xref: /linux/tools/testing/selftests/landlock/fs_test.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 #include "common.h"
41 
42 #ifndef renameat2
43 int renameat2(int olddirfd, const char *oldpath, int newdirfd,
44 	      const char *newpath, unsigned int flags)
45 {
46 	return syscall(__NR_renameat2, olddirfd, oldpath, newdirfd, newpath,
47 		       flags);
48 }
49 #endif
50 
51 #ifndef open_tree
52 int open_tree(int dfd, const char *filename, unsigned int flags)
53 {
54 	return syscall(__NR_open_tree, dfd, filename, flags);
55 }
56 #endif
57 
58 #ifndef RENAME_EXCHANGE
59 #define RENAME_EXCHANGE (1 << 1)
60 #endif
61 
62 #define BINARY_PATH "./true"
63 
64 /* Paths (sibling number and depth) */
65 static const char dir_s1d1[] = TMP_DIR "/s1d1";
66 static const char file1_s1d1[] = TMP_DIR "/s1d1/f1";
67 static const char file2_s1d1[] = TMP_DIR "/s1d1/f2";
68 static const char dir_s1d2[] = TMP_DIR "/s1d1/s1d2";
69 static const char file1_s1d2[] = TMP_DIR "/s1d1/s1d2/f1";
70 static const char file2_s1d2[] = TMP_DIR "/s1d1/s1d2/f2";
71 static const char dir_s1d3[] = TMP_DIR "/s1d1/s1d2/s1d3";
72 static const char file1_s1d3[] = TMP_DIR "/s1d1/s1d2/s1d3/f1";
73 static const char file2_s1d3[] = TMP_DIR "/s1d1/s1d2/s1d3/f2";
74 
75 static const char dir_s2d1[] = TMP_DIR "/s2d1";
76 static const char file1_s2d1[] = TMP_DIR "/s2d1/f1";
77 static const char dir_s2d2[] = TMP_DIR "/s2d1/s2d2";
78 static const char file1_s2d2[] = TMP_DIR "/s2d1/s2d2/f1";
79 static const char dir_s2d3[] = TMP_DIR "/s2d1/s2d2/s2d3";
80 static const char file1_s2d3[] = TMP_DIR "/s2d1/s2d2/s2d3/f1";
81 static const char file2_s2d3[] = TMP_DIR "/s2d1/s2d2/s2d3/f2";
82 
83 static const char dir_s3d1[] = TMP_DIR "/s3d1";
84 static const char file1_s3d1[] = TMP_DIR "/s3d1/f1";
85 /* dir_s3d2 is a mount point. */
86 static const char dir_s3d2[] = TMP_DIR "/s3d1/s3d2";
87 static const char dir_s3d3[] = TMP_DIR "/s3d1/s3d2/s3d3";
88 
89 /*
90  * layout1 hierarchy:
91  *
92  * tmp
93  * ├── s1d1
94  * │   ├── f1
95  * │   ├── f2
96  * │   └── s1d2
97  * │       ├── f1
98  * │       ├── f2
99  * │       └── s1d3
100  * │           ├── f1
101  * │           └── f2
102  * ├── s2d1
103  * │   ├── f1
104  * │   └── s2d2
105  * │       ├── f1
106  * │       └── s2d3
107  * │           ├── f1
108  * │           └── f2
109  * └── s3d1
110  *     ├── f1
111  *     └── s3d2
112  *         └── s3d3
113  */
114 
115 static bool fgrep(FILE *const inf, const char *const str)
116 {
117 	char line[32];
118 	const int slen = strlen(str);
119 
120 	while (!feof(inf)) {
121 		if (!fgets(line, sizeof(line), inf))
122 			break;
123 		if (strncmp(line, str, slen))
124 			continue;
125 
126 		return true;
127 	}
128 
129 	return false;
130 }
131 
132 static bool supports_filesystem(const char *const filesystem)
133 {
134 	char str[32];
135 	int len;
136 	bool res = true;
137 	FILE *const inf = fopen("/proc/filesystems", "r");
138 
139 	/*
140 	 * Consider that the filesystem is supported if we cannot get the
141 	 * supported ones.
142 	 */
143 	if (!inf)
144 		return true;
145 
146 	/* filesystem can be null for bind mounts. */
147 	if (!filesystem)
148 		goto out;
149 
150 	len = snprintf(str, sizeof(str), "nodev\t%s\n", filesystem);
151 	if (len >= sizeof(str))
152 		/* Ignores too-long filesystem names. */
153 		goto out;
154 
155 	res = fgrep(inf, str);
156 
157 out:
158 	fclose(inf);
159 	return res;
160 }
161 
162 static bool cwd_matches_fs(unsigned int fs_magic)
163 {
164 	struct statfs statfs_buf;
165 
166 	if (!fs_magic)
167 		return true;
168 
169 	if (statfs(".", &statfs_buf))
170 		return true;
171 
172 	return statfs_buf.f_type == fs_magic;
173 }
174 
175 static void mkdir_parents(struct __test_metadata *const _metadata,
176 			  const char *const path)
177 {
178 	char *walker;
179 	const char *parent;
180 	int i, err;
181 
182 	ASSERT_NE(path[0], '\0');
183 	walker = strdup(path);
184 	ASSERT_NE(NULL, walker);
185 	parent = walker;
186 	for (i = 1; walker[i]; i++) {
187 		if (walker[i] != '/')
188 			continue;
189 		walker[i] = '\0';
190 		err = mkdir(parent, 0700);
191 		ASSERT_FALSE(err && errno != EEXIST)
192 		{
193 			TH_LOG("Failed to create directory \"%s\": %s", parent,
194 			       strerror(errno));
195 		}
196 		walker[i] = '/';
197 	}
198 	free(walker);
199 }
200 
201 static void create_directory(struct __test_metadata *const _metadata,
202 			     const char *const path)
203 {
204 	mkdir_parents(_metadata, path);
205 	ASSERT_EQ(0, mkdir(path, 0700))
206 	{
207 		TH_LOG("Failed to create directory \"%s\": %s", path,
208 		       strerror(errno));
209 	}
210 }
211 
212 static void create_file(struct __test_metadata *const _metadata,
213 			const char *const path)
214 {
215 	mkdir_parents(_metadata, path);
216 	ASSERT_EQ(0, mknod(path, S_IFREG | 0700, 0))
217 	{
218 		TH_LOG("Failed to create file \"%s\": %s", path,
219 		       strerror(errno));
220 	}
221 }
222 
223 static int remove_path(const char *const path)
224 {
225 	char *walker;
226 	int i, ret, err = 0;
227 
228 	walker = strdup(path);
229 	if (!walker) {
230 		err = ENOMEM;
231 		goto out;
232 	}
233 	if (unlink(path) && rmdir(path)) {
234 		if (errno != ENOENT && errno != ENOTDIR)
235 			err = errno;
236 		goto out;
237 	}
238 	for (i = strlen(walker); i > 0; i--) {
239 		if (walker[i] != '/')
240 			continue;
241 		walker[i] = '\0';
242 		ret = rmdir(walker);
243 		if (ret) {
244 			if (errno != ENOTEMPTY && errno != EBUSY)
245 				err = errno;
246 			goto out;
247 		}
248 		if (strcmp(walker, TMP_DIR) == 0)
249 			goto out;
250 	}
251 
252 out:
253 	free(walker);
254 	return err;
255 }
256 
257 struct mnt_opt {
258 	const char *const source;
259 	const char *const type;
260 	const unsigned long flags;
261 	const char *const data;
262 };
263 
264 #define MNT_TMP_DATA "size=4m,mode=700"
265 
266 static const struct mnt_opt mnt_tmp = {
267 	.type = "tmpfs",
268 	.data = MNT_TMP_DATA,
269 };
270 
271 static int mount_opt(const struct mnt_opt *const mnt, const char *const target)
272 {
273 	return mount(mnt->source ?: mnt->type, target, mnt->type, mnt->flags,
274 		     mnt->data);
275 }
276 
277 static void prepare_layout_opt(struct __test_metadata *const _metadata,
278 			       const struct mnt_opt *const mnt)
279 {
280 	disable_caps(_metadata);
281 	umask(0077);
282 	create_directory(_metadata, TMP_DIR);
283 
284 	/*
285 	 * Do not pollute the rest of the system: creates a private mount point
286 	 * for tests relying on pivot_root(2) and move_mount(2).
287 	 */
288 	set_cap(_metadata, CAP_SYS_ADMIN);
289 	ASSERT_EQ(0, unshare(CLONE_NEWNS | CLONE_NEWCGROUP));
290 	ASSERT_EQ(0, mount_opt(mnt, TMP_DIR))
291 	{
292 		TH_LOG("Failed to mount the %s filesystem: %s", mnt->type,
293 		       strerror(errno));
294 		/*
295 		 * FIXTURE_TEARDOWN() is not called when FIXTURE_SETUP()
296 		 * failed, so we need to explicitly do a minimal cleanup to
297 		 * avoid cascading errors with other tests that don't depend on
298 		 * the same filesystem.
299 		 */
300 		remove_path(TMP_DIR);
301 	}
302 	ASSERT_EQ(0, mount(NULL, TMP_DIR, NULL, MS_PRIVATE | MS_REC, NULL));
303 	clear_cap(_metadata, CAP_SYS_ADMIN);
304 }
305 
306 static void prepare_layout(struct __test_metadata *const _metadata)
307 {
308 	prepare_layout_opt(_metadata, &mnt_tmp);
309 }
310 
311 static void cleanup_layout(struct __test_metadata *const _metadata)
312 {
313 	set_cap(_metadata, CAP_SYS_ADMIN);
314 	if (umount(TMP_DIR)) {
315 		/*
316 		 * According to the test environment, the mount point of the
317 		 * current directory may be shared or not, which changes the
318 		 * visibility of the nested TMP_DIR mount point for the test's
319 		 * parent process doing this cleanup.
320 		 */
321 		ASSERT_EQ(EINVAL, errno);
322 	}
323 	clear_cap(_metadata, CAP_SYS_ADMIN);
324 	EXPECT_EQ(0, remove_path(TMP_DIR));
325 }
326 
327 /* clang-format off */
328 FIXTURE(layout0) {};
329 /* clang-format on */
330 
331 FIXTURE_SETUP(layout0)
332 {
333 	prepare_layout(_metadata);
334 }
335 
336 FIXTURE_TEARDOWN_PARENT(layout0)
337 {
338 	cleanup_layout(_metadata);
339 }
340 
341 static void create_layout1(struct __test_metadata *const _metadata)
342 {
343 	create_file(_metadata, file1_s1d1);
344 	create_file(_metadata, file1_s1d2);
345 	create_file(_metadata, file1_s1d3);
346 	create_file(_metadata, file2_s1d1);
347 	create_file(_metadata, file2_s1d2);
348 	create_file(_metadata, file2_s1d3);
349 
350 	create_file(_metadata, file1_s2d1);
351 	create_file(_metadata, file1_s2d2);
352 	create_file(_metadata, file1_s2d3);
353 	create_file(_metadata, file2_s2d3);
354 
355 	create_file(_metadata, file1_s3d1);
356 	create_directory(_metadata, dir_s3d2);
357 	set_cap(_metadata, CAP_SYS_ADMIN);
358 	ASSERT_EQ(0, mount_opt(&mnt_tmp, dir_s3d2));
359 	clear_cap(_metadata, CAP_SYS_ADMIN);
360 
361 	ASSERT_EQ(0, mkdir(dir_s3d3, 0700));
362 }
363 
364 static void remove_layout1(struct __test_metadata *const _metadata)
365 {
366 	EXPECT_EQ(0, remove_path(file2_s1d3));
367 	EXPECT_EQ(0, remove_path(file2_s1d2));
368 	EXPECT_EQ(0, remove_path(file2_s1d1));
369 	EXPECT_EQ(0, remove_path(file1_s1d3));
370 	EXPECT_EQ(0, remove_path(file1_s1d2));
371 	EXPECT_EQ(0, remove_path(file1_s1d1));
372 	EXPECT_EQ(0, remove_path(dir_s1d3));
373 
374 	EXPECT_EQ(0, remove_path(file2_s2d3));
375 	EXPECT_EQ(0, remove_path(file1_s2d3));
376 	EXPECT_EQ(0, remove_path(file1_s2d2));
377 	EXPECT_EQ(0, remove_path(file1_s2d1));
378 	EXPECT_EQ(0, remove_path(dir_s2d2));
379 
380 	EXPECT_EQ(0, remove_path(file1_s3d1));
381 	EXPECT_EQ(0, remove_path(dir_s3d3));
382 	set_cap(_metadata, CAP_SYS_ADMIN);
383 	umount(dir_s3d2);
384 	clear_cap(_metadata, CAP_SYS_ADMIN);
385 	EXPECT_EQ(0, remove_path(dir_s3d2));
386 }
387 
388 /* clang-format off */
389 FIXTURE(layout1) {};
390 /* clang-format on */
391 
392 FIXTURE_SETUP(layout1)
393 {
394 	prepare_layout(_metadata);
395 
396 	create_layout1(_metadata);
397 }
398 
399 FIXTURE_TEARDOWN_PARENT(layout1)
400 {
401 	remove_layout1(_metadata);
402 
403 	cleanup_layout(_metadata);
404 }
405 
406 /*
407  * This helper enables to use the ASSERT_* macros and print the line number
408  * pointing to the test caller.
409  */
410 static int test_open_rel(const int dirfd, const char *const path,
411 			 const int flags)
412 {
413 	int fd;
414 
415 	/* Works with file and directories. */
416 	fd = openat(dirfd, path, flags | O_CLOEXEC);
417 	if (fd < 0)
418 		return errno;
419 	/*
420 	 * Mixing error codes from close(2) and open(2) should not lead to any
421 	 * (access type) confusion for this test.
422 	 */
423 	if (close(fd) != 0)
424 		return errno;
425 	return 0;
426 }
427 
428 static int test_open(const char *const path, const int flags)
429 {
430 	return test_open_rel(AT_FDCWD, path, flags);
431 }
432 
433 TEST_F_FORK(layout1, no_restriction)
434 {
435 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
436 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
437 	ASSERT_EQ(0, test_open(file2_s1d1, O_RDONLY));
438 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
439 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
440 	ASSERT_EQ(0, test_open(file2_s1d2, O_RDONLY));
441 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
442 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
443 
444 	ASSERT_EQ(0, test_open(dir_s2d1, O_RDONLY));
445 	ASSERT_EQ(0, test_open(file1_s2d1, O_RDONLY));
446 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY));
447 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDONLY));
448 	ASSERT_EQ(0, test_open(dir_s2d3, O_RDONLY));
449 	ASSERT_EQ(0, test_open(file1_s2d3, O_RDONLY));
450 
451 	ASSERT_EQ(0, test_open(dir_s3d1, O_RDONLY));
452 	ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY));
453 	ASSERT_EQ(0, test_open(dir_s3d3, O_RDONLY));
454 }
455 
456 TEST_F_FORK(layout1, inval)
457 {
458 	struct landlock_path_beneath_attr path_beneath = {
459 		.allowed_access = LANDLOCK_ACCESS_FS_READ_FILE |
460 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
461 		.parent_fd = -1,
462 	};
463 	struct landlock_ruleset_attr ruleset_attr = {
464 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE |
465 				     LANDLOCK_ACCESS_FS_WRITE_FILE,
466 	};
467 	int ruleset_fd;
468 
469 	path_beneath.parent_fd =
470 		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
471 	ASSERT_LE(0, path_beneath.parent_fd);
472 
473 	ruleset_fd = open(dir_s1d1, O_PATH | O_DIRECTORY | O_CLOEXEC);
474 	ASSERT_LE(0, ruleset_fd);
475 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
476 					&path_beneath, 0));
477 	/* Returns EBADF because ruleset_fd is not a landlock-ruleset FD. */
478 	ASSERT_EQ(EBADF, errno);
479 	ASSERT_EQ(0, close(ruleset_fd));
480 
481 	ruleset_fd = open(dir_s1d1, O_DIRECTORY | O_CLOEXEC);
482 	ASSERT_LE(0, ruleset_fd);
483 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
484 					&path_beneath, 0));
485 	/* Returns EBADFD because ruleset_fd is not a valid ruleset. */
486 	ASSERT_EQ(EBADFD, errno);
487 	ASSERT_EQ(0, close(ruleset_fd));
488 
489 	/* Gets a real ruleset. */
490 	ruleset_fd =
491 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
492 	ASSERT_LE(0, ruleset_fd);
493 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
494 				       &path_beneath, 0));
495 	ASSERT_EQ(0, close(path_beneath.parent_fd));
496 
497 	/* Tests without O_PATH. */
498 	path_beneath.parent_fd = open(dir_s1d2, O_DIRECTORY | O_CLOEXEC);
499 	ASSERT_LE(0, path_beneath.parent_fd);
500 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
501 				       &path_beneath, 0));
502 	ASSERT_EQ(0, close(path_beneath.parent_fd));
503 
504 	/* Tests with a ruleset FD. */
505 	path_beneath.parent_fd = ruleset_fd;
506 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
507 					&path_beneath, 0));
508 	ASSERT_EQ(EBADFD, errno);
509 
510 	/* Checks unhandled allowed_access. */
511 	path_beneath.parent_fd =
512 		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
513 	ASSERT_LE(0, path_beneath.parent_fd);
514 
515 	/* Test with legitimate values. */
516 	path_beneath.allowed_access |= LANDLOCK_ACCESS_FS_EXECUTE;
517 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
518 					&path_beneath, 0));
519 	ASSERT_EQ(EINVAL, errno);
520 	path_beneath.allowed_access &= ~LANDLOCK_ACCESS_FS_EXECUTE;
521 
522 	/* Tests with denied-by-default access right. */
523 	path_beneath.allowed_access |= LANDLOCK_ACCESS_FS_REFER;
524 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
525 					&path_beneath, 0));
526 	ASSERT_EQ(EINVAL, errno);
527 	path_beneath.allowed_access &= ~LANDLOCK_ACCESS_FS_REFER;
528 
529 	/* Test with unknown (64-bits) value. */
530 	path_beneath.allowed_access |= (1ULL << 60);
531 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
532 					&path_beneath, 0));
533 	ASSERT_EQ(EINVAL, errno);
534 	path_beneath.allowed_access &= ~(1ULL << 60);
535 
536 	/* Test with no access. */
537 	path_beneath.allowed_access = 0;
538 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
539 					&path_beneath, 0));
540 	ASSERT_EQ(ENOMSG, errno);
541 	path_beneath.allowed_access &= ~(1ULL << 60);
542 
543 	ASSERT_EQ(0, close(path_beneath.parent_fd));
544 
545 	/* Enforces the ruleset. */
546 	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
547 	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
548 
549 	ASSERT_EQ(0, close(ruleset_fd));
550 }
551 
552 /* clang-format off */
553 
554 #define ACCESS_FILE ( \
555 	LANDLOCK_ACCESS_FS_EXECUTE | \
556 	LANDLOCK_ACCESS_FS_WRITE_FILE | \
557 	LANDLOCK_ACCESS_FS_READ_FILE | \
558 	LANDLOCK_ACCESS_FS_TRUNCATE | \
559 	LANDLOCK_ACCESS_FS_IOCTL_DEV)
560 
561 #define ACCESS_LAST LANDLOCK_ACCESS_FS_IOCTL_DEV
562 
563 #define ACCESS_ALL ( \
564 	ACCESS_FILE | \
565 	LANDLOCK_ACCESS_FS_READ_DIR | \
566 	LANDLOCK_ACCESS_FS_REMOVE_DIR | \
567 	LANDLOCK_ACCESS_FS_REMOVE_FILE | \
568 	LANDLOCK_ACCESS_FS_MAKE_CHAR | \
569 	LANDLOCK_ACCESS_FS_MAKE_DIR | \
570 	LANDLOCK_ACCESS_FS_MAKE_REG | \
571 	LANDLOCK_ACCESS_FS_MAKE_SOCK | \
572 	LANDLOCK_ACCESS_FS_MAKE_FIFO | \
573 	LANDLOCK_ACCESS_FS_MAKE_BLOCK | \
574 	LANDLOCK_ACCESS_FS_MAKE_SYM | \
575 	LANDLOCK_ACCESS_FS_REFER)
576 
577 /* clang-format on */
578 
579 TEST_F_FORK(layout1, file_and_dir_access_rights)
580 {
581 	__u64 access;
582 	int err;
583 	struct landlock_path_beneath_attr path_beneath_file = {},
584 					  path_beneath_dir = {};
585 	struct landlock_ruleset_attr ruleset_attr = {
586 		.handled_access_fs = ACCESS_ALL,
587 	};
588 	const int ruleset_fd =
589 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
590 
591 	ASSERT_LE(0, ruleset_fd);
592 
593 	/* Tests access rights for files. */
594 	path_beneath_file.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
595 	ASSERT_LE(0, path_beneath_file.parent_fd);
596 
597 	/* Tests access rights for directories. */
598 	path_beneath_dir.parent_fd =
599 		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
600 	ASSERT_LE(0, path_beneath_dir.parent_fd);
601 
602 	for (access = 1; access <= ACCESS_LAST; access <<= 1) {
603 		path_beneath_dir.allowed_access = access;
604 		ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
605 					       LANDLOCK_RULE_PATH_BENEATH,
606 					       &path_beneath_dir, 0));
607 
608 		path_beneath_file.allowed_access = access;
609 		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
610 					&path_beneath_file, 0);
611 		if (access & ACCESS_FILE) {
612 			ASSERT_EQ(0, err);
613 		} else {
614 			ASSERT_EQ(-1, err);
615 			ASSERT_EQ(EINVAL, errno);
616 		}
617 	}
618 	ASSERT_EQ(0, close(path_beneath_file.parent_fd));
619 	ASSERT_EQ(0, close(path_beneath_dir.parent_fd));
620 	ASSERT_EQ(0, close(ruleset_fd));
621 }
622 
623 TEST_F_FORK(layout0, ruleset_with_unknown_access)
624 {
625 	__u64 access_mask;
626 
627 	for (access_mask = 1ULL << 63; access_mask != ACCESS_LAST;
628 	     access_mask >>= 1) {
629 		struct landlock_ruleset_attr ruleset_attr = {
630 			.handled_access_fs = access_mask,
631 		};
632 
633 		ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr,
634 						      sizeof(ruleset_attr), 0));
635 		ASSERT_EQ(EINVAL, errno);
636 	}
637 }
638 
639 TEST_F_FORK(layout0, rule_with_unknown_access)
640 {
641 	__u64 access;
642 	struct landlock_path_beneath_attr path_beneath = {};
643 	const struct landlock_ruleset_attr ruleset_attr = {
644 		.handled_access_fs = ACCESS_ALL,
645 	};
646 	const int ruleset_fd =
647 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
648 
649 	ASSERT_LE(0, ruleset_fd);
650 
651 	path_beneath.parent_fd =
652 		open(TMP_DIR, O_PATH | O_DIRECTORY | O_CLOEXEC);
653 	ASSERT_LE(0, path_beneath.parent_fd);
654 
655 	for (access = 1ULL << 63; access != ACCESS_LAST; access >>= 1) {
656 		path_beneath.allowed_access = access;
657 		EXPECT_EQ(-1, landlock_add_rule(ruleset_fd,
658 						LANDLOCK_RULE_PATH_BENEATH,
659 						&path_beneath, 0));
660 		EXPECT_EQ(EINVAL, errno);
661 	}
662 	ASSERT_EQ(0, close(path_beneath.parent_fd));
663 	ASSERT_EQ(0, close(ruleset_fd));
664 }
665 
666 TEST_F_FORK(layout1, rule_with_unhandled_access)
667 {
668 	struct landlock_ruleset_attr ruleset_attr = {
669 		.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
670 	};
671 	struct landlock_path_beneath_attr path_beneath = {};
672 	int ruleset_fd;
673 	__u64 access;
674 
675 	ruleset_fd =
676 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
677 	ASSERT_LE(0, ruleset_fd);
678 
679 	path_beneath.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
680 	ASSERT_LE(0, path_beneath.parent_fd);
681 
682 	for (access = 1; access > 0; access <<= 1) {
683 		int err;
684 
685 		path_beneath.allowed_access = access;
686 		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
687 					&path_beneath, 0);
688 		if (access == ruleset_attr.handled_access_fs) {
689 			EXPECT_EQ(0, err);
690 		} else {
691 			EXPECT_EQ(-1, err);
692 			EXPECT_EQ(EINVAL, errno);
693 		}
694 	}
695 
696 	EXPECT_EQ(0, close(path_beneath.parent_fd));
697 	EXPECT_EQ(0, close(ruleset_fd));
698 }
699 
700 static void add_path_beneath(struct __test_metadata *const _metadata,
701 			     const int ruleset_fd, const __u64 allowed_access,
702 			     const char *const path)
703 {
704 	struct landlock_path_beneath_attr path_beneath = {
705 		.allowed_access = allowed_access,
706 	};
707 
708 	path_beneath.parent_fd = open(path, O_PATH | O_CLOEXEC);
709 	ASSERT_LE(0, path_beneath.parent_fd)
710 	{
711 		TH_LOG("Failed to open directory \"%s\": %s", path,
712 		       strerror(errno));
713 	}
714 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
715 				       &path_beneath, 0))
716 	{
717 		TH_LOG("Failed to update the ruleset with \"%s\": %s", path,
718 		       strerror(errno));
719 	}
720 	ASSERT_EQ(0, close(path_beneath.parent_fd));
721 }
722 
723 struct rule {
724 	const char *path;
725 	__u64 access;
726 };
727 
728 /* clang-format off */
729 
730 #define ACCESS_RO ( \
731 	LANDLOCK_ACCESS_FS_READ_FILE | \
732 	LANDLOCK_ACCESS_FS_READ_DIR)
733 
734 #define ACCESS_RW ( \
735 	ACCESS_RO | \
736 	LANDLOCK_ACCESS_FS_WRITE_FILE)
737 
738 /* clang-format on */
739 
740 static int create_ruleset(struct __test_metadata *const _metadata,
741 			  const __u64 handled_access_fs,
742 			  const struct rule rules[])
743 {
744 	int ruleset_fd, i;
745 	struct landlock_ruleset_attr ruleset_attr = {
746 		.handled_access_fs = handled_access_fs,
747 	};
748 
749 	ASSERT_NE(NULL, rules)
750 	{
751 		TH_LOG("No rule list");
752 	}
753 	ASSERT_NE(NULL, rules[0].path)
754 	{
755 		TH_LOG("Empty rule list");
756 	}
757 
758 	ruleset_fd =
759 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
760 	ASSERT_LE(0, ruleset_fd)
761 	{
762 		TH_LOG("Failed to create a ruleset: %s", strerror(errno));
763 	}
764 
765 	for (i = 0; rules[i].path; i++) {
766 		if (!rules[i].access)
767 			continue;
768 
769 		add_path_beneath(_metadata, ruleset_fd, rules[i].access,
770 				 rules[i].path);
771 	}
772 	return ruleset_fd;
773 }
774 
775 TEST_F_FORK(layout0, proc_nsfs)
776 {
777 	const struct rule rules[] = {
778 		{
779 			.path = "/dev/null",
780 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
781 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
782 		},
783 		{},
784 	};
785 	struct landlock_path_beneath_attr path_beneath;
786 	const int ruleset_fd = create_ruleset(
787 		_metadata, rules[0].access | LANDLOCK_ACCESS_FS_READ_DIR,
788 		rules);
789 
790 	ASSERT_LE(0, ruleset_fd);
791 	ASSERT_EQ(0, test_open("/proc/self/ns/mnt", O_RDONLY));
792 
793 	enforce_ruleset(_metadata, ruleset_fd);
794 
795 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
796 	ASSERT_EQ(EACCES, test_open("/dev", O_RDONLY));
797 	ASSERT_EQ(0, test_open("/dev/null", O_RDONLY));
798 	ASSERT_EQ(EACCES, test_open("/dev/full", O_RDONLY));
799 
800 	ASSERT_EQ(EACCES, test_open("/proc", O_RDONLY));
801 	ASSERT_EQ(EACCES, test_open("/proc/self", O_RDONLY));
802 	ASSERT_EQ(EACCES, test_open("/proc/self/ns", O_RDONLY));
803 	/*
804 	 * Because nsfs is an internal filesystem, /proc/self/ns/mnt is a
805 	 * disconnected path.  Such path cannot be identified and must then be
806 	 * allowed.
807 	 */
808 	ASSERT_EQ(0, test_open("/proc/self/ns/mnt", O_RDONLY));
809 
810 	/*
811 	 * Checks that it is not possible to add nsfs-like filesystem
812 	 * references to a ruleset.
813 	 */
814 	path_beneath.allowed_access = LANDLOCK_ACCESS_FS_READ_FILE |
815 				      LANDLOCK_ACCESS_FS_WRITE_FILE,
816 	path_beneath.parent_fd = open("/proc/self/ns/mnt", O_PATH | O_CLOEXEC);
817 	ASSERT_LE(0, path_beneath.parent_fd);
818 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
819 					&path_beneath, 0));
820 	ASSERT_EQ(EBADFD, errno);
821 	ASSERT_EQ(0, close(path_beneath.parent_fd));
822 }
823 
824 TEST_F_FORK(layout0, unpriv)
825 {
826 	const struct rule rules[] = {
827 		{
828 			.path = TMP_DIR,
829 			.access = ACCESS_RO,
830 		},
831 		{},
832 	};
833 	int ruleset_fd;
834 
835 	drop_caps(_metadata);
836 
837 	ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules);
838 	ASSERT_LE(0, ruleset_fd);
839 	ASSERT_EQ(-1, landlock_restrict_self(ruleset_fd, 0));
840 	ASSERT_EQ(EPERM, errno);
841 
842 	/* enforce_ruleset() calls prctl(no_new_privs). */
843 	enforce_ruleset(_metadata, ruleset_fd);
844 	ASSERT_EQ(0, close(ruleset_fd));
845 }
846 
847 TEST_F_FORK(layout1, effective_access)
848 {
849 	const struct rule rules[] = {
850 		{
851 			.path = dir_s1d2,
852 			.access = ACCESS_RO,
853 		},
854 		{
855 			.path = file1_s2d2,
856 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
857 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
858 		},
859 		{},
860 	};
861 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
862 	char buf;
863 	int reg_fd;
864 
865 	ASSERT_LE(0, ruleset_fd);
866 	enforce_ruleset(_metadata, ruleset_fd);
867 	ASSERT_EQ(0, close(ruleset_fd));
868 
869 	/* Tests on a directory (with or without O_PATH). */
870 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
871 	ASSERT_EQ(0, test_open("/", O_RDONLY | O_PATH));
872 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
873 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY | O_PATH));
874 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
875 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY | O_PATH));
876 
877 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
878 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
879 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
880 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
881 
882 	/* Tests on a file (with or without O_PATH). */
883 	ASSERT_EQ(EACCES, test_open(dir_s2d2, O_RDONLY));
884 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY | O_PATH));
885 
886 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDONLY));
887 
888 	/* Checks effective read and write actions. */
889 	reg_fd = open(file1_s2d2, O_RDWR | O_CLOEXEC);
890 	ASSERT_LE(0, reg_fd);
891 	ASSERT_EQ(1, write(reg_fd, ".", 1));
892 	ASSERT_LE(0, lseek(reg_fd, 0, SEEK_SET));
893 	ASSERT_EQ(1, read(reg_fd, &buf, 1));
894 	ASSERT_EQ('.', buf);
895 	ASSERT_EQ(0, close(reg_fd));
896 
897 	/* Just in case, double-checks effective actions. */
898 	reg_fd = open(file1_s2d2, O_RDONLY | O_CLOEXEC);
899 	ASSERT_LE(0, reg_fd);
900 	ASSERT_EQ(-1, write(reg_fd, &buf, 1));
901 	ASSERT_EQ(EBADF, errno);
902 	ASSERT_EQ(0, close(reg_fd));
903 }
904 
905 TEST_F_FORK(layout1, unhandled_access)
906 {
907 	const struct rule rules[] = {
908 		{
909 			.path = dir_s1d2,
910 			.access = ACCESS_RO,
911 		},
912 		{},
913 	};
914 	/* Here, we only handle read accesses, not write accesses. */
915 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules);
916 
917 	ASSERT_LE(0, ruleset_fd);
918 	enforce_ruleset(_metadata, ruleset_fd);
919 	ASSERT_EQ(0, close(ruleset_fd));
920 
921 	/*
922 	 * Because the policy does not handle LANDLOCK_ACCESS_FS_WRITE_FILE,
923 	 * opening for write-only should be allowed, but not read-write.
924 	 */
925 	ASSERT_EQ(0, test_open(file1_s1d1, O_WRONLY));
926 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
927 
928 	ASSERT_EQ(0, test_open(file1_s1d2, O_WRONLY));
929 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDWR));
930 }
931 
932 TEST_F_FORK(layout1, ruleset_overlap)
933 {
934 	const struct rule rules[] = {
935 		/* These rules should be ORed among them. */
936 		{
937 			.path = dir_s1d2,
938 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
939 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
940 		},
941 		{
942 			.path = dir_s1d2,
943 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
944 				  LANDLOCK_ACCESS_FS_READ_DIR,
945 		},
946 		{},
947 	};
948 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
949 
950 	ASSERT_LE(0, ruleset_fd);
951 	enforce_ruleset(_metadata, ruleset_fd);
952 	ASSERT_EQ(0, close(ruleset_fd));
953 
954 	/* Checks s1d1 hierarchy. */
955 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
956 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
957 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
958 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
959 
960 	/* Checks s1d2 hierarchy. */
961 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
962 	ASSERT_EQ(0, test_open(file1_s1d2, O_WRONLY));
963 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDWR));
964 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
965 
966 	/* Checks s1d3 hierarchy. */
967 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
968 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
969 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
970 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
971 }
972 
973 TEST_F_FORK(layout1, layer_rule_unions)
974 {
975 	const struct rule layer1[] = {
976 		{
977 			.path = dir_s1d2,
978 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
979 		},
980 		/* dir_s1d3 should allow READ_FILE and WRITE_FILE (O_RDWR). */
981 		{
982 			.path = dir_s1d3,
983 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
984 		},
985 		{},
986 	};
987 	const struct rule layer2[] = {
988 		/* Doesn't change anything from layer1. */
989 		{
990 			.path = dir_s1d2,
991 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
992 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
993 		},
994 		{},
995 	};
996 	const struct rule layer3[] = {
997 		/* Only allows write (but not read) to dir_s1d3. */
998 		{
999 			.path = dir_s1d2,
1000 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1001 		},
1002 		{},
1003 	};
1004 	int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1);
1005 
1006 	ASSERT_LE(0, ruleset_fd);
1007 	enforce_ruleset(_metadata, ruleset_fd);
1008 	ASSERT_EQ(0, close(ruleset_fd));
1009 
1010 	/* Checks s1d1 hierarchy with layer1. */
1011 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1012 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1013 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
1014 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1015 
1016 	/* Checks s1d2 hierarchy with layer1. */
1017 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
1018 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1019 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
1020 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1021 
1022 	/* Checks s1d3 hierarchy with layer1. */
1023 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1024 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
1025 	/* dir_s1d3 should allow READ_FILE and WRITE_FILE (O_RDWR). */
1026 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1027 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1028 
1029 	/* Doesn't change anything from layer1. */
1030 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2);
1031 	ASSERT_LE(0, ruleset_fd);
1032 	enforce_ruleset(_metadata, ruleset_fd);
1033 	ASSERT_EQ(0, close(ruleset_fd));
1034 
1035 	/* Checks s1d1 hierarchy with layer2. */
1036 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1037 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1038 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
1039 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1040 
1041 	/* Checks s1d2 hierarchy with layer2. */
1042 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
1043 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1044 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
1045 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1046 
1047 	/* Checks s1d3 hierarchy with layer2. */
1048 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1049 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
1050 	/* dir_s1d3 should allow READ_FILE and WRITE_FILE (O_RDWR). */
1051 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1052 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1053 
1054 	/* Only allows write (but not read) to dir_s1d3. */
1055 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer3);
1056 	ASSERT_LE(0, ruleset_fd);
1057 	enforce_ruleset(_metadata, ruleset_fd);
1058 	ASSERT_EQ(0, close(ruleset_fd));
1059 
1060 	/* Checks s1d1 hierarchy with layer3. */
1061 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1062 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1063 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
1064 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1065 
1066 	/* Checks s1d2 hierarchy with layer3. */
1067 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDONLY));
1068 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1069 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
1070 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1071 
1072 	/* Checks s1d3 hierarchy with layer3. */
1073 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDONLY));
1074 	ASSERT_EQ(0, test_open(file1_s1d3, O_WRONLY));
1075 	/* dir_s1d3 should now deny READ_FILE and WRITE_FILE (O_RDWR). */
1076 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDWR));
1077 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1078 }
1079 
1080 TEST_F_FORK(layout1, non_overlapping_accesses)
1081 {
1082 	const struct rule layer1[] = {
1083 		{
1084 			.path = dir_s1d2,
1085 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
1086 		},
1087 		{},
1088 	};
1089 	const struct rule layer2[] = {
1090 		{
1091 			.path = dir_s1d3,
1092 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
1093 		},
1094 		{},
1095 	};
1096 	int ruleset_fd;
1097 
1098 	ASSERT_EQ(0, unlink(file1_s1d1));
1099 	ASSERT_EQ(0, unlink(file1_s1d2));
1100 
1101 	ruleset_fd =
1102 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, layer1);
1103 	ASSERT_LE(0, ruleset_fd);
1104 	enforce_ruleset(_metadata, ruleset_fd);
1105 	ASSERT_EQ(0, close(ruleset_fd));
1106 
1107 	ASSERT_EQ(-1, mknod(file1_s1d1, S_IFREG | 0700, 0));
1108 	ASSERT_EQ(EACCES, errno);
1109 	ASSERT_EQ(0, mknod(file1_s1d2, S_IFREG | 0700, 0));
1110 	ASSERT_EQ(0, unlink(file1_s1d2));
1111 
1112 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_REMOVE_FILE,
1113 				    layer2);
1114 	ASSERT_LE(0, ruleset_fd);
1115 	enforce_ruleset(_metadata, ruleset_fd);
1116 	ASSERT_EQ(0, close(ruleset_fd));
1117 
1118 	/* Unchanged accesses for file creation. */
1119 	ASSERT_EQ(-1, mknod(file1_s1d1, S_IFREG | 0700, 0));
1120 	ASSERT_EQ(EACCES, errno);
1121 	ASSERT_EQ(0, mknod(file1_s1d2, S_IFREG | 0700, 0));
1122 
1123 	/* Checks file removing. */
1124 	ASSERT_EQ(-1, unlink(file1_s1d2));
1125 	ASSERT_EQ(EACCES, errno);
1126 	ASSERT_EQ(0, unlink(file1_s1d3));
1127 }
1128 
1129 TEST_F_FORK(layout1, interleaved_masked_accesses)
1130 {
1131 	/*
1132 	 * Checks overly restrictive rules:
1133 	 * layer 1: allows R   s1d1/s1d2/s1d3/file1
1134 	 * layer 2: allows RW  s1d1/s1d2/s1d3
1135 	 *          allows  W  s1d1/s1d2
1136 	 *          denies R   s1d1/s1d2
1137 	 * layer 3: allows R   s1d1
1138 	 * layer 4: allows R   s1d1/s1d2
1139 	 *          denies  W  s1d1/s1d2
1140 	 * layer 5: allows R   s1d1/s1d2
1141 	 * layer 6: allows   X ----
1142 	 * layer 7: allows  W  s1d1/s1d2
1143 	 *          denies R   s1d1/s1d2
1144 	 */
1145 	const struct rule layer1_read[] = {
1146 		/* Allows read access to file1_s1d3 with the first layer. */
1147 		{
1148 			.path = file1_s1d3,
1149 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1150 		},
1151 		{},
1152 	};
1153 	/* First rule with write restrictions. */
1154 	const struct rule layer2_read_write[] = {
1155 		/* Start by granting read-write access via its parent directory... */
1156 		{
1157 			.path = dir_s1d3,
1158 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
1159 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
1160 		},
1161 		/* ...but also denies read access via its grandparent directory. */
1162 		{
1163 			.path = dir_s1d2,
1164 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1165 		},
1166 		{},
1167 	};
1168 	const struct rule layer3_read[] = {
1169 		/* Allows read access via its great-grandparent directory. */
1170 		{
1171 			.path = dir_s1d1,
1172 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1173 		},
1174 		{},
1175 	};
1176 	const struct rule layer4_read_write[] = {
1177 		/*
1178 		 * Try to confuse the deny access by denying write (but not
1179 		 * read) access via its grandparent directory.
1180 		 */
1181 		{
1182 			.path = dir_s1d2,
1183 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1184 		},
1185 		{},
1186 	};
1187 	const struct rule layer5_read[] = {
1188 		/*
1189 		 * Try to override layer2's deny read access by explicitly
1190 		 * allowing read access via file1_s1d3's grandparent.
1191 		 */
1192 		{
1193 			.path = dir_s1d2,
1194 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1195 		},
1196 		{},
1197 	};
1198 	const struct rule layer6_execute[] = {
1199 		/*
1200 		 * Restricts an unrelated file hierarchy with a new access
1201 		 * (non-overlapping) type.
1202 		 */
1203 		{
1204 			.path = dir_s2d1,
1205 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
1206 		},
1207 		{},
1208 	};
1209 	const struct rule layer7_read_write[] = {
1210 		/*
1211 		 * Finally, denies read access to file1_s1d3 via its
1212 		 * grandparent.
1213 		 */
1214 		{
1215 			.path = dir_s1d2,
1216 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
1217 		},
1218 		{},
1219 	};
1220 	int ruleset_fd;
1221 
1222 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
1223 				    layer1_read);
1224 	ASSERT_LE(0, ruleset_fd);
1225 	enforce_ruleset(_metadata, ruleset_fd);
1226 	ASSERT_EQ(0, close(ruleset_fd));
1227 
1228 	/* Checks that read access is granted for file1_s1d3 with layer 1. */
1229 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1230 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1231 	ASSERT_EQ(0, test_open(file2_s1d3, O_WRONLY));
1232 
1233 	ruleset_fd = create_ruleset(_metadata,
1234 				    LANDLOCK_ACCESS_FS_READ_FILE |
1235 					    LANDLOCK_ACCESS_FS_WRITE_FILE,
1236 				    layer2_read_write);
1237 	ASSERT_LE(0, ruleset_fd);
1238 	enforce_ruleset(_metadata, ruleset_fd);
1239 	ASSERT_EQ(0, close(ruleset_fd));
1240 
1241 	/* Checks that previous access rights are unchanged with layer 2. */
1242 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1243 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1244 	ASSERT_EQ(0, test_open(file2_s1d3, O_WRONLY));
1245 
1246 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
1247 				    layer3_read);
1248 	ASSERT_LE(0, ruleset_fd);
1249 	enforce_ruleset(_metadata, ruleset_fd);
1250 	ASSERT_EQ(0, close(ruleset_fd));
1251 
1252 	/* Checks that previous access rights are unchanged with layer 3. */
1253 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDWR));
1254 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1255 	ASSERT_EQ(0, test_open(file2_s1d3, O_WRONLY));
1256 
1257 	/* This time, denies write access for the file hierarchy. */
1258 	ruleset_fd = create_ruleset(_metadata,
1259 				    LANDLOCK_ACCESS_FS_READ_FILE |
1260 					    LANDLOCK_ACCESS_FS_WRITE_FILE,
1261 				    layer4_read_write);
1262 	ASSERT_LE(0, ruleset_fd);
1263 	enforce_ruleset(_metadata, ruleset_fd);
1264 	ASSERT_EQ(0, close(ruleset_fd));
1265 
1266 	/*
1267 	 * Checks that the only change with layer 4 is that write access is
1268 	 * denied.
1269 	 */
1270 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1271 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1272 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1273 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1274 
1275 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
1276 				    layer5_read);
1277 	ASSERT_LE(0, ruleset_fd);
1278 	enforce_ruleset(_metadata, ruleset_fd);
1279 	ASSERT_EQ(0, close(ruleset_fd));
1280 
1281 	/* Checks that previous access rights are unchanged with layer 5. */
1282 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1283 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1284 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1285 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1286 
1287 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_EXECUTE,
1288 				    layer6_execute);
1289 	ASSERT_LE(0, ruleset_fd);
1290 	enforce_ruleset(_metadata, ruleset_fd);
1291 	ASSERT_EQ(0, close(ruleset_fd));
1292 
1293 	/* Checks that previous access rights are unchanged with layer 6. */
1294 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1295 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1296 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1297 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1298 
1299 	ruleset_fd = create_ruleset(_metadata,
1300 				    LANDLOCK_ACCESS_FS_READ_FILE |
1301 					    LANDLOCK_ACCESS_FS_WRITE_FILE,
1302 				    layer7_read_write);
1303 	ASSERT_LE(0, ruleset_fd);
1304 	enforce_ruleset(_metadata, ruleset_fd);
1305 	ASSERT_EQ(0, close(ruleset_fd));
1306 
1307 	/* Checks read access is now denied with layer 7. */
1308 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDONLY));
1309 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1310 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_WRONLY));
1311 	ASSERT_EQ(EACCES, test_open(file2_s1d3, O_RDONLY));
1312 }
1313 
1314 TEST_F_FORK(layout1, inherit_subset)
1315 {
1316 	const struct rule rules[] = {
1317 		{
1318 			.path = dir_s1d2,
1319 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
1320 				  LANDLOCK_ACCESS_FS_READ_DIR,
1321 		},
1322 		{},
1323 	};
1324 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1325 
1326 	ASSERT_LE(0, ruleset_fd);
1327 	enforce_ruleset(_metadata, ruleset_fd);
1328 
1329 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1330 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1331 
1332 	/* Write access is forbidden. */
1333 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1334 	/* Readdir access is allowed. */
1335 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1336 
1337 	/* Write access is forbidden. */
1338 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1339 	/* Readdir access is allowed. */
1340 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1341 
1342 	/*
1343 	 * Tests shared rule extension: the following rules should not grant
1344 	 * any new access, only remove some.  Once enforced, these rules are
1345 	 * ANDed with the previous ones.
1346 	 */
1347 	add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_WRITE_FILE,
1348 			 dir_s1d2);
1349 	/*
1350 	 * According to ruleset_fd, dir_s1d2 should now have the
1351 	 * LANDLOCK_ACCESS_FS_READ_FILE and LANDLOCK_ACCESS_FS_WRITE_FILE
1352 	 * access rights (even if this directory is opened a second time).
1353 	 * However, when enforcing this updated ruleset, the ruleset tied to
1354 	 * the current process (i.e. its domain) will still only have the
1355 	 * dir_s1d2 with LANDLOCK_ACCESS_FS_READ_FILE and
1356 	 * LANDLOCK_ACCESS_FS_READ_DIR accesses, but
1357 	 * LANDLOCK_ACCESS_FS_WRITE_FILE must not be allowed because it would
1358 	 * be a privilege escalation.
1359 	 */
1360 	enforce_ruleset(_metadata, ruleset_fd);
1361 
1362 	/* Same tests and results as above. */
1363 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1364 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1365 
1366 	/* It is still forbidden to write in file1_s1d2. */
1367 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1368 	/* Readdir access is still allowed. */
1369 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1370 
1371 	/* It is still forbidden to write in file1_s1d3. */
1372 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1373 	/* Readdir access is still allowed. */
1374 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1375 
1376 	/*
1377 	 * Try to get more privileges by adding new access rights to the parent
1378 	 * directory: dir_s1d1.
1379 	 */
1380 	add_path_beneath(_metadata, ruleset_fd, ACCESS_RW, dir_s1d1);
1381 	enforce_ruleset(_metadata, ruleset_fd);
1382 
1383 	/* Same tests and results as above. */
1384 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1385 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1386 
1387 	/* It is still forbidden to write in file1_s1d2. */
1388 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1389 	/* Readdir access is still allowed. */
1390 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1391 
1392 	/* It is still forbidden to write in file1_s1d3. */
1393 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1394 	/* Readdir access is still allowed. */
1395 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1396 
1397 	/*
1398 	 * Now, dir_s1d3 get a new rule tied to it, only allowing
1399 	 * LANDLOCK_ACCESS_FS_WRITE_FILE.  The (kernel internal) difference is
1400 	 * that there was no rule tied to it before.
1401 	 */
1402 	add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_WRITE_FILE,
1403 			 dir_s1d3);
1404 	enforce_ruleset(_metadata, ruleset_fd);
1405 	ASSERT_EQ(0, close(ruleset_fd));
1406 
1407 	/*
1408 	 * Same tests and results as above, except for open(dir_s1d3) which is
1409 	 * now denied because the new rule mask the rule previously inherited
1410 	 * from dir_s1d2.
1411 	 */
1412 
1413 	/* Same tests and results as above. */
1414 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
1415 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
1416 
1417 	/* It is still forbidden to write in file1_s1d2. */
1418 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
1419 	/* Readdir access is still allowed. */
1420 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1421 
1422 	/* It is still forbidden to write in file1_s1d3. */
1423 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
1424 	/*
1425 	 * Readdir of dir_s1d3 is still allowed because of the OR policy inside
1426 	 * the same layer.
1427 	 */
1428 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1429 }
1430 
1431 TEST_F_FORK(layout1, inherit_superset)
1432 {
1433 	const struct rule rules[] = {
1434 		{
1435 			.path = dir_s1d3,
1436 			.access = ACCESS_RO,
1437 		},
1438 		{},
1439 	};
1440 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1441 
1442 	ASSERT_LE(0, ruleset_fd);
1443 	enforce_ruleset(_metadata, ruleset_fd);
1444 
1445 	/* Readdir access is denied for dir_s1d2. */
1446 	ASSERT_EQ(EACCES, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1447 	/* Readdir access is allowed for dir_s1d3. */
1448 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1449 	/* File access is allowed for file1_s1d3. */
1450 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1451 
1452 	/* Now dir_s1d2, parent of dir_s1d3, gets a new rule tied to it. */
1453 	add_path_beneath(_metadata, ruleset_fd,
1454 			 LANDLOCK_ACCESS_FS_READ_FILE |
1455 				 LANDLOCK_ACCESS_FS_READ_DIR,
1456 			 dir_s1d2);
1457 	enforce_ruleset(_metadata, ruleset_fd);
1458 	ASSERT_EQ(0, close(ruleset_fd));
1459 
1460 	/* Readdir access is still denied for dir_s1d2. */
1461 	ASSERT_EQ(EACCES, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
1462 	/* Readdir access is still allowed for dir_s1d3. */
1463 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
1464 	/* File access is still allowed for file1_s1d3. */
1465 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
1466 }
1467 
1468 TEST_F_FORK(layout0, max_layers)
1469 {
1470 	int i, err;
1471 	const struct rule rules[] = {
1472 		{
1473 			.path = TMP_DIR,
1474 			.access = ACCESS_RO,
1475 		},
1476 		{},
1477 	};
1478 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1479 
1480 	ASSERT_LE(0, ruleset_fd);
1481 	for (i = 0; i < 16; i++)
1482 		enforce_ruleset(_metadata, ruleset_fd);
1483 
1484 	for (i = 0; i < 2; i++) {
1485 		err = landlock_restrict_self(ruleset_fd, 0);
1486 		ASSERT_EQ(-1, err);
1487 		ASSERT_EQ(E2BIG, errno);
1488 	}
1489 	ASSERT_EQ(0, close(ruleset_fd));
1490 }
1491 
1492 TEST_F_FORK(layout1, empty_or_same_ruleset)
1493 {
1494 	struct landlock_ruleset_attr ruleset_attr = {};
1495 	int ruleset_fd;
1496 
1497 	/* Tests empty handled_access_fs. */
1498 	ruleset_fd =
1499 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
1500 	ASSERT_LE(-1, ruleset_fd);
1501 	ASSERT_EQ(ENOMSG, errno);
1502 
1503 	/* Enforces policy which deny read access to all files. */
1504 	ruleset_attr.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE;
1505 	ruleset_fd =
1506 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
1507 	ASSERT_LE(0, ruleset_fd);
1508 	enforce_ruleset(_metadata, ruleset_fd);
1509 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1510 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1511 
1512 	/* Nests a policy which deny read access to all directories. */
1513 	ruleset_attr.handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR;
1514 	ruleset_fd =
1515 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
1516 	ASSERT_LE(0, ruleset_fd);
1517 	enforce_ruleset(_metadata, ruleset_fd);
1518 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
1519 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
1520 
1521 	/* Enforces a second time with the same ruleset. */
1522 	enforce_ruleset(_metadata, ruleset_fd);
1523 	ASSERT_EQ(0, close(ruleset_fd));
1524 }
1525 
1526 TEST_F_FORK(layout1, rule_on_mountpoint)
1527 {
1528 	const struct rule rules[] = {
1529 		{
1530 			.path = dir_s1d1,
1531 			.access = ACCESS_RO,
1532 		},
1533 		{
1534 			/* dir_s3d2 is a mount point. */
1535 			.path = dir_s3d2,
1536 			.access = ACCESS_RO,
1537 		},
1538 		{},
1539 	};
1540 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1541 
1542 	ASSERT_LE(0, ruleset_fd);
1543 	enforce_ruleset(_metadata, ruleset_fd);
1544 	ASSERT_EQ(0, close(ruleset_fd));
1545 
1546 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1547 
1548 	ASSERT_EQ(EACCES, test_open(dir_s2d1, O_RDONLY));
1549 
1550 	ASSERT_EQ(EACCES, test_open(dir_s3d1, O_RDONLY));
1551 	ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY));
1552 	ASSERT_EQ(0, test_open(dir_s3d3, O_RDONLY));
1553 }
1554 
1555 TEST_F_FORK(layout1, rule_over_mountpoint)
1556 {
1557 	const struct rule rules[] = {
1558 		{
1559 			.path = dir_s1d1,
1560 			.access = ACCESS_RO,
1561 		},
1562 		{
1563 			/* dir_s3d2 is a mount point. */
1564 			.path = dir_s3d1,
1565 			.access = ACCESS_RO,
1566 		},
1567 		{},
1568 	};
1569 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1570 
1571 	ASSERT_LE(0, ruleset_fd);
1572 	enforce_ruleset(_metadata, ruleset_fd);
1573 	ASSERT_EQ(0, close(ruleset_fd));
1574 
1575 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1576 
1577 	ASSERT_EQ(EACCES, test_open(dir_s2d1, O_RDONLY));
1578 
1579 	ASSERT_EQ(0, test_open(dir_s3d1, O_RDONLY));
1580 	ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY));
1581 	ASSERT_EQ(0, test_open(dir_s3d3, O_RDONLY));
1582 }
1583 
1584 /*
1585  * This test verifies that we can apply a landlock rule on the root directory
1586  * (which might require special handling).
1587  */
1588 TEST_F_FORK(layout1, rule_over_root_allow_then_deny)
1589 {
1590 	struct rule rules[] = {
1591 		{
1592 			.path = "/",
1593 			.access = ACCESS_RO,
1594 		},
1595 		{},
1596 	};
1597 	int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1598 
1599 	ASSERT_LE(0, ruleset_fd);
1600 	enforce_ruleset(_metadata, ruleset_fd);
1601 	ASSERT_EQ(0, close(ruleset_fd));
1602 
1603 	/* Checks allowed access. */
1604 	ASSERT_EQ(0, test_open("/", O_RDONLY));
1605 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
1606 
1607 	rules[0].access = LANDLOCK_ACCESS_FS_READ_FILE;
1608 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1609 	ASSERT_LE(0, ruleset_fd);
1610 	enforce_ruleset(_metadata, ruleset_fd);
1611 	ASSERT_EQ(0, close(ruleset_fd));
1612 
1613 	/* Checks denied access (on a directory). */
1614 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
1615 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
1616 }
1617 
1618 TEST_F_FORK(layout1, rule_over_root_deny)
1619 {
1620 	const struct rule rules[] = {
1621 		{
1622 			.path = "/",
1623 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
1624 		},
1625 		{},
1626 	};
1627 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1628 
1629 	ASSERT_LE(0, ruleset_fd);
1630 	enforce_ruleset(_metadata, ruleset_fd);
1631 	ASSERT_EQ(0, close(ruleset_fd));
1632 
1633 	/* Checks denied access (on a directory). */
1634 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
1635 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY));
1636 }
1637 
1638 TEST_F_FORK(layout1, rule_inside_mount_ns)
1639 {
1640 	const struct rule rules[] = {
1641 		{
1642 			.path = "s3d3",
1643 			.access = ACCESS_RO,
1644 		},
1645 		{},
1646 	};
1647 	int ruleset_fd;
1648 
1649 	set_cap(_metadata, CAP_SYS_ADMIN);
1650 	ASSERT_EQ(0, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3))
1651 	{
1652 		TH_LOG("Failed to pivot root: %s", strerror(errno));
1653 	};
1654 	ASSERT_EQ(0, chdir("/"));
1655 	clear_cap(_metadata, CAP_SYS_ADMIN);
1656 
1657 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1658 	ASSERT_LE(0, ruleset_fd);
1659 	enforce_ruleset(_metadata, ruleset_fd);
1660 	ASSERT_EQ(0, close(ruleset_fd));
1661 
1662 	ASSERT_EQ(0, test_open("s3d3", O_RDONLY));
1663 	ASSERT_EQ(EACCES, test_open("/", O_RDONLY));
1664 }
1665 
1666 TEST_F_FORK(layout1, mount_and_pivot)
1667 {
1668 	const struct rule rules[] = {
1669 		{
1670 			.path = dir_s3d2,
1671 			.access = ACCESS_RO,
1672 		},
1673 		{},
1674 	};
1675 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1676 
1677 	ASSERT_LE(0, ruleset_fd);
1678 	enforce_ruleset(_metadata, ruleset_fd);
1679 	ASSERT_EQ(0, close(ruleset_fd));
1680 
1681 	set_cap(_metadata, CAP_SYS_ADMIN);
1682 	ASSERT_EQ(-1, mount(NULL, dir_s3d2, NULL, MS_RDONLY, NULL));
1683 	ASSERT_EQ(EPERM, errno);
1684 	ASSERT_EQ(-1, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3));
1685 	ASSERT_EQ(EPERM, errno);
1686 	clear_cap(_metadata, CAP_SYS_ADMIN);
1687 }
1688 
1689 TEST_F_FORK(layout1, move_mount)
1690 {
1691 	const struct rule rules[] = {
1692 		{
1693 			.path = dir_s3d2,
1694 			.access = ACCESS_RO,
1695 		},
1696 		{},
1697 	};
1698 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1699 
1700 	ASSERT_LE(0, ruleset_fd);
1701 
1702 	set_cap(_metadata, CAP_SYS_ADMIN);
1703 	ASSERT_EQ(0, syscall(__NR_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
1704 			     dir_s1d2, 0))
1705 	{
1706 		TH_LOG("Failed to move mount: %s", strerror(errno));
1707 	}
1708 
1709 	ASSERT_EQ(0, syscall(__NR_move_mount, AT_FDCWD, dir_s1d2, AT_FDCWD,
1710 			     dir_s3d2, 0));
1711 	clear_cap(_metadata, CAP_SYS_ADMIN);
1712 
1713 	enforce_ruleset(_metadata, ruleset_fd);
1714 	ASSERT_EQ(0, close(ruleset_fd));
1715 
1716 	set_cap(_metadata, CAP_SYS_ADMIN);
1717 	ASSERT_EQ(-1, syscall(__NR_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
1718 			      dir_s1d2, 0));
1719 	ASSERT_EQ(EPERM, errno);
1720 	clear_cap(_metadata, CAP_SYS_ADMIN);
1721 }
1722 
1723 TEST_F_FORK(layout1, topology_changes_with_net_only)
1724 {
1725 	const struct landlock_ruleset_attr ruleset_net = {
1726 		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
1727 				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
1728 	};
1729 	int ruleset_fd;
1730 
1731 	/* Add network restrictions. */
1732 	ruleset_fd =
1733 		landlock_create_ruleset(&ruleset_net, sizeof(ruleset_net), 0);
1734 	ASSERT_LE(0, ruleset_fd);
1735 	enforce_ruleset(_metadata, ruleset_fd);
1736 	ASSERT_EQ(0, close(ruleset_fd));
1737 
1738 	/* Mount, remount, move_mount, umount, and pivot_root checks. */
1739 	set_cap(_metadata, CAP_SYS_ADMIN);
1740 	ASSERT_EQ(0, mount_opt(&mnt_tmp, dir_s1d2));
1741 	ASSERT_EQ(0, mount(NULL, dir_s1d2, NULL, MS_PRIVATE | MS_REC, NULL));
1742 	ASSERT_EQ(0, syscall(__NR_move_mount, AT_FDCWD, dir_s1d2, AT_FDCWD,
1743 			     dir_s2d2, 0));
1744 	ASSERT_EQ(0, umount(dir_s2d2));
1745 	ASSERT_EQ(0, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3));
1746 	ASSERT_EQ(0, chdir("/"));
1747 	clear_cap(_metadata, CAP_SYS_ADMIN);
1748 }
1749 
1750 TEST_F_FORK(layout1, topology_changes_with_net_and_fs)
1751 {
1752 	const struct landlock_ruleset_attr ruleset_net_fs = {
1753 		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
1754 				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
1755 		.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
1756 	};
1757 	int ruleset_fd;
1758 
1759 	/* Add network and filesystem restrictions. */
1760 	ruleset_fd = landlock_create_ruleset(&ruleset_net_fs,
1761 					     sizeof(ruleset_net_fs), 0);
1762 	ASSERT_LE(0, ruleset_fd);
1763 	enforce_ruleset(_metadata, ruleset_fd);
1764 	ASSERT_EQ(0, close(ruleset_fd));
1765 
1766 	/* Mount, remount, move_mount, umount, and pivot_root checks. */
1767 	set_cap(_metadata, CAP_SYS_ADMIN);
1768 	ASSERT_EQ(-1, mount_opt(&mnt_tmp, dir_s1d2));
1769 	ASSERT_EQ(EPERM, errno);
1770 	ASSERT_EQ(-1, mount(NULL, dir_s3d2, NULL, MS_PRIVATE | MS_REC, NULL));
1771 	ASSERT_EQ(EPERM, errno);
1772 	ASSERT_EQ(-1, syscall(__NR_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
1773 			      dir_s2d2, 0));
1774 	ASSERT_EQ(EPERM, errno);
1775 	ASSERT_EQ(-1, umount(dir_s3d2));
1776 	ASSERT_EQ(EPERM, errno);
1777 	ASSERT_EQ(-1, syscall(__NR_pivot_root, dir_s3d2, dir_s3d3));
1778 	ASSERT_EQ(EPERM, errno);
1779 	clear_cap(_metadata, CAP_SYS_ADMIN);
1780 }
1781 
1782 TEST_F_FORK(layout1, release_inodes)
1783 {
1784 	const struct rule rules[] = {
1785 		{
1786 			.path = dir_s1d1,
1787 			.access = ACCESS_RO,
1788 		},
1789 		{
1790 			.path = dir_s3d2,
1791 			.access = ACCESS_RO,
1792 		},
1793 		{
1794 			.path = dir_s3d3,
1795 			.access = ACCESS_RO,
1796 		},
1797 		{},
1798 	};
1799 	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
1800 
1801 	ASSERT_LE(0, ruleset_fd);
1802 	/* Unmount a file hierarchy while it is being used by a ruleset. */
1803 	set_cap(_metadata, CAP_SYS_ADMIN);
1804 	ASSERT_EQ(0, umount(dir_s3d2));
1805 	clear_cap(_metadata, CAP_SYS_ADMIN);
1806 
1807 	enforce_ruleset(_metadata, ruleset_fd);
1808 	ASSERT_EQ(0, close(ruleset_fd));
1809 
1810 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
1811 	ASSERT_EQ(EACCES, test_open(dir_s3d2, O_RDONLY));
1812 	/* This dir_s3d3 would not be allowed and does not exist anyway. */
1813 	ASSERT_EQ(ENOENT, test_open(dir_s3d3, O_RDONLY));
1814 }
1815 
1816 enum relative_access {
1817 	REL_OPEN,
1818 	REL_CHDIR,
1819 	REL_CHROOT_ONLY,
1820 	REL_CHROOT_CHDIR,
1821 };
1822 
1823 static void test_relative_path(struct __test_metadata *const _metadata,
1824 			       const enum relative_access rel)
1825 {
1826 	/*
1827 	 * Common layer to check that chroot doesn't ignore it (i.e. a chroot
1828 	 * is not a disconnected root directory).
1829 	 */
1830 	const struct rule layer1_base[] = {
1831 		{
1832 			.path = TMP_DIR,
1833 			.access = ACCESS_RO,
1834 		},
1835 		{},
1836 	};
1837 	const struct rule layer2_subs[] = {
1838 		{
1839 			.path = dir_s1d2,
1840 			.access = ACCESS_RO,
1841 		},
1842 		{
1843 			.path = dir_s2d2,
1844 			.access = ACCESS_RO,
1845 		},
1846 		{},
1847 	};
1848 	int dirfd, ruleset_fd;
1849 
1850 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_base);
1851 	ASSERT_LE(0, ruleset_fd);
1852 	enforce_ruleset(_metadata, ruleset_fd);
1853 	ASSERT_EQ(0, close(ruleset_fd));
1854 
1855 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2_subs);
1856 
1857 	ASSERT_LE(0, ruleset_fd);
1858 	switch (rel) {
1859 	case REL_OPEN:
1860 	case REL_CHDIR:
1861 		break;
1862 	case REL_CHROOT_ONLY:
1863 		ASSERT_EQ(0, chdir(dir_s2d2));
1864 		break;
1865 	case REL_CHROOT_CHDIR:
1866 		ASSERT_EQ(0, chdir(dir_s1d2));
1867 		break;
1868 	default:
1869 		ASSERT_TRUE(false);
1870 		return;
1871 	}
1872 
1873 	set_cap(_metadata, CAP_SYS_CHROOT);
1874 	enforce_ruleset(_metadata, ruleset_fd);
1875 
1876 	switch (rel) {
1877 	case REL_OPEN:
1878 		dirfd = open(dir_s1d2, O_DIRECTORY);
1879 		ASSERT_LE(0, dirfd);
1880 		break;
1881 	case REL_CHDIR:
1882 		ASSERT_EQ(0, chdir(dir_s1d2));
1883 		dirfd = AT_FDCWD;
1884 		break;
1885 	case REL_CHROOT_ONLY:
1886 		/* Do chroot into dir_s1d2 (relative to dir_s2d2). */
1887 		ASSERT_EQ(0, chroot("../../s1d1/s1d2"))
1888 		{
1889 			TH_LOG("Failed to chroot: %s", strerror(errno));
1890 		}
1891 		dirfd = AT_FDCWD;
1892 		break;
1893 	case REL_CHROOT_CHDIR:
1894 		/* Do chroot into dir_s1d2. */
1895 		ASSERT_EQ(0, chroot("."))
1896 		{
1897 			TH_LOG("Failed to chroot: %s", strerror(errno));
1898 		}
1899 		dirfd = AT_FDCWD;
1900 		break;
1901 	}
1902 
1903 	ASSERT_EQ((rel == REL_CHROOT_CHDIR) ? 0 : EACCES,
1904 		  test_open_rel(dirfd, "..", O_RDONLY));
1905 	ASSERT_EQ(0, test_open_rel(dirfd, ".", O_RDONLY));
1906 
1907 	if (rel == REL_CHROOT_ONLY) {
1908 		/* The current directory is dir_s2d2. */
1909 		ASSERT_EQ(0, test_open_rel(dirfd, "./s2d3", O_RDONLY));
1910 	} else {
1911 		/* The current directory is dir_s1d2. */
1912 		ASSERT_EQ(0, test_open_rel(dirfd, "./s1d3", O_RDONLY));
1913 	}
1914 
1915 	if (rel == REL_CHROOT_ONLY || rel == REL_CHROOT_CHDIR) {
1916 		/* Checks the root dir_s1d2. */
1917 		ASSERT_EQ(0, test_open_rel(dirfd, "/..", O_RDONLY));
1918 		ASSERT_EQ(0, test_open_rel(dirfd, "/", O_RDONLY));
1919 		ASSERT_EQ(0, test_open_rel(dirfd, "/f1", O_RDONLY));
1920 		ASSERT_EQ(0, test_open_rel(dirfd, "/s1d3", O_RDONLY));
1921 	}
1922 
1923 	if (rel != REL_CHROOT_CHDIR) {
1924 		ASSERT_EQ(EACCES, test_open_rel(dirfd, "../../s1d1", O_RDONLY));
1925 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s1d1/s1d2", O_RDONLY));
1926 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s1d1/s1d2/s1d3",
1927 					   O_RDONLY));
1928 
1929 		ASSERT_EQ(EACCES, test_open_rel(dirfd, "../../s2d1", O_RDONLY));
1930 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s2d1/s2d2", O_RDONLY));
1931 		ASSERT_EQ(0, test_open_rel(dirfd, "../../s2d1/s2d2/s2d3",
1932 					   O_RDONLY));
1933 	}
1934 
1935 	if (rel == REL_OPEN)
1936 		ASSERT_EQ(0, close(dirfd));
1937 	ASSERT_EQ(0, close(ruleset_fd));
1938 }
1939 
1940 TEST_F_FORK(layout1, relative_open)
1941 {
1942 	test_relative_path(_metadata, REL_OPEN);
1943 }
1944 
1945 TEST_F_FORK(layout1, relative_chdir)
1946 {
1947 	test_relative_path(_metadata, REL_CHDIR);
1948 }
1949 
1950 TEST_F_FORK(layout1, relative_chroot_only)
1951 {
1952 	test_relative_path(_metadata, REL_CHROOT_ONLY);
1953 }
1954 
1955 TEST_F_FORK(layout1, relative_chroot_chdir)
1956 {
1957 	test_relative_path(_metadata, REL_CHROOT_CHDIR);
1958 }
1959 
1960 static void copy_binary(struct __test_metadata *const _metadata,
1961 			const char *const dst_path)
1962 {
1963 	int dst_fd, src_fd;
1964 	struct stat statbuf;
1965 
1966 	dst_fd = open(dst_path, O_WRONLY | O_TRUNC | O_CLOEXEC);
1967 	ASSERT_LE(0, dst_fd)
1968 	{
1969 		TH_LOG("Failed to open \"%s\": %s", dst_path, strerror(errno));
1970 	}
1971 	src_fd = open(BINARY_PATH, O_RDONLY | O_CLOEXEC);
1972 	ASSERT_LE(0, src_fd)
1973 	{
1974 		TH_LOG("Failed to open \"" BINARY_PATH "\": %s",
1975 		       strerror(errno));
1976 	}
1977 	ASSERT_EQ(0, fstat(src_fd, &statbuf));
1978 	ASSERT_EQ(statbuf.st_size,
1979 		  sendfile(dst_fd, src_fd, 0, statbuf.st_size));
1980 	ASSERT_EQ(0, close(src_fd));
1981 	ASSERT_EQ(0, close(dst_fd));
1982 }
1983 
1984 static void test_execute(struct __test_metadata *const _metadata, const int err,
1985 			 const char *const path)
1986 {
1987 	int status;
1988 	char *const argv[] = { (char *)path, NULL };
1989 	const pid_t child = fork();
1990 
1991 	ASSERT_LE(0, child);
1992 	if (child == 0) {
1993 		ASSERT_EQ(err ? -1 : 0, execve(path, argv, NULL))
1994 		{
1995 			TH_LOG("Failed to execute \"%s\": %s", path,
1996 			       strerror(errno));
1997 		};
1998 		ASSERT_EQ(err, errno);
1999 		_exit(__test_passed(_metadata) ? 2 : 1);
2000 		return;
2001 	}
2002 	ASSERT_EQ(child, waitpid(child, &status, 0));
2003 	ASSERT_EQ(1, WIFEXITED(status));
2004 	ASSERT_EQ(err ? 2 : 0, WEXITSTATUS(status))
2005 	{
2006 		TH_LOG("Unexpected return code for \"%s\": %s", path,
2007 		       strerror(errno));
2008 	};
2009 }
2010 
2011 TEST_F_FORK(layout1, execute)
2012 {
2013 	const struct rule rules[] = {
2014 		{
2015 			.path = dir_s1d2,
2016 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
2017 		},
2018 		{},
2019 	};
2020 	const int ruleset_fd =
2021 		create_ruleset(_metadata, rules[0].access, rules);
2022 
2023 	ASSERT_LE(0, ruleset_fd);
2024 	copy_binary(_metadata, file1_s1d1);
2025 	copy_binary(_metadata, file1_s1d2);
2026 	copy_binary(_metadata, file1_s1d3);
2027 
2028 	enforce_ruleset(_metadata, ruleset_fd);
2029 	ASSERT_EQ(0, close(ruleset_fd));
2030 
2031 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
2032 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
2033 	test_execute(_metadata, EACCES, file1_s1d1);
2034 
2035 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
2036 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
2037 	test_execute(_metadata, 0, file1_s1d2);
2038 
2039 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
2040 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
2041 	test_execute(_metadata, 0, file1_s1d3);
2042 }
2043 
2044 TEST_F_FORK(layout1, link)
2045 {
2046 	const struct rule layer1[] = {
2047 		{
2048 			.path = dir_s1d2,
2049 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2050 		},
2051 		{},
2052 	};
2053 	const struct rule layer2[] = {
2054 		{
2055 			.path = dir_s1d3,
2056 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2057 		},
2058 		{},
2059 	};
2060 	int ruleset_fd = create_ruleset(_metadata, layer1[0].access, layer1);
2061 
2062 	ASSERT_LE(0, ruleset_fd);
2063 
2064 	ASSERT_EQ(0, unlink(file1_s1d1));
2065 	ASSERT_EQ(0, unlink(file1_s1d2));
2066 	ASSERT_EQ(0, unlink(file1_s1d3));
2067 
2068 	enforce_ruleset(_metadata, ruleset_fd);
2069 	ASSERT_EQ(0, close(ruleset_fd));
2070 
2071 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
2072 	ASSERT_EQ(EACCES, errno);
2073 
2074 	/* Denies linking because of reparenting. */
2075 	ASSERT_EQ(-1, link(file1_s2d1, file1_s1d2));
2076 	ASSERT_EQ(EXDEV, errno);
2077 	ASSERT_EQ(-1, link(file2_s1d2, file1_s1d3));
2078 	ASSERT_EQ(EXDEV, errno);
2079 	ASSERT_EQ(-1, link(file2_s1d3, file1_s1d2));
2080 	ASSERT_EQ(EXDEV, errno);
2081 
2082 	ASSERT_EQ(0, link(file2_s1d2, file1_s1d2));
2083 	ASSERT_EQ(0, link(file2_s1d3, file1_s1d3));
2084 
2085 	/* Prepares for next unlinks. */
2086 	ASSERT_EQ(0, unlink(file2_s1d2));
2087 	ASSERT_EQ(0, unlink(file2_s1d3));
2088 
2089 	ruleset_fd = create_ruleset(_metadata, layer2[0].access, layer2);
2090 	ASSERT_LE(0, ruleset_fd);
2091 	enforce_ruleset(_metadata, ruleset_fd);
2092 	ASSERT_EQ(0, close(ruleset_fd));
2093 
2094 	/* Checks that linkind doesn't require the ability to delete a file. */
2095 	ASSERT_EQ(0, link(file1_s1d2, file2_s1d2));
2096 	ASSERT_EQ(0, link(file1_s1d3, file2_s1d3));
2097 }
2098 
2099 static int test_rename(const char *const oldpath, const char *const newpath)
2100 {
2101 	if (rename(oldpath, newpath))
2102 		return errno;
2103 	return 0;
2104 }
2105 
2106 static int test_exchange(const char *const oldpath, const char *const newpath)
2107 {
2108 	if (renameat2(AT_FDCWD, oldpath, AT_FDCWD, newpath, RENAME_EXCHANGE))
2109 		return errno;
2110 	return 0;
2111 }
2112 
2113 TEST_F_FORK(layout1, rename_file)
2114 {
2115 	const struct rule rules[] = {
2116 		{
2117 			.path = dir_s1d3,
2118 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2119 		},
2120 		{
2121 			.path = dir_s2d2,
2122 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2123 		},
2124 		{},
2125 	};
2126 	const int ruleset_fd =
2127 		create_ruleset(_metadata, rules[0].access, rules);
2128 
2129 	ASSERT_LE(0, ruleset_fd);
2130 
2131 	ASSERT_EQ(0, unlink(file1_s1d2));
2132 
2133 	enforce_ruleset(_metadata, ruleset_fd);
2134 	ASSERT_EQ(0, close(ruleset_fd));
2135 
2136 	/*
2137 	 * Tries to replace a file, from a directory that allows file removal,
2138 	 * but to a different directory (which also allows file removal).
2139 	 */
2140 	ASSERT_EQ(-1, rename(file1_s2d3, file1_s1d3));
2141 	ASSERT_EQ(EXDEV, errno);
2142 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, file1_s1d3,
2143 				RENAME_EXCHANGE));
2144 	ASSERT_EQ(EXDEV, errno);
2145 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, dir_s1d3,
2146 				RENAME_EXCHANGE));
2147 	ASSERT_EQ(EXDEV, errno);
2148 
2149 	/*
2150 	 * Tries to replace a file, from a directory that denies file removal,
2151 	 * to a different directory (which allows file removal).
2152 	 */
2153 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
2154 	ASSERT_EQ(EACCES, errno);
2155 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, file1_s1d3,
2156 				RENAME_EXCHANGE));
2157 	ASSERT_EQ(EACCES, errno);
2158 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d2, AT_FDCWD, file1_s1d3,
2159 				RENAME_EXCHANGE));
2160 	ASSERT_EQ(EXDEV, errno);
2161 
2162 	/* Exchanges files and directories that partially allow removal. */
2163 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d2, AT_FDCWD, file1_s2d1,
2164 				RENAME_EXCHANGE));
2165 	ASSERT_EQ(EACCES, errno);
2166 	/* Checks that file1_s2d1 cannot be removed (instead of ENOTDIR). */
2167 	ASSERT_EQ(-1, rename(dir_s2d2, file1_s2d1));
2168 	ASSERT_EQ(EACCES, errno);
2169 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, dir_s2d2,
2170 				RENAME_EXCHANGE));
2171 	ASSERT_EQ(EACCES, errno);
2172 	/* Checks that file1_s1d1 cannot be removed (instead of EISDIR). */
2173 	ASSERT_EQ(-1, rename(file1_s1d1, dir_s1d2));
2174 	ASSERT_EQ(EACCES, errno);
2175 
2176 	/* Renames files with different parents. */
2177 	ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d2));
2178 	ASSERT_EQ(EXDEV, errno);
2179 	ASSERT_EQ(0, unlink(file1_s1d3));
2180 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
2181 	ASSERT_EQ(EACCES, errno);
2182 
2183 	/* Exchanges and renames files with same parent. */
2184 	ASSERT_EQ(0, renameat2(AT_FDCWD, file2_s2d3, AT_FDCWD, file1_s2d3,
2185 			       RENAME_EXCHANGE));
2186 	ASSERT_EQ(0, rename(file2_s2d3, file1_s2d3));
2187 
2188 	/* Exchanges files and directories with same parent, twice. */
2189 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s2d3,
2190 			       RENAME_EXCHANGE));
2191 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s2d3,
2192 			       RENAME_EXCHANGE));
2193 }
2194 
2195 TEST_F_FORK(layout1, rename_dir)
2196 {
2197 	const struct rule rules[] = {
2198 		{
2199 			.path = dir_s1d2,
2200 			.access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
2201 		},
2202 		{
2203 			.path = dir_s2d1,
2204 			.access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
2205 		},
2206 		{},
2207 	};
2208 	const int ruleset_fd =
2209 		create_ruleset(_metadata, rules[0].access, rules);
2210 
2211 	ASSERT_LE(0, ruleset_fd);
2212 
2213 	/* Empties dir_s1d3 to allow renaming. */
2214 	ASSERT_EQ(0, unlink(file1_s1d3));
2215 	ASSERT_EQ(0, unlink(file2_s1d3));
2216 
2217 	enforce_ruleset(_metadata, ruleset_fd);
2218 	ASSERT_EQ(0, close(ruleset_fd));
2219 
2220 	/* Exchanges and renames directory to a different parent. */
2221 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_s1d3,
2222 				RENAME_EXCHANGE));
2223 	ASSERT_EQ(EXDEV, errno);
2224 	ASSERT_EQ(-1, rename(dir_s2d3, dir_s1d3));
2225 	ASSERT_EQ(EXDEV, errno);
2226 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s1d3,
2227 				RENAME_EXCHANGE));
2228 	ASSERT_EQ(EXDEV, errno);
2229 
2230 	/*
2231 	 * Exchanges directory to the same parent, which doesn't allow
2232 	 * directory removal.
2233 	 */
2234 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s1d1, AT_FDCWD, dir_s2d1,
2235 				RENAME_EXCHANGE));
2236 	ASSERT_EQ(EACCES, errno);
2237 	/* Checks that dir_s1d2 cannot be removed (instead of ENOTDIR). */
2238 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s1d1));
2239 	ASSERT_EQ(EACCES, errno);
2240 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, dir_s1d2,
2241 				RENAME_EXCHANGE));
2242 	ASSERT_EQ(EACCES, errno);
2243 	/* Checks that dir_s1d2 cannot be removed (instead of EISDIR). */
2244 	ASSERT_EQ(-1, rename(file1_s1d1, dir_s1d2));
2245 	ASSERT_EQ(EACCES, errno);
2246 
2247 	/*
2248 	 * Exchanges and renames directory to the same parent, which allows
2249 	 * directory removal.
2250 	 */
2251 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, file1_s1d2,
2252 			       RENAME_EXCHANGE));
2253 	ASSERT_EQ(0, unlink(dir_s1d3));
2254 	ASSERT_EQ(0, mkdir(dir_s1d3, 0700));
2255 	ASSERT_EQ(0, rename(file1_s1d2, dir_s1d3));
2256 	ASSERT_EQ(0, rmdir(dir_s1d3));
2257 }
2258 
2259 TEST_F_FORK(layout1, reparent_refer)
2260 {
2261 	const struct rule layer1[] = {
2262 		{
2263 			.path = dir_s1d2,
2264 			.access = LANDLOCK_ACCESS_FS_REFER,
2265 		},
2266 		{
2267 			.path = dir_s2d2,
2268 			.access = LANDLOCK_ACCESS_FS_REFER,
2269 		},
2270 		{},
2271 	};
2272 	int ruleset_fd =
2273 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_REFER, layer1);
2274 
2275 	ASSERT_LE(0, ruleset_fd);
2276 	enforce_ruleset(_metadata, ruleset_fd);
2277 	ASSERT_EQ(0, close(ruleset_fd));
2278 
2279 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d1));
2280 	ASSERT_EQ(EXDEV, errno);
2281 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d2));
2282 	ASSERT_EQ(EXDEV, errno);
2283 	ASSERT_EQ(-1, rename(dir_s1d2, dir_s2d3));
2284 	ASSERT_EQ(EXDEV, errno);
2285 
2286 	ASSERT_EQ(-1, rename(dir_s1d3, dir_s2d1));
2287 	ASSERT_EQ(EXDEV, errno);
2288 	ASSERT_EQ(-1, rename(dir_s1d3, dir_s2d2));
2289 	ASSERT_EQ(EXDEV, errno);
2290 	/*
2291 	 * Moving should only be allowed when the source and the destination
2292 	 * parent directory have REFER.
2293 	 */
2294 	ASSERT_EQ(-1, rename(dir_s1d3, dir_s2d3));
2295 	ASSERT_EQ(ENOTEMPTY, errno);
2296 	ASSERT_EQ(0, unlink(file1_s2d3));
2297 	ASSERT_EQ(0, unlink(file2_s2d3));
2298 	ASSERT_EQ(0, rename(dir_s1d3, dir_s2d3));
2299 }
2300 
2301 /* Checks renames beneath dir_s1d1. */
2302 static void refer_denied_by_default(struct __test_metadata *const _metadata,
2303 				    const struct rule layer1[],
2304 				    const int layer1_err,
2305 				    const struct rule layer2[])
2306 {
2307 	int ruleset_fd;
2308 
2309 	ASSERT_EQ(0, unlink(file1_s1d2));
2310 
2311 	ruleset_fd = create_ruleset(_metadata, layer1[0].access, layer1);
2312 	ASSERT_LE(0, ruleset_fd);
2313 	enforce_ruleset(_metadata, ruleset_fd);
2314 	ASSERT_EQ(0, close(ruleset_fd));
2315 
2316 	/*
2317 	 * If the first layer handles LANDLOCK_ACCESS_FS_REFER (according to
2318 	 * layer1_err), then it allows some different-parent renames and links.
2319 	 */
2320 	ASSERT_EQ(layer1_err, test_rename(file1_s1d1, file1_s1d2));
2321 	if (layer1_err == 0)
2322 		ASSERT_EQ(layer1_err, test_rename(file1_s1d2, file1_s1d1));
2323 	ASSERT_EQ(layer1_err, test_exchange(file2_s1d1, file2_s1d2));
2324 	ASSERT_EQ(layer1_err, test_exchange(file2_s1d2, file2_s1d1));
2325 
2326 	ruleset_fd = create_ruleset(_metadata, layer2[0].access, layer2);
2327 	ASSERT_LE(0, ruleset_fd);
2328 	enforce_ruleset(_metadata, ruleset_fd);
2329 	ASSERT_EQ(0, close(ruleset_fd));
2330 
2331 	/*
2332 	 * Now, either the first or the second layer does not handle
2333 	 * LANDLOCK_ACCESS_FS_REFER, which means that any different-parent
2334 	 * renames and links are denied, thus making the layer handling
2335 	 * LANDLOCK_ACCESS_FS_REFER null and void.
2336 	 */
2337 	ASSERT_EQ(EXDEV, test_rename(file1_s1d1, file1_s1d2));
2338 	ASSERT_EQ(EXDEV, test_exchange(file2_s1d1, file2_s1d2));
2339 	ASSERT_EQ(EXDEV, test_exchange(file2_s1d2, file2_s1d1));
2340 }
2341 
2342 const struct rule layer_dir_s1d1_refer[] = {
2343 	{
2344 		.path = dir_s1d1,
2345 		.access = LANDLOCK_ACCESS_FS_REFER,
2346 	},
2347 	{},
2348 };
2349 
2350 const struct rule layer_dir_s1d1_execute[] = {
2351 	{
2352 		/* Matches a parent directory. */
2353 		.path = dir_s1d1,
2354 		.access = LANDLOCK_ACCESS_FS_EXECUTE,
2355 	},
2356 	{},
2357 };
2358 
2359 const struct rule layer_dir_s2d1_execute[] = {
2360 	{
2361 		/* Does not match a parent directory. */
2362 		.path = dir_s2d1,
2363 		.access = LANDLOCK_ACCESS_FS_EXECUTE,
2364 	},
2365 	{},
2366 };
2367 
2368 /*
2369  * Tests precedence over renames: denied by default for different parent
2370  * directories, *with* a rule matching a parent directory, but not directly
2371  * denying access (with MAKE_REG nor REMOVE).
2372  */
2373 TEST_F_FORK(layout1, refer_denied_by_default1)
2374 {
2375 	refer_denied_by_default(_metadata, layer_dir_s1d1_refer, 0,
2376 				layer_dir_s1d1_execute);
2377 }
2378 
2379 /*
2380  * Same test but this time turning around the ABI version order: the first
2381  * layer does not handle LANDLOCK_ACCESS_FS_REFER.
2382  */
2383 TEST_F_FORK(layout1, refer_denied_by_default2)
2384 {
2385 	refer_denied_by_default(_metadata, layer_dir_s1d1_execute, EXDEV,
2386 				layer_dir_s1d1_refer);
2387 }
2388 
2389 /*
2390  * Tests precedence over renames: denied by default for different parent
2391  * directories, *without* a rule matching a parent directory, but not directly
2392  * denying access (with MAKE_REG nor REMOVE).
2393  */
2394 TEST_F_FORK(layout1, refer_denied_by_default3)
2395 {
2396 	refer_denied_by_default(_metadata, layer_dir_s1d1_refer, 0,
2397 				layer_dir_s2d1_execute);
2398 }
2399 
2400 /*
2401  * Same test but this time turning around the ABI version order: the first
2402  * layer does not handle LANDLOCK_ACCESS_FS_REFER.
2403  */
2404 TEST_F_FORK(layout1, refer_denied_by_default4)
2405 {
2406 	refer_denied_by_default(_metadata, layer_dir_s2d1_execute, EXDEV,
2407 				layer_dir_s1d1_refer);
2408 }
2409 
2410 /*
2411  * Tests walking through a denied root mount.
2412  */
2413 TEST_F_FORK(layout1, refer_mount_root_deny)
2414 {
2415 	const struct landlock_ruleset_attr ruleset_attr = {
2416 		.handled_access_fs = LANDLOCK_ACCESS_FS_MAKE_DIR,
2417 	};
2418 	int root_fd, ruleset_fd;
2419 
2420 	/* Creates a mount object from a non-mount point. */
2421 	set_cap(_metadata, CAP_SYS_ADMIN);
2422 	root_fd =
2423 		open_tree(AT_FDCWD, dir_s1d1,
2424 			  AT_EMPTY_PATH | OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC);
2425 	clear_cap(_metadata, CAP_SYS_ADMIN);
2426 	ASSERT_LE(0, root_fd);
2427 
2428 	ruleset_fd =
2429 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
2430 	ASSERT_LE(0, ruleset_fd);
2431 
2432 	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
2433 	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
2434 	EXPECT_EQ(0, close(ruleset_fd));
2435 
2436 	/* Link denied by Landlock: EACCES. */
2437 	EXPECT_EQ(-1, linkat(root_fd, ".", root_fd, "does_not_exist", 0));
2438 	EXPECT_EQ(EACCES, errno);
2439 
2440 	/* renameat2() always returns EBUSY. */
2441 	EXPECT_EQ(-1, renameat2(root_fd, ".", root_fd, "does_not_exist", 0));
2442 	EXPECT_EQ(EBUSY, errno);
2443 
2444 	EXPECT_EQ(0, close(root_fd));
2445 }
2446 
2447 TEST_F_FORK(layout1, reparent_link)
2448 {
2449 	const struct rule layer1[] = {
2450 		{
2451 			.path = dir_s1d2,
2452 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2453 		},
2454 		{
2455 			.path = dir_s1d3,
2456 			.access = LANDLOCK_ACCESS_FS_REFER,
2457 		},
2458 		{
2459 			.path = dir_s2d2,
2460 			.access = LANDLOCK_ACCESS_FS_REFER,
2461 		},
2462 		{
2463 			.path = dir_s2d3,
2464 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2465 		},
2466 		{},
2467 	};
2468 	const int ruleset_fd = create_ruleset(
2469 		_metadata,
2470 		LANDLOCK_ACCESS_FS_MAKE_REG | LANDLOCK_ACCESS_FS_REFER, layer1);
2471 
2472 	ASSERT_LE(0, ruleset_fd);
2473 	enforce_ruleset(_metadata, ruleset_fd);
2474 	ASSERT_EQ(0, close(ruleset_fd));
2475 
2476 	ASSERT_EQ(0, unlink(file1_s1d1));
2477 	ASSERT_EQ(0, unlink(file1_s1d2));
2478 	ASSERT_EQ(0, unlink(file1_s1d3));
2479 
2480 	/* Denies linking because of missing MAKE_REG. */
2481 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
2482 	ASSERT_EQ(EACCES, errno);
2483 	/* Denies linking because of missing source and destination REFER. */
2484 	ASSERT_EQ(-1, link(file1_s2d1, file1_s1d2));
2485 	ASSERT_EQ(EXDEV, errno);
2486 	/* Denies linking because of missing source REFER. */
2487 	ASSERT_EQ(-1, link(file1_s2d1, file1_s1d3));
2488 	ASSERT_EQ(EXDEV, errno);
2489 
2490 	/* Denies linking because of missing MAKE_REG. */
2491 	ASSERT_EQ(-1, link(file1_s2d2, file1_s1d1));
2492 	ASSERT_EQ(EACCES, errno);
2493 	/* Denies linking because of missing destination REFER. */
2494 	ASSERT_EQ(-1, link(file1_s2d2, file1_s1d2));
2495 	ASSERT_EQ(EXDEV, errno);
2496 
2497 	/* Allows linking because of REFER and MAKE_REG. */
2498 	ASSERT_EQ(0, link(file1_s2d2, file1_s1d3));
2499 	ASSERT_EQ(0, unlink(file1_s2d2));
2500 	/* Reverse linking denied because of missing MAKE_REG. */
2501 	ASSERT_EQ(-1, link(file1_s1d3, file1_s2d2));
2502 	ASSERT_EQ(EACCES, errno);
2503 	ASSERT_EQ(0, unlink(file1_s2d3));
2504 	/* Checks reverse linking. */
2505 	ASSERT_EQ(0, link(file1_s1d3, file1_s2d3));
2506 	ASSERT_EQ(0, unlink(file1_s1d3));
2507 
2508 	/*
2509 	 * This is OK for a file link, but it should not be allowed for a
2510 	 * directory rename (because of the superset of access rights.
2511 	 */
2512 	ASSERT_EQ(0, link(file1_s2d3, file1_s1d3));
2513 	ASSERT_EQ(0, unlink(file1_s1d3));
2514 
2515 	ASSERT_EQ(-1, link(file2_s1d2, file1_s1d3));
2516 	ASSERT_EQ(EXDEV, errno);
2517 	ASSERT_EQ(-1, link(file2_s1d3, file1_s1d2));
2518 	ASSERT_EQ(EXDEV, errno);
2519 
2520 	ASSERT_EQ(0, link(file2_s1d2, file1_s1d2));
2521 	ASSERT_EQ(0, link(file2_s1d3, file1_s1d3));
2522 }
2523 
2524 TEST_F_FORK(layout1, reparent_rename)
2525 {
2526 	/* Same rules as for reparent_link. */
2527 	const struct rule layer1[] = {
2528 		{
2529 			.path = dir_s1d2,
2530 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2531 		},
2532 		{
2533 			.path = dir_s1d3,
2534 			.access = LANDLOCK_ACCESS_FS_REFER,
2535 		},
2536 		{
2537 			.path = dir_s2d2,
2538 			.access = LANDLOCK_ACCESS_FS_REFER,
2539 		},
2540 		{
2541 			.path = dir_s2d3,
2542 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2543 		},
2544 		{},
2545 	};
2546 	const int ruleset_fd = create_ruleset(
2547 		_metadata,
2548 		LANDLOCK_ACCESS_FS_MAKE_REG | LANDLOCK_ACCESS_FS_REFER, layer1);
2549 
2550 	ASSERT_LE(0, ruleset_fd);
2551 	enforce_ruleset(_metadata, ruleset_fd);
2552 	ASSERT_EQ(0, close(ruleset_fd));
2553 
2554 	ASSERT_EQ(0, unlink(file1_s1d2));
2555 	ASSERT_EQ(0, unlink(file1_s1d3));
2556 
2557 	/* Denies renaming because of missing MAKE_REG. */
2558 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file2_s1d1, AT_FDCWD, file1_s1d1,
2559 				RENAME_EXCHANGE));
2560 	ASSERT_EQ(EACCES, errno);
2561 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, file2_s1d1,
2562 				RENAME_EXCHANGE));
2563 	ASSERT_EQ(EACCES, errno);
2564 	ASSERT_EQ(0, unlink(file1_s1d1));
2565 	ASSERT_EQ(-1, rename(file2_s1d1, file1_s1d1));
2566 	ASSERT_EQ(EACCES, errno);
2567 	/* Even denies same file exchange. */
2568 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file2_s1d1, AT_FDCWD, file2_s1d1,
2569 				RENAME_EXCHANGE));
2570 	ASSERT_EQ(EACCES, errno);
2571 
2572 	/* Denies renaming because of missing source and destination REFER. */
2573 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d2));
2574 	ASSERT_EQ(EXDEV, errno);
2575 	/*
2576 	 * Denies renaming because of missing MAKE_REG, source and destination
2577 	 * REFER.
2578 	 */
2579 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, file2_s1d1,
2580 				RENAME_EXCHANGE));
2581 	ASSERT_EQ(EACCES, errno);
2582 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file2_s1d1, AT_FDCWD, file1_s2d1,
2583 				RENAME_EXCHANGE));
2584 	ASSERT_EQ(EACCES, errno);
2585 
2586 	/* Denies renaming because of missing source REFER. */
2587 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
2588 	ASSERT_EQ(EXDEV, errno);
2589 	/* Denies renaming because of missing MAKE_REG. */
2590 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d1, AT_FDCWD, file2_s1d3,
2591 				RENAME_EXCHANGE));
2592 	ASSERT_EQ(EACCES, errno);
2593 
2594 	/* Denies renaming because of missing MAKE_REG. */
2595 	ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d1));
2596 	ASSERT_EQ(EACCES, errno);
2597 	/* Denies renaming because of missing destination REFER*/
2598 	ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d2));
2599 	ASSERT_EQ(EXDEV, errno);
2600 
2601 	/* Denies exchange because of one missing MAKE_REG. */
2602 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, file2_s1d3,
2603 				RENAME_EXCHANGE));
2604 	ASSERT_EQ(EACCES, errno);
2605 	/* Allows renaming because of REFER and MAKE_REG. */
2606 	ASSERT_EQ(0, rename(file1_s2d2, file1_s1d3));
2607 
2608 	/* Reverse renaming denied because of missing MAKE_REG. */
2609 	ASSERT_EQ(-1, rename(file1_s1d3, file1_s2d2));
2610 	ASSERT_EQ(EACCES, errno);
2611 	ASSERT_EQ(0, unlink(file1_s2d3));
2612 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2613 
2614 	/* Tests reverse renaming. */
2615 	ASSERT_EQ(0, rename(file1_s2d3, file1_s1d3));
2616 	ASSERT_EQ(0, renameat2(AT_FDCWD, file2_s2d3, AT_FDCWD, file1_s1d3,
2617 			       RENAME_EXCHANGE));
2618 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2619 
2620 	/*
2621 	 * This is OK for a file rename, but it should not be allowed for a
2622 	 * directory rename (because of the superset of access rights).
2623 	 */
2624 	ASSERT_EQ(0, rename(file1_s2d3, file1_s1d3));
2625 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2626 
2627 	/*
2628 	 * Tests superset restrictions applied to directories.  Not only the
2629 	 * dir_s2d3's parent (dir_s2d2) should be taken into account but also
2630 	 * access rights tied to dir_s2d3. dir_s2d2 is missing one access right
2631 	 * compared to dir_s1d3/file1_s1d3 (MAKE_REG) but it is provided
2632 	 * directly by the moved dir_s2d3.
2633 	 */
2634 	ASSERT_EQ(0, rename(dir_s2d3, file1_s1d3));
2635 	ASSERT_EQ(0, rename(file1_s1d3, dir_s2d3));
2636 	/*
2637 	 * The first rename is allowed but not the exchange because dir_s1d3's
2638 	 * parent (dir_s1d2) doesn't have REFER.
2639 	 */
2640 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, dir_s1d3,
2641 				RENAME_EXCHANGE));
2642 	ASSERT_EQ(EXDEV, errno);
2643 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, file1_s2d3,
2644 				RENAME_EXCHANGE));
2645 	ASSERT_EQ(EXDEV, errno);
2646 	ASSERT_EQ(-1, rename(file1_s2d3, dir_s1d3));
2647 	ASSERT_EQ(EXDEV, errno);
2648 
2649 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s1d3));
2650 	ASSERT_EQ(EXDEV, errno);
2651 	ASSERT_EQ(-1, rename(file2_s1d3, file1_s1d2));
2652 	ASSERT_EQ(EXDEV, errno);
2653 
2654 	/* Renaming in the same directory is always allowed. */
2655 	ASSERT_EQ(0, rename(file2_s1d2, file1_s1d2));
2656 	ASSERT_EQ(0, rename(file2_s1d3, file1_s1d3));
2657 
2658 	ASSERT_EQ(0, unlink(file1_s1d2));
2659 	/* Denies because of missing source MAKE_REG and destination REFER. */
2660 	ASSERT_EQ(-1, rename(dir_s2d3, file1_s1d2));
2661 	ASSERT_EQ(EXDEV, errno);
2662 
2663 	ASSERT_EQ(0, unlink(file1_s1d3));
2664 	/* Denies because of missing source MAKE_REG and REFER. */
2665 	ASSERT_EQ(-1, rename(dir_s2d2, file1_s1d3));
2666 	ASSERT_EQ(EXDEV, errno);
2667 }
2668 
2669 static void
2670 reparent_exdev_layers_enforce1(struct __test_metadata *const _metadata)
2671 {
2672 	const struct rule layer1[] = {
2673 		{
2674 			.path = dir_s1d2,
2675 			.access = LANDLOCK_ACCESS_FS_REFER,
2676 		},
2677 		{
2678 			/* Interesting for the layer2 tests. */
2679 			.path = dir_s1d3,
2680 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2681 		},
2682 		{
2683 			.path = dir_s2d2,
2684 			.access = LANDLOCK_ACCESS_FS_REFER,
2685 		},
2686 		{
2687 			.path = dir_s2d3,
2688 			.access = LANDLOCK_ACCESS_FS_MAKE_REG,
2689 		},
2690 		{},
2691 	};
2692 	const int ruleset_fd = create_ruleset(
2693 		_metadata,
2694 		LANDLOCK_ACCESS_FS_MAKE_REG | LANDLOCK_ACCESS_FS_REFER, layer1);
2695 
2696 	ASSERT_LE(0, ruleset_fd);
2697 	enforce_ruleset(_metadata, ruleset_fd);
2698 	ASSERT_EQ(0, close(ruleset_fd));
2699 }
2700 
2701 static void
2702 reparent_exdev_layers_enforce2(struct __test_metadata *const _metadata)
2703 {
2704 	const struct rule layer2[] = {
2705 		{
2706 			.path = dir_s2d3,
2707 			.access = LANDLOCK_ACCESS_FS_MAKE_DIR,
2708 		},
2709 		{},
2710 	};
2711 	/*
2712 	 * Same checks as before but with a second layer and a new MAKE_DIR
2713 	 * rule (and no explicit handling of REFER).
2714 	 */
2715 	const int ruleset_fd =
2716 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_MAKE_DIR, layer2);
2717 
2718 	ASSERT_LE(0, ruleset_fd);
2719 	enforce_ruleset(_metadata, ruleset_fd);
2720 	ASSERT_EQ(0, close(ruleset_fd));
2721 }
2722 
2723 TEST_F_FORK(layout1, reparent_exdev_layers_rename1)
2724 {
2725 	ASSERT_EQ(0, unlink(file1_s2d2));
2726 	ASSERT_EQ(0, unlink(file1_s2d3));
2727 
2728 	reparent_exdev_layers_enforce1(_metadata);
2729 
2730 	/*
2731 	 * Moving the dir_s1d3 directory below dir_s2d2 is allowed by Landlock
2732 	 * because it doesn't inherit new access rights.
2733 	 */
2734 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d2));
2735 	ASSERT_EQ(0, rename(file1_s2d2, dir_s1d3));
2736 
2737 	/*
2738 	 * Moving the dir_s1d3 directory below dir_s2d3 is allowed, even if it
2739 	 * gets a new inherited access rights (MAKE_REG), because MAKE_REG is
2740 	 * already allowed for dir_s1d3.
2741 	 */
2742 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d3));
2743 	ASSERT_EQ(0, rename(file1_s2d3, dir_s1d3));
2744 
2745 	/*
2746 	 * However, moving the file1_s1d3 file below dir_s2d3 is allowed
2747 	 * because it cannot inherit MAKE_REG right (which is dedicated to
2748 	 * directories).
2749 	 */
2750 	ASSERT_EQ(0, rename(file1_s1d3, file1_s2d3));
2751 
2752 	reparent_exdev_layers_enforce2(_metadata);
2753 
2754 	/*
2755 	 * Moving the dir_s1d3 directory below dir_s2d2 is now denied because
2756 	 * MAKE_DIR is not tied to dir_s2d2.
2757 	 */
2758 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d2));
2759 	ASSERT_EQ(EACCES, errno);
2760 
2761 	/*
2762 	 * Moving the dir_s1d3 directory below dir_s2d3 is forbidden because it
2763 	 * would grants MAKE_REG and MAKE_DIR rights to it.
2764 	 */
2765 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d3));
2766 	ASSERT_EQ(EXDEV, errno);
2767 
2768 	/*
2769 	 * Moving the file2_s1d3 file below dir_s2d3 is denied because the
2770 	 * second layer does not handle REFER, which is always denied by
2771 	 * default.
2772 	 */
2773 	ASSERT_EQ(-1, rename(file2_s1d3, file1_s2d3));
2774 	ASSERT_EQ(EXDEV, errno);
2775 }
2776 
2777 TEST_F_FORK(layout1, reparent_exdev_layers_rename2)
2778 {
2779 	reparent_exdev_layers_enforce1(_metadata);
2780 
2781 	/* Checks EACCES predominance over EXDEV. */
2782 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d2));
2783 	ASSERT_EQ(EACCES, errno);
2784 	ASSERT_EQ(-1, rename(file1_s1d2, file1_s2d2));
2785 	ASSERT_EQ(EACCES, errno);
2786 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d3));
2787 	ASSERT_EQ(EXDEV, errno);
2788 	/* Modify layout! */
2789 	ASSERT_EQ(0, rename(file1_s1d2, file1_s2d3));
2790 
2791 	/* Without REFER source. */
2792 	ASSERT_EQ(-1, rename(dir_s1d1, file1_s2d2));
2793 	ASSERT_EQ(EXDEV, errno);
2794 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s2d2));
2795 	ASSERT_EQ(EXDEV, errno);
2796 
2797 	reparent_exdev_layers_enforce2(_metadata);
2798 
2799 	/* Checks EACCES predominance over EXDEV. */
2800 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d2));
2801 	ASSERT_EQ(EACCES, errno);
2802 	/* Checks with actual file2_s1d2. */
2803 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s2d2));
2804 	ASSERT_EQ(EACCES, errno);
2805 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s2d3));
2806 	ASSERT_EQ(EXDEV, errno);
2807 	/*
2808 	 * Modifying the layout is now denied because the second layer does not
2809 	 * handle REFER, which is always denied by default.
2810 	 */
2811 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s2d3));
2812 	ASSERT_EQ(EXDEV, errno);
2813 
2814 	/* Without REFER source, EACCES wins over EXDEV. */
2815 	ASSERT_EQ(-1, rename(dir_s1d1, file1_s2d2));
2816 	ASSERT_EQ(EACCES, errno);
2817 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s2d2));
2818 	ASSERT_EQ(EACCES, errno);
2819 }
2820 
2821 TEST_F_FORK(layout1, reparent_exdev_layers_exchange1)
2822 {
2823 	const char *const dir_file1_s1d2 = file1_s1d2, *const dir_file2_s2d3 =
2824 							       file2_s2d3;
2825 
2826 	ASSERT_EQ(0, unlink(file1_s1d2));
2827 	ASSERT_EQ(0, mkdir(file1_s1d2, 0700));
2828 	ASSERT_EQ(0, unlink(file2_s2d3));
2829 	ASSERT_EQ(0, mkdir(file2_s2d3, 0700));
2830 
2831 	reparent_exdev_layers_enforce1(_metadata);
2832 
2833 	/* Error predominance with file exchange: returns EXDEV and EACCES. */
2834 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, file1_s2d3,
2835 				RENAME_EXCHANGE));
2836 	ASSERT_EQ(EACCES, errno);
2837 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, file1_s1d1,
2838 				RENAME_EXCHANGE));
2839 	ASSERT_EQ(EACCES, errno);
2840 
2841 	/*
2842 	 * Checks with directories which creation could be allowed, but denied
2843 	 * because of access rights that would be inherited.
2844 	 */
2845 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD,
2846 				dir_file2_s2d3, RENAME_EXCHANGE));
2847 	ASSERT_EQ(EXDEV, errno);
2848 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD,
2849 				dir_file1_s1d2, RENAME_EXCHANGE));
2850 	ASSERT_EQ(EXDEV, errno);
2851 
2852 	/* Checks with same access rights. */
2853 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, dir_s2d3,
2854 			       RENAME_EXCHANGE));
2855 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_s1d3,
2856 			       RENAME_EXCHANGE));
2857 
2858 	/* Checks with different (child-only) access rights. */
2859 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_file1_s1d2,
2860 			       RENAME_EXCHANGE));
2861 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD, dir_s2d3,
2862 			       RENAME_EXCHANGE));
2863 
2864 	/*
2865 	 * Checks that exchange between file and directory are consistent.
2866 	 *
2867 	 * Moving a file (file1_s2d2) to a directory which only grants more
2868 	 * directory-related access rights is allowed, and at the same time
2869 	 * moving a directory (dir_file2_s2d3) to another directory which
2870 	 * grants less access rights is allowed too.
2871 	 *
2872 	 * See layout1.reparent_exdev_layers_exchange3 for inverted arguments.
2873 	 */
2874 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
2875 			       RENAME_EXCHANGE));
2876 	/*
2877 	 * However, moving back the directory is denied because it would get
2878 	 * more access rights than the current state and because file creation
2879 	 * is forbidden (in dir_s2d2).
2880 	 */
2881 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
2882 				RENAME_EXCHANGE));
2883 	ASSERT_EQ(EACCES, errno);
2884 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
2885 				RENAME_EXCHANGE));
2886 	ASSERT_EQ(EACCES, errno);
2887 
2888 	reparent_exdev_layers_enforce2(_metadata);
2889 
2890 	/* Error predominance with file exchange: returns EXDEV and EACCES. */
2891 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, file1_s2d3,
2892 				RENAME_EXCHANGE));
2893 	ASSERT_EQ(EACCES, errno);
2894 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d3, AT_FDCWD, file1_s1d1,
2895 				RENAME_EXCHANGE));
2896 	ASSERT_EQ(EACCES, errno);
2897 
2898 	/* Checks with directories which creation is now denied. */
2899 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD,
2900 				dir_file2_s2d3, RENAME_EXCHANGE));
2901 	ASSERT_EQ(EACCES, errno);
2902 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD,
2903 				dir_file1_s1d2, RENAME_EXCHANGE));
2904 	ASSERT_EQ(EACCES, errno);
2905 
2906 	/* Checks with different (child-only) access rights. */
2907 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s1d3, AT_FDCWD, dir_s2d3,
2908 				RENAME_EXCHANGE));
2909 	/* Denied because of MAKE_DIR. */
2910 	ASSERT_EQ(EACCES, errno);
2911 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_s1d3,
2912 				RENAME_EXCHANGE));
2913 	ASSERT_EQ(EACCES, errno);
2914 
2915 	/* Checks with different (child-only) access rights. */
2916 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_s2d3, AT_FDCWD, dir_file1_s1d2,
2917 				RENAME_EXCHANGE));
2918 	/* Denied because of MAKE_DIR. */
2919 	ASSERT_EQ(EACCES, errno);
2920 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file1_s1d2, AT_FDCWD, dir_s2d3,
2921 				RENAME_EXCHANGE));
2922 	ASSERT_EQ(EACCES, errno);
2923 
2924 	/* See layout1.reparent_exdev_layers_exchange2 for complement. */
2925 }
2926 
2927 TEST_F_FORK(layout1, reparent_exdev_layers_exchange2)
2928 {
2929 	const char *const dir_file2_s2d3 = file2_s2d3;
2930 
2931 	ASSERT_EQ(0, unlink(file2_s2d3));
2932 	ASSERT_EQ(0, mkdir(file2_s2d3, 0700));
2933 
2934 	reparent_exdev_layers_enforce1(_metadata);
2935 	reparent_exdev_layers_enforce2(_metadata);
2936 
2937 	/* Checks that exchange between file and directory are consistent. */
2938 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
2939 				RENAME_EXCHANGE));
2940 	ASSERT_EQ(EACCES, errno);
2941 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
2942 				RENAME_EXCHANGE));
2943 	ASSERT_EQ(EACCES, errno);
2944 }
2945 
2946 TEST_F_FORK(layout1, reparent_exdev_layers_exchange3)
2947 {
2948 	const char *const dir_file2_s2d3 = file2_s2d3;
2949 
2950 	ASSERT_EQ(0, unlink(file2_s2d3));
2951 	ASSERT_EQ(0, mkdir(file2_s2d3, 0700));
2952 
2953 	reparent_exdev_layers_enforce1(_metadata);
2954 
2955 	/*
2956 	 * Checks that exchange between file and directory are consistent,
2957 	 * including with inverted arguments (see
2958 	 * layout1.reparent_exdev_layers_exchange1).
2959 	 */
2960 	ASSERT_EQ(0, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
2961 			       RENAME_EXCHANGE));
2962 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_file2_s2d3,
2963 				RENAME_EXCHANGE));
2964 	ASSERT_EQ(EACCES, errno);
2965 	ASSERT_EQ(-1, renameat2(AT_FDCWD, dir_file2_s2d3, AT_FDCWD, file1_s2d2,
2966 				RENAME_EXCHANGE));
2967 	ASSERT_EQ(EACCES, errno);
2968 }
2969 
2970 TEST_F_FORK(layout1, reparent_remove)
2971 {
2972 	const struct rule layer1[] = {
2973 		{
2974 			.path = dir_s1d1,
2975 			.access = LANDLOCK_ACCESS_FS_REFER |
2976 				  LANDLOCK_ACCESS_FS_REMOVE_DIR,
2977 		},
2978 		{
2979 			.path = dir_s1d2,
2980 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
2981 		},
2982 		{
2983 			.path = dir_s2d1,
2984 			.access = LANDLOCK_ACCESS_FS_REFER |
2985 				  LANDLOCK_ACCESS_FS_REMOVE_FILE,
2986 		},
2987 		{},
2988 	};
2989 	const int ruleset_fd = create_ruleset(
2990 		_metadata,
2991 		LANDLOCK_ACCESS_FS_REFER | LANDLOCK_ACCESS_FS_REMOVE_DIR |
2992 			LANDLOCK_ACCESS_FS_REMOVE_FILE,
2993 		layer1);
2994 
2995 	ASSERT_LE(0, ruleset_fd);
2996 	enforce_ruleset(_metadata, ruleset_fd);
2997 	ASSERT_EQ(0, close(ruleset_fd));
2998 
2999 	/* Access denied because of wrong/swapped remove file/dir. */
3000 	ASSERT_EQ(-1, rename(file1_s1d1, dir_s2d2));
3001 	ASSERT_EQ(EACCES, errno);
3002 	ASSERT_EQ(-1, rename(dir_s2d2, file1_s1d1));
3003 	ASSERT_EQ(EACCES, errno);
3004 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, dir_s2d2,
3005 				RENAME_EXCHANGE));
3006 	ASSERT_EQ(EACCES, errno);
3007 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s1d1, AT_FDCWD, dir_s2d3,
3008 				RENAME_EXCHANGE));
3009 	ASSERT_EQ(EACCES, errno);
3010 
3011 	/* Access allowed thanks to the matching rights. */
3012 	ASSERT_EQ(-1, rename(file1_s2d1, dir_s1d2));
3013 	ASSERT_EQ(EISDIR, errno);
3014 	ASSERT_EQ(-1, rename(dir_s1d2, file1_s2d1));
3015 	ASSERT_EQ(ENOTDIR, errno);
3016 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d1));
3017 	ASSERT_EQ(ENOTDIR, errno);
3018 	ASSERT_EQ(0, unlink(file1_s2d1));
3019 	ASSERT_EQ(0, unlink(file1_s1d3));
3020 	ASSERT_EQ(0, unlink(file2_s1d3));
3021 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d1));
3022 
3023 	/* Effectively removes a file and a directory by exchanging them. */
3024 	ASSERT_EQ(0, mkdir(dir_s1d3, 0700));
3025 	ASSERT_EQ(0, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s1d3,
3026 			       RENAME_EXCHANGE));
3027 	ASSERT_EQ(-1, renameat2(AT_FDCWD, file1_s2d2, AT_FDCWD, dir_s1d3,
3028 				RENAME_EXCHANGE));
3029 	ASSERT_EQ(EACCES, errno);
3030 }
3031 
3032 TEST_F_FORK(layout1, reparent_dom_superset)
3033 {
3034 	const struct rule layer1[] = {
3035 		{
3036 			.path = dir_s1d2,
3037 			.access = LANDLOCK_ACCESS_FS_REFER,
3038 		},
3039 		{
3040 			.path = file1_s1d2,
3041 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
3042 		},
3043 		{
3044 			.path = dir_s1d3,
3045 			.access = LANDLOCK_ACCESS_FS_MAKE_SOCK |
3046 				  LANDLOCK_ACCESS_FS_EXECUTE,
3047 		},
3048 		{
3049 			.path = dir_s2d2,
3050 			.access = LANDLOCK_ACCESS_FS_REFER |
3051 				  LANDLOCK_ACCESS_FS_EXECUTE |
3052 				  LANDLOCK_ACCESS_FS_MAKE_SOCK,
3053 		},
3054 		{
3055 			.path = dir_s2d3,
3056 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3057 				  LANDLOCK_ACCESS_FS_MAKE_FIFO,
3058 		},
3059 		{},
3060 	};
3061 	int ruleset_fd = create_ruleset(_metadata,
3062 					LANDLOCK_ACCESS_FS_REFER |
3063 						LANDLOCK_ACCESS_FS_EXECUTE |
3064 						LANDLOCK_ACCESS_FS_MAKE_SOCK |
3065 						LANDLOCK_ACCESS_FS_READ_FILE |
3066 						LANDLOCK_ACCESS_FS_MAKE_FIFO,
3067 					layer1);
3068 
3069 	ASSERT_LE(0, ruleset_fd);
3070 	enforce_ruleset(_metadata, ruleset_fd);
3071 	ASSERT_EQ(0, close(ruleset_fd));
3072 
3073 	ASSERT_EQ(-1, rename(file1_s1d2, file1_s2d1));
3074 	ASSERT_EQ(EXDEV, errno);
3075 	/*
3076 	 * Moving file1_s1d2 beneath dir_s2d3 would grant it the READ_FILE
3077 	 * access right.
3078 	 */
3079 	ASSERT_EQ(-1, rename(file1_s1d2, file1_s2d3));
3080 	ASSERT_EQ(EXDEV, errno);
3081 	/*
3082 	 * Moving file1_s1d2 should be allowed even if dir_s2d2 grants a
3083 	 * superset of access rights compared to dir_s1d2, because file1_s1d2
3084 	 * already has these access rights anyway.
3085 	 */
3086 	ASSERT_EQ(0, rename(file1_s1d2, file1_s2d2));
3087 	ASSERT_EQ(0, rename(file1_s2d2, file1_s1d2));
3088 
3089 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d1));
3090 	ASSERT_EQ(EXDEV, errno);
3091 	/*
3092 	 * Moving dir_s1d3 beneath dir_s2d3 would grant it the MAKE_FIFO access
3093 	 * right.
3094 	 */
3095 	ASSERT_EQ(-1, rename(dir_s1d3, file1_s2d3));
3096 	ASSERT_EQ(EXDEV, errno);
3097 	/*
3098 	 * Moving dir_s1d3 should be allowed even if dir_s2d2 grants a superset
3099 	 * of access rights compared to dir_s1d2, because dir_s1d3 already has
3100 	 * these access rights anyway.
3101 	 */
3102 	ASSERT_EQ(0, rename(dir_s1d3, file1_s2d2));
3103 	ASSERT_EQ(0, rename(file1_s2d2, dir_s1d3));
3104 
3105 	/*
3106 	 * Moving file1_s2d3 beneath dir_s1d2 is allowed, but moving it back
3107 	 * will be denied because the new inherited access rights from dir_s1d2
3108 	 * will be less than the destination (original) dir_s2d3.  This is a
3109 	 * sinkhole scenario where we cannot move back files or directories.
3110 	 */
3111 	ASSERT_EQ(0, rename(file1_s2d3, file2_s1d2));
3112 	ASSERT_EQ(-1, rename(file2_s1d2, file1_s2d3));
3113 	ASSERT_EQ(EXDEV, errno);
3114 	ASSERT_EQ(0, unlink(file2_s1d2));
3115 	ASSERT_EQ(0, unlink(file2_s2d3));
3116 	/*
3117 	 * Checks similar directory one-way move: dir_s2d3 loses EXECUTE and
3118 	 * MAKE_SOCK which were inherited from dir_s1d3.
3119 	 */
3120 	ASSERT_EQ(0, rename(dir_s2d3, file2_s1d2));
3121 	ASSERT_EQ(-1, rename(file2_s1d2, dir_s2d3));
3122 	ASSERT_EQ(EXDEV, errno);
3123 }
3124 
3125 TEST_F_FORK(layout1, remove_dir)
3126 {
3127 	const struct rule rules[] = {
3128 		{
3129 			.path = dir_s1d2,
3130 			.access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
3131 		},
3132 		{},
3133 	};
3134 	const int ruleset_fd =
3135 		create_ruleset(_metadata, rules[0].access, rules);
3136 
3137 	ASSERT_LE(0, ruleset_fd);
3138 
3139 	ASSERT_EQ(0, unlink(file1_s1d1));
3140 	ASSERT_EQ(0, unlink(file1_s1d2));
3141 	ASSERT_EQ(0, unlink(file1_s1d3));
3142 	ASSERT_EQ(0, unlink(file2_s1d3));
3143 
3144 	enforce_ruleset(_metadata, ruleset_fd);
3145 	ASSERT_EQ(0, close(ruleset_fd));
3146 
3147 	ASSERT_EQ(0, rmdir(dir_s1d3));
3148 	ASSERT_EQ(0, mkdir(dir_s1d3, 0700));
3149 	ASSERT_EQ(0, unlinkat(AT_FDCWD, dir_s1d3, AT_REMOVEDIR));
3150 
3151 	/* dir_s1d2 itself cannot be removed. */
3152 	ASSERT_EQ(-1, rmdir(dir_s1d2));
3153 	ASSERT_EQ(EACCES, errno);
3154 	ASSERT_EQ(-1, unlinkat(AT_FDCWD, dir_s1d2, AT_REMOVEDIR));
3155 	ASSERT_EQ(EACCES, errno);
3156 	ASSERT_EQ(-1, rmdir(dir_s1d1));
3157 	ASSERT_EQ(EACCES, errno);
3158 	ASSERT_EQ(-1, unlinkat(AT_FDCWD, dir_s1d1, AT_REMOVEDIR));
3159 	ASSERT_EQ(EACCES, errno);
3160 }
3161 
3162 TEST_F_FORK(layout1, remove_file)
3163 {
3164 	const struct rule rules[] = {
3165 		{
3166 			.path = dir_s1d2,
3167 			.access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
3168 		},
3169 		{},
3170 	};
3171 	const int ruleset_fd =
3172 		create_ruleset(_metadata, rules[0].access, rules);
3173 
3174 	ASSERT_LE(0, ruleset_fd);
3175 	enforce_ruleset(_metadata, ruleset_fd);
3176 	ASSERT_EQ(0, close(ruleset_fd));
3177 
3178 	ASSERT_EQ(-1, unlink(file1_s1d1));
3179 	ASSERT_EQ(EACCES, errno);
3180 	ASSERT_EQ(-1, unlinkat(AT_FDCWD, file1_s1d1, 0));
3181 	ASSERT_EQ(EACCES, errno);
3182 	ASSERT_EQ(0, unlink(file1_s1d2));
3183 	ASSERT_EQ(0, unlinkat(AT_FDCWD, file1_s1d3, 0));
3184 }
3185 
3186 static void test_make_file(struct __test_metadata *const _metadata,
3187 			   const __u64 access, const mode_t mode,
3188 			   const dev_t dev)
3189 {
3190 	const struct rule rules[] = {
3191 		{
3192 			.path = dir_s1d2,
3193 			.access = access,
3194 		},
3195 		{},
3196 	};
3197 	const int ruleset_fd = create_ruleset(_metadata, access, rules);
3198 
3199 	ASSERT_LE(0, ruleset_fd);
3200 
3201 	ASSERT_EQ(0, unlink(file1_s1d1));
3202 	ASSERT_EQ(0, unlink(file2_s1d1));
3203 	ASSERT_EQ(0, mknod(file2_s1d1, mode | 0400, dev))
3204 	{
3205 		TH_LOG("Failed to make file \"%s\": %s", file2_s1d1,
3206 		       strerror(errno));
3207 	};
3208 
3209 	ASSERT_EQ(0, unlink(file1_s1d2));
3210 	ASSERT_EQ(0, unlink(file2_s1d2));
3211 
3212 	ASSERT_EQ(0, unlink(file1_s1d3));
3213 	ASSERT_EQ(0, unlink(file2_s1d3));
3214 
3215 	enforce_ruleset(_metadata, ruleset_fd);
3216 	ASSERT_EQ(0, close(ruleset_fd));
3217 
3218 	ASSERT_EQ(-1, mknod(file1_s1d1, mode | 0400, dev));
3219 	ASSERT_EQ(EACCES, errno);
3220 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
3221 	ASSERT_EQ(EACCES, errno);
3222 	ASSERT_EQ(-1, rename(file2_s1d1, file1_s1d1));
3223 	ASSERT_EQ(EACCES, errno);
3224 
3225 	ASSERT_EQ(0, mknod(file1_s1d2, mode | 0400, dev))
3226 	{
3227 		TH_LOG("Failed to make file \"%s\": %s", file1_s1d2,
3228 		       strerror(errno));
3229 	};
3230 	ASSERT_EQ(0, link(file1_s1d2, file2_s1d2));
3231 	ASSERT_EQ(0, unlink(file2_s1d2));
3232 	ASSERT_EQ(0, rename(file1_s1d2, file2_s1d2));
3233 
3234 	ASSERT_EQ(0, mknod(file1_s1d3, mode | 0400, dev));
3235 	ASSERT_EQ(0, link(file1_s1d3, file2_s1d3));
3236 	ASSERT_EQ(0, unlink(file2_s1d3));
3237 	ASSERT_EQ(0, rename(file1_s1d3, file2_s1d3));
3238 }
3239 
3240 TEST_F_FORK(layout1, make_char)
3241 {
3242 	/* Creates a /dev/null device. */
3243 	set_cap(_metadata, CAP_MKNOD);
3244 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_CHAR, S_IFCHR,
3245 		       makedev(1, 3));
3246 }
3247 
3248 TEST_F_FORK(layout1, make_block)
3249 {
3250 	/* Creates a /dev/loop0 device. */
3251 	set_cap(_metadata, CAP_MKNOD);
3252 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_BLOCK, S_IFBLK,
3253 		       makedev(7, 0));
3254 }
3255 
3256 TEST_F_FORK(layout1, make_reg_1)
3257 {
3258 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, S_IFREG, 0);
3259 }
3260 
3261 TEST_F_FORK(layout1, make_reg_2)
3262 {
3263 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, 0, 0);
3264 }
3265 
3266 TEST_F_FORK(layout1, make_sock)
3267 {
3268 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_SOCK, S_IFSOCK, 0);
3269 }
3270 
3271 TEST_F_FORK(layout1, make_fifo)
3272 {
3273 	test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_FIFO, S_IFIFO, 0);
3274 }
3275 
3276 TEST_F_FORK(layout1, make_sym)
3277 {
3278 	const struct rule rules[] = {
3279 		{
3280 			.path = dir_s1d2,
3281 			.access = LANDLOCK_ACCESS_FS_MAKE_SYM,
3282 		},
3283 		{},
3284 	};
3285 	const int ruleset_fd =
3286 		create_ruleset(_metadata, rules[0].access, rules);
3287 
3288 	ASSERT_LE(0, ruleset_fd);
3289 
3290 	ASSERT_EQ(0, unlink(file1_s1d1));
3291 	ASSERT_EQ(0, unlink(file2_s1d1));
3292 	ASSERT_EQ(0, symlink("none", file2_s1d1));
3293 
3294 	ASSERT_EQ(0, unlink(file1_s1d2));
3295 	ASSERT_EQ(0, unlink(file2_s1d2));
3296 
3297 	ASSERT_EQ(0, unlink(file1_s1d3));
3298 	ASSERT_EQ(0, unlink(file2_s1d3));
3299 
3300 	enforce_ruleset(_metadata, ruleset_fd);
3301 	ASSERT_EQ(0, close(ruleset_fd));
3302 
3303 	ASSERT_EQ(-1, symlink("none", file1_s1d1));
3304 	ASSERT_EQ(EACCES, errno);
3305 	ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
3306 	ASSERT_EQ(EACCES, errno);
3307 	ASSERT_EQ(-1, rename(file2_s1d1, file1_s1d1));
3308 	ASSERT_EQ(EACCES, errno);
3309 
3310 	ASSERT_EQ(0, symlink("none", file1_s1d2));
3311 	ASSERT_EQ(0, link(file1_s1d2, file2_s1d2));
3312 	ASSERT_EQ(0, unlink(file2_s1d2));
3313 	ASSERT_EQ(0, rename(file1_s1d2, file2_s1d2));
3314 
3315 	ASSERT_EQ(0, symlink("none", file1_s1d3));
3316 	ASSERT_EQ(0, link(file1_s1d3, file2_s1d3));
3317 	ASSERT_EQ(0, unlink(file2_s1d3));
3318 	ASSERT_EQ(0, rename(file1_s1d3, file2_s1d3));
3319 }
3320 
3321 TEST_F_FORK(layout1, make_dir)
3322 {
3323 	const struct rule rules[] = {
3324 		{
3325 			.path = dir_s1d2,
3326 			.access = LANDLOCK_ACCESS_FS_MAKE_DIR,
3327 		},
3328 		{},
3329 	};
3330 	const int ruleset_fd =
3331 		create_ruleset(_metadata, rules[0].access, rules);
3332 
3333 	ASSERT_LE(0, ruleset_fd);
3334 
3335 	ASSERT_EQ(0, unlink(file1_s1d1));
3336 	ASSERT_EQ(0, unlink(file1_s1d2));
3337 	ASSERT_EQ(0, unlink(file1_s1d3));
3338 
3339 	enforce_ruleset(_metadata, ruleset_fd);
3340 	ASSERT_EQ(0, close(ruleset_fd));
3341 
3342 	/* Uses file_* as directory names. */
3343 	ASSERT_EQ(-1, mkdir(file1_s1d1, 0700));
3344 	ASSERT_EQ(EACCES, errno);
3345 	ASSERT_EQ(0, mkdir(file1_s1d2, 0700));
3346 	ASSERT_EQ(0, mkdir(file1_s1d3, 0700));
3347 }
3348 
3349 static int open_proc_fd(struct __test_metadata *const _metadata, const int fd,
3350 			const int open_flags)
3351 {
3352 	static const char path_template[] = "/proc/self/fd/%d";
3353 	char procfd_path[sizeof(path_template) + 10];
3354 	const int procfd_path_size =
3355 		snprintf(procfd_path, sizeof(procfd_path), path_template, fd);
3356 
3357 	ASSERT_LT(procfd_path_size, sizeof(procfd_path));
3358 	return open(procfd_path, open_flags);
3359 }
3360 
3361 TEST_F_FORK(layout1, proc_unlinked_file)
3362 {
3363 	const struct rule rules[] = {
3364 		{
3365 			.path = file1_s1d2,
3366 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
3367 		},
3368 		{},
3369 	};
3370 	int reg_fd, proc_fd;
3371 	const int ruleset_fd = create_ruleset(
3372 		_metadata,
3373 		LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_WRITE_FILE,
3374 		rules);
3375 
3376 	ASSERT_LE(0, ruleset_fd);
3377 	enforce_ruleset(_metadata, ruleset_fd);
3378 	ASSERT_EQ(0, close(ruleset_fd));
3379 
3380 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDWR));
3381 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
3382 	reg_fd = open(file1_s1d2, O_RDONLY | O_CLOEXEC);
3383 	ASSERT_LE(0, reg_fd);
3384 	ASSERT_EQ(0, unlink(file1_s1d2));
3385 
3386 	proc_fd = open_proc_fd(_metadata, reg_fd, O_RDONLY | O_CLOEXEC);
3387 	ASSERT_LE(0, proc_fd);
3388 	ASSERT_EQ(0, close(proc_fd));
3389 
3390 	proc_fd = open_proc_fd(_metadata, reg_fd, O_RDWR | O_CLOEXEC);
3391 	ASSERT_EQ(-1, proc_fd)
3392 	{
3393 		TH_LOG("Successfully opened /proc/self/fd/%d: %s", reg_fd,
3394 		       strerror(errno));
3395 	}
3396 	ASSERT_EQ(EACCES, errno);
3397 
3398 	ASSERT_EQ(0, close(reg_fd));
3399 }
3400 
3401 TEST_F_FORK(layout1, proc_pipe)
3402 {
3403 	int proc_fd;
3404 	int pipe_fds[2];
3405 	char buf = '\0';
3406 	const struct rule rules[] = {
3407 		{
3408 			.path = dir_s1d2,
3409 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3410 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
3411 		},
3412 		{},
3413 	};
3414 	/* Limits read and write access to files tied to the filesystem. */
3415 	const int ruleset_fd =
3416 		create_ruleset(_metadata, rules[0].access, rules);
3417 
3418 	ASSERT_LE(0, ruleset_fd);
3419 	enforce_ruleset(_metadata, ruleset_fd);
3420 	ASSERT_EQ(0, close(ruleset_fd));
3421 
3422 	/* Checks enforcement for normal files. */
3423 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDWR));
3424 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDWR));
3425 
3426 	/* Checks access to pipes through FD. */
3427 	ASSERT_EQ(0, pipe2(pipe_fds, O_CLOEXEC));
3428 	ASSERT_EQ(1, write(pipe_fds[1], ".", 1))
3429 	{
3430 		TH_LOG("Failed to write in pipe: %s", strerror(errno));
3431 	}
3432 	ASSERT_EQ(1, read(pipe_fds[0], &buf, 1));
3433 	ASSERT_EQ('.', buf);
3434 
3435 	/* Checks write access to pipe through /proc/self/fd . */
3436 	proc_fd = open_proc_fd(_metadata, pipe_fds[1], O_WRONLY | O_CLOEXEC);
3437 	ASSERT_LE(0, proc_fd);
3438 	ASSERT_EQ(1, write(proc_fd, ".", 1))
3439 	{
3440 		TH_LOG("Failed to write through /proc/self/fd/%d: %s",
3441 		       pipe_fds[1], strerror(errno));
3442 	}
3443 	ASSERT_EQ(0, close(proc_fd));
3444 
3445 	/* Checks read access to pipe through /proc/self/fd . */
3446 	proc_fd = open_proc_fd(_metadata, pipe_fds[0], O_RDONLY | O_CLOEXEC);
3447 	ASSERT_LE(0, proc_fd);
3448 	buf = '\0';
3449 	ASSERT_EQ(1, read(proc_fd, &buf, 1))
3450 	{
3451 		TH_LOG("Failed to read through /proc/self/fd/%d: %s",
3452 		       pipe_fds[1], strerror(errno));
3453 	}
3454 	ASSERT_EQ(0, close(proc_fd));
3455 
3456 	ASSERT_EQ(0, close(pipe_fds[0]));
3457 	ASSERT_EQ(0, close(pipe_fds[1]));
3458 }
3459 
3460 /* Invokes truncate(2) and returns its errno or 0. */
3461 static int test_truncate(const char *const path)
3462 {
3463 	if (truncate(path, 10) < 0)
3464 		return errno;
3465 	return 0;
3466 }
3467 
3468 /*
3469  * Invokes creat(2) and returns its errno or 0.
3470  * Closes the opened file descriptor on success.
3471  */
3472 static int test_creat(const char *const path)
3473 {
3474 	int fd = creat(path, 0600);
3475 
3476 	if (fd < 0)
3477 		return errno;
3478 
3479 	/*
3480 	 * Mixing error codes from close(2) and creat(2) should not lead to any
3481 	 * (access type) confusion for this test.
3482 	 */
3483 	if (close(fd) < 0)
3484 		return errno;
3485 	return 0;
3486 }
3487 
3488 /*
3489  * Exercises file truncation when it's not restricted,
3490  * as it was the case before LANDLOCK_ACCESS_FS_TRUNCATE existed.
3491  */
3492 TEST_F_FORK(layout1, truncate_unhandled)
3493 {
3494 	const char *const file_r = file1_s1d1;
3495 	const char *const file_w = file2_s1d1;
3496 	const char *const file_none = file1_s1d2;
3497 	const struct rule rules[] = {
3498 		{
3499 			.path = file_r,
3500 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
3501 		},
3502 		{
3503 			.path = file_w,
3504 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3505 		},
3506 		/* Implicitly: No rights for file_none. */
3507 		{},
3508 	};
3509 
3510 	const __u64 handled = LANDLOCK_ACCESS_FS_READ_FILE |
3511 			      LANDLOCK_ACCESS_FS_WRITE_FILE;
3512 	int ruleset_fd;
3513 
3514 	/* Enables Landlock. */
3515 	ruleset_fd = create_ruleset(_metadata, handled, rules);
3516 
3517 	ASSERT_LE(0, ruleset_fd);
3518 	enforce_ruleset(_metadata, ruleset_fd);
3519 	ASSERT_EQ(0, close(ruleset_fd));
3520 
3521 	/*
3522 	 * Checks read right: truncate and open with O_TRUNC work, unless the
3523 	 * file is attempted to be opened for writing.
3524 	 */
3525 	EXPECT_EQ(0, test_truncate(file_r));
3526 	EXPECT_EQ(0, test_open(file_r, O_RDONLY | O_TRUNC));
3527 	EXPECT_EQ(EACCES, test_open(file_r, O_WRONLY | O_TRUNC));
3528 	EXPECT_EQ(EACCES, test_creat(file_r));
3529 
3530 	/*
3531 	 * Checks write right: truncate and open with O_TRUNC work, unless the
3532 	 * file is attempted to be opened for reading.
3533 	 */
3534 	EXPECT_EQ(0, test_truncate(file_w));
3535 	EXPECT_EQ(EACCES, test_open(file_w, O_RDONLY | O_TRUNC));
3536 	EXPECT_EQ(0, test_open(file_w, O_WRONLY | O_TRUNC));
3537 	EXPECT_EQ(0, test_creat(file_w));
3538 
3539 	/*
3540 	 * Checks "no rights" case: truncate works but all open attempts fail,
3541 	 * including creat.
3542 	 */
3543 	EXPECT_EQ(0, test_truncate(file_none));
3544 	EXPECT_EQ(EACCES, test_open(file_none, O_RDONLY | O_TRUNC));
3545 	EXPECT_EQ(EACCES, test_open(file_none, O_WRONLY | O_TRUNC));
3546 	EXPECT_EQ(EACCES, test_creat(file_none));
3547 }
3548 
3549 TEST_F_FORK(layout1, truncate)
3550 {
3551 	const char *const file_rwt = file1_s1d1;
3552 	const char *const file_rw = file2_s1d1;
3553 	const char *const file_rt = file1_s1d2;
3554 	const char *const file_t = file2_s1d2;
3555 	const char *const file_none = file1_s1d3;
3556 	const char *const dir_t = dir_s2d1;
3557 	const char *const file_in_dir_t = file1_s2d1;
3558 	const char *const dir_w = dir_s3d1;
3559 	const char *const file_in_dir_w = file1_s3d1;
3560 	const struct rule rules[] = {
3561 		{
3562 			.path = file_rwt,
3563 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3564 				  LANDLOCK_ACCESS_FS_WRITE_FILE |
3565 				  LANDLOCK_ACCESS_FS_TRUNCATE,
3566 		},
3567 		{
3568 			.path = file_rw,
3569 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3570 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
3571 		},
3572 		{
3573 			.path = file_rt,
3574 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
3575 				  LANDLOCK_ACCESS_FS_TRUNCATE,
3576 		},
3577 		{
3578 			.path = file_t,
3579 			.access = LANDLOCK_ACCESS_FS_TRUNCATE,
3580 		},
3581 		/* Implicitly: No access rights for file_none. */
3582 		{
3583 			.path = dir_t,
3584 			.access = LANDLOCK_ACCESS_FS_TRUNCATE,
3585 		},
3586 		{
3587 			.path = dir_w,
3588 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3589 		},
3590 		{},
3591 	};
3592 	const __u64 handled = LANDLOCK_ACCESS_FS_READ_FILE |
3593 			      LANDLOCK_ACCESS_FS_WRITE_FILE |
3594 			      LANDLOCK_ACCESS_FS_TRUNCATE;
3595 	int ruleset_fd;
3596 
3597 	/* Enables Landlock. */
3598 	ruleset_fd = create_ruleset(_metadata, handled, rules);
3599 
3600 	ASSERT_LE(0, ruleset_fd);
3601 	enforce_ruleset(_metadata, ruleset_fd);
3602 	ASSERT_EQ(0, close(ruleset_fd));
3603 
3604 	/* Checks read, write and truncate rights: truncation works. */
3605 	EXPECT_EQ(0, test_truncate(file_rwt));
3606 	EXPECT_EQ(0, test_open(file_rwt, O_RDONLY | O_TRUNC));
3607 	EXPECT_EQ(0, test_open(file_rwt, O_WRONLY | O_TRUNC));
3608 
3609 	/* Checks read and write rights: no truncate variant works. */
3610 	EXPECT_EQ(EACCES, test_truncate(file_rw));
3611 	EXPECT_EQ(EACCES, test_open(file_rw, O_RDONLY | O_TRUNC));
3612 	EXPECT_EQ(EACCES, test_open(file_rw, O_WRONLY | O_TRUNC));
3613 
3614 	/*
3615 	 * Checks read and truncate rights: truncation works.
3616 	 *
3617 	 * Note: Files can get truncated using open() even with O_RDONLY.
3618 	 */
3619 	EXPECT_EQ(0, test_truncate(file_rt));
3620 	EXPECT_EQ(0, test_open(file_rt, O_RDONLY | O_TRUNC));
3621 	EXPECT_EQ(EACCES, test_open(file_rt, O_WRONLY | O_TRUNC));
3622 
3623 	/* Checks truncate right: truncate works, but can't open file. */
3624 	EXPECT_EQ(0, test_truncate(file_t));
3625 	EXPECT_EQ(EACCES, test_open(file_t, O_RDONLY | O_TRUNC));
3626 	EXPECT_EQ(EACCES, test_open(file_t, O_WRONLY | O_TRUNC));
3627 
3628 	/* Checks "no rights" case: No form of truncation works. */
3629 	EXPECT_EQ(EACCES, test_truncate(file_none));
3630 	EXPECT_EQ(EACCES, test_open(file_none, O_RDONLY | O_TRUNC));
3631 	EXPECT_EQ(EACCES, test_open(file_none, O_WRONLY | O_TRUNC));
3632 
3633 	/*
3634 	 * Checks truncate right on directory: truncate works on contained
3635 	 * files.
3636 	 */
3637 	EXPECT_EQ(0, test_truncate(file_in_dir_t));
3638 	EXPECT_EQ(EACCES, test_open(file_in_dir_t, O_RDONLY | O_TRUNC));
3639 	EXPECT_EQ(EACCES, test_open(file_in_dir_t, O_WRONLY | O_TRUNC));
3640 
3641 	/*
3642 	 * Checks creat in dir_w: This requires the truncate right when
3643 	 * overwriting an existing file, but does not require it when the file
3644 	 * is new.
3645 	 */
3646 	EXPECT_EQ(EACCES, test_creat(file_in_dir_w));
3647 
3648 	ASSERT_EQ(0, unlink(file_in_dir_w));
3649 	EXPECT_EQ(0, test_creat(file_in_dir_w));
3650 }
3651 
3652 /* Invokes ftruncate(2) and returns its errno or 0. */
3653 static int test_ftruncate(int fd)
3654 {
3655 	if (ftruncate(fd, 10) < 0)
3656 		return errno;
3657 	return 0;
3658 }
3659 
3660 TEST_F_FORK(layout1, ftruncate)
3661 {
3662 	/*
3663 	 * This test opens a new file descriptor at different stages of
3664 	 * Landlock restriction:
3665 	 *
3666 	 * without restriction:                    ftruncate works
3667 	 * something else but truncate restricted: ftruncate works
3668 	 * truncate restricted and permitted:      ftruncate works
3669 	 * truncate restricted and not permitted:  ftruncate fails
3670 	 *
3671 	 * Whether this works or not is expected to depend on the time when the
3672 	 * FD was opened, not to depend on the time when ftruncate() was
3673 	 * called.
3674 	 */
3675 	const char *const path = file1_s1d1;
3676 	const __u64 handled1 = LANDLOCK_ACCESS_FS_READ_FILE |
3677 			       LANDLOCK_ACCESS_FS_WRITE_FILE;
3678 	const struct rule layer1[] = {
3679 		{
3680 			.path = path,
3681 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3682 		},
3683 		{},
3684 	};
3685 	const __u64 handled2 = LANDLOCK_ACCESS_FS_TRUNCATE;
3686 	const struct rule layer2[] = {
3687 		{
3688 			.path = path,
3689 			.access = LANDLOCK_ACCESS_FS_TRUNCATE,
3690 		},
3691 		{},
3692 	};
3693 	const __u64 handled3 = LANDLOCK_ACCESS_FS_TRUNCATE |
3694 			       LANDLOCK_ACCESS_FS_WRITE_FILE;
3695 	const struct rule layer3[] = {
3696 		{
3697 			.path = path,
3698 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
3699 		},
3700 		{},
3701 	};
3702 	int fd_layer0, fd_layer1, fd_layer2, fd_layer3, ruleset_fd;
3703 
3704 	fd_layer0 = open(path, O_WRONLY);
3705 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3706 
3707 	ruleset_fd = create_ruleset(_metadata, handled1, layer1);
3708 	ASSERT_LE(0, ruleset_fd);
3709 	enforce_ruleset(_metadata, ruleset_fd);
3710 	ASSERT_EQ(0, close(ruleset_fd));
3711 
3712 	fd_layer1 = open(path, O_WRONLY);
3713 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3714 	EXPECT_EQ(0, test_ftruncate(fd_layer1));
3715 
3716 	ruleset_fd = create_ruleset(_metadata, handled2, layer2);
3717 	ASSERT_LE(0, ruleset_fd);
3718 	enforce_ruleset(_metadata, ruleset_fd);
3719 	ASSERT_EQ(0, close(ruleset_fd));
3720 
3721 	fd_layer2 = open(path, O_WRONLY);
3722 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3723 	EXPECT_EQ(0, test_ftruncate(fd_layer1));
3724 	EXPECT_EQ(0, test_ftruncate(fd_layer2));
3725 
3726 	ruleset_fd = create_ruleset(_metadata, handled3, layer3);
3727 	ASSERT_LE(0, ruleset_fd);
3728 	enforce_ruleset(_metadata, ruleset_fd);
3729 	ASSERT_EQ(0, close(ruleset_fd));
3730 
3731 	fd_layer3 = open(path, O_WRONLY);
3732 	EXPECT_EQ(0, test_ftruncate(fd_layer0));
3733 	EXPECT_EQ(0, test_ftruncate(fd_layer1));
3734 	EXPECT_EQ(0, test_ftruncate(fd_layer2));
3735 	EXPECT_EQ(EACCES, test_ftruncate(fd_layer3));
3736 
3737 	ASSERT_EQ(0, close(fd_layer0));
3738 	ASSERT_EQ(0, close(fd_layer1));
3739 	ASSERT_EQ(0, close(fd_layer2));
3740 	ASSERT_EQ(0, close(fd_layer3));
3741 }
3742 
3743 /* clang-format off */
3744 FIXTURE(ftruncate) {};
3745 /* clang-format on */
3746 
3747 FIXTURE_SETUP(ftruncate)
3748 {
3749 	prepare_layout(_metadata);
3750 	create_file(_metadata, file1_s1d1);
3751 }
3752 
3753 FIXTURE_TEARDOWN_PARENT(ftruncate)
3754 {
3755 	EXPECT_EQ(0, remove_path(file1_s1d1));
3756 	cleanup_layout(_metadata);
3757 }
3758 
3759 FIXTURE_VARIANT(ftruncate)
3760 {
3761 	const __u64 handled;
3762 	const __u64 allowed;
3763 	const int expected_open_result;
3764 	const int expected_ftruncate_result;
3765 };
3766 
3767 /* clang-format off */
3768 FIXTURE_VARIANT_ADD(ftruncate, w_w) {
3769 	/* clang-format on */
3770 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE,
3771 	.allowed = LANDLOCK_ACCESS_FS_WRITE_FILE,
3772 	.expected_open_result = 0,
3773 	.expected_ftruncate_result = 0,
3774 };
3775 
3776 /* clang-format off */
3777 FIXTURE_VARIANT_ADD(ftruncate, t_t) {
3778 	/* clang-format on */
3779 	.handled = LANDLOCK_ACCESS_FS_TRUNCATE,
3780 	.allowed = LANDLOCK_ACCESS_FS_TRUNCATE,
3781 	.expected_open_result = 0,
3782 	.expected_ftruncate_result = 0,
3783 };
3784 
3785 /* clang-format off */
3786 FIXTURE_VARIANT_ADD(ftruncate, wt_w) {
3787 	/* clang-format on */
3788 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3789 	.allowed = LANDLOCK_ACCESS_FS_WRITE_FILE,
3790 	.expected_open_result = 0,
3791 	.expected_ftruncate_result = EACCES,
3792 };
3793 
3794 /* clang-format off */
3795 FIXTURE_VARIANT_ADD(ftruncate, wt_wt) {
3796 	/* clang-format on */
3797 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3798 	.allowed = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3799 	.expected_open_result = 0,
3800 	.expected_ftruncate_result = 0,
3801 };
3802 
3803 /* clang-format off */
3804 FIXTURE_VARIANT_ADD(ftruncate, wt_t) {
3805 	/* clang-format on */
3806 	.handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
3807 	.allowed = LANDLOCK_ACCESS_FS_TRUNCATE,
3808 	.expected_open_result = EACCES,
3809 };
3810 
3811 TEST_F_FORK(ftruncate, open_and_ftruncate)
3812 {
3813 	const char *const path = file1_s1d1;
3814 	const struct rule rules[] = {
3815 		{
3816 			.path = path,
3817 			.access = variant->allowed,
3818 		},
3819 		{},
3820 	};
3821 	int fd, ruleset_fd;
3822 
3823 	/* Enables Landlock. */
3824 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
3825 	ASSERT_LE(0, ruleset_fd);
3826 	enforce_ruleset(_metadata, ruleset_fd);
3827 	ASSERT_EQ(0, close(ruleset_fd));
3828 
3829 	fd = open(path, O_WRONLY);
3830 	EXPECT_EQ(variant->expected_open_result, (fd < 0 ? errno : 0));
3831 	if (fd >= 0) {
3832 		EXPECT_EQ(variant->expected_ftruncate_result,
3833 			  test_ftruncate(fd));
3834 		ASSERT_EQ(0, close(fd));
3835 	}
3836 }
3837 
3838 TEST_F_FORK(ftruncate, open_and_ftruncate_in_different_processes)
3839 {
3840 	int child, fd, status;
3841 	int socket_fds[2];
3842 
3843 	ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
3844 				socket_fds));
3845 
3846 	child = fork();
3847 	ASSERT_LE(0, child);
3848 	if (child == 0) {
3849 		/*
3850 		 * Enables Landlock in the child process, open a file descriptor
3851 		 * where truncation is forbidden and send it to the
3852 		 * non-landlocked parent process.
3853 		 */
3854 		const char *const path = file1_s1d1;
3855 		const struct rule rules[] = {
3856 			{
3857 				.path = path,
3858 				.access = variant->allowed,
3859 			},
3860 			{},
3861 		};
3862 		int fd, ruleset_fd;
3863 
3864 		ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
3865 		ASSERT_LE(0, ruleset_fd);
3866 		enforce_ruleset(_metadata, ruleset_fd);
3867 		ASSERT_EQ(0, close(ruleset_fd));
3868 
3869 		fd = open(path, O_WRONLY);
3870 		ASSERT_EQ(variant->expected_open_result, (fd < 0 ? errno : 0));
3871 
3872 		if (fd >= 0) {
3873 			ASSERT_EQ(0, send_fd(socket_fds[0], fd));
3874 			ASSERT_EQ(0, close(fd));
3875 		}
3876 
3877 		ASSERT_EQ(0, close(socket_fds[0]));
3878 
3879 		_exit(_metadata->exit_code);
3880 		return;
3881 	}
3882 
3883 	if (variant->expected_open_result == 0) {
3884 		fd = recv_fd(socket_fds[1]);
3885 		ASSERT_LE(0, fd);
3886 
3887 		EXPECT_EQ(variant->expected_ftruncate_result,
3888 			  test_ftruncate(fd));
3889 		ASSERT_EQ(0, close(fd));
3890 	}
3891 
3892 	ASSERT_EQ(child, waitpid(child, &status, 0));
3893 	ASSERT_EQ(1, WIFEXITED(status));
3894 	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
3895 
3896 	ASSERT_EQ(0, close(socket_fds[0]));
3897 	ASSERT_EQ(0, close(socket_fds[1]));
3898 }
3899 
3900 /* Invokes the FS_IOC_GETFLAGS IOCTL and returns its errno or 0. */
3901 static int test_fs_ioc_getflags_ioctl(int fd)
3902 {
3903 	uint32_t flags;
3904 
3905 	if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0)
3906 		return errno;
3907 	return 0;
3908 }
3909 
3910 TEST(memfd_ftruncate_and_ioctl)
3911 {
3912 	const struct landlock_ruleset_attr attr = {
3913 		.handled_access_fs = ACCESS_ALL,
3914 	};
3915 	int ruleset_fd, fd, i;
3916 
3917 	/*
3918 	 * We exercise the same test both with and without Landlock enabled, to
3919 	 * ensure that it behaves the same in both cases.
3920 	 */
3921 	for (i = 0; i < 2; i++) {
3922 		/* Creates a new memfd. */
3923 		fd = memfd_create("name", MFD_CLOEXEC);
3924 		ASSERT_LE(0, fd);
3925 
3926 		/*
3927 		 * Checks that operations associated with the opened file
3928 		 * (ftruncate, ioctl) are permitted on file descriptors that are
3929 		 * created in ways other than open(2).
3930 		 */
3931 		EXPECT_EQ(0, test_ftruncate(fd));
3932 		EXPECT_EQ(0, test_fs_ioc_getflags_ioctl(fd));
3933 
3934 		ASSERT_EQ(0, close(fd));
3935 
3936 		/* Enables Landlock. */
3937 		ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
3938 		ASSERT_LE(0, ruleset_fd);
3939 		enforce_ruleset(_metadata, ruleset_fd);
3940 		ASSERT_EQ(0, close(ruleset_fd));
3941 	}
3942 }
3943 
3944 static int test_fionread_ioctl(int fd)
3945 {
3946 	size_t sz = 0;
3947 
3948 	if (ioctl(fd, FIONREAD, &sz) < 0 && errno == EACCES)
3949 		return errno;
3950 	return 0;
3951 }
3952 
3953 TEST_F_FORK(layout1, o_path_ftruncate_and_ioctl)
3954 {
3955 	const struct landlock_ruleset_attr attr = {
3956 		.handled_access_fs = ACCESS_ALL,
3957 	};
3958 	int ruleset_fd, fd;
3959 
3960 	/*
3961 	 * Checks that for files opened with O_PATH, both ioctl(2) and
3962 	 * ftruncate(2) yield EBADF, as it is documented in open(2) for the
3963 	 * O_PATH flag.
3964 	 */
3965 	fd = open(dir_s1d1, O_PATH | O_CLOEXEC);
3966 	ASSERT_LE(0, fd);
3967 
3968 	EXPECT_EQ(EBADF, test_ftruncate(fd));
3969 	EXPECT_EQ(EBADF, test_fs_ioc_getflags_ioctl(fd));
3970 
3971 	ASSERT_EQ(0, close(fd));
3972 
3973 	/* Enables Landlock. */
3974 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
3975 	ASSERT_LE(0, ruleset_fd);
3976 	enforce_ruleset(_metadata, ruleset_fd);
3977 	ASSERT_EQ(0, close(ruleset_fd));
3978 
3979 	/*
3980 	 * Checks that after enabling Landlock,
3981 	 * - the file can still be opened with O_PATH
3982 	 * - both ioctl and truncate still yield EBADF (not EACCES).
3983 	 */
3984 	fd = open(dir_s1d1, O_PATH | O_CLOEXEC);
3985 	ASSERT_LE(0, fd);
3986 
3987 	EXPECT_EQ(EBADF, test_ftruncate(fd));
3988 	EXPECT_EQ(EBADF, test_fs_ioc_getflags_ioctl(fd));
3989 
3990 	ASSERT_EQ(0, close(fd));
3991 }
3992 
3993 /*
3994  * ioctl_error - generically call the given ioctl with a pointer to a
3995  * sufficiently large zeroed-out memory region.
3996  *
3997  * Returns the IOCTLs error, or 0.
3998  */
3999 static int ioctl_error(struct __test_metadata *const _metadata, int fd,
4000 		       unsigned int cmd)
4001 {
4002 	char buf[128]; /* sufficiently large */
4003 	int res, stdinbak_fd;
4004 
4005 	/*
4006 	 * Depending on the IOCTL command, parts of the zeroed-out buffer might
4007 	 * be interpreted as file descriptor numbers.  We do not want to
4008 	 * accidentally operate on file descriptor 0 (stdin), so we temporarily
4009 	 * move stdin to a different FD and close FD 0 for the IOCTL call.
4010 	 */
4011 	stdinbak_fd = dup(0);
4012 	ASSERT_LT(0, stdinbak_fd);
4013 	ASSERT_EQ(0, close(0));
4014 
4015 	/* Invokes the IOCTL with a zeroed-out buffer. */
4016 	bzero(&buf, sizeof(buf));
4017 	res = ioctl(fd, cmd, &buf);
4018 
4019 	/* Restores the old FD 0 and closes the backup FD. */
4020 	ASSERT_EQ(0, dup2(stdinbak_fd, 0));
4021 	ASSERT_EQ(0, close(stdinbak_fd));
4022 
4023 	if (res < 0)
4024 		return errno;
4025 
4026 	return 0;
4027 }
4028 
4029 /* Define some linux/falloc.h IOCTL commands which are not available in uapi headers. */
4030 struct space_resv {
4031 	__s16 l_type;
4032 	__s16 l_whence;
4033 	__s64 l_start;
4034 	__s64 l_len; /* len == 0 means until end of file */
4035 	__s32 l_sysid;
4036 	__u32 l_pid;
4037 	__s32 l_pad[4]; /* reserved area */
4038 };
4039 
4040 #define FS_IOC_RESVSP _IOW('X', 40, struct space_resv)
4041 #define FS_IOC_UNRESVSP _IOW('X', 41, struct space_resv)
4042 #define FS_IOC_RESVSP64 _IOW('X', 42, struct space_resv)
4043 #define FS_IOC_UNRESVSP64 _IOW('X', 43, struct space_resv)
4044 #define FS_IOC_ZERO_RANGE _IOW('X', 57, struct space_resv)
4045 
4046 /*
4047  * Tests a series of blanket-permitted and denied IOCTLs.
4048  */
4049 TEST_F_FORK(layout1, blanket_permitted_ioctls)
4050 {
4051 	const struct landlock_ruleset_attr attr = {
4052 		.handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4053 	};
4054 	int ruleset_fd, fd;
4055 
4056 	/* Enables Landlock. */
4057 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4058 	ASSERT_LE(0, ruleset_fd);
4059 	enforce_ruleset(_metadata, ruleset_fd);
4060 	ASSERT_EQ(0, close(ruleset_fd));
4061 
4062 	fd = open("/dev/null", O_RDWR | O_CLOEXEC);
4063 	ASSERT_LE(0, fd);
4064 
4065 	/*
4066 	 * Checks permitted commands.
4067 	 * These ones may return errors, but should not be blocked by Landlock.
4068 	 */
4069 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIOCLEX));
4070 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIONCLEX));
4071 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIONBIO));
4072 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIOASYNC));
4073 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIOQSIZE));
4074 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIFREEZE));
4075 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FITHAW));
4076 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FS_IOC_FIEMAP));
4077 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIGETBSZ));
4078 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FICLONE));
4079 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FICLONERANGE));
4080 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FIDEDUPERANGE));
4081 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FS_IOC_GETFSUUID));
4082 	EXPECT_NE(EACCES, ioctl_error(_metadata, fd, FS_IOC_GETFSSYSFSPATH));
4083 
4084 	/*
4085 	 * Checks blocked commands.
4086 	 * A call to a blocked IOCTL command always returns EACCES.
4087 	 */
4088 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FIONREAD));
4089 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_GETFLAGS));
4090 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_SETFLAGS));
4091 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_FSGETXATTR));
4092 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_FSSETXATTR));
4093 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FIBMAP));
4094 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_RESVSP));
4095 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_RESVSP64));
4096 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_UNRESVSP));
4097 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_UNRESVSP64));
4098 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_ZERO_RANGE));
4099 
4100 	/* Default case is also blocked. */
4101 	EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, 0xc00ffeee));
4102 
4103 	ASSERT_EQ(0, close(fd));
4104 }
4105 
4106 /*
4107  * Named pipes are not governed by the LANDLOCK_ACCESS_FS_IOCTL_DEV right,
4108  * because they are not character or block devices.
4109  */
4110 TEST_F_FORK(layout1, named_pipe_ioctl)
4111 {
4112 	pid_t child_pid;
4113 	int fd, ruleset_fd;
4114 	const char *const path = file1_s1d1;
4115 	const struct landlock_ruleset_attr attr = {
4116 		.handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4117 	};
4118 
4119 	ASSERT_EQ(0, unlink(path));
4120 	ASSERT_EQ(0, mkfifo(path, 0600));
4121 
4122 	/* Enables Landlock. */
4123 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4124 	ASSERT_LE(0, ruleset_fd);
4125 	enforce_ruleset(_metadata, ruleset_fd);
4126 	ASSERT_EQ(0, close(ruleset_fd));
4127 
4128 	/* The child process opens the pipe for writing. */
4129 	child_pid = fork();
4130 	ASSERT_NE(-1, child_pid);
4131 	if (child_pid == 0) {
4132 		fd = open(path, O_WRONLY);
4133 		close(fd);
4134 		exit(0);
4135 	}
4136 
4137 	fd = open(path, O_RDONLY);
4138 	ASSERT_LE(0, fd);
4139 
4140 	/* FIONREAD is implemented by pipefifo_fops. */
4141 	EXPECT_EQ(0, test_fionread_ioctl(fd));
4142 
4143 	ASSERT_EQ(0, close(fd));
4144 	ASSERT_EQ(0, unlink(path));
4145 
4146 	ASSERT_EQ(child_pid, waitpid(child_pid, NULL, 0));
4147 }
4148 
4149 /* For named UNIX domain sockets, no IOCTL restrictions apply. */
4150 TEST_F_FORK(layout1, named_unix_domain_socket_ioctl)
4151 {
4152 	const char *const path = file1_s1d1;
4153 	int srv_fd, cli_fd, ruleset_fd;
4154 	socklen_t size;
4155 	struct sockaddr_un srv_un, cli_un;
4156 	const struct landlock_ruleset_attr attr = {
4157 		.handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4158 	};
4159 
4160 	/* Sets up a server */
4161 	srv_un.sun_family = AF_UNIX;
4162 	strncpy(srv_un.sun_path, path, sizeof(srv_un.sun_path));
4163 
4164 	ASSERT_EQ(0, unlink(path));
4165 	srv_fd = socket(AF_UNIX, SOCK_STREAM, 0);
4166 	ASSERT_LE(0, srv_fd);
4167 
4168 	size = offsetof(struct sockaddr_un, sun_path) + strlen(srv_un.sun_path);
4169 	ASSERT_EQ(0, bind(srv_fd, (struct sockaddr *)&srv_un, size));
4170 	ASSERT_EQ(0, listen(srv_fd, 10 /* qlen */));
4171 
4172 	/* Enables Landlock. */
4173 	ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
4174 	ASSERT_LE(0, ruleset_fd);
4175 	enforce_ruleset(_metadata, ruleset_fd);
4176 	ASSERT_EQ(0, close(ruleset_fd));
4177 
4178 	/* Sets up a client connection to it */
4179 	cli_un.sun_family = AF_UNIX;
4180 	cli_fd = socket(AF_UNIX, SOCK_STREAM, 0);
4181 	ASSERT_LE(0, cli_fd);
4182 
4183 	size = offsetof(struct sockaddr_un, sun_path) + strlen(cli_un.sun_path);
4184 	ASSERT_EQ(0, bind(cli_fd, (struct sockaddr *)&cli_un, size));
4185 
4186 	bzero(&cli_un, sizeof(cli_un));
4187 	cli_un.sun_family = AF_UNIX;
4188 	strncpy(cli_un.sun_path, path, sizeof(cli_un.sun_path));
4189 	size = offsetof(struct sockaddr_un, sun_path) + strlen(cli_un.sun_path);
4190 
4191 	ASSERT_EQ(0, connect(cli_fd, (struct sockaddr *)&cli_un, size));
4192 
4193 	/* FIONREAD and other IOCTLs should not be forbidden. */
4194 	EXPECT_EQ(0, test_fionread_ioctl(cli_fd));
4195 
4196 	ASSERT_EQ(0, close(cli_fd));
4197 }
4198 
4199 /* clang-format off */
4200 FIXTURE(ioctl) {};
4201 
4202 FIXTURE_SETUP(ioctl) {};
4203 
4204 FIXTURE_TEARDOWN(ioctl) {};
4205 /* clang-format on */
4206 
4207 FIXTURE_VARIANT(ioctl)
4208 {
4209 	const __u64 handled;
4210 	const __u64 allowed;
4211 	const mode_t open_mode;
4212 	/*
4213 	 * FIONREAD is used as a characteristic device-specific IOCTL command.
4214 	 * It is implemented in fs/ioctl.c for regular files,
4215 	 * but we do not blanket-permit it for devices.
4216 	 */
4217 	const int expected_fionread_result;
4218 };
4219 
4220 /* clang-format off */
4221 FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_none) {
4222 	/* clang-format on */
4223 	.handled = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4224 	.allowed = 0,
4225 	.open_mode = O_RDWR,
4226 	.expected_fionread_result = EACCES,
4227 };
4228 
4229 /* clang-format off */
4230 FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_i) {
4231 	/* clang-format on */
4232 	.handled = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4233 	.allowed = LANDLOCK_ACCESS_FS_IOCTL_DEV,
4234 	.open_mode = O_RDWR,
4235 	.expected_fionread_result = 0,
4236 };
4237 
4238 /* clang-format off */
4239 FIXTURE_VARIANT_ADD(ioctl, unhandled) {
4240 	/* clang-format on */
4241 	.handled = LANDLOCK_ACCESS_FS_EXECUTE,
4242 	.allowed = LANDLOCK_ACCESS_FS_EXECUTE,
4243 	.open_mode = O_RDWR,
4244 	.expected_fionread_result = 0,
4245 };
4246 
4247 TEST_F_FORK(ioctl, handle_dir_access_file)
4248 {
4249 	const int flag = 0;
4250 	const struct rule rules[] = {
4251 		{
4252 			.path = "/dev",
4253 			.access = variant->allowed,
4254 		},
4255 		{},
4256 	};
4257 	int file_fd, ruleset_fd;
4258 
4259 	/* Enables Landlock. */
4260 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4261 	ASSERT_LE(0, ruleset_fd);
4262 	enforce_ruleset(_metadata, ruleset_fd);
4263 	ASSERT_EQ(0, close(ruleset_fd));
4264 
4265 	file_fd = open("/dev/zero", variant->open_mode);
4266 	ASSERT_LE(0, file_fd);
4267 
4268 	/* Checks that IOCTL commands return the expected errors. */
4269 	EXPECT_EQ(variant->expected_fionread_result,
4270 		  test_fionread_ioctl(file_fd));
4271 
4272 	/* Checks that unrestrictable commands are unrestricted. */
4273 	EXPECT_EQ(0, ioctl(file_fd, FIOCLEX));
4274 	EXPECT_EQ(0, ioctl(file_fd, FIONCLEX));
4275 	EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag));
4276 	EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag));
4277 	EXPECT_EQ(0, ioctl(file_fd, FIGETBSZ, &flag));
4278 
4279 	ASSERT_EQ(0, close(file_fd));
4280 }
4281 
4282 TEST_F_FORK(ioctl, handle_dir_access_dir)
4283 {
4284 	const int flag = 0;
4285 	const struct rule rules[] = {
4286 		{
4287 			.path = "/dev",
4288 			.access = variant->allowed,
4289 		},
4290 		{},
4291 	};
4292 	int dir_fd, ruleset_fd;
4293 
4294 	/* Enables Landlock. */
4295 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4296 	ASSERT_LE(0, ruleset_fd);
4297 	enforce_ruleset(_metadata, ruleset_fd);
4298 	ASSERT_EQ(0, close(ruleset_fd));
4299 
4300 	/*
4301 	 * Ignore variant->open_mode for this test, as we intend to open a
4302 	 * directory.  If the directory can not be opened, the variant is
4303 	 * infeasible to test with an opened directory.
4304 	 */
4305 	dir_fd = open("/dev", O_RDONLY);
4306 	if (dir_fd < 0)
4307 		return;
4308 
4309 	/*
4310 	 * Checks that IOCTL commands return the expected errors.
4311 	 * We do not use the expected values from the fixture here.
4312 	 *
4313 	 * When using IOCTL on a directory, no Landlock restrictions apply.
4314 	 */
4315 	EXPECT_EQ(0, test_fionread_ioctl(dir_fd));
4316 
4317 	/* Checks that unrestrictable commands are unrestricted. */
4318 	EXPECT_EQ(0, ioctl(dir_fd, FIOCLEX));
4319 	EXPECT_EQ(0, ioctl(dir_fd, FIONCLEX));
4320 	EXPECT_EQ(0, ioctl(dir_fd, FIONBIO, &flag));
4321 	EXPECT_EQ(0, ioctl(dir_fd, FIOASYNC, &flag));
4322 	EXPECT_EQ(0, ioctl(dir_fd, FIGETBSZ, &flag));
4323 
4324 	ASSERT_EQ(0, close(dir_fd));
4325 }
4326 
4327 TEST_F_FORK(ioctl, handle_file_access_file)
4328 {
4329 	const int flag = 0;
4330 	const struct rule rules[] = {
4331 		{
4332 			.path = "/dev/zero",
4333 			.access = variant->allowed,
4334 		},
4335 		{},
4336 	};
4337 	int file_fd, ruleset_fd;
4338 
4339 	/* Enables Landlock. */
4340 	ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
4341 	ASSERT_LE(0, ruleset_fd);
4342 	enforce_ruleset(_metadata, ruleset_fd);
4343 	ASSERT_EQ(0, close(ruleset_fd));
4344 
4345 	file_fd = open("/dev/zero", variant->open_mode);
4346 	ASSERT_LE(0, file_fd)
4347 	{
4348 		TH_LOG("Failed to open /dev/zero: %s", strerror(errno));
4349 	}
4350 
4351 	/* Checks that IOCTL commands return the expected errors. */
4352 	EXPECT_EQ(variant->expected_fionread_result,
4353 		  test_fionread_ioctl(file_fd));
4354 
4355 	/* Checks that unrestrictable commands are unrestricted. */
4356 	EXPECT_EQ(0, ioctl(file_fd, FIOCLEX));
4357 	EXPECT_EQ(0, ioctl(file_fd, FIONCLEX));
4358 	EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag));
4359 	EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag));
4360 	EXPECT_EQ(0, ioctl(file_fd, FIGETBSZ, &flag));
4361 
4362 	ASSERT_EQ(0, close(file_fd));
4363 }
4364 
4365 /* clang-format off */
4366 FIXTURE(layout1_bind) {};
4367 /* clang-format on */
4368 
4369 FIXTURE_SETUP(layout1_bind)
4370 {
4371 	prepare_layout(_metadata);
4372 
4373 	create_layout1(_metadata);
4374 
4375 	set_cap(_metadata, CAP_SYS_ADMIN);
4376 	ASSERT_EQ(0, mount(dir_s1d2, dir_s2d2, NULL, MS_BIND, NULL));
4377 	clear_cap(_metadata, CAP_SYS_ADMIN);
4378 }
4379 
4380 FIXTURE_TEARDOWN_PARENT(layout1_bind)
4381 {
4382 	/* umount(dir_s2d2)) is handled by namespace lifetime. */
4383 
4384 	remove_layout1(_metadata);
4385 
4386 	cleanup_layout(_metadata);
4387 }
4388 
4389 static const char bind_dir_s1d3[] = TMP_DIR "/s2d1/s2d2/s1d3";
4390 static const char bind_file1_s1d3[] = TMP_DIR "/s2d1/s2d2/s1d3/f1";
4391 
4392 /*
4393  * layout1_bind hierarchy:
4394  *
4395  * tmp
4396  * ├── s1d1
4397  * │   ├── f1
4398  * │   ├── f2
4399  * │   └── s1d2
4400  * │       ├── f1
4401  * │       ├── f2
4402  * │       └── s1d3
4403  * │           ├── f1
4404  * │           └── f2
4405  * ├── s2d1
4406  * │   ├── f1
4407  * │   └── s2d2
4408  * │       ├── f1
4409  * │       ├── f2
4410  * │       └── s1d3
4411  * │           ├── f1
4412  * │           └── f2
4413  * └── s3d1
4414  *     └── s3d2
4415  *         └── s3d3
4416  */
4417 
4418 TEST_F_FORK(layout1_bind, no_restriction)
4419 {
4420 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY));
4421 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
4422 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
4423 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
4424 	ASSERT_EQ(0, test_open(dir_s1d3, O_RDONLY));
4425 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
4426 
4427 	ASSERT_EQ(0, test_open(dir_s2d1, O_RDONLY));
4428 	ASSERT_EQ(0, test_open(file1_s2d1, O_RDONLY));
4429 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY));
4430 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDONLY));
4431 	ASSERT_EQ(ENOENT, test_open(dir_s2d3, O_RDONLY));
4432 	ASSERT_EQ(ENOENT, test_open(file1_s2d3, O_RDONLY));
4433 
4434 	ASSERT_EQ(0, test_open(bind_dir_s1d3, O_RDONLY));
4435 	ASSERT_EQ(0, test_open(bind_file1_s1d3, O_RDONLY));
4436 
4437 	ASSERT_EQ(0, test_open(dir_s3d1, O_RDONLY));
4438 }
4439 
4440 TEST_F_FORK(layout1_bind, same_content_same_file)
4441 {
4442 	/*
4443 	 * Sets access right on parent directories of both source and
4444 	 * destination mount points.
4445 	 */
4446 	const struct rule layer1_parent[] = {
4447 		{
4448 			.path = dir_s1d1,
4449 			.access = ACCESS_RO,
4450 		},
4451 		{
4452 			.path = dir_s2d1,
4453 			.access = ACCESS_RW,
4454 		},
4455 		{},
4456 	};
4457 	/*
4458 	 * Sets access rights on the same bind-mounted directories.  The result
4459 	 * should be ACCESS_RW for both directories, but not both hierarchies
4460 	 * because of the first layer.
4461 	 */
4462 	const struct rule layer2_mount_point[] = {
4463 		{
4464 			.path = dir_s1d2,
4465 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4466 		},
4467 		{
4468 			.path = dir_s2d2,
4469 			.access = ACCESS_RW,
4470 		},
4471 		{},
4472 	};
4473 	/* Only allow read-access to the s1d3 hierarchies. */
4474 	const struct rule layer3_source[] = {
4475 		{
4476 			.path = dir_s1d3,
4477 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4478 		},
4479 		{},
4480 	};
4481 	/* Removes all access rights. */
4482 	const struct rule layer4_destination[] = {
4483 		{
4484 			.path = bind_file1_s1d3,
4485 			.access = LANDLOCK_ACCESS_FS_WRITE_FILE,
4486 		},
4487 		{},
4488 	};
4489 	int ruleset_fd;
4490 
4491 	/* Sets rules for the parent directories. */
4492 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_parent);
4493 	ASSERT_LE(0, ruleset_fd);
4494 	enforce_ruleset(_metadata, ruleset_fd);
4495 	ASSERT_EQ(0, close(ruleset_fd));
4496 
4497 	/* Checks source hierarchy. */
4498 	ASSERT_EQ(0, test_open(file1_s1d1, O_RDONLY));
4499 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
4500 	ASSERT_EQ(0, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
4501 
4502 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
4503 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
4504 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
4505 
4506 	/* Checks destination hierarchy. */
4507 	ASSERT_EQ(0, test_open(file1_s2d1, O_RDWR));
4508 	ASSERT_EQ(0, test_open(dir_s2d1, O_RDONLY | O_DIRECTORY));
4509 
4510 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDWR));
4511 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY | O_DIRECTORY));
4512 
4513 	/* Sets rules for the mount points. */
4514 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2_mount_point);
4515 	ASSERT_LE(0, ruleset_fd);
4516 	enforce_ruleset(_metadata, ruleset_fd);
4517 	ASSERT_EQ(0, close(ruleset_fd));
4518 
4519 	/* Checks source hierarchy. */
4520 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_RDONLY));
4521 	ASSERT_EQ(EACCES, test_open(file1_s1d1, O_WRONLY));
4522 	ASSERT_EQ(EACCES, test_open(dir_s1d1, O_RDONLY | O_DIRECTORY));
4523 
4524 	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
4525 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
4526 	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
4527 
4528 	/* Checks destination hierarchy. */
4529 	ASSERT_EQ(EACCES, test_open(file1_s2d1, O_RDONLY));
4530 	ASSERT_EQ(EACCES, test_open(file1_s2d1, O_WRONLY));
4531 	ASSERT_EQ(EACCES, test_open(dir_s2d1, O_RDONLY | O_DIRECTORY));
4532 
4533 	ASSERT_EQ(0, test_open(file1_s2d2, O_RDWR));
4534 	ASSERT_EQ(0, test_open(dir_s2d2, O_RDONLY | O_DIRECTORY));
4535 	ASSERT_EQ(0, test_open(bind_dir_s1d3, O_RDONLY | O_DIRECTORY));
4536 
4537 	/* Sets a (shared) rule only on the source. */
4538 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer3_source);
4539 	ASSERT_LE(0, ruleset_fd);
4540 	enforce_ruleset(_metadata, ruleset_fd);
4541 	ASSERT_EQ(0, close(ruleset_fd));
4542 
4543 	/* Checks source hierarchy. */
4544 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_RDONLY));
4545 	ASSERT_EQ(EACCES, test_open(file1_s1d2, O_WRONLY));
4546 	ASSERT_EQ(EACCES, test_open(dir_s1d2, O_RDONLY | O_DIRECTORY));
4547 
4548 	ASSERT_EQ(0, test_open(file1_s1d3, O_RDONLY));
4549 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
4550 	ASSERT_EQ(EACCES, test_open(dir_s1d3, O_RDONLY | O_DIRECTORY));
4551 
4552 	/* Checks destination hierarchy. */
4553 	ASSERT_EQ(EACCES, test_open(file1_s2d2, O_RDONLY));
4554 	ASSERT_EQ(EACCES, test_open(file1_s2d2, O_WRONLY));
4555 	ASSERT_EQ(EACCES, test_open(dir_s2d2, O_RDONLY | O_DIRECTORY));
4556 
4557 	ASSERT_EQ(0, test_open(bind_file1_s1d3, O_RDONLY));
4558 	ASSERT_EQ(EACCES, test_open(bind_file1_s1d3, O_WRONLY));
4559 	ASSERT_EQ(EACCES, test_open(bind_dir_s1d3, O_RDONLY | O_DIRECTORY));
4560 
4561 	/* Sets a (shared) rule only on the destination. */
4562 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer4_destination);
4563 	ASSERT_LE(0, ruleset_fd);
4564 	enforce_ruleset(_metadata, ruleset_fd);
4565 	ASSERT_EQ(0, close(ruleset_fd));
4566 
4567 	/* Checks source hierarchy. */
4568 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_RDONLY));
4569 	ASSERT_EQ(EACCES, test_open(file1_s1d3, O_WRONLY));
4570 
4571 	/* Checks destination hierarchy. */
4572 	ASSERT_EQ(EACCES, test_open(bind_file1_s1d3, O_RDONLY));
4573 	ASSERT_EQ(EACCES, test_open(bind_file1_s1d3, O_WRONLY));
4574 }
4575 
4576 TEST_F_FORK(layout1_bind, reparent_cross_mount)
4577 {
4578 	const struct rule layer1[] = {
4579 		{
4580 			/* dir_s2d1 is beneath the dir_s2d2 mount point. */
4581 			.path = dir_s2d1,
4582 			.access = LANDLOCK_ACCESS_FS_REFER,
4583 		},
4584 		{
4585 			.path = bind_dir_s1d3,
4586 			.access = LANDLOCK_ACCESS_FS_EXECUTE,
4587 		},
4588 		{},
4589 	};
4590 	int ruleset_fd = create_ruleset(
4591 		_metadata,
4592 		LANDLOCK_ACCESS_FS_REFER | LANDLOCK_ACCESS_FS_EXECUTE, layer1);
4593 
4594 	ASSERT_LE(0, ruleset_fd);
4595 	enforce_ruleset(_metadata, ruleset_fd);
4596 	ASSERT_EQ(0, close(ruleset_fd));
4597 
4598 	/* Checks basic denied move. */
4599 	ASSERT_EQ(-1, rename(file1_s1d1, file1_s1d2));
4600 	ASSERT_EQ(EXDEV, errno);
4601 
4602 	/* Checks real cross-mount move (Landlock is not involved). */
4603 	ASSERT_EQ(-1, rename(file1_s2d1, file1_s2d2));
4604 	ASSERT_EQ(EXDEV, errno);
4605 
4606 	/* Checks move that will give more accesses. */
4607 	ASSERT_EQ(-1, rename(file1_s2d2, bind_file1_s1d3));
4608 	ASSERT_EQ(EXDEV, errno);
4609 
4610 	/* Checks legitimate downgrade move. */
4611 	ASSERT_EQ(0, rename(bind_file1_s1d3, file1_s2d2));
4612 }
4613 
4614 #define LOWER_BASE TMP_DIR "/lower"
4615 #define LOWER_DATA LOWER_BASE "/data"
4616 static const char lower_fl1[] = LOWER_DATA "/fl1";
4617 static const char lower_dl1[] = LOWER_DATA "/dl1";
4618 static const char lower_dl1_fl2[] = LOWER_DATA "/dl1/fl2";
4619 static const char lower_fo1[] = LOWER_DATA "/fo1";
4620 static const char lower_do1[] = LOWER_DATA "/do1";
4621 static const char lower_do1_fo2[] = LOWER_DATA "/do1/fo2";
4622 static const char lower_do1_fl3[] = LOWER_DATA "/do1/fl3";
4623 
4624 static const char (*lower_base_files[])[] = {
4625 	&lower_fl1,
4626 	&lower_fo1,
4627 	NULL,
4628 };
4629 static const char (*lower_base_directories[])[] = {
4630 	&lower_dl1,
4631 	&lower_do1,
4632 	NULL,
4633 };
4634 static const char (*lower_sub_files[])[] = {
4635 	&lower_dl1_fl2,
4636 	&lower_do1_fo2,
4637 	&lower_do1_fl3,
4638 	NULL,
4639 };
4640 
4641 #define UPPER_BASE TMP_DIR "/upper"
4642 #define UPPER_DATA UPPER_BASE "/data"
4643 #define UPPER_WORK UPPER_BASE "/work"
4644 static const char upper_fu1[] = UPPER_DATA "/fu1";
4645 static const char upper_du1[] = UPPER_DATA "/du1";
4646 static const char upper_du1_fu2[] = UPPER_DATA "/du1/fu2";
4647 static const char upper_fo1[] = UPPER_DATA "/fo1";
4648 static const char upper_do1[] = UPPER_DATA "/do1";
4649 static const char upper_do1_fo2[] = UPPER_DATA "/do1/fo2";
4650 static const char upper_do1_fu3[] = UPPER_DATA "/do1/fu3";
4651 
4652 static const char (*upper_base_files[])[] = {
4653 	&upper_fu1,
4654 	&upper_fo1,
4655 	NULL,
4656 };
4657 static const char (*upper_base_directories[])[] = {
4658 	&upper_du1,
4659 	&upper_do1,
4660 	NULL,
4661 };
4662 static const char (*upper_sub_files[])[] = {
4663 	&upper_du1_fu2,
4664 	&upper_do1_fo2,
4665 	&upper_do1_fu3,
4666 	NULL,
4667 };
4668 
4669 #define MERGE_BASE TMP_DIR "/merge"
4670 #define MERGE_DATA MERGE_BASE "/data"
4671 static const char merge_fl1[] = MERGE_DATA "/fl1";
4672 static const char merge_dl1[] = MERGE_DATA "/dl1";
4673 static const char merge_dl1_fl2[] = MERGE_DATA "/dl1/fl2";
4674 static const char merge_fu1[] = MERGE_DATA "/fu1";
4675 static const char merge_du1[] = MERGE_DATA "/du1";
4676 static const char merge_du1_fu2[] = MERGE_DATA "/du1/fu2";
4677 static const char merge_fo1[] = MERGE_DATA "/fo1";
4678 static const char merge_do1[] = MERGE_DATA "/do1";
4679 static const char merge_do1_fo2[] = MERGE_DATA "/do1/fo2";
4680 static const char merge_do1_fl3[] = MERGE_DATA "/do1/fl3";
4681 static const char merge_do1_fu3[] = MERGE_DATA "/do1/fu3";
4682 
4683 static const char (*merge_base_files[])[] = {
4684 	&merge_fl1,
4685 	&merge_fu1,
4686 	&merge_fo1,
4687 	NULL,
4688 };
4689 static const char (*merge_base_directories[])[] = {
4690 	&merge_dl1,
4691 	&merge_du1,
4692 	&merge_do1,
4693 	NULL,
4694 };
4695 static const char (*merge_sub_files[])[] = {
4696 	&merge_dl1_fl2, &merge_du1_fu2, &merge_do1_fo2,
4697 	&merge_do1_fl3, &merge_do1_fu3, NULL,
4698 };
4699 
4700 /*
4701  * layout2_overlay hierarchy:
4702  *
4703  * tmp
4704  * ├── lower
4705  * │   └── data
4706  * │       ├── dl1
4707  * │       │   └── fl2
4708  * │       ├── do1
4709  * │       │   ├── fl3
4710  * │       │   └── fo2
4711  * │       ├── fl1
4712  * │       └── fo1
4713  * ├── merge
4714  * │   └── data
4715  * │       ├── dl1
4716  * │       │   └── fl2
4717  * │       ├── do1
4718  * │       │   ├── fl3
4719  * │       │   ├── fo2
4720  * │       │   └── fu3
4721  * │       ├── du1
4722  * │       │   └── fu2
4723  * │       ├── fl1
4724  * │       ├── fo1
4725  * │       └── fu1
4726  * └── upper
4727  *     ├── data
4728  *     │   ├── do1
4729  *     │   │   ├── fo2
4730  *     │   │   └── fu3
4731  *     │   ├── du1
4732  *     │   │   └── fu2
4733  *     │   ├── fo1
4734  *     │   └── fu1
4735  *     └── work
4736  *         └── work
4737  */
4738 
4739 FIXTURE(layout2_overlay)
4740 {
4741 	bool skip_test;
4742 };
4743 
4744 FIXTURE_SETUP(layout2_overlay)
4745 {
4746 	if (!supports_filesystem("overlay")) {
4747 		self->skip_test = true;
4748 		SKIP(return, "overlayfs is not supported (setup)");
4749 	}
4750 
4751 	prepare_layout(_metadata);
4752 
4753 	create_directory(_metadata, LOWER_BASE);
4754 	set_cap(_metadata, CAP_SYS_ADMIN);
4755 	/* Creates tmpfs mount points to get deterministic overlayfs. */
4756 	ASSERT_EQ(0, mount_opt(&mnt_tmp, LOWER_BASE));
4757 	clear_cap(_metadata, CAP_SYS_ADMIN);
4758 	create_file(_metadata, lower_fl1);
4759 	create_file(_metadata, lower_dl1_fl2);
4760 	create_file(_metadata, lower_fo1);
4761 	create_file(_metadata, lower_do1_fo2);
4762 	create_file(_metadata, lower_do1_fl3);
4763 
4764 	create_directory(_metadata, UPPER_BASE);
4765 	set_cap(_metadata, CAP_SYS_ADMIN);
4766 	ASSERT_EQ(0, mount_opt(&mnt_tmp, UPPER_BASE));
4767 	clear_cap(_metadata, CAP_SYS_ADMIN);
4768 	create_file(_metadata, upper_fu1);
4769 	create_file(_metadata, upper_du1_fu2);
4770 	create_file(_metadata, upper_fo1);
4771 	create_file(_metadata, upper_do1_fo2);
4772 	create_file(_metadata, upper_do1_fu3);
4773 	ASSERT_EQ(0, mkdir(UPPER_WORK, 0700));
4774 
4775 	create_directory(_metadata, MERGE_DATA);
4776 	set_cap(_metadata, CAP_SYS_ADMIN);
4777 	set_cap(_metadata, CAP_DAC_OVERRIDE);
4778 	ASSERT_EQ(0, mount("overlay", MERGE_DATA, "overlay", 0,
4779 			   "lowerdir=" LOWER_DATA ",upperdir=" UPPER_DATA
4780 			   ",workdir=" UPPER_WORK));
4781 	clear_cap(_metadata, CAP_DAC_OVERRIDE);
4782 	clear_cap(_metadata, CAP_SYS_ADMIN);
4783 }
4784 
4785 FIXTURE_TEARDOWN_PARENT(layout2_overlay)
4786 {
4787 	if (self->skip_test)
4788 		SKIP(return, "overlayfs is not supported (teardown)");
4789 
4790 	EXPECT_EQ(0, remove_path(lower_do1_fl3));
4791 	EXPECT_EQ(0, remove_path(lower_dl1_fl2));
4792 	EXPECT_EQ(0, remove_path(lower_fl1));
4793 	EXPECT_EQ(0, remove_path(lower_do1_fo2));
4794 	EXPECT_EQ(0, remove_path(lower_fo1));
4795 
4796 	/* umount(LOWER_BASE)) is handled by namespace lifetime. */
4797 	EXPECT_EQ(0, remove_path(LOWER_BASE));
4798 
4799 	EXPECT_EQ(0, remove_path(upper_do1_fu3));
4800 	EXPECT_EQ(0, remove_path(upper_du1_fu2));
4801 	EXPECT_EQ(0, remove_path(upper_fu1));
4802 	EXPECT_EQ(0, remove_path(upper_do1_fo2));
4803 	EXPECT_EQ(0, remove_path(upper_fo1));
4804 	EXPECT_EQ(0, remove_path(UPPER_WORK "/work"));
4805 
4806 	/* umount(UPPER_BASE)) is handled by namespace lifetime. */
4807 	EXPECT_EQ(0, remove_path(UPPER_BASE));
4808 
4809 	/* umount(MERGE_DATA)) is handled by namespace lifetime. */
4810 	EXPECT_EQ(0, remove_path(MERGE_DATA));
4811 
4812 	cleanup_layout(_metadata);
4813 }
4814 
4815 TEST_F_FORK(layout2_overlay, no_restriction)
4816 {
4817 	if (self->skip_test)
4818 		SKIP(return, "overlayfs is not supported (test)");
4819 
4820 	ASSERT_EQ(0, test_open(lower_fl1, O_RDONLY));
4821 	ASSERT_EQ(0, test_open(lower_dl1, O_RDONLY));
4822 	ASSERT_EQ(0, test_open(lower_dl1_fl2, O_RDONLY));
4823 	ASSERT_EQ(0, test_open(lower_fo1, O_RDONLY));
4824 	ASSERT_EQ(0, test_open(lower_do1, O_RDONLY));
4825 	ASSERT_EQ(0, test_open(lower_do1_fo2, O_RDONLY));
4826 	ASSERT_EQ(0, test_open(lower_do1_fl3, O_RDONLY));
4827 
4828 	ASSERT_EQ(0, test_open(upper_fu1, O_RDONLY));
4829 	ASSERT_EQ(0, test_open(upper_du1, O_RDONLY));
4830 	ASSERT_EQ(0, test_open(upper_du1_fu2, O_RDONLY));
4831 	ASSERT_EQ(0, test_open(upper_fo1, O_RDONLY));
4832 	ASSERT_EQ(0, test_open(upper_do1, O_RDONLY));
4833 	ASSERT_EQ(0, test_open(upper_do1_fo2, O_RDONLY));
4834 	ASSERT_EQ(0, test_open(upper_do1_fu3, O_RDONLY));
4835 
4836 	ASSERT_EQ(0, test_open(merge_fl1, O_RDONLY));
4837 	ASSERT_EQ(0, test_open(merge_dl1, O_RDONLY));
4838 	ASSERT_EQ(0, test_open(merge_dl1_fl2, O_RDONLY));
4839 	ASSERT_EQ(0, test_open(merge_fu1, O_RDONLY));
4840 	ASSERT_EQ(0, test_open(merge_du1, O_RDONLY));
4841 	ASSERT_EQ(0, test_open(merge_du1_fu2, O_RDONLY));
4842 	ASSERT_EQ(0, test_open(merge_fo1, O_RDONLY));
4843 	ASSERT_EQ(0, test_open(merge_do1, O_RDONLY));
4844 	ASSERT_EQ(0, test_open(merge_do1_fo2, O_RDONLY));
4845 	ASSERT_EQ(0, test_open(merge_do1_fl3, O_RDONLY));
4846 	ASSERT_EQ(0, test_open(merge_do1_fu3, O_RDONLY));
4847 }
4848 
4849 #define for_each_path(path_list, path_entry, i)               \
4850 	for (i = 0, path_entry = *path_list[i]; path_list[i]; \
4851 	     path_entry = *path_list[++i])
4852 
4853 TEST_F_FORK(layout2_overlay, same_content_different_file)
4854 {
4855 	/* Sets access right on parent directories of both layers. */
4856 	const struct rule layer1_base[] = {
4857 		{
4858 			.path = LOWER_BASE,
4859 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4860 		},
4861 		{
4862 			.path = UPPER_BASE,
4863 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4864 		},
4865 		{
4866 			.path = MERGE_BASE,
4867 			.access = ACCESS_RW,
4868 		},
4869 		{},
4870 	};
4871 	const struct rule layer2_data[] = {
4872 		{
4873 			.path = LOWER_DATA,
4874 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4875 		},
4876 		{
4877 			.path = UPPER_DATA,
4878 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4879 		},
4880 		{
4881 			.path = MERGE_DATA,
4882 			.access = ACCESS_RW,
4883 		},
4884 		{},
4885 	};
4886 	/* Sets access right on directories inside both layers. */
4887 	const struct rule layer3_subdirs[] = {
4888 		{
4889 			.path = lower_dl1,
4890 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4891 		},
4892 		{
4893 			.path = lower_do1,
4894 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4895 		},
4896 		{
4897 			.path = upper_du1,
4898 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4899 		},
4900 		{
4901 			.path = upper_do1,
4902 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4903 		},
4904 		{
4905 			.path = merge_dl1,
4906 			.access = ACCESS_RW,
4907 		},
4908 		{
4909 			.path = merge_du1,
4910 			.access = ACCESS_RW,
4911 		},
4912 		{
4913 			.path = merge_do1,
4914 			.access = ACCESS_RW,
4915 		},
4916 		{},
4917 	};
4918 	/* Tighten access rights to the files. */
4919 	const struct rule layer4_files[] = {
4920 		{
4921 			.path = lower_dl1_fl2,
4922 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4923 		},
4924 		{
4925 			.path = lower_do1_fo2,
4926 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4927 		},
4928 		{
4929 			.path = lower_do1_fl3,
4930 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4931 		},
4932 		{
4933 			.path = upper_du1_fu2,
4934 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4935 		},
4936 		{
4937 			.path = upper_do1_fo2,
4938 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4939 		},
4940 		{
4941 			.path = upper_do1_fu3,
4942 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
4943 		},
4944 		{
4945 			.path = merge_dl1_fl2,
4946 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
4947 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
4948 		},
4949 		{
4950 			.path = merge_du1_fu2,
4951 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
4952 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
4953 		},
4954 		{
4955 			.path = merge_do1_fo2,
4956 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
4957 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
4958 		},
4959 		{
4960 			.path = merge_do1_fl3,
4961 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
4962 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
4963 		},
4964 		{
4965 			.path = merge_do1_fu3,
4966 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
4967 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
4968 		},
4969 		{},
4970 	};
4971 	const struct rule layer5_merge_only[] = {
4972 		{
4973 			.path = MERGE_DATA,
4974 			.access = LANDLOCK_ACCESS_FS_READ_FILE |
4975 				  LANDLOCK_ACCESS_FS_WRITE_FILE,
4976 		},
4977 		{},
4978 	};
4979 	int ruleset_fd;
4980 	size_t i;
4981 	const char *path_entry;
4982 
4983 	if (self->skip_test)
4984 		SKIP(return, "overlayfs is not supported (test)");
4985 
4986 	/* Sets rules on base directories (i.e. outside overlay scope). */
4987 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_base);
4988 	ASSERT_LE(0, ruleset_fd);
4989 	enforce_ruleset(_metadata, ruleset_fd);
4990 	ASSERT_EQ(0, close(ruleset_fd));
4991 
4992 	/* Checks lower layer. */
4993 	for_each_path(lower_base_files, path_entry, i) {
4994 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
4995 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
4996 	}
4997 	for_each_path(lower_base_directories, path_entry, i) {
4998 		ASSERT_EQ(EACCES,
4999 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5000 	}
5001 	for_each_path(lower_sub_files, path_entry, i) {
5002 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5003 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5004 	}
5005 	/* Checks upper layer. */
5006 	for_each_path(upper_base_files, path_entry, i) {
5007 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5008 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5009 	}
5010 	for_each_path(upper_base_directories, path_entry, i) {
5011 		ASSERT_EQ(EACCES,
5012 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5013 	}
5014 	for_each_path(upper_sub_files, path_entry, i) {
5015 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5016 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5017 	}
5018 	/*
5019 	 * Checks that access rights are independent from the lower and upper
5020 	 * layers: write access to upper files viewed through the merge point
5021 	 * is still allowed, and write access to lower file viewed (and copied)
5022 	 * through the merge point is still allowed.
5023 	 */
5024 	for_each_path(merge_base_files, path_entry, i) {
5025 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5026 	}
5027 	for_each_path(merge_base_directories, path_entry, i) {
5028 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY | O_DIRECTORY));
5029 	}
5030 	for_each_path(merge_sub_files, path_entry, i) {
5031 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5032 	}
5033 
5034 	/* Sets rules on data directories (i.e. inside overlay scope). */
5035 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer2_data);
5036 	ASSERT_LE(0, ruleset_fd);
5037 	enforce_ruleset(_metadata, ruleset_fd);
5038 	ASSERT_EQ(0, close(ruleset_fd));
5039 
5040 	/* Checks merge. */
5041 	for_each_path(merge_base_files, path_entry, i) {
5042 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5043 	}
5044 	for_each_path(merge_base_directories, path_entry, i) {
5045 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY | O_DIRECTORY));
5046 	}
5047 	for_each_path(merge_sub_files, path_entry, i) {
5048 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5049 	}
5050 
5051 	/* Same checks with tighter rules. */
5052 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer3_subdirs);
5053 	ASSERT_LE(0, ruleset_fd);
5054 	enforce_ruleset(_metadata, ruleset_fd);
5055 	ASSERT_EQ(0, close(ruleset_fd));
5056 
5057 	/* Checks changes for lower layer. */
5058 	for_each_path(lower_base_files, path_entry, i) {
5059 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5060 	}
5061 	/* Checks changes for upper layer. */
5062 	for_each_path(upper_base_files, path_entry, i) {
5063 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5064 	}
5065 	/* Checks all merge accesses. */
5066 	for_each_path(merge_base_files, path_entry, i) {
5067 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDWR));
5068 	}
5069 	for_each_path(merge_base_directories, path_entry, i) {
5070 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY | O_DIRECTORY));
5071 	}
5072 	for_each_path(merge_sub_files, path_entry, i) {
5073 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5074 	}
5075 
5076 	/* Sets rules directly on overlayed files. */
5077 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer4_files);
5078 	ASSERT_LE(0, ruleset_fd);
5079 	enforce_ruleset(_metadata, ruleset_fd);
5080 	ASSERT_EQ(0, close(ruleset_fd));
5081 
5082 	/* Checks unchanged accesses on lower layer. */
5083 	for_each_path(lower_sub_files, path_entry, i) {
5084 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5085 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5086 	}
5087 	/* Checks unchanged accesses on upper layer. */
5088 	for_each_path(upper_sub_files, path_entry, i) {
5089 		ASSERT_EQ(0, test_open(path_entry, O_RDONLY));
5090 		ASSERT_EQ(EACCES, test_open(path_entry, O_WRONLY));
5091 	}
5092 	/* Checks all merge accesses. */
5093 	for_each_path(merge_base_files, path_entry, i) {
5094 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDWR));
5095 	}
5096 	for_each_path(merge_base_directories, path_entry, i) {
5097 		ASSERT_EQ(EACCES,
5098 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5099 	}
5100 	for_each_path(merge_sub_files, path_entry, i) {
5101 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5102 	}
5103 
5104 	/* Only allowes access to the merge hierarchy. */
5105 	ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer5_merge_only);
5106 	ASSERT_LE(0, ruleset_fd);
5107 	enforce_ruleset(_metadata, ruleset_fd);
5108 	ASSERT_EQ(0, close(ruleset_fd));
5109 
5110 	/* Checks new accesses on lower layer. */
5111 	for_each_path(lower_sub_files, path_entry, i) {
5112 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5113 	}
5114 	/* Checks new accesses on upper layer. */
5115 	for_each_path(upper_sub_files, path_entry, i) {
5116 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDONLY));
5117 	}
5118 	/* Checks all merge accesses. */
5119 	for_each_path(merge_base_files, path_entry, i) {
5120 		ASSERT_EQ(EACCES, test_open(path_entry, O_RDWR));
5121 	}
5122 	for_each_path(merge_base_directories, path_entry, i) {
5123 		ASSERT_EQ(EACCES,
5124 			  test_open(path_entry, O_RDONLY | O_DIRECTORY));
5125 	}
5126 	for_each_path(merge_sub_files, path_entry, i) {
5127 		ASSERT_EQ(0, test_open(path_entry, O_RDWR));
5128 	}
5129 }
5130 
5131 FIXTURE(layout3_fs)
5132 {
5133 	bool has_created_dir;
5134 	bool has_created_file;
5135 	bool skip_test;
5136 };
5137 
5138 FIXTURE_VARIANT(layout3_fs)
5139 {
5140 	const struct mnt_opt mnt;
5141 	const char *const file_path;
5142 	unsigned int cwd_fs_magic;
5143 };
5144 
5145 /* clang-format off */
5146 FIXTURE_VARIANT_ADD(layout3_fs, tmpfs) {
5147 	/* clang-format on */
5148 	.mnt = {
5149 		.type = "tmpfs",
5150 		.data = MNT_TMP_DATA,
5151 	},
5152 	.file_path = file1_s1d1,
5153 };
5154 
5155 FIXTURE_VARIANT_ADD(layout3_fs, ramfs) {
5156 	.mnt = {
5157 		.type = "ramfs",
5158 		.data = "mode=700",
5159 	},
5160 	.file_path = TMP_DIR "/dir/file",
5161 };
5162 
5163 FIXTURE_VARIANT_ADD(layout3_fs, cgroup2) {
5164 	.mnt = {
5165 		.type = "cgroup2",
5166 	},
5167 	.file_path = TMP_DIR "/test/cgroup.procs",
5168 };
5169 
5170 FIXTURE_VARIANT_ADD(layout3_fs, proc) {
5171 	.mnt = {
5172 		.type = "proc",
5173 	},
5174 	.file_path = TMP_DIR "/self/status",
5175 };
5176 
5177 FIXTURE_VARIANT_ADD(layout3_fs, sysfs) {
5178 	.mnt = {
5179 		.type = "sysfs",
5180 	},
5181 	.file_path = TMP_DIR "/kernel/notes",
5182 };
5183 
5184 FIXTURE_VARIANT_ADD(layout3_fs, hostfs) {
5185 	.mnt = {
5186 		.source = TMP_DIR,
5187 		.flags = MS_BIND,
5188 	},
5189 	.file_path = TMP_DIR "/dir/file",
5190 	.cwd_fs_magic = HOSTFS_SUPER_MAGIC,
5191 };
5192 
5193 static char *dirname_alloc(const char *path)
5194 {
5195 	char *dup;
5196 
5197 	if (!path)
5198 		return NULL;
5199 
5200 	dup = strdup(path);
5201 	if (!dup)
5202 		return NULL;
5203 
5204 	return dirname(dup);
5205 }
5206 
5207 FIXTURE_SETUP(layout3_fs)
5208 {
5209 	struct stat statbuf;
5210 	char *dir_path = dirname_alloc(variant->file_path);
5211 
5212 	if (!supports_filesystem(variant->mnt.type) ||
5213 	    !cwd_matches_fs(variant->cwd_fs_magic)) {
5214 		self->skip_test = true;
5215 		SKIP(return, "this filesystem is not supported (setup)");
5216 	}
5217 
5218 	prepare_layout_opt(_metadata, &variant->mnt);
5219 
5220 	/* Creates directory when required. */
5221 	if (stat(dir_path, &statbuf)) {
5222 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5223 		EXPECT_EQ(0, mkdir(dir_path, 0700))
5224 		{
5225 			TH_LOG("Failed to create directory \"%s\": %s",
5226 			       dir_path, strerror(errno));
5227 		}
5228 		self->has_created_dir = true;
5229 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5230 	}
5231 
5232 	/* Creates file when required. */
5233 	if (stat(variant->file_path, &statbuf)) {
5234 		int fd;
5235 
5236 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5237 		fd = creat(variant->file_path, 0600);
5238 		EXPECT_LE(0, fd)
5239 		{
5240 			TH_LOG("Failed to create file \"%s\": %s",
5241 			       variant->file_path, strerror(errno));
5242 		}
5243 		EXPECT_EQ(0, close(fd));
5244 		self->has_created_file = true;
5245 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5246 	}
5247 
5248 	free(dir_path);
5249 }
5250 
5251 FIXTURE_TEARDOWN_PARENT(layout3_fs)
5252 {
5253 	if (self->skip_test)
5254 		SKIP(return, "this filesystem is not supported (teardown)");
5255 
5256 	if (self->has_created_file) {
5257 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5258 		/*
5259 		 * Don't check for error because the file might already
5260 		 * have been removed (cf. release_inode test).
5261 		 */
5262 		unlink(variant->file_path);
5263 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5264 	}
5265 
5266 	if (self->has_created_dir) {
5267 		char *dir_path = dirname_alloc(variant->file_path);
5268 
5269 		set_cap(_metadata, CAP_DAC_OVERRIDE);
5270 		/*
5271 		 * Don't check for error because the directory might already
5272 		 * have been removed (cf. release_inode test).
5273 		 */
5274 		rmdir(dir_path);
5275 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
5276 		free(dir_path);
5277 	}
5278 
5279 	cleanup_layout(_metadata);
5280 }
5281 
5282 static void layer3_fs_tag_inode(struct __test_metadata *const _metadata,
5283 				FIXTURE_DATA(layout3_fs) * self,
5284 				const FIXTURE_VARIANT(layout3_fs) * variant,
5285 				const char *const rule_path)
5286 {
5287 	const struct rule layer1_allow_read_file[] = {
5288 		{
5289 			.path = rule_path,
5290 			.access = LANDLOCK_ACCESS_FS_READ_FILE,
5291 		},
5292 		{},
5293 	};
5294 	const struct landlock_ruleset_attr layer2_deny_everything_attr = {
5295 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
5296 	};
5297 	const char *const dev_null_path = "/dev/null";
5298 	int ruleset_fd;
5299 
5300 	if (self->skip_test)
5301 		SKIP(return, "this filesystem is not supported (test)");
5302 
5303 	/* Checks without Landlock. */
5304 	EXPECT_EQ(0, test_open(dev_null_path, O_RDONLY | O_CLOEXEC));
5305 	EXPECT_EQ(0, test_open(variant->file_path, O_RDONLY | O_CLOEXEC));
5306 
5307 	ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_FILE,
5308 				    layer1_allow_read_file);
5309 	EXPECT_LE(0, ruleset_fd);
5310 	enforce_ruleset(_metadata, ruleset_fd);
5311 	EXPECT_EQ(0, close(ruleset_fd));
5312 
5313 	EXPECT_EQ(EACCES, test_open(dev_null_path, O_RDONLY | O_CLOEXEC));
5314 	EXPECT_EQ(0, test_open(variant->file_path, O_RDONLY | O_CLOEXEC));
5315 
5316 	/* Forbids directory reading. */
5317 	ruleset_fd =
5318 		landlock_create_ruleset(&layer2_deny_everything_attr,
5319 					sizeof(layer2_deny_everything_attr), 0);
5320 	EXPECT_LE(0, ruleset_fd);
5321 	enforce_ruleset(_metadata, ruleset_fd);
5322 	EXPECT_EQ(0, close(ruleset_fd));
5323 
5324 	/* Checks with Landlock and forbidden access. */
5325 	EXPECT_EQ(EACCES, test_open(dev_null_path, O_RDONLY | O_CLOEXEC));
5326 	EXPECT_EQ(EACCES, test_open(variant->file_path, O_RDONLY | O_CLOEXEC));
5327 }
5328 
5329 /* Matrix of tests to check file hierarchy evaluation. */
5330 
5331 TEST_F_FORK(layout3_fs, tag_inode_dir_parent)
5332 {
5333 	/* The current directory must not be the root for this test. */
5334 	layer3_fs_tag_inode(_metadata, self, variant, ".");
5335 }
5336 
5337 TEST_F_FORK(layout3_fs, tag_inode_dir_mnt)
5338 {
5339 	layer3_fs_tag_inode(_metadata, self, variant, TMP_DIR);
5340 }
5341 
5342 TEST_F_FORK(layout3_fs, tag_inode_dir_child)
5343 {
5344 	char *dir_path = dirname_alloc(variant->file_path);
5345 
5346 	layer3_fs_tag_inode(_metadata, self, variant, dir_path);
5347 	free(dir_path);
5348 }
5349 
5350 TEST_F_FORK(layout3_fs, tag_inode_file)
5351 {
5352 	layer3_fs_tag_inode(_metadata, self, variant, variant->file_path);
5353 }
5354 
5355 /* Light version of layout1.release_inodes */
5356 TEST_F_FORK(layout3_fs, release_inodes)
5357 {
5358 	const struct rule layer1[] = {
5359 		{
5360 			.path = TMP_DIR,
5361 			.access = LANDLOCK_ACCESS_FS_READ_DIR,
5362 		},
5363 		{},
5364 	};
5365 	int ruleset_fd;
5366 
5367 	if (self->skip_test)
5368 		SKIP(return, "this filesystem is not supported (test)");
5369 
5370 	/* Clean up for the teardown to not fail. */
5371 	if (self->has_created_file)
5372 		EXPECT_EQ(0, remove_path(variant->file_path));
5373 
5374 	if (self->has_created_dir) {
5375 		char *dir_path = dirname_alloc(variant->file_path);
5376 
5377 		/* Don't check for error because of cgroup specificities. */
5378 		remove_path(dir_path);
5379 		free(dir_path);
5380 	}
5381 
5382 	ruleset_fd =
5383 		create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_DIR, layer1);
5384 	ASSERT_LE(0, ruleset_fd);
5385 
5386 	/* Unmount the filesystem while it is being used by a ruleset. */
5387 	set_cap(_metadata, CAP_SYS_ADMIN);
5388 	ASSERT_EQ(0, umount(TMP_DIR));
5389 	clear_cap(_metadata, CAP_SYS_ADMIN);
5390 
5391 	/* Replaces with a new mount point to simplify FIXTURE_TEARDOWN. */
5392 	set_cap(_metadata, CAP_SYS_ADMIN);
5393 	ASSERT_EQ(0, mount_opt(&mnt_tmp, TMP_DIR));
5394 	clear_cap(_metadata, CAP_SYS_ADMIN);
5395 
5396 	enforce_ruleset(_metadata, ruleset_fd);
5397 	ASSERT_EQ(0, close(ruleset_fd));
5398 
5399 	/* Checks that access to the new mount point is denied. */
5400 	ASSERT_EQ(EACCES, test_open(TMP_DIR, O_RDONLY));
5401 }
5402 
5403 TEST_HARNESS_MAIN
5404