannot inherit MAKE_REG right (which is dedicated to
2903 	 * directories).
2904 	 */
2905 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2906 
2907 	reparent_exdev_layers_enforce2(_metadata);
2908 
2909 	/*
2910 	 * Moving the dir_s1d3 directory below dir_s2d2 is now denied because
2911 	 * MAKE_DIR is not tied to dir_s2d2.
2912 	 */
2913 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d2));
2914 	ASSERT_EQ(EACCES, errno);
2915 
2916 	/*
2917 	 * Moving the dir_s1d3 directory below dir_s2d3 is forbidden because it
2918 	 * would grants MAKE_REG and MAKE_DIR rights to it.
2919 	 */
2920 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d3));
2921 	ASSERT_EQ(EXDEV, errno);
2922 
2923 	/*
2924 	 * Moving the file2_s1d3 file below dir_s2d3 is denied because the
2925 	 * second layer does not handle REFER, which is always denied by
2926 	 * default.
2927 	 */
2928 	ASSERT_EQ(-1, rename(file2_s1d3, file1_s2d3));
2929 	ASSERT_EQ(EXDEV, errno);
2930 }
2931 
2932 TEST_F_FORK(layout1, reparent_exdev_layers_rename2)
2933 {
2934 	reparent_exdev_layers_enforce1(_metadata);
2935 
2936 	/* Checks EACCES predominance over EXDEV. */
2937 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d2));
2938 	ASSERT_EQ(EACCES, errno);
2939 	ASSERT_EQ(-1, rename(file1_s1d2, file1_s2d2));
2940 	ASSERT_EQ(EACCES, errno);
2941 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d3));
2942 	ASSERT_EQ(EXDEV, errno);
2943 	/* Modify layout! */
2944 	ASSERT_EQ(0, rename(file1_s1d2, file1_s2d3));
2945 
2946 	/* Without REFER source. */
2947 	ASSERT_EQ(-1, rename(dir_s1d1, file1_s2d2));
2948 	ASSERT_EQ(EXDEV, errno);
2949 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s2d2));
2950 	ASSERT_EQ(EXDEV, errno);
2951 
2952 	reparent_exdev_layers_enforce2(_metadata);
2953 
2954 	/* Checks EACCES predominance over EXDEV. */
2955 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d2));
2956 	ASSERT_EQ(EACCES, errno);
2957 	/* Checks with actual file2_s1d2. */
2958 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s2d2));
2959 	ASSERT_EQ(EACCES, errno);
2960 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d3));
2961 	ASSERT_EQ(EXDEV, errno);
2962 	/*
2963 	 * Modifying the layout is now denied because the second layer does not
2964 	 * handle REFER, which is always denied by default.
2965 	 */
2966 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s2d3));
2967 	ASSERT_EQ(EXDEV, errno);
2968 
2969 	/* Without REFER source, EACCES wins over EXDEV. */
2970 	ASSERT_EQ(-1, rename(dir_s1d1, file1_s2d2));
2971 	ASSERT_EQ(EACCES, errno);
2972 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s2d2));
2973 	ASSERT_EQ(EACCES, errno);
2974 }
2975 
2976 TEST_F_FORK(layout1, reparent_exdev_layers_exchange1)
2977 {
2978 	const char *const dir_file1_s1d2 = file1_s1d2, *const dir_file2_s2d3 =
2979 							       file2_s2d3;
2980 
2981 	ASSERT_EQ(0, unlink(file1_s1d2));
2982 	ASSERT_EQ(0, mkdir(file1_s1d2, 0700));
2983 	ASSERT_EQ(0, unlink(file2_s2d3));
2984 	ASSERT_EQ(0, mkdir(file2_s2d3, 0700));
2985 
2986 	reparent_exdev_layers_enforce1(_metadata);
2987 
2988 	/* Error predominance with file exchange: returns EXDEV and EACCES. */
2989 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, file1_s2d3,
2990 				RENAME_EXCHANGE));
2991 	ASSERT_EQ(EACCES, errno);
2992 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, file1_s1d1,
2993 				RENAME_EXCHANGE));
2994 	ASSERT_EQ(EACCES, errno);
2995 
2996 	/*
2997 	 * Checks with directories which creation could be allowed, but denied
2998 	 * because of access rights that would be inherited.
2999 	 */
3000 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD,
3001 				dir_file2_s2d3, RENAME_EXCHANGE));
3002 	ASSERT_EQ(EXDEV, errno);
3003 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD,
3004 				dir_file1_s1d2, RENAME_EXCHANGE));
3005 	ASSERT_EQ(EXDEV, errno);
3006 
3007 	/* Checks with same access rights. */
3008 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, dir_s2d3,
3009 			       RENAME_EXCHANGE));
3010 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_s1d3,
3011 			       RENAME_EXCHANGE));
3012 
3013 	/* Checks with different (child-only) access rights. */
3014 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_file1_s1d2,
3015 			       RENAME_EXCHANGE));
3016 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD, dir_s2d3,
3017 			       RENAME_EXCHANGE));
3018 
3019 	/*
3020 	 * Checks that exchange between file and directory are consistent.
3021 	 *
3022 	 * Moving a file (file1_s2d2) to a directory which only grants more
3023 	 * directory-related access rights is allowed, and at the same time
3024 	 * moving a directory (dir_file2_s2d3) to another directory which
3025 	 * grants less access rights is allowed too.
3026 	 *
3027 	 * See layout1.reparent_exdev_layers_exchange3 for inverted arguments.
3028 	 */
3029 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
3030 			       RENAME_EXCHANGE));
3031 	/*
3032 	 * However, moving back the directory is denied because it would get
3033 	 * more access rights than the current state and because file creation
3034 	 * is forbidden (in dir_s2d2).
3035 	 */
3036 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
3037 				RENAME_EXCHANGE));
3038 	ASSERT_EQ(EACCES, errno);
3039 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
3040 				RENAME_EXCHANGE));
3041 	ASSERT_EQ(EACCES, errno);
3042 
3043 	reparent_exdev_layers_enforce2(_metadata);
3044 
3045 	/* Error predominance with file exchange: returns EXDEV and EACCES. */
3046 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, file1_s2d3,
3047 				RENAME_EXCHANGE));
3048 	ASSERT_EQ(EACCES, errno);
3049 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, file1_s1d1,
3050 				RENAME_EXCHANGE));
3051 	ASSERT_EQ(EACCES, errno);
3052 
3053 	/* Checks with directories which creation is now denied. */
3054 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD,
3055 				dir_file2_s2d3, RENAME_EXCHANGE));
3056 	ASSERT_EQ(EACCES, errno);
3057 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD,
3058 				dir_file1_s1d2, RENAME_EXCHANGE));
3059 	ASSERT_EQ(EACCES, errno);
3060 
3061 	/* Checks with different (child-only) access rights. */
3062 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, dir_s2d3,
3063 				RENAME_EXCHANGE));
3064 	/* Denied because of MAKE_DIR. */
3065 	ASSERT_EQ(EACCES, errno);
3066 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_s1d3,
3067 				RENAME_EXCHANGE));
3068 	ASSERT_EQ(EACCES, errno);
3069 
3070 	/* Checks with different (child-only) access rights. */
3071 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_file1_s1d2,
3072 				RENAME_EXCHANGE));
3073 	/* Denied because of MAKE_DIR. */
3074 	ASSERT_EQ(EACCES, errno);
3075 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD, dir_s2d3,
3076 				RENAME_EXCHANGE));
3077 	ASSERT_EQ(EACCES, errno);
3078 
3079 	/* See layout1.reparent_exdev_layers_exchange2 for complement. */
3080 }
3081 
3082 TEST_F_FORK(layout1, reparent_exdev_layers_exchange2)
3083 {
3084 	const char *const dir_file2_s2d3 = file2_s2d3;
3085 
3086 	ASSERT_EQ(0, unlink(file2_s2d3));
3087 	ASSERT_EQ(0, mkdir(file2_s2d3, 0700));
3088 
3089 	reparent_exdev_layers_enforce1(_metadata);
3090 	reparent_exdev_layers_enforce2(_metadata);
3091 
3092 	/* Checks that exchange between file and directory are consistent. */
3093 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
3094 				RENAME_EXCHANGE));
3095 	ASSERT_EQ(EACCES, errno);
3096 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
3097 				RENAME_EXCHANGE));
3098 	ASSERT_EQ(EACCES, errno);
3099 }
3100 
3101 TEST_F_FORK(layout1, reparent_exdev_layers_exchange3)
3102 {
3103 	const char *const dir_file2_s2d3 = file2_s2d3;
3104 
3105 	ASSERT_EQ(0, unlink(file2_s2d3));
3106 	ASSERT_EQ(0, mkdir(file2_s2d3, 0700));
3107 
3108 	reparent_exdev_layers_enforce1(_metadata);
3109 
3110 	/*
3111 	 * Checks that exchange between file and directory are consistent,
3112 	 * including with inverted arguments (see
3113 	 * layout1.reparent_exdev_layers_exchange1).
3114 	 */
3115 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
3116 			       RENAME_EXCHANGE));
3117 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
3118 				RENAME_EXCHANGE));
3119 	ASSERT_EQ(EACCES, errno);
3120 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
3121 				RENAME_EXCHANGE));
3122 	ASSERT_EQ(EACCES, errno);
3123 }
3124 
3125 TEST_F_FORK(layout1, reparent_remove)
3126 {
3127 	const struct rule layer1[] = {
3128 		{
3129 			.path = dir_s1d1,
3130 			.access = LANDLOCK_ACCESS_FS_REFER |
3131 				  LANDLOCK_ACCESS_FS_REMOVE_DIR,
3132 		},
3133 		{
3134 			.path = dir_s1d2,
3135 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
3136 		},
3137 		{
3138 			.path = dir_s2d1,
3139 			.access = LANDLOCK_ACCESS_FS_REFER |
3140 				  LANDLOCK_ACCESS_FS_REMOVE_FILE,
3141 		},
3142 		{},
3143 	};
3144 	const int ruleset_fd = create_ruleset(
3145 		_metadata,
3146 		LANDLOCK_ACCESS_FS_REFER | LANDLOCK_ACCESS_FS_REMOVE_DIR |
3147 			LANDLOCK_ACCESS_FS_REMOVE_FILE,
3148 		layer1);
3149 
3150 	ASSERT_LE(0, ruleset_fd);
3151 	enforce_ruleset(_metadata, ruleset_fd);
3152 	ASSERT_EQ(0, close(ruleset_fd));
3153 
3154 	/* Access denied because of wrong/swapped remove file/dir. */
3155 	ASSERT_EQ(-1, rename(file1_s1d1, dir_s2d2));
3156 	ASSERT_EQ(EACCES, errno);
3157 	ASSERT_EQ(-1, rename(dir_s2d2, file1_s1d1));
3158 	ASSERT_EQ(EACCES, errno);
3159 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, dir_s2d2,
3160 				RENAME_EXCHANGE));
3161 	ASSERT_EQ(EACCES, errno);
3162 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, dir_s2d3,
3163 				RENAME_EXCHANGE));
3164 	ASSERT_EQ(EACCES, errno);
3165 
3166 	/* Access allowed thanks to the matching rights. */
3167 	ASSERT_EQ(-1, rename(file1_s2d1, dir_s1d2));
3168 	ASSERT_EQ(EISDIR, errno);
3169 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s2d1));
3170 	ASSERT_EQ(ENOTDIR, errno);
3171 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d1));
3172 	ASSERT_EQ(ENOTDIR, errno);
3173 	ASSERT_EQ(0, unlink(file1_s2d1));
3174 	ASSERT_EQ(0, unlink(file1_s1d3));
3175 	ASSERT_EQ(0, unlink(file2_s1d3));
3176 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d1));
3177 
3178 	/* Effectively removes a file and a directory by exchanging them. */
3179 	ASSERT_EQ(0, mkdir(dir_s1d3, 0700));
3180 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s1d3,
3181 			       RENAME_EXCHANGE));
3182 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s1d3,
3183 				RENAME_EXCHANGE));
3184 	ASSERT_EQ(EACCES, errno);
3185 }
3186 
3187 TEST_F_FORK(layout1, reparent_dom_superset)
3188 {
3189 	const struct rule layer1[] = {
3190 		{
3191 			.path = dir_s1d2,
3192 			.access = LANDLOCK_ACCESS_FS_REFER,
3193 		},
3194 		{
3195 			.path = file1_s1d2,
3196 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
3197 		},
3198 		{
3199 			.path = dir_s1d3,
3200 			.access = LANDLOCK_ACCESS_FS_MAKE_SOCK |
3201 				  LANDLOCK_ACCESS_FS_EXECUTE,
3202 		},
3203 		{
3204 			.path = dir_s2d2,
3205 			.access = LANDLOCK_ACCESS_FS_REFER |
3206 				  LANDLOCK_ACCESS_FS_EXECUTE |
3207 				  LANDLOCK_ACCESS_FS_MAKE_SOCK,
3208 		},
3209 		{
3210 			.path = dir_s2d3,
3211 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3212 				  LANDLOCK_ACCESS_FS_MAKE_FIFO,
3213 		},
3214 		{},
3215 	};
3216 	int ruleset_fd = create_ruleset(_metadata,
3217 					LANDLOCK_ACCESS_FS_REFER |
3218 						LANDLOCK_ACCESS_FS_EXECUTE |
3219 						LANDLOCK_ACCESS_FS_MAKE_SOCK |
3220 						LANDLOCK_ACCESS_FS_READ_FILE |
3221 						LANDLOCK_ACCESS_FS_MAKE_FIFO,
3222 					layer1);
3223 
3224 	ASSERT_LE(0, ruleset_fd);
3225 	enforce_ruleset(_metadata, ruleset_fd);
3226 	ASSERT_EQ(0, close(ruleset_fd));
3227 
3228 	ASSERT_EQ(-1, rename(file1_s1d2, file1_s2d1));
3229 	ASSERT_EQ(EXDEV, errno);
3230 	/*
3231 	 * Moving file1_s1d2 beneath dir_s2d3 would grant it the READ_FILE
3232 	 * access right.
3233 	 */
3234 	ASSERT_EQ(-1, rename(file1_s1d2, file1_s2d3));
3235 	ASSERT_EQ(EXDEV, errno);
3236 	/*
3237 	 * Moving file1_s1d2 should be allowed even if dir_s2d2 grants a
3238 	 * superset of access rights compared to dir_s1d2, because file1_s1d2
3239 	 * already has these access rights anyway.
3240 	 */
3241 	ASSERT_EQ(0, rename(file1_s1d2, file1_s2d2));
3242 	ASSERT_EQ(0, rename(file1_s2d2, file1_s1d2));
3243 
3244 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d1));
3245 	ASSERT_EQ(EXDEV, errno);
3246 	/*
3247 	 * Moving dir_s1d3 beneath dir_s2d3 would grant it the MAKE_FIFO access
3248 	 * right.
3249 	 */
3250 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d3));
3251 	ASSERT_EQ(EXDEV, errno);
3252 	/*
3253 	 * Moving dir_s1d3 should be allowed even if dir_s2d2 grants a superset
3254 	 * of access rights compared to dir_s1d2, because dir_s1d3 already has
3255 	 * these access rights anyway.
3256 	 */
3257 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d2));
3258 	ASSERT_EQ(0, rename(file1_s2d2, dir_s1d3));
3259 
3260 	/*
3261 	 * Moving file1_s2d3 beneath dir_s1d2 is allowed, but moving it back
3262 	 * will be denied because the new inherited access rights from dir_s1d2
3263 	 * will be less than the destination (original) dir_s2d3.  This is a
3264 	 * sinkhole scenario where we cannot move back files or directories.
3265 	 */
3266 	ASSERT_EQ(0, rename(file1_s2d3, file2_s1d2));
3267 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s2d3));
3268 	ASSERT_EQ(EXDEV, errno);
3269 	ASSERT_EQ(0, unlink(file2_s1d2));
3270 	ASSERT_EQ(0, unlink(file2_s2d3));
3271 	/*
3272 	 * Checks similar directory one-way move: dir_s2d3 loses EXECUTE and
3273 	 * MAKE_SOCK which were inherited from dir_s1d3.
3274 	 */
3275 	ASSERT_EQ(0, rename(dir_s2d3, file2_s1d2));
3276 	ASSERT_EQ(-1, rename(file2_s1d2, dir_s2d3));
3277 	ASSERT_EQ(EXDEV, errno);
3278 }
3279 
3280 TEST_F_FORK(layout1, remove_dir)
3281 {
3282 	const struct rule rules[] = {
3283 		{
3284 			.path = dir_s1d2,
3285 			.access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
3286 		},
3287 		{},
3288 	};
3289 	const int ruleset_fd =
3290 		create_ruleset(_metadata, rules[0].access, rules);
3291 
3292 	ASSERT_LE(0, ruleset_fd);
3293 
3294 	ASSERT_EQ(0, unlink(file1_s1d1));
3295 	ASSERT_EQ(0, unlink(file1_s1d2));
3296 	ASSERT_EQ(0, unlink(file1_s1d3));
3297 	ASSERT_EQ(0, unlink(file2_s1d3));
3298 
3299 	enforce_ruleset(_metadata, ruleset_fd);
3300 	ASSERT_EQ(0, close(ruleset_fd));
3301 
3302 	ASSERT_EQ(0, rmdir(dir_s1d3));
3303 	ASSERT_EQ(0, mkdir(dir_s1d3, 0700));
3304 	ASSERT_EQ(0, unlinkat(AT_FDCWD, dir_s1d3, AT_REMOVEDIR));
3305 
3306 	/* dir_s1d2 itself cannot be removed. */
3307 	ASSERT_EQ(-1, rmdir(dir_s1d2));
3308 	ASSERT_EQ(EACCES, errno);
3309 	ASSERT_EQ(-1, unlinkat(AT_FDCWD, dir_s1d2, AT_REMOVEDIR));
3310 	ASSERT_EQ(EACCES, errno);
3311 	ASSERT_EQ(-1, rmdir(dir_s1d1));
3312 	ASSERT_EQ(EACCES, errno);
3313 	ASSERT_EQ(-1, unlinkat(AT_FDCWD, dir_s1d1, AT_REMOVEDIR));
3314 	ASSERT_EQ(EACCES, errno);
3315 }
3316 
3317 TEST_F_FORK(layout1, remove_file)
3318 {
3319 	const struct rule rules[] = {
3320 		{
3321 			.path = dir_s1d2,
3322 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
3323 		},
3324 		{},
3325 	};
3326 	const int ruleset_fd =
3327 		create_ruleset(_metadata, rules[0].access, rules);
3328 
3329 	ASSERT_LE(0, ruleset_fd);
3330 	enforce_ruleset(_metadata, ruleset_fd);
3331 	ASSERT_EQ(0, close(ruleset_fd));
3332 
3333 	ASSERT_EQ(-1, unlink(file1_s1d1));
3334 	ASSERT_EQ(EACCES, errno);
3335 	ASSERT_EQ(-1, unlinkat(AT_FDCWD, file1_s1d1, 0));
3336 	ASSERT_EQ(EACCES, errno);
3337 	ASSERT_EQ(0, unlink(file1_s1d2));
3338 	ASSERT_EQ(0, unlinkat(AT_FDCWD, file1_s1d3, 0));
3339 }
3340 
3341 static void test_make_file(struct __test_metadata *const _metadata,
3342 			   const __u64 access, const mode_t mode,
3343 			   const dev_t dev)
3344 {
3345 	const struct rule rules[] = {
3346 		{
3347 			.path = dir_s1d2,
3348 			.access = access,
3349 		},
3350 		{},
3351 	};
3352 	const int ruleset_fd = create_ruleset(_metadata, access, rules);
3353 
3354 	ASSERT_LE(0, ruleset_fd);
3355 
3356 	ASSERT_EQ(0, unlink(file1_s1d1));
3357 	ASSERT_EQ(0, unlink(file2_s1d1));
3358 	ASSERT_EQ(0, mknod(file2_s1d1, mode | 0400, dev))
3359 	{
3360 		TH_LOG("Failed to make file \"%s\": %s", file2_s1d1,
3361 		       strerror(errno));
3362 	};
3363 
3364 	ASSERT_EQ(0, unlink(file1_s1d2));
3365 	ASSERT_EQ(0, unlink(file2_s1d2));
3366 
3367 	ASSERT_EQ(0, unlink(file1_s1d3));
3368 	ASSERT_EQ(0, unlink(file2_s1d3));
3369 
3370 	enforce_ruleset(_metadata, ruleset_fd);
3371 	ASSERT_EQ(0, close(ruleset_fd));
3372 
3373 	ASSERT_EQ(-1, mknod(file1_s1d1, mode | 0400, dev));
3374 	ASSERT_EQ(EACCES, errno);
3375 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
3376 	ASSERT_EQ(EACCES, errno);
3377 	ASSERT_EQ(-1, rename(file2_s1d1, file1_s1d1));
3378 	ASSERT_EQ(EACCES, errno);
3379 
3380 	ASSERT_EQ(0, mknod(file1_s1d2, mode | 0400, dev))
3381 	{
3382 		TH_LOG("Failed to make file \"%s\": %s", file1_s1d2,
3383 		       strerror(errno));
3384 	};
3385 	ASSERT_EQ(0, link(file1_s1d2, file2_s1d2));
3386 	ASSERT_EQ(0, unlink(file2_s1d2));
3387 	ASSERT_EQ(0, rename(file1_s1d2, file2_s1d2));
3388 
3389 	ASSERT_EQ(0, mknod(file1_s1d3, mode | 0400, dev));
3390 	ASSERT_EQ(0, link(file1_s1d3, file2_s1d3));
3391 	ASSERT_EQ(0, unlink(file2_s1d3));
3392 	ASSERT_EQ(0, rename(file1_s1d3, file2_s1d3));
3393 }
3394 
3395 TEST_F_FORK(layout1, make_char)
3396 {
3397 	/* Creates a /dev/null device. */
3398 	set_cap(_metadata, CAP_MKNOD);
3399 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_CHAR, S_IFCHR,
3400 		       makedev(1, 3));
3401 }
3402 
3403 TEST_F_FORK(layout1, make_block)
3404 {
3405 	/* Creates a /dev/loop0 device. */
3406 	set_cap(_metadata, CAP_MKNOD);
3407 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_BLOCK, S_IFBLK,
3408 		       makedev(7, 0));
3409 }
3410 
3411 TEST_F_FORK(layout1, make_reg_1)
3412 {
3413 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, S_IFREG, 0);
3414 }
3415 
3416 TEST_F_FORK(layout1, make_reg_2)
3417 {
3418 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, 0, 0);
3419 }
3420 
3421 TEST_F_FORK(layout1, make_sock)
3422 {
3423 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_SOCK, S_IFSOCK, 0);
3424 }
3425 
3426 TEST_F_FORK(layout1, make_fifo)
3427 {
3428 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_FIFO, S_IFIFO, 0);
3429 }
3430 
3431 TEST_F_FORK(layout1, make_sym)
3432 {
3433 	const struct rule rules[] = {
3434 		{
3435 			.path = dir_s1d2,
3436 			.access = LANDLOCK_ACCESS_FS_MAKE_SYM,
3437 		},
3438 		{},
3439 	};
3440 	const int ruleset_fd =
3441 		create_ruleset(_metadata, rules[0].access, rules);
3442 
3443 	ASSERT_LE(0, ruleset_fd);
3444 
3445 	ASSERT_EQ(0, unlink(file1_s1d1));
3446 	ASSERT_EQ(0, unlink(file2_s1d1));
3447 	ASSERT_EQ(0, symlink("none", file2_s1d1));
3448 
3449 	ASSERT_EQ(0, unlink(file1_s1d2));
3450 	ASSERT_EQ(0, unlink(file2_s1d2));
3451 
3452 	ASSERT_EQ(0, unlink(file1_s1d3));
3453 	ASSERT_EQ(0, unlink(file2_s1d3));
3454 
3455 	enforce_ruleset(_metadata, ruleset_fd);
3456 	ASSERT_EQ(0, close(ruleset_fd));
3457 
3458 	ASSERT_EQ(-1, symlink("none", file1_s1d1));
3459 	ASSERT_EQ(EACCES, errno);
3460 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
3461 	ASSERT_EQ(EACCES, errno);
3462 	ASSERT_EQ(-1, rename(file2_s1d1, file1_s1d1));
3463 	ASSERT_EQ(EACCES, errno);
3464 
3465 	ASSERT_EQ(0, symlink("none", file1_s1d2));
3466 	ASSERT_EQ(0, link(file1_s1d2, file2_s1d2));
3467 	ASSERT_EQ(0, unlink(file2_s1d2));
3468 	ASSERT_EQ(0, rename(file1_s1d2, file2_s1d2));
3469 
3470 	ASSERT_EQ(0, symlink("none", file1_s1d3));
3471 	ASSERT_EQ(0, link(file1_s1d3, file2_s1d3));
3472 	ASSERT_EQ(0, unlink(file2_s1d3));
3473 	ASSERT_EQ(0, rename(file1_s1d3, file2_s1d3));
3474 }
3475 
3476 TEST_F_FORK(layout1, make_dir)
3477 {
3478 	const struct rule rules[] = {
3479 		{
3480 			.path = dir_s1d2,
3481 			.access = LANDLOCK_ACCESS_FS_MAKE_DIR,
3482 		},
3483 		{},
3484 	};
3485 	const int ruleset_fd =
3486 		create_ruleset(_metadata, rules[0].access, rules);
3487 
3488 	ASSERT_LE(0, ruleset_fd);
3489 
3490 	ASSERT_EQ(0, unlink(file1_s1d1));
3491 	ASSERT_EQ(0, unlink(file1_s1d2));
3492 	ASSERT_EQ(0, unlink(file1_s1d3));
3493 
3494 	enforce_ruleset(_metadata, ruleset_fd);
3495 	ASSERT_EQ(0, close(ruleset_fd));
3496 
3497 	/* Uses file_* as directory names. */
3498 	ASSERT_EQ(-1, mkdir(file1_s1d1, 0700));
3499 	ASSERT_EQ(EACCES, errno);
3500 	ASSERT_EQ(0, mkdir(file1_s1d2, 0700));
3501 	ASSERT_EQ(0, mkdir(file1_s1d3, 0700));
3502 }
3503 
3504 static int open_proc_fd(struct __test_metadata *const _metadata, const int fd,
3505 			const int open_flags)
3506 {
3507 	static const char path_template[] = "/proc/self/fd/%d";
3508 	char procfd_path[sizeof(path_template) + 10];
3509 	const int procfd_path_size =
3510 		snprintf(procfd_path, sizeof(procfd_path), path_template, fd);
3511 
3512 	ASSERT_LT(procfd_path_size, sizeof(procfd_path));
3513 	return open(procfd_path, open_flags);
3514 }
3515 
3516 TEST_F_FORK(layout1, proc_unlinked_file)
3517 {
3518 	const struct rule rules[] = {
3519 		{
3520 			.path = file1_s1d2,
3521 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
3522 		},
3523 		{},
3524 	};
3525 	int reg_fd, proc_fd;
3526 	const int ruleset_fd = create_ruleset(
3527 		_metadata,
3528 		LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_WRITE_FILE,
3529 		rules);
3530 
3531 	ASSERT_LE(0, ruleset_fd);
3532 	enforce_ruleset(_metadata, ruleset_fd);
3533 	ASSERT_EQ(0, close(ruleset_fd));
3534 
3535 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
3536 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
3537 	reg_fd = open(file1_s1d2, O_RDONLY | O_CLOEXEC);
3538 	ASSERT_LE(0, reg_fd);
3539 	ASSERT_EQ(0, unlink(file1_s1d2));
3540 
3541 	proc_fd = open_proc_fd(_metadata, reg_fd, O_RDONLY | O_CLOEXEC);
3542 	ASSERT_LE(0, proc_fd);
3543 	ASSERT_EQ(0, close(proc_fd));
3544 
3545 	proc_fd = open_proc_fd(_metadata, reg_fd, O_RDWR | O_CLOEXEC);
3546 	ASSERT_EQ(-1, proc_fd)
3547 	{
3548 		TH_LOG("Successfully opened /proc/self/fd/%d: %s", reg_fd,
3549 		       strerror(errno));
3550 	}
3551 	ASSERT_EQ(EACCES, errno);
3552 
3553 	ASSERT_EQ(0, close(reg_fd));
3554 }
3555 
3556 TEST_F_FORK(layout1, proc_pipe)
3557 {
3558 	int proc_fd;
3559 	int pipe_fds[2];
3560 	char buf = '\0';
3561 	const struct rule rules[] = {
3562 		{
3563 			.path = dir_s1d2,
3564 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3565 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
3566 		},
3567 		{},
3568 	};
3569 	/* Limits read and write access to files tied to the filesystem. */
3570 	const int ruleset_fd =
3571 		create_ruleset(_metadata, rules[0].access, rules);
3572 
3573 	ASSERT_LE(0, ruleset_fd);
3574 	enforce_ruleset(_metadata, ruleset_fd);
3575 	ASSERT_EQ(0, close(ruleset_fd));
3576 
3577 	/* Checks enforcement for normal files. */
3578 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDWR));
3579 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
3580 
3581 	/* Checks access to pipes through FD. */
3582 	ASSERT_EQ(0, pipe2(pipe_fds, O_CLOEXEC));
3583 	ASSERT_EQ(1, write(pipe_fds[1], ".", 1))
3584 	{
3585 		TH_LOG("Failed to write in pipe: %s", strerror(errno));
3586 	}
3587 	ASSERT_EQ(1, read(pipe_fds[0], &buf, 1));
3588 	ASSERT_EQ('.', buf);
3589 
3590 	/* Checks write access to pipe through /proc/self/fd . */
3591 	proc_fd = open_proc_fd(_metadata, pipe_fds[1], O_WRONLY | O_CLOEXEC);
3592 	ASSERT_LE(0, proc_fd);
3593 	ASSERT_EQ(1, write(proc_fd, ".", 1))
3594 	{
3595 		TH_LOG("Failed to write through /proc/self/fd/%d: %s",
3596 		       pipe_fds[1], strerror(errno));
3597 	}
3598 	ASSERT_EQ(0, close(proc_fd));
3599 
3600 	/* Checks read access to pipe through /proc/self/fd . */
3601 	proc_fd = open_proc_fd(_metadata, pipe_fds[0], O_RDONLY | O_CLOEXEC);
3602 	ASSERT_LE(0, proc_fd);
3603 	buf = '\0';
3604 	ASSERT_EQ(1, read(proc_fd, &buf, 1))
3605 	{
3606 		TH_LOG("Failed to read through /proc/self/fd/%d: %s",
3607 		       pipe_fds[1], strerror(errno));
3608 	}
3609 	ASSERT_EQ(0, close(proc_fd));
3610 
3611 	ASSERT_EQ(0, close(pipe_fds[0]));
3612 	ASSERT_EQ(0, close(pipe_fds[1]));
3613 }
3614 
3615 /* Invokes truncate(2) and returns its errno or 0. */
3616 static int test_truncate(const char *const path)
3617 {
3618 	if (truncate(path, 10) < 0)
3619 		return errno;
3620 	return 0;
3621 }
3622 
3623 /*
3624  * Invokes creat(2) and returns its errno or 0.
3625  * Closes the opened file descriptor on success.
3626  */
3627 static int test_creat(const char *const path)
3628 {
3629 	int fd = creat(path, 0600);
3630 
3631 	if (fd < 0)
3632 		return errno;
3633 
3634 	/*
3635 	 * Mixing error codes from close(2) and creat(2) should not lead to any
3636 	 * (access type) confusion for this test.
3637 	 */
3638 	if (close(fd) < 0)
3639 		return errno;
3640 	return 0;
3641 }
3642 
3643 /*
3644  * Exercises file truncation when it's not restricted,
3645  * as it was the case before LANDLOCK_ACCESS_FS_TRUNCATE existed.
3646  */
3647 TEST_F_FORK(layout1, truncate_unhandled)
3648 {
3649 	const char *const file_r = file1_s1d1;
3650 	const char *const file_w = file2_s1d1;
3651 	const char *const file_none = file1_s1d2;
3652 	const struct rule rules[] = {
3653 		{
3654 			.path = file_r,
3655 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
3656 		},
3657 		{
3658 			.path = file_w,
3659 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3660 		},
3661 		/* Implicitly: No rights for file_none. */
3662 		{},
3663 	};
3664 
3665 	const __u64 handled = LANDLOCK_ACCESS_FS_READ_FILE |
3666 			      LANDLOCK_ACCESS_FS_WRITE_FILE;
3667 	int ruleset_fd;
3668 
3669 	/* Enables Landlock. */
3670 	ruleset_fd = create_ruleset(_metadata, handled, rules);
3671 
3672 	ASSERT_LE(0, ruleset_fd);
3673 	enforce_ruleset(_metadata, ruleset_fd);
3674 	ASSERT_EQ(0, close(ruleset_fd));
3675 
3676 	/*
3677 	 * Checks read right: truncate and open with O_TRUNC work, unless the
3678 	 * file is attempted to be opened for writing.
3679 	 */
3680 	EXPECT_EQ(0, test_truncate(file_r));
3681 	EXPECT_EQ(0, test_open(file_r, O_RDONLY | O_TRUNC));
3682 	EXPECT_EQ(EACCES, test_open(file_r, O_WRONLY | O_TRUNC));
3683 	EXPECT_EQ(EACCES, test_creat(file_r));
3684 
3685 	/*
3686 	 * Checks write right: truncate and open with O_TRUNC work, unless the
3687 	 * file is attempted to be opened for reading.
3688 	 */
3689 	EXPECT_EQ(0, test_truncate(file_w));
3690 	EXPECT_EQ(EACCES, test_open(file_w, O_RDONLY | O_TRUNC));
3691 	EXPECT_EQ(0, test_open(file_w, O_WRONLY | O_TRUNC));
3692 	EXPECT_EQ(0, test_creat(file_w));
3693 
3694 	/*
3695 	 * Checks "no rights" case: truncate works but all open attempts fail,
3696 	 * including creat.
3697 	 */
3698 	EXPECT_EQ(0, test_truncate(file_none));
3699 	EXPECT_EQ(EACCES, test_open(file_none, O_RDONLY | O_TRUNC));
3700 	EXPECT_EQ(EACCES, test_open(file_none, O_WRONLY | O_TRUNC));
3701 	EXPECT_EQ(EACCES, test_creat(file_none));
3702 }
3703 
3704 TEST_F_FORK(layout1, truncate)
3705 {
3706 	const char *const file_rwt = file1_s1d1;
3707 	const char *const file_rw = file2_s1d1;
3708 	const char *const file_rt = file1_s1d2;
3709 	const char *const file_t = file2_s1d2;
3710 	const char *const file_none = file1_s1d3;
3711 	const char *const dir_t = dir_s2d1;
3712 	const char *const file_in_dir_t = file1_s2d1;
3713 	const char *const dir_w = dir_s3d1;
3714 	const char *const file_in_dir_w = file1_s3d1;
3715 	const struct rule rules[] = {
3716 		{
3717 			.path = file_rwt,
3718 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3719 				  LANDLOCK_ACCESS_FS_WRITE_FILE |
3720 				  LANDLOCK_ACCESS_FS_TRUNCATE,
3721 		},
3722 		{
3723 			.path = file_rw,
3724 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3725 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
3726 		},
3727 		{
3728 			.path = file_rt,
3729 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3730 				  LANDLOCK_ACCESS_FS_TRUNCATE,
3731 		},
3732 		{
3733 			.path = file_t,
3734 			.access = LANDLOCK_ACCESS_FS_TRUNCATE,
3735 		},
3736 		/* Implicitly: No access rights for file_none. */
3737 		{
3738 			.path = dir_t,
3739 			.access = LANDLOCK_ACCESS_FS_TRUNCATE,
3740 		},
3741 		{
3742 			.path = dir_w,
3743 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3744 		},
3745 		{},
3746 	};
3747 	const __u64 handled = LANDLOCK_ACCESS_FS_READ_FILE |
3748 			      LANDLOCK_ACCESS_FS_WRITE_FILE |
3749 			      LANDLOCK_ACCESS_FS_TRUNCATE;
3750 	int ruleset_fd;
3751 
3752 	/* Enables Landlock. */
3753 	ruleset_fd = create_ruleset(_metadata, handled, rules);
3754 
3755 	ASSERT_LE(0, ruleset_fd);
3756 	enforce_ruleset(_metadata, ruleset_fd);
3757 	ASSERT_EQ(0, close(ruleset_fd));
3758 
3759 	/* Checks read, write and truncate rights: truncation works. */
3760 	EXPECT_EQ(0, test_truncate(file_rwt));
3761 	EXPECT_EQ(0, test_open(file_rwt, O_RDONLY | O_TRUNC));
3762 	EXPECT_EQ(0, test_open(file_rwt, O_WRONLY | O_TRUNC));
3763 
3764 	/* Checks read and write rights: no truncate variant works. */
3765 	EXPECT_EQ(EACCES, test_truncate(file_rw));
3766 	EXPECT_EQ(EACCES, test_open(file_rw, O_RDONLY | O_TRUNC));
3767 	EXPECT_EQ(EACCES, test_open(file_rw, O_WRONLY | O_TRUNC));
3768 
3769 	/*
3770 	 * Checks read and truncate rights: truncation works.
3771 	 *
3772 	 * Note: Files can get truncated using open() even with O_RDONLY.
3773 	 */
3774 	EXPECT_EQ(0, test_truncate(file_rt));
3775 	EXPECT_EQ(0, test_open(file_rt, O_RDONLY | O_TRUNC));
3776 	EXPECT_EQ(EACCES, test_open(file_rt, O_WRONLY | O_TRUNC));
3777 
3778 	/* Checks truncate right: truncate works, but can't open file. */
3779 	EXPECT_EQ(0, test_truncate(file_t));
3780 	EXPECT_EQ(EACCES, test_open(file_t, O_RDONLY | O_TRUNC));
3781 	EXPECT_EQ(EACCES, test_open(file_t, O_WRONLY | O_TRUNC));
3782 
3783 	/* Checks "no rights" case: No form of truncation works. */
3784 	EXPECT_EQ(EACCES, test_truncate(file_none));
3785 	EXPECT_EQ(EACCES, test_open(file_none, O_RDONLY | O_TRUNC));
3786 	EXPECT_EQ(EACCES, test_open(file_none, O_WRONLY | O_TRUNC));
3787 
3788 	/*
3789 	 * Checks truncate right on directory: truncate works on contained
3790 	 * files.
3791 	 */
3792 	EXPECT_EQ(0, test_truncate(file_in_dir_t));
3793 	EXPECT_EQ(EACCES, test_open(file_in_dir_t, O_RDONLY | O_TRUNC));
3794 	EXPECT_EQ(EACCES, test_open(file_in_dir_t, O_WRONLY | O_TRUNC));
3795 
3796 	/*
3797 	 * Checks creat in dir_w: This requires the truncate right when
3798 	 * overwriting an existing file, but does not require it when the file
3799 	 * is new.
3800 	 */
3801 	EXPECT_EQ(EACCES, test_creat(file_in_dir_w));
3802 
3803 	ASSERT_EQ(0, unlink(file_in_dir_w));
3804 	EXPECT_EQ(0, test_creat(file_in_dir_w));
3805 }
3806 
3807 /* Invokes ftruncate(2) and returns its errno or 0. */
3808 static int test_ftruncate(int fd)
3809 {
3810 	if (ftruncate(fd, 10) < 0)
3811 		return errno;
3812 	return 0;
3813 }
3814 
3815 TEST_F_FORK(layout1, ftruncate)
3816 {
3817 	/*
3818 	 * This test opens a new file descriptor at different stages of
3819 	 * Landlock restriction:
3820 	 *
3821 	 * without restriction:                    ftruncate works
3822 	 * something else but truncate restricted: ftruncate works
3823 	 * truncate restricted and permitted:      ftruncate works
3824 	 * truncate restricted and not permitted:  ftruncate fails
3825 	 *
3826 	 * Whether this works or not is expected to depend on the time when the
3827 	 * FD was opened, not to depend on the time when ftruncate() was
3828 	 * called.
3829 	 */
3830 	const char *const path = file1_s1d1;
3831 	const __u64 handled1 = LANDLOCK_ACCESS_FS_READ_FILE |
3832 			       LANDLOCK_ACCESS_FS_WRITE_FILE;
3833 	const struct rule layer1[] = {
3834 		{
3835 			.path = path,
3836 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3837 		},
3838 		{},
3839 	};
3840 	const __u64 handled2 = LANDLOCK_ACCESS_FS_TRUNCATE;
3841 	const struct rule layer2[] = {
3842 		{
3843 			.path = path,
3844 			.access = LANDLOCK_ACCESS_FS_TRUNCATE,
3845 		},
3846 		{},
3847 	};
3848 	const __u64 handled3 = LANDLOCK_ACCESS_FS_TRUNCATE |
3849 			       LANDLOCK_ACCESS_FS_WRITE_FILE;
3850 	const struct rule layer3[] = {
3851 		{
3852 			.path = path,
3853 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3854 		},
3855 		{},
3856 	};
3857 	int fd_layer0, fd_layer1, fd_layer2, fd_layer3, ruleset_fd;
3858 
3859 	fd_layer0 = open(path, O_WRONLY);
3860 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3861 
3862 	ruleset_fd = create_ruleset(_metadata, handled1, layer1);
3863 	ASSERT_LE(0, ruleset_fd);
3864 	enforce_ruleset(_metadata, ruleset_fd);
3865 	ASSERT_EQ(0, close(ruleset_fd));
3866 
3867 	fd_layer1 = open(path, O_WRONLY);
3868 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3869 	EXPECT_EQ(0, test_ftruncate(fd_layer1));
3870 
3871 	ruleset_fd = create_ruleset(_metadata, handled2, layer2);
3872 	ASSERT_LE(0, ruleset_fd);
3873 	enforce_ruleset(_metadata, ruleset_fd);
3874 	ASSERT_EQ(0, close(ruleset_fd));
3875 
3876 	fd_layer2 = open(path, O_WRONLY);
3877 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3878 	EXPECT_EQ(0, test_ftruncate(fd_layer1));
3879 	EXPECT_EQ(0, test_ftruncate(fd_layer2));
3880 
3881 	ruleset_fd = create_ruleset(_metadata, handled3, layer3);
3882 	ASSERT_LE(0, ruleset_fd);
3883 	enforce_ruleset(_metadata, ruleset_fd);
3884 	ASSERT_EQ(0, close(ruleset_fd));
3885 
3886 	fd_layer3 = open(path, O_WRONLY);
3887 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3888 	EXPECT_EQ(0, test_ftruncate(fd_layer1));
3889 	EXPECT_EQ(0, test_ftruncate(fd_layer2));
3890 	EXPECT_EQ(EACCES, test_ftruncate(fd_layer3));
3891 
3892 	ASSERT_EQ(0, close(fd_layer0));
3893 	ASSERT_EQ(0, close(fd_layer1));
3894 	ASSERT_EQ(0, close(fd_layer2));
3895 	ASSERT_EQ(0, close(fd_layer3));
3896 }
3897 
3898 /* clang-format off */
3899 FIXTURE(ftruncate) {};
3900 /* clang-format on */
3901 
3902 FIXTURE_SETUP(ftruncate)
3903 {
3904 	prepare_layout(_metadata);
3905 	create_file(_metadata, file1_s1d1);
3906 }
3907 
3908 FIXTURE_TEARDOWN_PARENT(ftruncate)
3909 {
3910 	EXPECT_EQ(0, remove_path(file1_s1d1));
3911 	cleanup_layout(_metadata);
3912 }
3913 
3914 FIXTURE_VARIANT(ftruncate)
3915 {
3916 	const __u64 handled;
3917 	const __u64 allowed;
3918 	const int expected_open_result;
3919 	const int expected_ftruncate_result;
3920 };
3921 
3922 /* clang-format off */
3923 FIXTURE_VARIANT_ADD(ftruncate, w_w) {
3924 	/* clang-format on */
3925 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE,
3926 	.allowed = LANDLOCK_ACCESS_FS_WRITE_FILE,
3927 	.expected_open_result = 0,
3928 	.expected_ftruncate_result = 0,
3929 };
3930 
3931 /* clang-format off */
3932 FIXTURE_VARIANT_ADD(ftruncate, t_t) {
3933 	/* clang-format on */
3934 	.handled = LANDLOCK_ACCESS_FS_TRUNCATE,
3935 	.allowed = LANDLOCK_ACCESS_FS_TRUNCATE,
3936 	.expected_open_result = 0,
3937 	.expected_ftruncate_result = 0,
3938 };
3939 
3940 /* clang-format off */
3941 FIXTURE_VARIANT_ADD(ftruncate, wt_w) {
3942 	/* clang-format on */
3943 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3944 	.allowed = LANDLOCK_ACCESS_FS_WRITE_FILE,
3945 	.expected_open_result = 0,
3946 	.expected_ftruncate_result = EACCES,
3947 };
3948 
3949 /* clang-format off */
3950 FIXTURE_VARIANT_ADD(ftruncate, wt_wt) {
3951 	/* clang-format on */
3952 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3953 	.allowed = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3954 	.expected_open_result = 0,
3955 	.expected_ftruncate_result = 0,
3956 };
3957 
3958 /* clang-format off */
3959 FIXTURE_VARIANT_ADD(ftruncate, wt_t) {
3960 	/* clang-format on */
3961 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3962 	.allowed = LANDLOCK_ACCESS_FS_TRUNCATE,
3963 	.expected_open_result = EACCES,
3964 };
3965 
3966 TEST_F_FORK(ftruncate, open_and_ftruncate)
3967 {
3968 	const char *const path = file1_s1d1;
3969 	const struct rule rules[] = {
3970 		{
3971 			.path = path,
3972 			.access = variant->allowed,
3973 		},
3974 		{},
3975 	};
3976 	int fd, ruleset_fd;
3977 
3978 	/* Enables Landlock. */
3979 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
3980 	ASSERT_LE(0, ruleset_fd);
3981 	enforce_ruleset(_metadata, ruleset_fd);
3982 	ASSERT_EQ(0, close(ruleset_fd));
3983 
3984 	fd = open(path, O_WRONLY);
3985 	EXPECT_EQ(variant->expected_open_result, (fd < 0 ? errno : 0));
3986 	if (fd >= 0) {
3987 		EXPECT_EQ(variant->expected_ftruncate_result,
3988 			  test_ftruncate(fd));
3989 		ASSERT_EQ(0, close(fd));
3990 	}
3991 }
3992 
3993 TEST_F_FORK(ftruncate, open_and_ftruncate_in_different_processes)
3994 {
3995 	int child, fd, status;
3996 	int socket_fds[2];
3997 
3998 	ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
3999 				socket_fds));
4000 
4001 	child = fork();
4002 	ASSERT_LE(0, child);
4003 	if (child == 0) {
4004 		/*
4005 		 * Enables Landlock in the child process, open a file descriptor
4006 		 * where truncation is forbidden and send it to the
4007 		 * non-landlocked parent process.
4008 		 */
4009 		const char *const path = file1_s1d1;
4010 		const struct rule rules[] = {
4011 			{
4012 				.path = path,
4013 				.access = variant->allowed,
4014 			},
4015 			{},
4016 		};
4017 		int fd, ruleset_fd;
4018 
4019 		ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4020 		ASSERT_LE(0, ruleset_fd);
4021 		enforce_ruleset(_metadata, ruleset_fd);
4022 		ASSERT_EQ(0, close(ruleset_fd));
4023 
4024 		fd = open(path, O_WRONLY);
4025 		ASSERT_EQ(variant->expected_open_result, (fd < 0 ? errno : 0));
4026 
4027 		if (fd >= 0) {
4028 			ASSERT_EQ(0, send_fd(socket_fds[0], fd));
4029 			ASSERT_EQ(0, close(fd));
4030 		}
4031 
4032 		ASSERT_EQ(0, close(socket_fds[0]));
4033 
4034 		_exit(_metadata->exit_code);
4035 		return;
4036 	}
4037 
4038 	if (variant->expected_open_result == 0) {
4039 		fd = recv_fd(socket_fds[1]);
4040 		ASSERT_LE(0, fd);
4041 
4042 		EXPECT_EQ(variant->expected_ftruncate_result,
4043 			  test_ftruncate(fd));
4044 		ASSERT_EQ(0, close(fd));
4045 	}
4046 
4047 	ASSERT_EQ(child, waitpid(child, &status, 0));
4048 	ASSERT_EQ(1, WIFEXITED(status));
4049 	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
4050 
4051 	ASSERT_EQ(0, close(socket_fds[0]));
4052 	ASSERT_EQ(0, close(socket_fds[1]));
4053 }
4054 
4055 /* Invokes the FS_IOC_GETFLAGS IOCTL and returns its errno or 0. */
4056 static int test_fs_ioc_getflags_ioctl(int fd)
4057 {
4058 	uint32_t flags;
4059 
4060 	if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0)
4061 		return errno;
4062 	return 0;
4063 }
4064 
4065 TEST(memfd_ftruncate_and_ioctl)
4066 {
4067 	const struct landlock_ruleset_attr attr = {
4068 		.handled_access_fs = ACCESS_ALL,
4069 	};
4070 	int ruleset_fd, fd, i;
4071 
4072 	/*
4073 	 * We exercise the same test both with and without Landlock enabled, to
4074 	 * ensure that it behaves the same in both cases.
4075 	 */
4076 	for (i = 0; i < 2; i++) {
4077 		/* Creates a new memfd. */
4078 		fd = memfd_create("name", MFD_CLOEXEC);
4079 		ASSERT_LE(0, fd);
4080 
4081 		/*
4082 		 * Checks that operations associated with the opened file
4083 		 * (ftruncate, ioctl) are permitted on file descriptors that are
4084 		 * created in ways other than open(2).
4085 		 */
4086 		EXPECT_EQ(0, test_ftruncate(fd));
4087 		EXPECT_EQ(0, test_fs_ioc_getflags_ioctl(fd));
4088 
4089 		ASSERT_EQ(0, close(fd));
4090 
4091 		/* Enables Landlock. */
4092 		ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4093 		ASSERT_LE(0, ruleset_fd);
4094 		enforce_ruleset(_metadata, ruleset_fd);
4095 		ASSERT_EQ(0, close(ruleset_fd));
4096 	}
4097 }
4098 
4099 static int test_fionread_ioctl(int fd)
4100 {
4101 	size_t sz = 0;
4102 
4103 	if (ioctl(fd, FIONREAD, &sz) < 0 && errno == EACCES)
4104 		return errno;
4105 	return 0;
4106 }
4107 
4108 TEST_F_FORK(layout1, o_path_ftruncate_and_ioctl)
4109 {
4110 	const struct landlock_ruleset_attr attr = {
4111 		.handled_access_fs = ACCESS_ALL,
4112 	};
4113 	int ruleset_fd, fd;
4114 
4115 	/*
4116 	 * Checks that for files opened with O_PATH, both ioctl(2) and
4117 	 * ftruncate(2) yield EBADF, as it is documented in open(2) for the
4118 	 * O_PATH flag.
4119 	 */
4120 	fd = open(dir_s1d1, O_PATH | O_CLOEXEC);
4121 	ASSERT_LE(0, fd);
4122 
4123 	EXPECT_EQ(EBADF, test_ftruncate(fd));
4124 	EXPECT_EQ(EBADF, test_fs_ioc_getflags_ioctl(fd));
4125 
4126 	ASSERT_EQ(0, close(fd));
4127 
4128 	/* Enables Landlock. */
4129 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4130 	ASSERT_LE(0, ruleset_fd);
4131 	enforce_ruleset(_metadata, ruleset_fd);
4132 	ASSERT_EQ(0, close(ruleset_fd));
4133 
4134 	/*
4135 	 * Checks that after enabling Landlock,
4136 	 * - the file can still be opened with O_PATH
4137 	 * - both ioctl and truncate still yield EBADF (not EACCES).
4138 	 */
4139 	fd = open(dir_s1d1, O_PATH | O_CLOEXEC);
4140 	ASSERT_LE(0, fd);
4141 
4142 	EXPECT_EQ(EBADF, test_ftruncate(fd));
4143 	EXPECT_EQ(EBADF, test_fs_ioc_getflags_ioctl(fd));
4144 
4145 	ASSERT_EQ(0, close(fd));
4146 }
4147 
4148 /*
4149  * ioctl_error - generically call the given ioctl with a pointer to a
4150  * sufficiently large zeroed-out memory region.
4151  *
4152  * Returns the IOCTLs error, or 0.
4153  */
4154 static int ioctl_error(struct __test_metadata *const _metadata, int fd,
4155 		       unsigned int cmd)
4156 {
4157 	char buf[128]; /* sufficiently large */
4158 	int res, stdinbak_fd;
4159 
4160 	/*
4161 	 * Depending on the IOCTL command, parts of the zeroed-out buffer might
4162 	 * be interpreted as file descriptor numbers.  We do not want to
4163 	 * accidentally operate on file descriptor 0 (stdin), so we temporarily
4164 	 * move stdin to a different FD and close FD 0 for the IOCTL call.
4165 	 */
4166 	stdinbak_fd = dup(0);
4167 	ASSERT_LT(0, stdinbak_fd);
4168 	ASSERT_EQ(0, close(0));
4169 
4170 	/* Invokes the IOCTL with a zeroed-out buffer. */
4171 	bzero(&buf, sizeof(buf));
4172 	res = ioctl(fd, cmd, &buf);
4173 
4174 	/* Restores the old FD 0 and closes the backup FD. */
4175 	ASSERT_EQ(0, dup2(stdinbak_fd, 0));
4176 	ASSERT_EQ(0, close(stdinbak_fd));
4177 
4178 	if (res < 0)
4179 		return errno;
4180 
4181 	return 0;
4182 }
4183 
4184 /* Define some linux/falloc.h IOCTL commands which are not available in uapi headers. */
4185 struct space_resv {
4186 	__s16 l_type;
4187 	__s16 l_whence;
4188 	__s64 l_start;
4189 	__s64 l_len; /* len == 0 means until end of file */
4190 	__s32 l_sysid;
4191 	__u32 l_pid;
4192 	__s32 l_pad[4]; /* reserved area */
4193 };
4194 
4195 #define FS_IOC_RESVSP _IOW('X', 40, struct space_resv)
4196 #define FS_IOC_UNRESVSP _IOW('X', 41, struct space_resv)
4197 #define FS_IOC_RESVSP64 _IOW('X', 42, struct space_resv)
4198 #define FS_IOC_UNRESVSP64 _IOW('X', 43, struct space_resv)
4199 #define FS_IOC_ZERO_RANGE _IOW('X', 57, struct space_resv)
4200 
4201 /*
4202  * Tests a series of blanket-permitted and denied IOCTLs.
4203  */
4204 TEST_F_FORK(layout1, blanket_permitted_ioctls)
4205 {
4206 	const struct landlock_ruleset_attr attr = {
4207 		.handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4208 	};
4209 	int ruleset_fd, fd;
4210 
4211 	/* Enables Landlock. */
4212 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4213 	ASSERT_LE(0, ruleset_fd);
4214 	enforce_ruleset(_metadata, ruleset_fd);
4215 	ASSERT_EQ(0, close(ruleset_fd));
4216 
4217 	fd = open("/dev/null", O_RDWR | O_CLOEXEC);
4218 	ASSERT_LE(0, fd);
4219 
4220 	/*
4221 	 * Checks permitted commands.
4222 	 * These ones may return errors, but should not be blocked by Landlock.
4223 	 */
4224 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIOCLEX));
4225 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIONCLEX));
4226 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIONBIO));
4227 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIOASYNC));
4228 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIOQSIZE));
4229 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIFREEZE));
4230 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FITHAW));
4231 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FS_IOC_FIEMAP));
4232 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIGETBSZ));
4233 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FICLONE));
4234 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FICLONERANGE));
4235 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIDEDUPERANGE));
4236 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FS_IOC_GETFSUUID));
4237 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FS_IOC_GETFSSYSFSPATH));
4238 
4239 	/*
4240 	 * Checks blocked commands.
4241 	 * A call to a blocked IOCTL command always returns EACCES.
4242 	 */
4243 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FIONREAD));
4244 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_GETFLAGS));
4245 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_SETFLAGS));
4246 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_FSGETXATTR));
4247 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_FSSETXATTR));
4248 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FIBMAP));
4249 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_RESVSP));
4250 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_RESVSP64));
4251 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_UNRESVSP));
4252 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_UNRESVSP64));
4253 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_ZERO_RANGE));
4254 
4255 	/* Default case is also blocked. */
4256 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, 0xc00ffeee));
4257 
4258 	ASSERT_EQ(0, close(fd));
4259 }
4260 
4261 /*
4262  * Named pipes are not governed by the LANDLOCK_ACCESS_FS_IOCTL_DEV right,
4263  * because they are not character or block devices.
4264  */
4265 TEST_F_FORK(layout1, named_pipe_ioctl)
4266 {
4267 	pid_t child_pid;
4268 	int fd, ruleset_fd;
4269 	const char *const path = file1_s1d1;
4270 	const struct landlock_ruleset_attr attr = {
4271 		.handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4272 	};
4273 
4274 	ASSERT_EQ(0, unlink(path));
4275 	ASSERT_EQ(0, mkfifo(path, 0600));
4276 
4277 	/* Enables Landlock. */
4278 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4279 	ASSERT_LE(0, ruleset_fd);
4280 	enforce_ruleset(_metadata, ruleset_fd);
4281 	ASSERT_EQ(0, close(ruleset_fd));
4282 
4283 	/* The child process opens the pipe for writing. */
4284 	child_pid = fork();
4285 	ASSERT_NE(-1, child_pid);
4286 	if (child_pid == 0) {
4287 		fd = open(path, O_WRONLY);
4288 		close(fd);
4289 		exit(0);
4290 	}
4291 
4292 	fd = open(path, O_RDONLY);
4293 	ASSERT_LE(0, fd);
4294 
4295 	/* FIONREAD is implemented by pipefifo_fops. */
4296 	EXPECT_EQ(0, test_fionread_ioctl(fd));
4297 
4298 	ASSERT_EQ(0, close(fd));
4299 	ASSERT_EQ(0, unlink(path));
4300 
4301 	ASSERT_EQ(child_pid, waitpid(child_pid, NULL, 0));
4302 }
4303 
4304 /* For named UNIX domain sockets, no IOCTL restrictions apply. */
4305 TEST_F_FORK(layout1, named_unix_domain_socket_ioctl)
4306 {
4307 	const char *const path = file1_s1d1;
4308 	int srv_fd, cli_fd, ruleset_fd;
4309 	socklen_t size;
4310 	struct sockaddr_un srv_un, cli_un;
4311 	const struct landlock_ruleset_attr attr = {
4312 		.handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4313 	};
4314 
4315 	/* Sets up a server */
4316 	srv_un.sun_family = AF_UNIX;
4317 	strncpy(srv_un.sun_path, path, sizeof(srv_un.sun_path));
4318 
4319 	ASSERT_EQ(0, unlink(path));
4320 	srv_fd = socket(AF_UNIX, SOCK_STREAM, 0);
4321 	ASSERT_LE(0, srv_fd);
4322 
4323 	size = offsetof(struct sockaddr_un, sun_path) + strlen(srv_un.sun_path);
4324 	ASSERT_EQ(0, bind(srv_fd, (struct sockaddr *)&srv_un, size));
4325 	ASSERT_EQ(0, listen(srv_fd, 10 /* qlen */));
4326 
4327 	/* Enables Landlock. */
4328 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4329 	ASSERT_LE(0, ruleset_fd);
4330 	enforce_ruleset(_metadata, ruleset_fd);
4331 	ASSERT_EQ(0, close(ruleset_fd));
4332 
4333 	/* Sets up a client connection to it */
4334 	cli_un.sun_family = AF_UNIX;
4335 	cli_fd = socket(AF_UNIX, SOCK_STREAM, 0);
4336 	ASSERT_LE(0, cli_fd);
4337 
4338 	size = offsetof(struct sockaddr_un, sun_path) + strlen(cli_un.sun_path);
4339 	ASSERT_EQ(0, bind(cli_fd, (struct sockaddr *)&cli_un, size));
4340 
4341 	bzero(&cli_un, sizeof(cli_un));
4342 	cli_un.sun_family = AF_UNIX;
4343 	strncpy(cli_un.sun_path, path, sizeof(cli_un.sun_path));
4344 	size = offsetof(struct sockaddr_un, sun_path) + strlen(cli_un.sun_path);
4345 
4346 	ASSERT_EQ(0, connect(cli_fd, (struct sockaddr *)&cli_un, size));
4347 
4348 	/* FIONREAD and other IOCTLs should not be forbidden. */
4349 	EXPECT_EQ(0, test_fionread_ioctl(cli_fd));
4350 
4351 	ASSERT_EQ(0, close(cli_fd));
4352 }
4353 
4354 /* clang-format off */
4355 FIXTURE(ioctl) {};
4356 
4357 FIXTURE_SETUP(ioctl) {};
4358 
4359 FIXTURE_TEARDOWN(ioctl) {};
4360 /* clang-format on */
4361 
4362 FIXTURE_VARIANT(ioctl)
4363 {
4364 	const __u64 handled;
4365 	const __u64 allowed;
4366 	const mode_t open_mode;
4367 	/*
4368 	 * FIONREAD is used as a characteristic device-specific IOCTL command.
4369 	 * It is implemented in fs/ioctl.c for regular files,
4370 	 * but we do not blanket-permit it for devices.
4371 	 */
4372 	const int expected_fionread_result;
4373 };
4374 
4375 /* clang-format off */
4376 FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_none) {
4377 	/* clang-format on */
4378 	.handled = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4379 	.allowed = 0,
4380 	.open_mode = O_RDWR,
4381 	.expected_fionread_result = EACCES,
4382 };
4383 
4384 /* clang-format off */
4385 FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_i) {
4386 	/* clang-format on */
4387 	.handled = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4388 	.allowed = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4389 	.open_mode = O_RDWR,
4390 	.expected_fionread_result = 0,
4391 };
4392 
4393 /* clang-format off */
4394 FIXTURE_VARIANT_ADD(ioctl, unhandled) {
4395 	/* clang-format on */
4396 	.handled = LANDLOCK_ACCESS_FS_EXECUTE,
4397 	.allowed = LANDLOCK_ACCESS_FS_EXECUTE,
4398 	.open_mode = O_RDWR,
4399 	.expected_fionread_result = 0,
4400 };
4401 
4402 TEST_F_FORK(ioctl, handle_dir_access_file)
4403 {
4404 	const int flag = 0;
4405 	const struct rule rules[] = {
4406 		{
4407 			.path = "/dev",
4408 			.access = variant->allowed,
4409 		},
4410 		{},
4411 	};
4412 	int file_fd, ruleset_fd;
4413 
4414 	/* Enables Landlock. */
4415 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4416 	ASSERT_LE(0, ruleset_fd);
4417 	enforce_ruleset(_metadata, ruleset_fd);
4418 	ASSERT_EQ(0, close(ruleset_fd));
4419 
4420 	file_fd = open("/dev/zero", variant->open_mode);
4421 	ASSERT_LE(0, file_fd);
4422 
4423 	/* Checks that IOCTL commands return the expected errors. */
4424 	EXPECT_EQ(variant->expected_fionread_result,
4425 		  test_fionread_ioctl(file_fd));
4426 
4427 	/* Checks that unrestrictable commands are unrestricted. */
4428 	EXPECT_EQ(0, ioctl(file_fd, FIOCLEX));
4429 	EXPECT_EQ(0, ioctl(file_fd, FIONCLEX));
4430 	EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag));
4431 	EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag));
4432 	EXPECT_EQ(0, ioctl(file_fd, FIGETBSZ, &flag));
4433 
4434 	ASSERT_EQ(0, close(file_fd));
4435 }
4436 
4437 TEST_F_FORK(ioctl, handle_dir_access_dir)
4438 {
4439 	const int flag = 0;
4440 	const struct rule rules[] = {
4441 		{
4442 			.path = "/dev",
4443 			.access = variant->allowed,
4444 		},
4445 		{},
4446 	};
4447 	int dir_fd, ruleset_fd;
4448 
4449 	/* Enables Landlock. */
4450 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4451 	ASSERT_LE(0, ruleset_fd);
4452 	enforce_ruleset(_metadata, ruleset_fd);
4453 	ASSERT_EQ(0, close(ruleset_fd));
4454 
4455 	/*
4456 	 * Ignore variant->open_mode for this test, as we intend to open a
4457 	 * directory.  If the directory can not be opened, the variant is
4458 	 * infeasible to test with an opened directory.
4459 	 */
4460 	dir_fd = open("/dev", O_RDONLY);
4461 	if (dir_fd < 0)
4462 		return;
4463 
4464 	/*
4465 	 * Checks that IOCTL commands return the expected errors.
4466 	 * We do not use the expected values from the fixture here.
4467 	 *
4468 	 * When using IOCTL on a directory, no Landlock restrictions apply.
4469 	 */
4470 	EXPECT_EQ(0, test_fionread_ioctl(dir_fd));
4471 
4472 	/* Checks that unrestrictable commands are unrestricted. */
4473 	EXPECT_EQ(0, ioctl(dir_fd, FIOCLEX));
4474 	EXPECT_EQ(0, ioctl(dir_fd, FIONCLEX));
4475 	EXPECT_EQ(0, ioctl(dir_fd, FIONBIO, &flag));
4476 	EXPECT_EQ(0, ioctl(dir_fd, FIOASYNC, &flag));
4477 	EXPECT_EQ(0, ioctl(dir_fd, FIGETBSZ, &flag));
4478 
4479 	ASSERT_EQ(0, close(dir_fd));
4480 }
4481 
4482 TEST_F_FORK(ioctl, handle_file_access_file)
4483 {
4484 	const int flag = 0;
4485 	const struct rule rules[] = {
4486 		{
4487 			.path = "/dev/zero",
4488 			.access = variant->allowed,
4489 		},
4490 		{},
4491 	};
4492 	int file_fd, ruleset_fd;
4493 
4494 	/* Enables Landlock. */
4495 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4496 	ASSERT_LE(0, ruleset_fd);
4497 	enforce_ruleset(_metadata, ruleset_fd);
4498 	ASSERT_EQ(0, close(ruleset_fd));
4499 
4500 	file_fd = open("/dev/zero", variant->open_mode);
4501 	ASSERT_LE(0, file_fd)
4502 	{
4503 		TH_LOG("Failed to open /dev/zero: %s", strerror(errno));
4504 	}
4505 
4506 	/* Checks that IOCTL commands return the expected errors. */
4507 	EXPECT_EQ(variant->expected_fionread_result,
4508 		  test_fionread_ioctl(file_fd));
4509 
4510 	/* Checks that unrestrictable commands are unrestricted. */
4511 	EXPECT_EQ(0, ioctl(file_fd, FIOCLEX));
4512 	EXPECT_EQ(0, ioctl(file_fd, FIONCLEX));
4513 	EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag));
4514 	EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag));
4515 	EXPECT_EQ(0, ioctl(file_fd, FIGETBSZ, &flag));
4516 
4517 	ASSERT_EQ(0, close(file_fd));
4518 }
4519 
4520 /* clang-format off */
4521 FIXTURE(layout1_bind) {};
4522 /* clang-format on */
4523 
4524 FIXTURE_SETUP(layout1_bind)
4525 {
4526 	prepare_layout(_metadata);
4527 
4528 	create_layout1(_metadata);
4529 
4530 	set_cap(_metadata, CAP_SYS_ADMIN);
4531 	ASSERT_EQ(0, mount(dir_s1d2, dir_s2d2, NULL, MS_BIND, NULL));
4532 	clear_cap(_metadata, CAP_SYS_ADMIN);
4533 }
4534 
4535 FIXTURE_TEARDOWN_PARENT(layout1_bind)
4536 {
4537 	/* umount(dir_s2d2)) is handled by namespace lifetime. */
4538 
4539 	remove_layout1(_metadata);
4540 
4541 	cleanup_layout(_metadata);
4542 }
4543 
4544 static const char bind_dir_s1d3[] = TMP_DIR "/s2d1/s2d2/s1d3";
4545 static const char bind_file1_s1d3[] = TMP_DIR "/s2d1/s2d2/s1d3/f1";
4546 
4547 /*
4548  * layout1_bind hierarchy:
4549  *
4550  * tmp
4551  * ├── s1d1
4552  * │   ├── f1
4553  * │   ├── f2
4554  * │   └── s1d2
4555  * │       ├── f1
4556  * │       ├── f2
4557  * │       └── s1d3
4558  * │           ├── f1
4559  * │           └── f2
4560  * ├── s2d1
4561  * │   ├── f1
4562  * │   └── s2d2
4563  * │       ├── f1
4564  * │       ├── f2
4565  * │       └── s1d3
4566  * │           ├── f1
4567  * │           └── f2
4568  * └── s3d1
4569  *     └── s3d2
4570  *         └── s3d3
4571  */
4572 
4573 TEST_F_FORK(layout1_bind, no_restriction)
4574 {
4575 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
4576 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
4577 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
4578 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
4579 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
4580 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
4581 
4582 	ASSERT_EQ(0, test_open(dir_s2d1, O_RDONLY));
4583 	ASSERT_EQ(0, test_open(file1_s2d1, O_RDONLY));
4584 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY));
4585 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDONLY));
4586 	ASSERT_EQ(ENOENT, test_open(dir_s2d3, O_RDONLY));
4587 	ASSERT_EQ(ENOENT, test_open(file1_s2d3, O_RDONLY));
4588 
4589 	ASSERT_EQ(0, test_open(bind_dir_s1d3, O_RDONLY));
4590 	ASSERT_EQ(0, test_open(bind_file1_s1d3, O_RDONLY));
4591 
4592 	ASSERT_EQ(0, test_open(dir_s3d1, O_RDONLY));
4593 }
4594 
4595 TEST_F_FORK(layout1_bind, same_content_same_file)
4596 {
4597 	/*
4598 	 * Sets access right on parent directories of both source and
4599 	 * destination mount points.
4600 	 */
4601 	const struct rule layer1_parent[] = {
4602 		{
4603 			.path = dir_s1d1,
4604 			.access = ACCESS_RO,
4605 		},
4606 		{
4607 			.path = dir_s2d1,
4608 			.access = ACCESS_RW,
4609 		},
4610 		{},
4611 	};
4612 	/*
4613 	 * Sets access rights on the same bind-mounted directories.  The result
4614 	 * should be ACCESS_RW for both directories, but not both hierarchies
4615 	 * because of the first layer.
4616 	 */
4617 	const struct rule layer2_mount_point[] = {
4618 		{
4619 			.path = dir_s1d2,
4620 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4621 		},
4622 		{
4623 			.path = dir_s2d2,
4624 			.access = ACCESS_RW,
4625 		},
4626 		{},
4627 	};
4628 	/* Only allow read-access to the s1d3 hierarchies. */
4629 	const struct rule layer3_source[] = {
4630 		{
4631 			.path = dir_s1d3,
4632 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4633 		},
4634 		{},
4635 	};
4636 	/* Removes all access rights. */
4637 	const struct rule layer4_destination[] = {
4638 		{
4639 			.path = bind_file1_s1d3,
4640 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
4641 		},
4642 		{},
4643 	};
4644 	int ruleset_fd;
4645 
4646 	/* Sets rules for the parent directories. */
4647 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_parent);
4648 	ASSERT_LE(0, ruleset_fd);
4649 	enforce_ruleset(_metadata, ruleset_fd);
4650 	ASSERT_EQ(0, close(ruleset_fd));
4651 
4652 	/* Checks source hierarchy. */
4653 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
4654 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
4655 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
4656 
4657 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
4658 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
4659 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
4660 
4661 	/* Checks destination hierarchy. */
4662 	ASSERT_EQ(0, test_open(file1_s2d1, O_RDWR));
4663 	ASSERT_EQ(0, test_open(dir_s2d1, O_RDONLY | O_DIRECTORY));
4664 
4665 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDWR));
4666 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY | O_DIRECTORY));
4667 
4668 	/* Sets rules for the mount points. */
4669 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2_mount_point);
4670 	ASSERT_LE(0, ruleset_fd);
4671 	enforce_ruleset(_metadata, ruleset_fd);
4672 	ASSERT_EQ(0, close(ruleset_fd));
4673 
4674 	/* Checks source hierarchy. */
4675 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
4676 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
4677 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
4678 
4679 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
4680 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
4681 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
4682 
4683 	/* Checks destination hierarchy. */
4684 	ASSERT_EQ(EACCES, test_open(file1_s2d1, O_RDONLY));
4685 	ASSERT_EQ(EACCES, test_open(file1_s2d1, O_WRONLY));
4686 	ASSERT_EQ(EACCES, test_open(dir_s2d1, O_RDONLY | O_DIRECTORY));
4687 
4688 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDWR));
4689 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY | O_DIRECTORY));
4690 	ASSERT_EQ(0, test_open(bind_dir_s1d3, O_RDONLY | O_DIRECTORY));
4691 
4692 	/* Sets a (shared) rule only on the source. */
4693 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer3_source);
4694 	ASSERT_LE(0, ruleset_fd);
4695 	enforce_ruleset(_metadata, ruleset_fd);
4696 	ASSERT_EQ(0, close(ruleset_fd));
4697 
4698 	/* Checks source hierarchy. */
4699 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDONLY));
4700 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
4701 	ASSERT_EQ(EACCES, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
4702 
4703 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
4704 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
4705 	ASSERT_EQ(EACCES, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
4706 
4707 	/* Checks destination hierarchy. */
4708 	ASSERT_EQ(EACCES, test_open(file1_s2d2, O_RDONLY));
4709 	ASSERT_EQ(EACCES, test_open(file1_s2d2, O_WRONLY));
4710 	ASSERT_EQ(EACCES, test_open(dir_s2d2, O_RDONLY | O_DIRECTORY));
4711 
4712 	ASSERT_EQ(0, test_open(bind_file1_s1d3, O_RDONLY));
4713 	ASSERT_EQ(EACCES, test_open(bind_file1_s1d3, O_WRONLY));
4714 	ASSERT_EQ(EACCES, test_open(bind_dir_s1d3, O_RDONLY | O_DIRECTORY));
4715 
4716 	/* Sets a (shared) rule only on the destination. */
4717 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer4_destination);
4718 	ASSERT_LE(0, ruleset_fd);
4719 	enforce_ruleset(_metadata, ruleset_fd);
4720 	ASSERT_EQ(0, close(ruleset_fd));
4721 
4722 	/* Checks source hierarchy. */
4723 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDONLY));
4724 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
4725 
4726 	/* Checks destination hierarchy. */
4727 	ASSERT_EQ(EACCES, test_open(bind_file1_s1d3, O_RDONLY));
4728 	ASSERT_EQ(EACCES, test_open(bind_file1_s1d3, O_WRONLY));
4729 }
4730 
4731 TEST_F_FORK(layout1_bind, reparent_cross_mount)
4732 {
4733 	const struct rule layer1[] = {
4734 		{
4735 			/* dir_s2d1 is beneath the dir_s2d2 mount point. */
4736 			.path = dir_s2d1,
4737 			.access = LANDLOCK_ACCESS_FS_REFER,
4738 		},
4739 		{
4740 			.path = bind_dir_s1d3,
4741 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
4742 		},
4743 		{},
4744 	};
4745 	int ruleset_fd = create_ruleset(
4746 		_metadata,
4747 		LANDLOCK_ACCESS_FS_REFER | LANDLOCK_ACCESS_FS_EXECUTE, layer1);
4748 
4749 	ASSERT_LE(0, ruleset_fd);
4750 	enforce_ruleset(_metadata, ruleset_fd);
4751 	ASSERT_EQ(0, close(ruleset_fd));
4752 
4753 	/* Checks basic denied move. */
4754 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s1d2));
4755 	ASSERT_EQ(EXDEV, errno);
4756 
4757 	/* Checks real cross-mount move (Landlock is not involved). */
4758 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s2d2));
4759 	ASSERT_EQ(EXDEV, errno);
4760 
4761 	/* Checks move that will give more accesses. */
4762 	ASSERT_EQ(-1, rename(file1_s2d2, bind_file1_s1d3));
4763 	ASSERT_EQ(EXDEV, errno);
4764 
4765 	/* Checks legitimate downgrade move. */
4766 	ASSERT_EQ(0, rename(bind_file1_s1d3, file1_s2d2));
4767 }
4768 
4769 #define LOWER_BASE TMP_DIR "/lower"
4770 #define LOWER_DATA LOWER_BASE "/data"
4771 static const char lower_fl1[] = LOWER_DATA "/fl1";
4772 static const char lower_dl1[] = LOWER_DATA "/dl1";
4773 static const char lower_dl1_fl2[] = LOWER_DATA "/dl1/fl2";
4774 static const char lower_fo1[] = LOWER_DATA "/fo1";
4775 static const char lower_do1[] = LOWER_DATA "/do1";
4776 static const char lower_do1_fo2[] = LOWER_DATA "/do1/fo2";
4777 static const char lower_do1_fl3[] = LOWER_DATA "/do1/fl3";
4778 
4779 static const char (*lower_base_files[])[] = {
4780 	&lower_fl1,
4781 	&lower_fo1,
4782 	NULL,
4783 };
4784 static const char (*lower_base_directories[])[] = {
4785 	&lower_dl1,
4786 	&lower_do1,
4787 	NULL,
4788 };
4789 static const char (*lower_sub_files[])[] = {
4790 	&lower_dl1_fl2,
4791 	&lower_do1_fo2,
4792 	&lower_do1_fl3,
4793 	NULL,
4794 };
4795 
4796 #define UPPER_BASE TMP_DIR "/upper"
4797 #define UPPER_DATA UPPER_BASE "/data"
4798 #define UPPER_WORK UPPER_BASE "/work"
4799 static const char upper_fu1[] = UPPER_DATA "/fu1";
4800 static const char upper_du1[] = UPPER_DATA "/du1";
4801 static const char upper_du1_fu2[] = UPPER_DATA "/du1/fu2";
4802 static const char upper_fo1[] = UPPER_DATA "/fo1";
4803 static const char upper_do1[] = UPPER_DATA "/do1";
4804 static const char upper_do1_fo2[] = UPPER_DATA "/do1/fo2";
4805 static const char upper_do1_fu3[] = UPPER_DATA "/do1/fu3";
4806 
4807 static const char (*upper_base_files[])[] = {
4808 	&upper_fu1,
4809 	&upper_fo1,
4810 	NULL,
4811 };
4812 static const char (*upper_base_directories[])[] = {
4813 	&upper_du1,
4814 	&upper_do1,
4815 	NULL,
4816 };
4817 static const char (*upper_sub_files[])[] = {
4818 	&upper_du1_fu2,
4819 	&upper_do1_fo2,
4820 	&upper_do1_fu3,
4821 	NULL,
4822 };
4823 
4824 #define MERGE_BASE TMP_DIR "/merge"
4825 #define MERGE_DATA MERGE_BASE "/data"
4826 static const char merge_fl1[] = MERGE_DATA "/fl1";
4827 static const char merge_dl1[] = MERGE_DATA "/dl1";
4828 static const char merge_dl1_fl2[] = MERGE_DATA "/dl1/fl2";
4829 static const char merge_fu1[] = MERGE_DATA "/fu1";
4830 static const char merge_du1[] = MERGE_DATA "/du1";
4831 static const char merge_du1_fu2[] = MERGE_DATA "/du1/fu2";
4832 static const char merge_fo1[] = MERGE_DATA "/fo1";
4833 static const char merge_do1[] = MERGE_DATA "/do1";
4834 static const char merge_do1_fo2[] = MERGE_DATA "/do1/fo2";
4835 static const char merge_do1_fl3[] = MERGE_DATA "/do1/fl3";
4836 static const char merge_do1_fu3[] = MERGE_DATA "/do1/fu3";
4837 
4838 static const char (*merge_base_files[])[] = {
4839 	&merge_fl1,
4840 	&merge_fu1,
4841 	&merge_fo1,
4842 	NULL,
4843 };
4844 static const char (*merge_base_directories[])[] = {
4845 	&merge_dl1,
4846 	&merge_du1,
4847 	&merge_do1,
4848 	NULL,
4849 };
4850 static const char (*merge_sub_files[])[] = {
4851 	&merge_dl1_fl2, &merge_du1_fu2, &merge_do1_fo2,
4852 	&merge_do1_fl3, &merge_do1_fu3, NULL,
4853 };
4854 
4855 /*
4856  * layout2_overlay hierarchy:
4857  *
4858  * tmp
4859  * ├── lower
4860  * │   └── data
4861  * │       ├── dl1
4862  * │       │   └── fl2
4863  * │       ├── do1
4864  * │       │   ├── fl3
4865  * │       │   └── fo2
4866  * │       ├── fl1
4867  * │       └── fo1
4868  * ├── merge
4869  * │   └── data
4870  * │       ├── dl1
4871  * │       │   └── fl2
4872  * │       ├── do1
4873  * │       │   ├── fl3
4874  * │       │   ├── fo2
4875  * │       │   └── fu3
4876  * │       ├── du1
4877  * │       │   └── fu2
4878  * │       ├── fl1
4879  * │       ├── fo1
4880  * │       └── fu1
4881  * └── upper
4882  *     ├── data
4883  *     │   ├── do1
4884  *     │   │   ├── fo2
4885  *     │   │   └── fu3
4886  *     │   ├── du1
4887  *     │   │   └── fu2
4888  *     │   ├── fo1
4889  *     │   └── fu1
4890  *     └── work
4891  *         └── work
4892  */
4893 
4894 FIXTURE(layout2_overlay)
4895 {
4896 	bool skip_test;
4897 };
4898 
4899 FIXTURE_SETUP(layout2_overlay)
4900 {
4901 	if (!supports_filesystem("overlay")) {
4902 		self->skip_test = true;
4903 		SKIP(return, "overlayfs is not supported (setup)");
4904 	}
4905 
4906 	prepare_layout(_metadata);
4907 
4908 	create_directory(_metadata, LOWER_BASE);
4909 	set_cap(_metadata, CAP_SYS_ADMIN);
4910 	/* Creates tmpfs mount points to get deterministic overlayfs. */
4911 	ASSERT_EQ(0, mount_opt(&mnt_tmp, LOWER_BASE));
4912 	clear_cap(_metadata, CAP_SYS_ADMIN);
4913 	create_file(_metadata, lower_fl1);
4914 	create_file(_metadata, lower_dl1_fl2);
4915 	create_file(_metadata, lower_fo1);
4916 	create_file(_metadata, lower_do1_fo2);
4917 	create_file(_metadata, lower_do1_fl3);
4918 
4919 	create_directory(_metadata, UPPER_BASE);
4920 	set_cap(_metadata, CAP_SYS_ADMIN);
4921 	ASSERT_EQ(0, mount_opt(&mnt_tmp, UPPER_BASE));
4922 	clear_cap(_metadata, CAP_SYS_ADMIN);
4923 	create_file(_metadata, upper_fu1);
4924 	create_file(_metadata, upper_du1_fu2);
4925 	create_file(_metadata, upper_fo1);
4926 	create_file(_metadata, upper_do1_fo2);
4927 	create_file(_metadata, upper_do1_fu3);
4928 	ASSERT_EQ(0, mkdir(UPPER_WORK, 0700));
4929 
4930 	create_directory(_metadata, MERGE_DATA);
4931 	set_cap(_metadata, CAP_SYS_ADMIN);
4932 	set_cap(_metadata, CAP_DAC_OVERRIDE);
4933 	ASSERT_EQ(0, mount("overlay", MERGE_DATA, "overlay", 0,
4934 			   "lowerdir=" LOWER_DATA ",upperdir=" UPPER_DATA
4935 			   ",workdir=" UPPER_WORK));
4936 	clear_cap(_metadata, CAP_DAC_OVERRIDE);
4937 	clear_cap(_metadata, CAP_SYS_ADMIN);
4938 }
4939 
4940 FIXTURE_TEARDOWN_PARENT(layout2_overlay)
4941 {
4942 	if (self->skip_test)
4943 		SKIP(return, "overlayfs is not supported (teardown)");
4944 
4945 	EXPECT_EQ(0, remove_path(lower_do1_fl3));
4946 	EXPECT_EQ(0, remove_path(lower_dl1_fl2));
4947 	EXPECT_EQ(0, remove_path(lower_fl1));
4948 	EXPECT_EQ(0, remove_path(lower_do1_fo2));
4949 	EXPECT_EQ(0, remove_path(lower_fo1));
4950 
4951 	/* umount(LOWER_BASE)) is handled by namespace lifetime. */
4952 	EXPECT_EQ(0, remove_path(LOWER_BASE));
4953 
4954 	EXPECT_EQ(0, remove_path(upper_do1_fu3));
4955 	EXPECT_EQ(0, remove_path(upper_du1_fu2));
4956 	EXPECT_EQ(0, remove_path(upper_fu1));
4957 	EXPECT_EQ(0, remove_path(upper_do1_fo2));
4958 	EXPECT_EQ(0, remove_path(upper_fo1));
4959 	EXPECT_EQ(0, remove_path(UPPER_WORK "/work"));
4960 
4961 	/* umount(UPPER_BASE)) is handled by namespace lifetime. */
4962 	EXPECT_EQ(0, remove_path(UPPER_BASE));
4963 
4964 	/* umount(MERGE_DATA)) is handled by namespace lifetime. */
4965 	EXPECT_EQ(0, remove_path(MERGE_DATA));
4966 
4967 	cleanup_layout(_metadata);
4968 }
4969 
4970 TEST_F_FORK(layout2_overlay, no_restriction)
4971 {
4972 	if (self->skip_test)
4973 		SKIP(return, "overlayfs is not supported (test)");
4974 
4975 	ASSERT_EQ(0, test_open(lower_fl1, O_RDONLY));
4976 	ASSERT_EQ(0, test_open(lower_dl1, O_RDONLY));
4977 	ASSERT_EQ(0, test_open(lower_dl1_fl2, O_RDONLY));
4978 	ASSERT_EQ(0, test_open(lower_fo1, O_RDONLY));
4979 	ASSERT_EQ(0, test_open(lower_do1, O_RDONLY));
4980 	ASSERT_EQ(0, test_open(lower_do1_fo2, O_RDONLY));
4981 	ASSERT_EQ(0, test_open(lower_do1_fl3, O_RDONLY));
4982 
4983 	ASSERT_EQ(0, test_open(upper_fu1, O_RDONLY));
4984 	ASSERT_EQ(0, test_open(upper_du1, O_RDONLY));
4985 	ASSERT_EQ(0, test_open(upper_du1_fu2, O_RDONLY));
4986 	ASSERT_EQ(0, test_open(upper_fo1, O_RDONLY));
4987 	ASSERT_EQ(0, test_open(upper_do1, O_RDONLY));
4988 	ASSERT_EQ(0, test_open(upper_do1_fo2, O_RDONLY));
4989 	ASSERT_EQ(0, test_open(upper_do1_fu3, O_RDONLY));
4990 
4991 	ASSERT_EQ(0, test_open(merge_fl1, O_RDONLY));
4992 	ASSERT_EQ(0, test_open(merge_dl1, O_RDONLY));
4993 	ASSERT_EQ(0, test_open(merge_dl1_fl2, O_RDONLY));
4994 	ASSERT_EQ(0, test_open(merge_fu1, O_RDONLY));
4995 	ASSERT_EQ(0, test_open(merge_du1, O_RDONLY));
4996 	ASSERT_EQ(0, test_open(merge_du1_fu2, O_RDONLY));
4997 	ASSERT_EQ(0, test_open(merge_fo1, O_RDONLY));
4998 	ASSERT_EQ(0, test_open(merge_do1, O_RDONLY));
4999 	ASSERT_EQ(0, test_open(merge_do1_fo2, O_RDONLY));
5000 	ASSERT_EQ(0, test_open(merge_do1_fl3, O_RDONLY));
5001 	ASSERT_EQ(0, test_open(merge_do1_fu3, O_RDONLY));
5002 }
5003 
5004 #define for_each_path(path_list, path_entry, i)               \
5005 	for (i = 0, path_entry = *path_list[i]; path_list[i]; \
5006 	     path_entry = *path_list[++i])
5007 
5008 TEST_F_FORK(layout2_overlay, same_content_different_file)
5009 {
5010 	/* Sets access right on parent directories of both layers. */
5011 	const struct rule layer1_base[] = {
5012 		{
5013 			.path = LOWER_BASE,
5014 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5015 		},
5016 		{
5017 			.path = UPPER_BASE,
5018 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5019 		},
5020 		{
5021 			.path = MERGE_BASE,
5022 			.access = ACCESS_RW,
5023 		},
5024 		{},
5025 	};
5026 	const struct rule layer2_data[] = {
5027 		{
5028 			.path = LOWER_DATA,
5029 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5030 		},
5031 		{
5032 			.path = UPPER_DATA,
5033 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5034 		},
5035 		{
5036 			.path = MERGE_DATA,
5037 			.access = ACCESS_RW,
5038 		},
5039 		{},
5040 	};
5041 	/* Sets access right on directories inside both layers. */
5042 	const struct rule layer3_subdirs[] = {
5043 		{
5044 			.path = lower_dl1,
5045 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5046 		},
5047 		{
5048 			.path = lower_do1,
5049 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5050 		},
5051 		{
5052 			.path = upper_du1,
5053 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5054 		},
5055 		{
5056 			.path = upper_do1,
5057 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5058 		},
5059 		{
5060 			.path = merge_dl1,
5061 			.access = ACCESS_RW,
5062 		},
5063 		{
5064 			.path = merge_du1,
5065 			.access = ACCESS_RW,
5066 		},
5067 		{
5068 			.path = merge_do1,
5069 			.access = ACCESS_RW,
5070 		},
5071 		{},
5072 	};
5073 	/* Tighten access rights to the files. */
5074 	const struct rule layer4_files[] = {
5075 		{
5076 			.path = lower_dl1_fl2,
5077 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5078 		},
5079 		{
5080 			.path = lower_do1_fo2,
5081 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5082 		},
5083 		{
5084 			.path = lower_do1_fl3,
5085 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5086 		},
5087 		{
5088 			.path = upper_du1_fu2,
5089 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5090 		},
5091 		{
5092 			.path = upper_do1_fo2,
5093 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5094 		},
5095 		{
5096 			.path = upper_do1_fu3,
5097 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5098 		},
5099 		{
5100 			.path = merge_dl1_fl2,
5101 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
5102 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
5103 		},
5104 		{
5105 			.path = merge_du1_fu2,
5106 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
5107 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
5108 		},
5109 		{
5110 			.path = merge_do1_fo2,
5111 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
5112 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
5113 		},
5114 		{
5115 			.path = merge_do1_fl3,
5116 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
5117 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
5118 		},
5119 		{
5120 			.path = merge_do1_fu3,
5121 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
5122 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
5123 		},
5124 		{},
5125 	};
5126 	const struct rule layer5_merge_only[] = {
5127 		{
5128 			.path = MERGE_DATA,
5129 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
5130 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
5131 		},
5132 		{},
5133 	};
5134 	int ruleset_fd;
5135 	size_t i;
5136 	const char *path_entry;
5137 
5138 	if (self->skip_test)
5139 		SKIP(return, "overlayfs is not supported (test)");
5140 
5141 	/* Sets rules on base directories (i.e. outside overlay scope). */
5142 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_base);
5143 	ASSERT_LE(0, ruleset_fd);
5144 	enforce_ruleset(_metadata, ruleset_fd);
5145 	ASSERT_EQ(0, close(ruleset_fd));
5146 
5147 	/* Checks lower layer. */
5148 	for_each_path(lower_base_files, path_entry, i) {
5149 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5150 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5151 	}
5152 	for_each_path(lower_base_directories, path_entry, i) {
5153 		ASSERT_EQ(EACCES,
5154 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5155 	}
5156 	for_each_path(lower_sub_files, path_entry, i) {
5157 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5158 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5159 	}
5160 	/* Checks upper layer. */
5161 	for_each_path(upper_base_files, path_entry, i) {
5162 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5163 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5164 	}
5165 	for_each_path(upper_base_directories, path_entry, i) {
5166 		ASSERT_EQ(EACCES,
5167 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5168 	}
5169 	for_each_path(upper_sub_files, path_entry, i) {
5170 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5171 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5172 	}
5173 	/*
5174 	 * Checks that access rights are independent from the lower and upper
5175 	 * layers: write access to upper files viewed through the merge point
5176 	 * is still allowed, and write access to lower file viewed (and copied)
5177 	 * through the merge point is still allowed.
5178 	 */
5179 	for_each_path(merge_base_files, path_entry, i) {
5180 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5181 	}
5182 	for_each_path(merge_base_directories, path_entry, i) {
5183 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY | O_DIRECTORY));
5184 	}
5185 	for_each_path(merge_sub_files, path_entry, i) {
5186 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5187 	}
5188 
5189 	/* Sets rules on data directories (i.e. inside overlay scope). */
5190 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2_data);
5191 	ASSERT_LE(0, ruleset_fd);
5192 	enforce_ruleset(_metadata, ruleset_fd);
5193 	ASSERT_EQ(0, close(ruleset_fd));
5194 
5195 	/* Checks merge. */
5196 	for_each_path(merge_base_files, path_entry, i) {
5197 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5198 	}
5199 	for_each_path(merge_base_directories, path_entry, i) {
5200 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY | O_DIRECTORY));
5201 	}
5202 	for_each_path(merge_sub_files, path_entry, i) {
5203 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5204 	}
5205 
5206 	/* Same checks with tighter rules. */
5207 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer3_subdirs);
5208 	ASSERT_LE(0, ruleset_fd);
5209 	enforce_ruleset(_metadata, ruleset_fd);
5210 	ASSERT_EQ(0, close(ruleset_fd));
5211 
5212 	/* Checks changes for lower layer. */
5213 	for_each_path(lower_base_files, path_entry, i) {
5214 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5215 	}
5216 	/* Checks changes for upper layer. */
5217 	for_each_path(upper_base_files, path_entry, i) {
5218 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5219 	}
5220 	/* Checks all merge accesses. */
5221 	for_each_path(merge_base_files, path_entry, i) {
5222 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDWR));
5223 	}
5224 	for_each_path(merge_base_directories, path_entry, i) {
5225 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY | O_DIRECTORY));
5226 	}
5227 	for_each_path(merge_sub_files, path_entry, i) {
5228 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5229 	}
5230 
5231 	/* Sets rules directly on overlayed files. */
5232 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer4_files);
5233 	ASSERT_LE(0, ruleset_fd);
5234 	enforce_ruleset(_metadata, ruleset_fd);
5235 	ASSERT_EQ(0, close(ruleset_fd));
5236 
5237 	/* Checks unchanged accesses on lower layer. */
5238 	for_each_path(lower_sub_files, path_entry, i) {
5239 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5240 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5241 	}
5242 	/* Checks unchanged accesses on upper layer. */
5243 	for_each_path(upper_sub_files, path_entry, i) {
5244 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5245 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5246 	}
5247 	/* Checks all merge accesses. */
5248 	for_each_path(merge_base_files, path_entry, i) {
5249 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDWR));
5250 	}
5251 	for_each_path(merge_base_directories, path_entry, i) {
5252 		ASSERT_EQ(EACCES,
5253 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5254 	}
5255 	for_each_path(merge_sub_files, path_entry, i) {
5256 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5257 	}
5258 
5259 	/* Only allowes access to the merge hierarchy. */
5260 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer5_merge_only);
5261 	ASSERT_LE(0, ruleset_fd);
5262 	enforce_ruleset(_metadata, ruleset_fd);
5263 	ASSERT_EQ(0, close(ruleset_fd));
5264 
5265 	/* Checks new accesses on lower layer. */
5266 	for_each_path(lower_sub_files, path_entry, i) {
5267 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5268 	}
5269 	/* Checks new accesses on upper layer. */
5270 	for_each_path(upper_sub_files, path_entry, i) {
5271 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5272 	}
5273 	/* Checks all merge accesses. */
5274 	for_each_path(merge_base_files, path_entry, i) {
5275 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDWR));
5276 	}
5277 	for_each_path(merge_base_directories, path_entry, i) {
5278 		ASSERT_EQ(EACCES,
5279 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5280 	}
5281 	for_each_path(merge_sub_files, path_entry, i) {
5282 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5283 	}
5284 }
5285 
5286 FIXTURE(layout3_fs)
5287 {
5288 	bool has_created_dir;
5289 	bool has_created_file;
5290 	bool skip_test;
5291 };
5292 
5293 FIXTURE_VARIANT(layout3_fs)
5294 {
5295 	const struct mnt_opt mnt;
5296 	const char *const file_path;
5297 	unsigned int cwd_fs_magic;
5298 };
5299 
5300 /* clang-format off */
5301 FIXTURE_VARIANT_ADD(layout3_fs, tmpfs) {
5302 	/* clang-format on */
5303 	.mnt = {
5304 		.type = "tmpfs",
5305 		.data = MNT_TMP_DATA,
5306 	},
5307 	.file_path = file1_s1d1,
5308 };
5309 
5310 FIXTURE_VARIANT_ADD(layout3_fs, ramfs) {
5311 	.mnt = {
5312 		.type = "ramfs",
5313 		.data = "mode=700",
5314 	},
5315 	.file_path = TMP_DIR "/dir/file",
5316 };
5317 
5318 FIXTURE_VARIANT_ADD(layout3_fs, cgroup2) {
5319 	.mnt = {
5320 		.type = "cgroup2",
5321 	},
5322 	.file_path = TMP_DIR "/test/cgroup.procs",
5323 };
5324 
5325 FIXTURE_VARIANT_ADD(layout3_fs, proc) {
5326 	.mnt = {
5327 		.type = "proc",
5328 	},
5329 	.file_path = TMP_DIR "/self/status",
5330 };
5331 
5332 FIXTURE_VARIANT_ADD(layout3_fs, sysfs) {
5333 	.mnt = {
5334 		.type = "sysfs",
5335 	},
5336 	.file_path = TMP_DIR "/kernel/notes",
5337 };
5338 
5339 FIXTURE_VARIANT_ADD(layout3_fs, hostfs) {
5340 	.mnt = {
5341 		.source = TMP_DIR,
5342 		.flags = MS_BIND,
5343 	},
5344 	.file_path = TMP_DIR "/dir/file",
5345 	.cwd_fs_magic = HOSTFS_SUPER_MAGIC,
5346 };
5347 
5348 static char *dirname_alloc(const char *path)
5349 {
5350 	char *dup;
5351 
5352 	if (!path)
5353 		return NULL;
5354 
5355 	dup = strdup(path);
5356 	if (!dup)
5357 		return NULL;
5358 
5359 	return dirname(dup);
5360 }
5361 
5362 FIXTURE_SETUP(layout3_fs)
5363 {
5364 	struct stat statbuf;
5365 	char *dir_path = dirname_alloc(variant->file_path);
5366 
5367 	if (!supports_filesystem(variant->mnt.type) ||
5368 	    !cwd_matches_fs(variant->cwd_fs_magic)) {
5369 		self->skip_test = true;
5370 		SKIP(return, "this filesystem is not supported (setup)");
5371 	}
5372 
5373 	prepare_layout_opt(_metadata, &variant->mnt);
5374 
5375 	/* Creates directory when required. */
5376 	if (stat(dir_path, &statbuf)) {
5377 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5378 		EXPECT_EQ(0, mkdir(dir_path, 0700))
5379 		{
5380 			TH_LOG("Failed to create directory \"%s\": %s",
5381 			       dir_path, strerror(errno));
5382 		}
5383 		self->has_created_dir = true;
5384 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5385 	}
5386 
5387 	/* Creates file when required. */
5388 	if (stat(variant->file_path, &statbuf)) {
5389 		int fd;
5390 
5391 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5392 		fd = creat(variant->file_path, 0600);
5393 		EXPECT_LE(0, fd)
5394 		{
5395 			TH_LOG("Failed to create file \"%s\": %s",
5396 			       variant->file_path, strerror(errno));
5397 		}
5398 		EXPECT_EQ(0, close(fd));
5399 		self->has_created_file = true;
5400 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5401 	}
5402 
5403 	free(dir_path);
5404 }
5405 
5406 FIXTURE_TEARDOWN_PARENT(layout3_fs)
5407 {
5408 	if (self->skip_test)
5409 		SKIP(return, "this filesystem is not supported (teardown)");
5410 
5411 	if (self->has_created_file) {
5412 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5413 		/*
5414 		 * Don't check for error because the file might already
5415 		 * have been removed (cf. release_inode test).
5416 		 */
5417 		unlink(variant->file_path);
5418 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5419 	}
5420 
5421 	if (self->has_created_dir) {
5422 		char *dir_path = dirname_alloc(variant->file_path);
5423 
5424 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5425 		/*
5426 		 * Don't check for error because the directory might already
5427 		 * have been removed (cf. release_inode test).
5428 		 */
5429 		rmdir(dir_path);
5430 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5431 		free(dir_path);
5432 	}
5433 
5434 	cleanup_layout(_metadata);
5435 }
5436 
5437 static void layer3_fs_tag_inode(struct __test_metadata *const _metadata,
5438 				FIXTURE_DATA(layout3_fs) * self,
5439 				const FIXTURE_VARIANT(layout3_fs) * variant,
5440 				const char *const rule_path)
5441 {
5442 	const struct rule layer1_allow_read_file[] = {
5443 		{
5444 			.path = rule_path,
5445 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5446 		},
5447 		{},
5448 	};
5449 	const struct landlock_ruleset_attr layer2_deny_everything_attr = {
5450 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
5451 	};
5452 	const char *const dev_null_path = "/dev/null";
5453 	int ruleset_fd;
5454 
5455 	if (self->skip_test)
5456 		SKIP(return, "this filesystem is not supported (test)");
5457 
5458 	/* Checks without Landlock. */
5459 	EXPECT_EQ(0, test_open(dev_null_path, O_RDONLY | O_CLOEXEC));
5460 	EXPECT_EQ(0, test_open(variant->file_path, O_RDONLY | O_CLOEXEC));
5461 
5462 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
5463 				    layer1_allow_read_file);
5464 	EXPECT_LE(0, ruleset_fd);
5465 	enforce_ruleset(_metadata, ruleset_fd);
5466 	EXPECT_EQ(0, close(ruleset_fd));
5467 
5468 	EXPECT_EQ(EACCES, test_open(dev_null_path, O_RDONLY | O_CLOEXEC));
5469 	EXPECT_EQ(0, test_open(variant->file_path, O_RDONLY | O_CLOEXEC));
5470 
5471 	/* Forbids directory reading. */
5472 	ruleset_fd =
5473 		landlock_create_ruleset(&layer2_deny_everything_attr,
5474 					sizeof(layer2_deny_everything_attr), 0);
5475 	EXPECT_LE(0, ruleset_fd);
5476 	enforce_ruleset(_metadata, ruleset_fd);
5477 	EXPECT_EQ(0, close(ruleset_fd));
5478 
5479 	/* Checks with Landlock and forbidden access. */
5480 	EXPECT_EQ(EACCES, test_open(dev_null_path, O_RDONLY | O_CLOEXEC));
5481 	EXPECT_EQ(EACCES, test_open(variant->file_path, O_RDONLY | O_CLOEXEC));
5482 }
5483 
5484 /* Matrix of tests to check file hierarchy evaluation. */
5485 
5486 TEST_F_FORK(layout3_fs, tag_inode_dir_parent)
5487 {
5488 	/* The current directory must not be the root for this test. */
5489 	layer3_fs_tag_inode(_metadata, self, variant, ".");
5490 }
5491 
5492 TEST_F_FORK(layout3_fs, tag_inode_dir_mnt)
5493 {
5494 	layer3_fs_tag_inode(_metadata, self, variant, TMP_DIR);
5495 }
5496 
5497 TEST_F_FORK(layout3_fs, tag_inode_dir_child)
5498 {
5499 	char *dir_path = dirname_alloc(variant->file_path);
5500 
5501 	layer3_fs_tag_inode(_metadata, self, variant, dir_path);
5502 	free(dir_path);
5503 }
5504 
5505 TEST_F_FORK(layout3_fs, tag_inode_file)
5506 {
5507 	layer3_fs_tag_inode(_metadata, self, variant, variant->file_path);
5508 }
5509 
5510 /* Light version of layout1.release_inodes */
5511 TEST_F_FORK(layout3_fs, release_inodes)
5512 {
5513 	const struct rule layer1[] = {
5514 		{
5515 			.path = TMP_DIR,
5516 			.access = LANDLOCK_ACCESS_FS_READ_DIR,
5517 		},
5518 		{},
5519 	};
5520 	int ruleset_fd;
5521 
5522 	if (self->skip_test)
5523 		SKIP(return, "this filesystem is not supported (test)");
5524 
5525 	/* Clean up for the teardown to not fail. */
5526 	if (self->has_created_file)
5527 		EXPECT_EQ(0, remove_path(variant->file_path));
5528 
5529 	if (self->has_created_dir) {
5530 		char *dir_path = dirname_alloc(variant->file_path);
5531 
5532 		/* Don't check for error because of cgroup specificities. */
5533 		remove_path(dir_path);
5534 		free(dir_path);
5535 	}
5536 
5537 	ruleset_fd =
5538 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_DIR, layer1);
5539 	ASSERT_LE(0, ruleset_fd);
5540 
5541 	/* Unmount the filesystem while it is being used by a ruleset. */
5542 	set_cap(_metadata, CAP_SYS_ADMIN);
5543 	ASSERT_EQ(0, umount(TMP_DIR));
5544 	clear_cap(_metadata, CAP_SYS_ADMIN);
5545 
5546 	/* Replaces with a new mount point to simplify FIXTURE_TEARDOWN. */
5547 	set_cap(_metadata, CAP_SYS_ADMIN);
5548 	ASSERT_EQ(0, mount_opt(&mnt_tmp, TMP_DIR));
5549 	clear_cap(_metadata, CAP_SYS_ADMIN);
5550 
5551 	enforce_ruleset(_metadata, ruleset_fd);
5552 	ASSERT_EQ(0, close(ruleset_fd));
5553 
5554 	/* Checks that access to the new mount point is denied. */
5555 	ASSERT_EQ(EACCES, test_open(TMP_DIR, O_RDONLY));
5556 }
5557 
5558 static int matches_log_fs_extra(struct __test_metadata *const _metadata,
5559 				int audit_fd, const char *const blockers,
5560 				const char *const path, const char *const extra)
5561 {
5562 	static const char log_template[] = REGEX_LANDLOCK_PREFIX
5563 		" blockers=fs\\.%s path=\"%s\" dev=\"[^\"]\\+\" ino=[0-9]\\+$";
5564 	char *absolute_path = NULL;
5565 	size_t log_match_remaining = sizeof(log_template) + strlen(blockers) +
5566 				     PATH_MAX * 2 +
5567 				     (extra ? strlen(extra) : 0) + 1;
5568 	char log_match[log_match_remaining];
5569 	char *log_match_cursor = log_match;
5570 	size_t chunk_len;
5571 
5572 	chunk_len = snprintf(log_match_cursor, log_match_remaining,
5573 			     REGEX_LANDLOCK_PREFIX " blockers=%s path=\"",
5574 			     blockers);
5575 	if (chunk_len < 0 || chunk_len >= log_match_remaining)
5576 		return -E2BIG;
5577 
5578 	/*
5579 	 * It is assume that absolute_path does not contain control characters nor
5580 	 * spaces, see audit_string_contains_control().
5581 	 */
5582 	absolute_path = realpath(path, NULL);
5583 	if (!absolute_path)
5584 		return -errno;
5585 
5586 	log_match_remaining -= chunk_len;
5587 	log_match_cursor += chunk_len;
5588 	log_match_cursor = regex_escape(absolute_path, log_match_cursor,
5589 					log_match_remaining);
5590 	free(absolute_path);
5591 	if (log_match_cursor < 0)
5592 		return (long long)log_match_cursor;
5593 
5594 	log_match_remaining -= log_match_cursor - log_match;
5595 	chunk_len = snprintf(log_match_cursor, log_match_remaining,
5596 			     "\" dev=\"[^\"]\\+\" ino=[0-9]\\+%s$",
5597 			     extra ?: "");
5598 	if (chunk_len < 0 || chunk_len >= log_match_remaining)
5599 		return -E2BIG;
5600 
5601 	return audit_match_record(audit_fd, AUDIT_LANDLOCK_ACCESS, log_match,
5602 				  NULL);
5603 }
5604 
5605 static int matches_log_fs(struct __test_metadata *const _metadata, int audit_fd,
5606 			  const char *const blockers, const char *const path)
5607 {
5608 	return matches_log_fs_extra(_metadata, audit_fd, blockers, path, NULL);
5609 }
5610 
5611 FIXTURE(audit_layout1)
5612 {
5613 	struct audit_filter audit_filter;
5614 	int audit_fd;
5615 };
5616 
5617 FIXTURE_SETUP(audit_layout1)
5618 {
5619 	prepare_layout(_metadata);
5620 
5621 	create_layout1(_metadata);
5622 
5623 	set_cap(_metadata, CAP_AUDIT_CONTROL);
5624 	self->audit_fd = audit_init_with_exe_filter(&self->audit_filter);
5625 	EXPECT_LE(0, self->audit_fd);
5626 	disable_caps(_metadata);
5627 }
5628 
5629 FIXTURE_TEARDOWN_PARENT(audit_layout1)
5630 {
5631 	remove_layout1(_metadata);
5632 
5633 	cleanup_layout(_metadata);
5634 
5635 	EXPECT_EQ(0, audit_cleanup(-1, NULL));
5636 }
5637 
5638 TEST_F(audit_layout1, execute_make)
5639 {
5640 	struct audit_records records;
5641 
5642 	copy_file(_metadata, bin_true, file1_s1d1);
5643 	test_execute(_metadata, 0, file1_s1d1);
5644 	test_check_exec(_metadata, 0, file1_s1d1);
5645 
5646 	drop_access_rights(_metadata,
5647 			   &(struct landlock_ruleset_attr){
5648 				   .handled_access_fs =
5649 					   LANDLOCK_ACCESS_FS_EXECUTE,
5650 			   });
5651 
5652 	test_execute(_metadata, EACCES, file1_s1d1);
5653 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.execute",
5654 				    file1_s1d1));
5655 	test_check_exec(_metadata, EACCES, file1_s1d1);
5656 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.execute",
5657 				    file1_s1d1));
5658 
5659 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5660 	EXPECT_EQ(0, records.access);
5661 	EXPECT_EQ(0, records.domain);
5662 }
5663 
5664 /*
5665  * Using a set of handled/denied access rights make it possible to check that
5666  * only the blocked ones are logged.
5667  */
5668 
5669 /* clang-format off */
5670 static const __u64 access_fs_16 =
5671 	LANDLOCK_ACCESS_FS_EXECUTE |
5672 	LANDLOCK_ACCESS_FS_WRITE_FILE |
5673 	LANDLOCK_ACCESS_FS_READ_FILE |
5674 	LANDLOCK_ACCESS_FS_READ_DIR |
5675 	LANDLOCK_ACCESS_FS_REMOVE_DIR |
5676 	LANDLOCK_ACCESS_FS_REMOVE_FILE |
5677 	LANDLOCK_ACCESS_FS_MAKE_CHAR |
5678 	LANDLOCK_ACCESS_FS_MAKE_DIR |
5679 	LANDLOCK_ACCESS_FS_MAKE_REG |
5680 	LANDLOCK_ACCESS_FS_MAKE_SOCK |
5681 	LANDLOCK_ACCESS_FS_MAKE_FIFO |
5682 	LANDLOCK_ACCESS_FS_MAKE_BLOCK |
5683 	LANDLOCK_ACCESS_FS_MAKE_SYM |
5684 	LANDLOCK_ACCESS_FS_REFER |
5685 	LANDLOCK_ACCESS_FS_TRUNCATE |
5686 	LANDLOCK_ACCESS_FS_IOCTL_DEV;
5687 /* clang-format on */
5688 
5689 TEST_F(audit_layout1, execute_read)
5690 {
5691 	struct audit_records records;
5692 
5693 	copy_file(_metadata, bin_true, file1_s1d1);
5694 	test_execute(_metadata, 0, file1_s1d1);
5695 	test_check_exec(_metadata, 0, file1_s1d1);
5696 
5697 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5698 					      .handled_access_fs = access_fs_16,
5699 				      });
5700 
5701 	/*
5702 	 * The only difference with the previous audit_layout1.execute_read test is
5703 	 * the extra ",fs\\.read_file" blocked by the executable file.
5704 	 */
5705 	test_execute(_metadata, EACCES, file1_s1d1);
5706 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5707 				    "fs\\.execute,fs\\.read_file", file1_s1d1));
5708 	test_check_exec(_metadata, EACCES, file1_s1d1);
5709 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5710 				    "fs\\.execute,fs\\.read_file", file1_s1d1));
5711 
5712 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5713 	EXPECT_EQ(0, records.access);
5714 	EXPECT_EQ(0, records.domain);
5715 }
5716 
5717 TEST_F(audit_layout1, write_file)
5718 {
5719 	struct audit_records records;
5720 
5721 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5722 					      .handled_access_fs = access_fs_16,
5723 				      });
5724 
5725 	EXPECT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
5726 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5727 				    "fs\\.write_file", file1_s1d1));
5728 
5729 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5730 	EXPECT_EQ(0, records.access);
5731 	EXPECT_EQ(1, records.domain);
5732 }
5733 
5734 TEST_F(audit_layout1, read_file)
5735 {
5736 	struct audit_records records;
5737 
5738 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5739 					      .handled_access_fs = access_fs_16,
5740 				      });
5741 
5742 	EXPECT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
5743 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.read_file",
5744 				    file1_s1d1));
5745 
5746 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5747 	EXPECT_EQ(0, records.access);
5748 	EXPECT_EQ(1, records.domain);
5749 }
5750 
5751 TEST_F(audit_layout1, read_dir)
5752 {
5753 	struct audit_records records;
5754 
5755 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5756 					      .handled_access_fs = access_fs_16,
5757 				      });
5758 
5759 	EXPECT_EQ(EACCES, test_open(dir_s1d1, O_DIRECTORY));
5760 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.read_dir",
5761 				    dir_s1d1));
5762 
5763 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5764 	EXPECT_EQ(0, records.access);
5765 	EXPECT_EQ(1, records.domain);
5766 }
5767 
5768 TEST_F(audit_layout1, remove_dir)
5769 {
5770 	struct audit_records records;
5771 
5772 	EXPECT_EQ(0, unlink(file1_s1d3));
5773 	EXPECT_EQ(0, unlink(file2_s1d3));
5774 
5775 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5776 					      .handled_access_fs = access_fs_16,
5777 				      });
5778 
5779 	EXPECT_EQ(-1, rmdir(dir_s1d3));
5780 	EXPECT_EQ(EACCES, errno);
5781 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5782 				    "fs\\.remove_dir", dir_s1d2));
5783 
5784 	EXPECT_EQ(-1, unlinkat(AT_FDCWD, dir_s1d3, AT_REMOVEDIR));
5785 	EXPECT_EQ(EACCES, errno);
5786 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5787 				    "fs\\.remove_dir", dir_s1d2));
5788 
5789 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5790 	EXPECT_EQ(0, records.access);
5791 	EXPECT_EQ(0, records.domain);
5792 }
5793 
5794 TEST_F(audit_layout1, remove_file)
5795 {
5796 	struct audit_records records;
5797 
5798 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5799 					      .handled_access_fs = access_fs_16,
5800 				      });
5801 
5802 	EXPECT_EQ(-1, unlink(file1_s1d3));
5803 	EXPECT_EQ(EACCES, errno);
5804 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5805 				    "fs\\.remove_file", dir_s1d3));
5806 
5807 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5808 	EXPECT_EQ(0, records.access);
5809 	EXPECT_EQ(1, records.domain);
5810 }
5811 
5812 TEST_F(audit_layout1, make_char)
5813 {
5814 	struct audit_records records;
5815 
5816 	EXPECT_EQ(0, unlink(file1_s1d3));
5817 
5818 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5819 					      .handled_access_fs = access_fs_16,
5820 				      });
5821 
5822 	EXPECT_EQ(-1, mknod(file1_s1d3, S_IFCHR | 0644, 0));
5823 	EXPECT_EQ(EACCES, errno);
5824 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.make_char",
5825 				    dir_s1d3));
5826 
5827 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5828 	EXPECT_EQ(0, records.access);
5829 	EXPECT_EQ(1, records.domain);
5830 }
5831 
5832 TEST_F(audit_layout1, make_dir)
5833 {
5834 	struct audit_records records;
5835 
5836 	EXPECT_EQ(0, unlink(file1_s1d3));
5837 
5838 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5839 					      .handled_access_fs = access_fs_16,
5840 				      });
5841 
5842 	EXPECT_EQ(-1, mkdir(file1_s1d3, 0755));
5843 	EXPECT_EQ(EACCES, errno);
5844 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.make_dir",
5845 				    dir_s1d3));
5846 
5847 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5848 	EXPECT_EQ(0, records.access);
5849 	EXPECT_EQ(1, records.domain);
5850 }
5851 
5852 TEST_F(audit_layout1, make_reg)
5853 {
5854 	struct audit_records records;
5855 
5856 	EXPECT_EQ(0, unlink(file1_s1d3));
5857 
5858 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5859 					      .handled_access_fs = access_fs_16,
5860 				      });
5861 
5862 	EXPECT_EQ(-1, mknod(file1_s1d3, S_IFREG | 0644, 0));
5863 	EXPECT_EQ(EACCES, errno);
5864 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.make_reg",
5865 				    dir_s1d3));
5866 
5867 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5868 	EXPECT_EQ(0, records.access);
5869 	EXPECT_EQ(1, records.domain);
5870 }
5871 
5872 TEST_F(audit_layout1, make_sock)
5873 {
5874 	struct audit_records records;
5875 
5876 	EXPECT_EQ(0, unlink(file1_s1d3));
5877 
5878 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5879 					      .handled_access_fs = access_fs_16,
5880 				      });
5881 
5882 	EXPECT_EQ(-1, mknod(file1_s1d3, S_IFSOCK | 0644, 0));
5883 	EXPECT_EQ(EACCES, errno);
5884 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.make_sock",
5885 				    dir_s1d3));
5886 
5887 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5888 	EXPECT_EQ(0, records.access);
5889 	EXPECT_EQ(1, records.domain);
5890 }
5891 
5892 TEST_F(audit_layout1, make_fifo)
5893 {
5894 	struct audit_records records;
5895 
5896 	EXPECT_EQ(0, unlink(file1_s1d3));
5897 
5898 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5899 					      .handled_access_fs = access_fs_16,
5900 				      });
5901 
5902 	EXPECT_EQ(-1, mknod(file1_s1d3, S_IFIFO | 0644, 0));
5903 	EXPECT_EQ(EACCES, errno);
5904 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.make_fifo",
5905 				    dir_s1d3));
5906 
5907 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5908 	EXPECT_EQ(0, records.access);
5909 	EXPECT_EQ(1, records.domain);
5910 }
5911 
5912 TEST_F(audit_layout1, make_block)
5913 {
5914 	struct audit_records records;
5915 
5916 	EXPECT_EQ(0, unlink(file1_s1d3));
5917 
5918 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5919 					      .handled_access_fs = access_fs_16,
5920 				      });
5921 
5922 	EXPECT_EQ(-1, mknod(file1_s1d3, S_IFBLK | 0644, 0));
5923 	EXPECT_EQ(EACCES, errno);
5924 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5925 				    "fs\\.make_block", dir_s1d3));
5926 
5927 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5928 	EXPECT_EQ(0, records.access);
5929 	EXPECT_EQ(1, records.domain);
5930 }
5931 
5932 TEST_F(audit_layout1, make_sym)
5933 {
5934 	struct audit_records records;
5935 
5936 	EXPECT_EQ(0, unlink(file1_s1d3));
5937 
5938 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5939 					      .handled_access_fs = access_fs_16,
5940 				      });
5941 
5942 	EXPECT_EQ(-1, symlink("target", file1_s1d3));
5943 	EXPECT_EQ(EACCES, errno);
5944 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.make_sym",
5945 				    dir_s1d3));
5946 
5947 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5948 	EXPECT_EQ(0, records.access);
5949 	EXPECT_EQ(1, records.domain);
5950 }
5951 
5952 TEST_F(audit_layout1, refer_handled)
5953 {
5954 	struct audit_records records;
5955 
5956 	EXPECT_EQ(0, unlink(file1_s1d3));
5957 
5958 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
5959 					      .handled_access_fs =
5960 						      LANDLOCK_ACCESS_FS_REFER,
5961 				      });
5962 
5963 	EXPECT_EQ(-1, link(file1_s1d1, file1_s1d3));
5964 	EXPECT_EQ(EXDEV, errno);
5965 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.refer",
5966 				    dir_s1d1));
5967 	EXPECT_EQ(0, matches_log_domain_allocated(self->audit_fd, NULL));
5968 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.refer",
5969 				    dir_s1d3));
5970 
5971 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5972 	EXPECT_EQ(0, records.access);
5973 	EXPECT_EQ(0, records.domain);
5974 }
5975 
5976 TEST_F(audit_layout1, refer_make)
5977 {
5978 	struct audit_records records;
5979 
5980 	EXPECT_EQ(0, unlink(file1_s1d3));
5981 
5982 	drop_access_rights(_metadata,
5983 			   &(struct landlock_ruleset_attr){
5984 				   .handled_access_fs =
5985 					   LANDLOCK_ACCESS_FS_MAKE_REG |
5986 					   LANDLOCK_ACCESS_FS_REFER,
5987 			   });
5988 
5989 	EXPECT_EQ(-1, link(file1_s1d1, file1_s1d3));
5990 	EXPECT_EQ(EACCES, errno);
5991 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.refer",
5992 				    dir_s1d1));
5993 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
5994 				    "fs\\.make_reg,fs\\.refer", dir_s1d3));
5995 
5996 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
5997 	EXPECT_EQ(0, records.access);
5998 	EXPECT_EQ(0, records.domain);
5999 }
6000 
6001 TEST_F(audit_layout1, refer_rename)
6002 {
6003 	struct audit_records records;
6004 
6005 	EXPECT_EQ(0, unlink(file1_s1d3));
6006 
6007 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
6008 					      .handled_access_fs = access_fs_16,
6009 				      });
6010 
6011 	EXPECT_EQ(EACCES, test_rename(file1_s1d2, file1_s2d3));
6012 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
6013 				    "fs\\.remove_file,fs\\.refer", dir_s1d2));
6014 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
6015 				    "fs\\.remove_file,fs\\.make_reg,fs\\.refer",
6016 				    dir_s2d3));
6017 
6018 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
6019 	EXPECT_EQ(0, records.access);
6020 	EXPECT_EQ(0, records.domain);
6021 }
6022 
6023 TEST_F(audit_layout1, refer_exchange)
6024 {
6025 	struct audit_records records;
6026 
6027 	EXPECT_EQ(0, unlink(file1_s1d3));
6028 
6029 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
6030 					      .handled_access_fs = access_fs_16,
6031 				      });
6032 
6033 	/*
6034 	 * The only difference with the previous audit_layout1.refer_rename test is
6035 	 * the extra ",fs\\.make_reg" blocked by the source directory.
6036 	 */
6037 	EXPECT_EQ(EACCES, test_exchange(file1_s1d2, file1_s2d3));
6038 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
6039 				    "fs\\.remove_file,fs\\.make_reg,fs\\.refer",
6040 				    dir_s1d2));
6041 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
6042 				    "fs\\.remove_file,fs\\.make_reg,fs\\.refer",
6043 				    dir_s2d3));
6044 
6045 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
6046 	EXPECT_EQ(0, records.access);
6047 	EXPECT_EQ(0, records.domain);
6048 }
6049 
6050 /*
6051  * This test checks that the audit record is correctly generated when the
6052  * operation is only partially denied.  This is the case for rename(2) when the
6053  * source file is allowed to be referenced but the destination directory is not.
6054  *
6055  * This is also a regression test for commit d617f0d72d80 ("landlock: Optimize
6056  * file path walks and prepare for audit support") and commit 058518c20920
6057  * ("landlock: Align partial refer access checks with final ones").
6058  */
6059 TEST_F(audit_layout1, refer_rename_half)
6060 {
6061 	struct audit_records records;
6062 	const struct rule layer1[] = {
6063 		{
6064 			.path = dir_s2d2,
6065 			.access = LANDLOCK_ACCESS_FS_REFER,
6066 		},
6067 		{},
6068 	};
6069 	int ruleset_fd =
6070 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_REFER, layer1);
6071 
6072 	ASSERT_LE(0, ruleset_fd);
6073 	enforce_ruleset(_metadata, ruleset_fd);
6074 	ASSERT_EQ(0, close(ruleset_fd));
6075 
6076 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d3));
6077 	ASSERT_EQ(EXDEV, errno);
6078 
6079 	/* Only half of the request is denied. */
6080 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.refer",
6081 				    dir_s1d1));
6082 
6083 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
6084 	EXPECT_EQ(0, records.access);
6085 	EXPECT_EQ(1, records.domain);
6086 }
6087 
6088 TEST_F(audit_layout1, truncate)
6089 {
6090 	struct audit_records records;
6091 
6092 	drop_access_rights(_metadata, &(struct landlock_ruleset_attr){
6093 					      .handled_access_fs = access_fs_16,
6094 				      });
6095 
6096 	EXPECT_EQ(-1, truncate(file1_s1d3, 0));
6097 	EXPECT_EQ(EACCES, errno);
6098 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.truncate",
6099 				    file1_s1d3));
6100 
6101 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
6102 	EXPECT_EQ(0, records.access);
6103 	EXPECT_EQ(1, records.domain);
6104 }
6105 
6106 TEST_F(audit_layout1, ioctl_dev)
6107 {
6108 	struct audit_records records;
6109 	int fd;
6110 
6111 	drop_access_rights(_metadata,
6112 			   &(struct landlock_ruleset_attr){
6113 				   .handled_access_fs =
6114 					   access_fs_16 &
6115 					   ~LANDLOCK_ACCESS_FS_READ_FILE,
6116 			   });
6117 
6118 	fd = open("/dev/null", O_RDONLY | O_CLOEXEC);
6119 	ASSERT_LE(0, fd);
6120 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FIONREAD));
6121 	EXPECT_EQ(0, matches_log_fs_extra(_metadata, self->audit_fd,
6122 					  "fs\\.ioctl_dev", "/dev/null",
6123 					  " ioctlcmd=0x541b"));
6124 
6125 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
6126 	EXPECT_EQ(0, records.access);
6127 	EXPECT_EQ(1, records.domain);
6128 }
6129 
6130 TEST_F(audit_layout1, mount)
6131 {
6132 	struct audit_records records;
6133 
6134 	drop_access_rights(_metadata,
6135 			   &(struct landlock_ruleset_attr){
6136 				   .handled_access_fs =
6137 					   LANDLOCK_ACCESS_FS_EXECUTE,
6138 			   });
6139 
6140 	set_cap(_metadata, CAP_SYS_ADMIN);
6141 	EXPECT_EQ(-1, mount(NULL, dir_s3d2, NULL, MS_RDONLY, NULL));
6142 	EXPECT_EQ(EPERM, errno);
6143 	clear_cap(_metadata, CAP_SYS_ADMIN);
6144 	EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd,
6145 				    "fs\\.change_topology", dir_s3d2));
6146 	EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
6147 	EXPECT_EQ(0, records.access);
6148 	EXPECT_EQ(1, records.domain);
6149 }
6150 
6151 TEST_HARNESS_MAIN
6152