1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 4 * 5 * Test code for seccomp bpf. 6 */ 7 8 #define _GNU_SOURCE 9 #include <sys/types.h> 10 11 /* 12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that, 13 * we need to use the kernel's siginfo.h file and trick glibc 14 * into accepting it. 15 */ 16 #if !__GLIBC_PREREQ(2, 26) 17 # include <asm/siginfo.h> 18 # define __have_siginfo_t 1 19 # define __have_sigval_t 1 20 # define __have_sigevent_t 1 21 #endif 22 23 #include <errno.h> 24 #include <linux/filter.h> 25 #include <sys/prctl.h> 26 #include <sys/ptrace.h> 27 #include <sys/user.h> 28 #include <linux/prctl.h> 29 #include <linux/ptrace.h> 30 #include <linux/seccomp.h> 31 #include <pthread.h> 32 #include <semaphore.h> 33 #include <signal.h> 34 #include <stddef.h> 35 #include <stdbool.h> 36 #include <string.h> 37 #include <time.h> 38 #include <limits.h> 39 #include <linux/elf.h> 40 #include <sys/uio.h> 41 #include <sys/utsname.h> 42 #include <sys/fcntl.h> 43 #include <sys/mman.h> 44 #include <sys/times.h> 45 #include <sys/socket.h> 46 #include <sys/ioctl.h> 47 #include <linux/kcmp.h> 48 #include <sys/resource.h> 49 50 #include <unistd.h> 51 #include <sys/syscall.h> 52 #include <poll.h> 53 54 #include "../kselftest_harness.h" 55 #include "../clone3/clone3_selftests.h" 56 57 /* Attempt to de-conflict with the selftests tree. */ 58 #ifndef SKIP 59 #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) 60 #endif 61 62 #ifndef PR_SET_PTRACER 63 # define PR_SET_PTRACER 0x59616d61 64 #endif 65 66 #ifndef PR_SET_NO_NEW_PRIVS 67 #define PR_SET_NO_NEW_PRIVS 38 68 #define PR_GET_NO_NEW_PRIVS 39 69 #endif 70 71 #ifndef PR_SECCOMP_EXT 72 #define PR_SECCOMP_EXT 43 73 #endif 74 75 #ifndef SECCOMP_EXT_ACT 76 #define SECCOMP_EXT_ACT 1 77 #endif 78 79 #ifndef SECCOMP_EXT_ACT_TSYNC 80 #define SECCOMP_EXT_ACT_TSYNC 1 81 #endif 82 83 #ifndef SECCOMP_MODE_STRICT 84 #define SECCOMP_MODE_STRICT 1 85 #endif 86 87 #ifndef SECCOMP_MODE_FILTER 88 #define SECCOMP_MODE_FILTER 2 89 #endif 90 91 #ifndef SECCOMP_RET_ALLOW 92 struct seccomp_data { 93 int nr; 94 __u32 arch; 95 __u64 instruction_pointer; 96 __u64 args[6]; 97 }; 98 #endif 99 100 #ifndef SECCOMP_RET_KILL_PROCESS 101 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */ 102 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */ 103 #endif 104 #ifndef SECCOMP_RET_KILL 105 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD 106 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ 107 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ 108 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ 109 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ 110 #endif 111 #ifndef SECCOMP_RET_LOG 112 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */ 113 #endif 114 115 #ifndef __NR_seccomp 116 # if defined(__i386__) 117 # define __NR_seccomp 354 118 # elif defined(__x86_64__) 119 # define __NR_seccomp 317 120 # elif defined(__arm__) 121 # define __NR_seccomp 383 122 # elif defined(__aarch64__) 123 # define __NR_seccomp 277 124 # elif defined(__riscv) 125 # define __NR_seccomp 277 126 # elif defined(__csky__) 127 # define __NR_seccomp 277 128 # elif defined(__hppa__) 129 # define __NR_seccomp 338 130 # elif defined(__powerpc__) 131 # define __NR_seccomp 358 132 # elif defined(__s390__) 133 # define __NR_seccomp 348 134 # elif defined(__xtensa__) 135 # define __NR_seccomp 337 136 # elif defined(__sh__) 137 # define __NR_seccomp 372 138 # else 139 # warning "seccomp syscall number unknown for this architecture" 140 # define __NR_seccomp 0xffff 141 # endif 142 #endif 143 144 #ifndef SECCOMP_SET_MODE_STRICT 145 #define SECCOMP_SET_MODE_STRICT 0 146 #endif 147 148 #ifndef SECCOMP_SET_MODE_FILTER 149 #define SECCOMP_SET_MODE_FILTER 1 150 #endif 151 152 #ifndef SECCOMP_GET_ACTION_AVAIL 153 #define SECCOMP_GET_ACTION_AVAIL 2 154 #endif 155 156 #ifndef SECCOMP_GET_NOTIF_SIZES 157 #define SECCOMP_GET_NOTIF_SIZES 3 158 #endif 159 160 #ifndef SECCOMP_FILTER_FLAG_TSYNC 161 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0) 162 #endif 163 164 #ifndef SECCOMP_FILTER_FLAG_LOG 165 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1) 166 #endif 167 168 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW 169 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2) 170 #endif 171 172 #ifndef PTRACE_SECCOMP_GET_METADATA 173 #define PTRACE_SECCOMP_GET_METADATA 0x420d 174 175 struct seccomp_metadata { 176 __u64 filter_off; /* Input: which filter */ 177 __u64 flags; /* Output: filter's flags */ 178 }; 179 #endif 180 181 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER 182 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3) 183 #endif 184 185 #ifndef SECCOMP_RET_USER_NOTIF 186 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U 187 188 #define SECCOMP_IOC_MAGIC '!' 189 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr) 190 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type) 191 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type) 192 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type) 193 194 /* Flags for seccomp notification fd ioctl. */ 195 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif) 196 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \ 197 struct seccomp_notif_resp) 198 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64) 199 200 struct seccomp_notif { 201 __u64 id; 202 __u32 pid; 203 __u32 flags; 204 struct seccomp_data data; 205 }; 206 207 struct seccomp_notif_resp { 208 __u64 id; 209 __s64 val; 210 __s32 error; 211 __u32 flags; 212 }; 213 214 struct seccomp_notif_sizes { 215 __u16 seccomp_notif; 216 __u16 seccomp_notif_resp; 217 __u16 seccomp_data; 218 }; 219 #endif 220 221 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD 222 /* On success, the return value is the remote process's added fd number */ 223 #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ 224 struct seccomp_notif_addfd) 225 226 /* valid flags for seccomp_notif_addfd */ 227 #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ 228 229 struct seccomp_notif_addfd { 230 __u64 id; 231 __u32 flags; 232 __u32 srcfd; 233 __u32 newfd; 234 __u32 newfd_flags; 235 }; 236 #endif 237 238 struct seccomp_notif_addfd_small { 239 __u64 id; 240 char weird[4]; 241 }; 242 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \ 243 SECCOMP_IOW(3, struct seccomp_notif_addfd_small) 244 245 struct seccomp_notif_addfd_big { 246 union { 247 struct seccomp_notif_addfd addfd; 248 char buf[sizeof(struct seccomp_notif_addfd) + 8]; 249 }; 250 }; 251 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \ 252 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big) 253 254 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY 255 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 256 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2 257 #endif 258 259 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE 260 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001 261 #endif 262 263 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH 264 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4) 265 #endif 266 267 #ifndef seccomp 268 int seccomp(unsigned int op, unsigned int flags, void *args) 269 { 270 errno = 0; 271 return syscall(__NR_seccomp, op, flags, args); 272 } 273 #endif 274 275 #if __BYTE_ORDER == __LITTLE_ENDIAN 276 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) 277 #elif __BYTE_ORDER == __BIG_ENDIAN 278 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) 279 #else 280 #error "wut? Unknown __BYTE_ORDER?!" 281 #endif 282 283 #define SIBLING_EXIT_UNKILLED 0xbadbeef 284 #define SIBLING_EXIT_FAILURE 0xbadface 285 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed 286 287 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2) 288 { 289 #ifdef __NR_kcmp 290 errno = 0; 291 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2); 292 #else 293 errno = ENOSYS; 294 return -1; 295 #endif 296 } 297 298 /* Have TH_LOG report actual location filecmp() is used. */ 299 #define filecmp(pid1, pid2, fd1, fd2) ({ \ 300 int _ret; \ 301 \ 302 _ret = __filecmp(pid1, pid2, fd1, fd2); \ 303 if (_ret != 0) { \ 304 if (_ret < 0 && errno == ENOSYS) { \ 305 TH_LOG("kcmp() syscall missing (test is less accurate)");\ 306 _ret = 0; \ 307 } \ 308 } \ 309 _ret; }) 310 311 TEST(kcmp) 312 { 313 int ret; 314 315 ret = __filecmp(getpid(), getpid(), 1, 1); 316 EXPECT_EQ(ret, 0); 317 if (ret != 0 && errno == ENOSYS) 318 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_CHECKPOINT_RESTORE?)"); 319 } 320 321 TEST(mode_strict_support) 322 { 323 long ret; 324 325 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 326 ASSERT_EQ(0, ret) { 327 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 328 } 329 syscall(__NR_exit, 0); 330 } 331 332 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) 333 { 334 long ret; 335 336 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 337 ASSERT_EQ(0, ret) { 338 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 339 } 340 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 341 NULL, NULL, NULL); 342 EXPECT_FALSE(true) { 343 TH_LOG("Unreachable!"); 344 } 345 } 346 347 /* Note! This doesn't test no new privs behavior */ 348 TEST(no_new_privs_support) 349 { 350 long ret; 351 352 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 353 EXPECT_EQ(0, ret) { 354 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 355 } 356 } 357 358 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */ 359 TEST(mode_filter_support) 360 { 361 long ret; 362 363 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 364 ASSERT_EQ(0, ret) { 365 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 366 } 367 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); 368 EXPECT_EQ(-1, ret); 369 EXPECT_EQ(EFAULT, errno) { 370 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); 371 } 372 } 373 374 TEST(mode_filter_without_nnp) 375 { 376 struct sock_filter filter[] = { 377 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 378 }; 379 struct sock_fprog prog = { 380 .len = (unsigned short)ARRAY_SIZE(filter), 381 .filter = filter, 382 }; 383 long ret; 384 385 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); 386 ASSERT_LE(0, ret) { 387 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); 388 } 389 errno = 0; 390 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 391 /* Succeeds with CAP_SYS_ADMIN, fails without */ 392 /* TODO(wad) check caps not euid */ 393 if (geteuid()) { 394 EXPECT_EQ(-1, ret); 395 EXPECT_EQ(EACCES, errno); 396 } else { 397 EXPECT_EQ(0, ret); 398 } 399 } 400 401 #define MAX_INSNS_PER_PATH 32768 402 403 TEST(filter_size_limits) 404 { 405 int i; 406 int count = BPF_MAXINSNS + 1; 407 struct sock_filter allow[] = { 408 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 409 }; 410 struct sock_filter *filter; 411 struct sock_fprog prog = { }; 412 long ret; 413 414 filter = calloc(count, sizeof(*filter)); 415 ASSERT_NE(NULL, filter); 416 417 for (i = 0; i < count; i++) 418 filter[i] = allow[0]; 419 420 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 421 ASSERT_EQ(0, ret); 422 423 prog.filter = filter; 424 prog.len = count; 425 426 /* Too many filter instructions in a single filter. */ 427 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 428 ASSERT_NE(0, ret) { 429 TH_LOG("Installing %d insn filter was allowed", prog.len); 430 } 431 432 /* One less is okay, though. */ 433 prog.len -= 1; 434 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 435 ASSERT_EQ(0, ret) { 436 TH_LOG("Installing %d insn filter wasn't allowed", prog.len); 437 } 438 } 439 440 TEST(filter_chain_limits) 441 { 442 int i; 443 int count = BPF_MAXINSNS; 444 struct sock_filter allow[] = { 445 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 446 }; 447 struct sock_filter *filter; 448 struct sock_fprog prog = { }; 449 long ret; 450 451 filter = calloc(count, sizeof(*filter)); 452 ASSERT_NE(NULL, filter); 453 454 for (i = 0; i < count; i++) 455 filter[i] = allow[0]; 456 457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 458 ASSERT_EQ(0, ret); 459 460 prog.filter = filter; 461 prog.len = 1; 462 463 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 464 ASSERT_EQ(0, ret); 465 466 prog.len = count; 467 468 /* Too many total filter instructions. */ 469 for (i = 0; i < MAX_INSNS_PER_PATH; i++) { 470 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 471 if (ret != 0) 472 break; 473 } 474 ASSERT_NE(0, ret) { 475 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", 476 i, count, i * (count + 4)); 477 } 478 } 479 480 TEST(mode_filter_cannot_move_to_strict) 481 { 482 struct sock_filter filter[] = { 483 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 484 }; 485 struct sock_fprog prog = { 486 .len = (unsigned short)ARRAY_SIZE(filter), 487 .filter = filter, 488 }; 489 long ret; 490 491 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 492 ASSERT_EQ(0, ret); 493 494 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 495 ASSERT_EQ(0, ret); 496 497 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); 498 EXPECT_EQ(-1, ret); 499 EXPECT_EQ(EINVAL, errno); 500 } 501 502 503 TEST(mode_filter_get_seccomp) 504 { 505 struct sock_filter filter[] = { 506 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 507 }; 508 struct sock_fprog prog = { 509 .len = (unsigned short)ARRAY_SIZE(filter), 510 .filter = filter, 511 }; 512 long ret; 513 514 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 515 ASSERT_EQ(0, ret); 516 517 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 518 EXPECT_EQ(0, ret); 519 520 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 521 ASSERT_EQ(0, ret); 522 523 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 524 EXPECT_EQ(2, ret); 525 } 526 527 528 TEST(ALLOW_all) 529 { 530 struct sock_filter filter[] = { 531 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 532 }; 533 struct sock_fprog prog = { 534 .len = (unsigned short)ARRAY_SIZE(filter), 535 .filter = filter, 536 }; 537 long ret; 538 539 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 540 ASSERT_EQ(0, ret); 541 542 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 543 ASSERT_EQ(0, ret); 544 } 545 546 TEST(empty_prog) 547 { 548 struct sock_filter filter[] = { 549 }; 550 struct sock_fprog prog = { 551 .len = (unsigned short)ARRAY_SIZE(filter), 552 .filter = filter, 553 }; 554 long ret; 555 556 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 557 ASSERT_EQ(0, ret); 558 559 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 560 EXPECT_EQ(-1, ret); 561 EXPECT_EQ(EINVAL, errno); 562 } 563 564 TEST(log_all) 565 { 566 struct sock_filter filter[] = { 567 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 568 }; 569 struct sock_fprog prog = { 570 .len = (unsigned short)ARRAY_SIZE(filter), 571 .filter = filter, 572 }; 573 long ret; 574 pid_t parent = getppid(); 575 576 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 577 ASSERT_EQ(0, ret); 578 579 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 580 ASSERT_EQ(0, ret); 581 582 /* getppid() should succeed and be logged (no check for logging) */ 583 EXPECT_EQ(parent, syscall(__NR_getppid)); 584 } 585 586 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) 587 { 588 struct sock_filter filter[] = { 589 BPF_STMT(BPF_RET|BPF_K, 0x10000000U), 590 }; 591 struct sock_fprog prog = { 592 .len = (unsigned short)ARRAY_SIZE(filter), 593 .filter = filter, 594 }; 595 long ret; 596 597 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 598 ASSERT_EQ(0, ret); 599 600 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 601 ASSERT_EQ(0, ret); 602 EXPECT_EQ(0, syscall(__NR_getpid)) { 603 TH_LOG("getpid() shouldn't ever return"); 604 } 605 } 606 607 /* return code >= 0x80000000 is unused. */ 608 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) 609 { 610 struct sock_filter filter[] = { 611 BPF_STMT(BPF_RET|BPF_K, 0x90000000U), 612 }; 613 struct sock_fprog prog = { 614 .len = (unsigned short)ARRAY_SIZE(filter), 615 .filter = filter, 616 }; 617 long ret; 618 619 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 620 ASSERT_EQ(0, ret); 621 622 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 623 ASSERT_EQ(0, ret); 624 EXPECT_EQ(0, syscall(__NR_getpid)) { 625 TH_LOG("getpid() shouldn't ever return"); 626 } 627 } 628 629 TEST_SIGNAL(KILL_all, SIGSYS) 630 { 631 struct sock_filter filter[] = { 632 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 633 }; 634 struct sock_fprog prog = { 635 .len = (unsigned short)ARRAY_SIZE(filter), 636 .filter = filter, 637 }; 638 long ret; 639 640 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 641 ASSERT_EQ(0, ret); 642 643 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 644 ASSERT_EQ(0, ret); 645 } 646 647 TEST_SIGNAL(KILL_one, SIGSYS) 648 { 649 struct sock_filter filter[] = { 650 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 651 offsetof(struct seccomp_data, nr)), 652 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 653 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 654 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 655 }; 656 struct sock_fprog prog = { 657 .len = (unsigned short)ARRAY_SIZE(filter), 658 .filter = filter, 659 }; 660 long ret; 661 pid_t parent = getppid(); 662 663 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 664 ASSERT_EQ(0, ret); 665 666 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 667 ASSERT_EQ(0, ret); 668 669 EXPECT_EQ(parent, syscall(__NR_getppid)); 670 /* getpid() should never return. */ 671 EXPECT_EQ(0, syscall(__NR_getpid)); 672 } 673 674 TEST_SIGNAL(KILL_one_arg_one, SIGSYS) 675 { 676 void *fatal_address; 677 struct sock_filter filter[] = { 678 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 679 offsetof(struct seccomp_data, nr)), 680 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0), 681 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 682 /* Only both with lower 32-bit for now. */ 683 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), 684 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 685 (unsigned long)&fatal_address, 0, 1), 686 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 687 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 688 }; 689 struct sock_fprog prog = { 690 .len = (unsigned short)ARRAY_SIZE(filter), 691 .filter = filter, 692 }; 693 long ret; 694 pid_t parent = getppid(); 695 struct tms timebuf; 696 clock_t clock = times(&timebuf); 697 698 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 699 ASSERT_EQ(0, ret); 700 701 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 702 ASSERT_EQ(0, ret); 703 704 EXPECT_EQ(parent, syscall(__NR_getppid)); 705 EXPECT_LE(clock, syscall(__NR_times, &timebuf)); 706 /* times() should never return. */ 707 EXPECT_EQ(0, syscall(__NR_times, &fatal_address)); 708 } 709 710 TEST_SIGNAL(KILL_one_arg_six, SIGSYS) 711 { 712 #ifndef __NR_mmap2 713 int sysno = __NR_mmap; 714 #else 715 int sysno = __NR_mmap2; 716 #endif 717 struct sock_filter filter[] = { 718 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 719 offsetof(struct seccomp_data, nr)), 720 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0), 721 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 722 /* Only both with lower 32-bit for now. */ 723 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), 724 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), 725 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 726 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 727 }; 728 struct sock_fprog prog = { 729 .len = (unsigned short)ARRAY_SIZE(filter), 730 .filter = filter, 731 }; 732 long ret; 733 pid_t parent = getppid(); 734 int fd; 735 void *map1, *map2; 736 int page_size = sysconf(_SC_PAGESIZE); 737 738 ASSERT_LT(0, page_size); 739 740 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 741 ASSERT_EQ(0, ret); 742 743 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 744 ASSERT_EQ(0, ret); 745 746 fd = open("/dev/zero", O_RDONLY); 747 ASSERT_NE(-1, fd); 748 749 EXPECT_EQ(parent, syscall(__NR_getppid)); 750 map1 = (void *)syscall(sysno, 751 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size); 752 EXPECT_NE(MAP_FAILED, map1); 753 /* mmap2() should never return. */ 754 map2 = (void *)syscall(sysno, 755 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE); 756 EXPECT_EQ(MAP_FAILED, map2); 757 758 /* The test failed, so clean up the resources. */ 759 munmap(map1, page_size); 760 munmap(map2, page_size); 761 close(fd); 762 } 763 764 /* This is a thread task to die via seccomp filter violation. */ 765 void *kill_thread(void *data) 766 { 767 bool die = (bool)data; 768 769 if (die) { 770 prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 771 return (void *)SIBLING_EXIT_FAILURE; 772 } 773 774 return (void *)SIBLING_EXIT_UNKILLED; 775 } 776 777 enum kill_t { 778 KILL_THREAD, 779 KILL_PROCESS, 780 RET_UNKNOWN 781 }; 782 783 /* Prepare a thread that will kill itself or both of us. */ 784 void kill_thread_or_group(struct __test_metadata *_metadata, 785 enum kill_t kill_how) 786 { 787 pthread_t thread; 788 void *status; 789 /* Kill only when calling __NR_prctl. */ 790 struct sock_filter filter_thread[] = { 791 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 792 offsetof(struct seccomp_data, nr)), 793 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 794 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), 795 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 796 }; 797 struct sock_fprog prog_thread = { 798 .len = (unsigned short)ARRAY_SIZE(filter_thread), 799 .filter = filter_thread, 800 }; 801 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAAA; 802 struct sock_filter filter_process[] = { 803 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 804 offsetof(struct seccomp_data, nr)), 805 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 806 BPF_STMT(BPF_RET|BPF_K, kill), 807 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 808 }; 809 struct sock_fprog prog_process = { 810 .len = (unsigned short)ARRAY_SIZE(filter_process), 811 .filter = filter_process, 812 }; 813 814 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 815 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 816 } 817 818 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, 819 kill_how == KILL_THREAD ? &prog_thread 820 : &prog_process)); 821 822 /* 823 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS 824 * flag cannot be downgraded by a new filter. 825 */ 826 if (kill_how == KILL_PROCESS) 827 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread)); 828 829 /* Start a thread that will exit immediately. */ 830 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false)); 831 ASSERT_EQ(0, pthread_join(thread, &status)); 832 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status); 833 834 /* Start a thread that will die immediately. */ 835 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true)); 836 ASSERT_EQ(0, pthread_join(thread, &status)); 837 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status); 838 839 /* 840 * If we get here, only the spawned thread died. Let the parent know 841 * the whole process didn't die (i.e. this thread, the spawner, 842 * stayed running). 843 */ 844 exit(42); 845 } 846 847 TEST(KILL_thread) 848 { 849 int status; 850 pid_t child_pid; 851 852 child_pid = fork(); 853 ASSERT_LE(0, child_pid); 854 if (child_pid == 0) { 855 kill_thread_or_group(_metadata, KILL_THREAD); 856 _exit(38); 857 } 858 859 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 860 861 /* If only the thread was killed, we'll see exit 42. */ 862 ASSERT_TRUE(WIFEXITED(status)); 863 ASSERT_EQ(42, WEXITSTATUS(status)); 864 } 865 866 TEST(KILL_process) 867 { 868 int status; 869 pid_t child_pid; 870 871 child_pid = fork(); 872 ASSERT_LE(0, child_pid); 873 if (child_pid == 0) { 874 kill_thread_or_group(_metadata, KILL_PROCESS); 875 _exit(38); 876 } 877 878 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 879 880 /* If the entire process was killed, we'll see SIGSYS. */ 881 ASSERT_TRUE(WIFSIGNALED(status)); 882 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 883 } 884 885 TEST(KILL_unknown) 886 { 887 int status; 888 pid_t child_pid; 889 890 child_pid = fork(); 891 ASSERT_LE(0, child_pid); 892 if (child_pid == 0) { 893 kill_thread_or_group(_metadata, RET_UNKNOWN); 894 _exit(38); 895 } 896 897 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 898 899 /* If the entire process was killed, we'll see SIGSYS. */ 900 EXPECT_TRUE(WIFSIGNALED(status)) { 901 TH_LOG("Unknown SECCOMP_RET is only killing the thread?"); 902 } 903 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 904 } 905 906 /* TODO(wad) add 64-bit versus 32-bit arg tests. */ 907 TEST(arg_out_of_range) 908 { 909 struct sock_filter filter[] = { 910 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), 911 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 912 }; 913 struct sock_fprog prog = { 914 .len = (unsigned short)ARRAY_SIZE(filter), 915 .filter = filter, 916 }; 917 long ret; 918 919 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 920 ASSERT_EQ(0, ret); 921 922 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 923 EXPECT_EQ(-1, ret); 924 EXPECT_EQ(EINVAL, errno); 925 } 926 927 #define ERRNO_FILTER(name, errno) \ 928 struct sock_filter _read_filter_##name[] = { \ 929 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \ 930 offsetof(struct seccomp_data, nr)), \ 931 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \ 932 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \ 933 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \ 934 }; \ 935 struct sock_fprog prog_##name = { \ 936 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \ 937 .filter = _read_filter_##name, \ 938 } 939 940 /* Make sure basic errno values are correctly passed through a filter. */ 941 TEST(ERRNO_valid) 942 { 943 ERRNO_FILTER(valid, E2BIG); 944 long ret; 945 pid_t parent = getppid(); 946 947 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 948 ASSERT_EQ(0, ret); 949 950 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid); 951 ASSERT_EQ(0, ret); 952 953 EXPECT_EQ(parent, syscall(__NR_getppid)); 954 EXPECT_EQ(-1, read(0, NULL, 0)); 955 EXPECT_EQ(E2BIG, errno); 956 } 957 958 /* Make sure an errno of zero is correctly handled by the arch code. */ 959 TEST(ERRNO_zero) 960 { 961 ERRNO_FILTER(zero, 0); 962 long ret; 963 pid_t parent = getppid(); 964 965 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 966 ASSERT_EQ(0, ret); 967 968 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero); 969 ASSERT_EQ(0, ret); 970 971 EXPECT_EQ(parent, syscall(__NR_getppid)); 972 /* "errno" of 0 is ok. */ 973 EXPECT_EQ(0, read(0, NULL, 0)); 974 } 975 976 /* 977 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller. 978 * This tests that the errno value gets capped correctly, fixed by 979 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO"). 980 */ 981 TEST(ERRNO_capped) 982 { 983 ERRNO_FILTER(capped, 4096); 984 long ret; 985 pid_t parent = getppid(); 986 987 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 988 ASSERT_EQ(0, ret); 989 990 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped); 991 ASSERT_EQ(0, ret); 992 993 EXPECT_EQ(parent, syscall(__NR_getppid)); 994 EXPECT_EQ(-1, read(0, NULL, 0)); 995 EXPECT_EQ(4095, errno); 996 } 997 998 /* 999 * Filters are processed in reverse order: last applied is executed first. 1000 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the 1001 * SECCOMP_RET_DATA mask results will follow the most recently applied 1002 * matching filter return (and not the lowest or highest value). 1003 */ 1004 TEST(ERRNO_order) 1005 { 1006 ERRNO_FILTER(first, 11); 1007 ERRNO_FILTER(second, 13); 1008 ERRNO_FILTER(third, 12); 1009 long ret; 1010 pid_t parent = getppid(); 1011 1012 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1013 ASSERT_EQ(0, ret); 1014 1015 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first); 1016 ASSERT_EQ(0, ret); 1017 1018 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second); 1019 ASSERT_EQ(0, ret); 1020 1021 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third); 1022 ASSERT_EQ(0, ret); 1023 1024 EXPECT_EQ(parent, syscall(__NR_getppid)); 1025 EXPECT_EQ(-1, read(0, NULL, 0)); 1026 EXPECT_EQ(12, errno); 1027 } 1028 1029 FIXTURE(TRAP) { 1030 struct sock_fprog prog; 1031 }; 1032 1033 FIXTURE_SETUP(TRAP) 1034 { 1035 struct sock_filter filter[] = { 1036 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1037 offsetof(struct seccomp_data, nr)), 1038 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 1039 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 1040 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1041 }; 1042 1043 memset(&self->prog, 0, sizeof(self->prog)); 1044 self->prog.filter = malloc(sizeof(filter)); 1045 ASSERT_NE(NULL, self->prog.filter); 1046 memcpy(self->prog.filter, filter, sizeof(filter)); 1047 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1048 } 1049 1050 FIXTURE_TEARDOWN(TRAP) 1051 { 1052 if (self->prog.filter) 1053 free(self->prog.filter); 1054 } 1055 1056 TEST_F_SIGNAL(TRAP, dfl, SIGSYS) 1057 { 1058 long ret; 1059 1060 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1061 ASSERT_EQ(0, ret); 1062 1063 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1064 ASSERT_EQ(0, ret); 1065 syscall(__NR_getpid); 1066 } 1067 1068 /* Ensure that SIGSYS overrides SIG_IGN */ 1069 TEST_F_SIGNAL(TRAP, ign, SIGSYS) 1070 { 1071 long ret; 1072 1073 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1074 ASSERT_EQ(0, ret); 1075 1076 signal(SIGSYS, SIG_IGN); 1077 1078 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1079 ASSERT_EQ(0, ret); 1080 syscall(__NR_getpid); 1081 } 1082 1083 static siginfo_t TRAP_info; 1084 static volatile int TRAP_nr; 1085 static void TRAP_action(int nr, siginfo_t *info, void *void_context) 1086 { 1087 memcpy(&TRAP_info, info, sizeof(TRAP_info)); 1088 TRAP_nr = nr; 1089 } 1090 1091 TEST_F(TRAP, handler) 1092 { 1093 int ret, test; 1094 struct sigaction act; 1095 sigset_t mask; 1096 1097 memset(&act, 0, sizeof(act)); 1098 sigemptyset(&mask); 1099 sigaddset(&mask, SIGSYS); 1100 1101 act.sa_sigaction = &TRAP_action; 1102 act.sa_flags = SA_SIGINFO; 1103 ret = sigaction(SIGSYS, &act, NULL); 1104 ASSERT_EQ(0, ret) { 1105 TH_LOG("sigaction failed"); 1106 } 1107 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); 1108 ASSERT_EQ(0, ret) { 1109 TH_LOG("sigprocmask failed"); 1110 } 1111 1112 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1113 ASSERT_EQ(0, ret); 1114 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1115 ASSERT_EQ(0, ret); 1116 TRAP_nr = 0; 1117 memset(&TRAP_info, 0, sizeof(TRAP_info)); 1118 /* Expect the registers to be rolled back. (nr = error) may vary 1119 * based on arch. */ 1120 ret = syscall(__NR_getpid); 1121 /* Silence gcc warning about volatile. */ 1122 test = TRAP_nr; 1123 EXPECT_EQ(SIGSYS, test); 1124 struct local_sigsys { 1125 void *_call_addr; /* calling user insn */ 1126 int _syscall; /* triggering system call number */ 1127 unsigned int _arch; /* AUDIT_ARCH_* of syscall */ 1128 } *sigsys = (struct local_sigsys *) 1129 #ifdef si_syscall 1130 &(TRAP_info.si_call_addr); 1131 #else 1132 &TRAP_info.si_pid; 1133 #endif 1134 EXPECT_EQ(__NR_getpid, sigsys->_syscall); 1135 /* Make sure arch is non-zero. */ 1136 EXPECT_NE(0, sigsys->_arch); 1137 EXPECT_NE(0, (unsigned long)sigsys->_call_addr); 1138 } 1139 1140 FIXTURE(precedence) { 1141 struct sock_fprog allow; 1142 struct sock_fprog log; 1143 struct sock_fprog trace; 1144 struct sock_fprog error; 1145 struct sock_fprog trap; 1146 struct sock_fprog kill; 1147 }; 1148 1149 FIXTURE_SETUP(precedence) 1150 { 1151 struct sock_filter allow_insns[] = { 1152 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1153 }; 1154 struct sock_filter log_insns[] = { 1155 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1156 offsetof(struct seccomp_data, nr)), 1157 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1158 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1159 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 1160 }; 1161 struct sock_filter trace_insns[] = { 1162 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1163 offsetof(struct seccomp_data, nr)), 1164 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1165 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1166 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), 1167 }; 1168 struct sock_filter error_insns[] = { 1169 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1170 offsetof(struct seccomp_data, nr)), 1171 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1172 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1173 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), 1174 }; 1175 struct sock_filter trap_insns[] = { 1176 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1177 offsetof(struct seccomp_data, nr)), 1178 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1179 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1180 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 1181 }; 1182 struct sock_filter kill_insns[] = { 1183 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1184 offsetof(struct seccomp_data, nr)), 1185 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1186 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1187 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1188 }; 1189 1190 memset(self, 0, sizeof(*self)); 1191 #define FILTER_ALLOC(_x) \ 1192 self->_x.filter = malloc(sizeof(_x##_insns)); \ 1193 ASSERT_NE(NULL, self->_x.filter); \ 1194 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ 1195 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) 1196 FILTER_ALLOC(allow); 1197 FILTER_ALLOC(log); 1198 FILTER_ALLOC(trace); 1199 FILTER_ALLOC(error); 1200 FILTER_ALLOC(trap); 1201 FILTER_ALLOC(kill); 1202 } 1203 1204 FIXTURE_TEARDOWN(precedence) 1205 { 1206 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) 1207 FILTER_FREE(allow); 1208 FILTER_FREE(log); 1209 FILTER_FREE(trace); 1210 FILTER_FREE(error); 1211 FILTER_FREE(trap); 1212 FILTER_FREE(kill); 1213 } 1214 1215 TEST_F(precedence, allow_ok) 1216 { 1217 pid_t parent, res = 0; 1218 long ret; 1219 1220 parent = getppid(); 1221 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1222 ASSERT_EQ(0, ret); 1223 1224 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1225 ASSERT_EQ(0, ret); 1226 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1227 ASSERT_EQ(0, ret); 1228 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1229 ASSERT_EQ(0, ret); 1230 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1231 ASSERT_EQ(0, ret); 1232 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1233 ASSERT_EQ(0, ret); 1234 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1235 ASSERT_EQ(0, ret); 1236 /* Should work just fine. */ 1237 res = syscall(__NR_getppid); 1238 EXPECT_EQ(parent, res); 1239 } 1240 1241 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) 1242 { 1243 pid_t parent, res = 0; 1244 long ret; 1245 1246 parent = getppid(); 1247 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1248 ASSERT_EQ(0, ret); 1249 1250 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1251 ASSERT_EQ(0, ret); 1252 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1253 ASSERT_EQ(0, ret); 1254 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1255 ASSERT_EQ(0, ret); 1256 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1257 ASSERT_EQ(0, ret); 1258 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1259 ASSERT_EQ(0, ret); 1260 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1261 ASSERT_EQ(0, ret); 1262 /* Should work just fine. */ 1263 res = syscall(__NR_getppid); 1264 EXPECT_EQ(parent, res); 1265 /* getpid() should never return. */ 1266 res = syscall(__NR_getpid); 1267 EXPECT_EQ(0, res); 1268 } 1269 1270 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) 1271 { 1272 pid_t parent; 1273 long ret; 1274 1275 parent = getppid(); 1276 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1277 ASSERT_EQ(0, ret); 1278 1279 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1280 ASSERT_EQ(0, ret); 1281 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1282 ASSERT_EQ(0, ret); 1283 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1284 ASSERT_EQ(0, ret); 1285 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1286 ASSERT_EQ(0, ret); 1287 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1288 ASSERT_EQ(0, ret); 1289 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1290 ASSERT_EQ(0, ret); 1291 /* Should work just fine. */ 1292 EXPECT_EQ(parent, syscall(__NR_getppid)); 1293 /* getpid() should never return. */ 1294 EXPECT_EQ(0, syscall(__NR_getpid)); 1295 } 1296 1297 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) 1298 { 1299 pid_t parent; 1300 long ret; 1301 1302 parent = getppid(); 1303 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1304 ASSERT_EQ(0, ret); 1305 1306 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1307 ASSERT_EQ(0, ret); 1308 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1309 ASSERT_EQ(0, ret); 1310 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1311 ASSERT_EQ(0, ret); 1312 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1313 ASSERT_EQ(0, ret); 1314 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1315 ASSERT_EQ(0, ret); 1316 /* Should work just fine. */ 1317 EXPECT_EQ(parent, syscall(__NR_getppid)); 1318 /* getpid() should never return. */ 1319 EXPECT_EQ(0, syscall(__NR_getpid)); 1320 } 1321 1322 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) 1323 { 1324 pid_t parent; 1325 long ret; 1326 1327 parent = getppid(); 1328 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1329 ASSERT_EQ(0, ret); 1330 1331 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1332 ASSERT_EQ(0, ret); 1333 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1334 ASSERT_EQ(0, ret); 1335 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1336 ASSERT_EQ(0, ret); 1337 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1338 ASSERT_EQ(0, ret); 1339 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1340 ASSERT_EQ(0, ret); 1341 /* Should work just fine. */ 1342 EXPECT_EQ(parent, syscall(__NR_getppid)); 1343 /* getpid() should never return. */ 1344 EXPECT_EQ(0, syscall(__NR_getpid)); 1345 } 1346 1347 TEST_F(precedence, errno_is_third) 1348 { 1349 pid_t parent; 1350 long ret; 1351 1352 parent = getppid(); 1353 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1354 ASSERT_EQ(0, ret); 1355 1356 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1357 ASSERT_EQ(0, ret); 1358 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1359 ASSERT_EQ(0, ret); 1360 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1361 ASSERT_EQ(0, ret); 1362 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1363 ASSERT_EQ(0, ret); 1364 /* Should work just fine. */ 1365 EXPECT_EQ(parent, syscall(__NR_getppid)); 1366 EXPECT_EQ(0, syscall(__NR_getpid)); 1367 } 1368 1369 TEST_F(precedence, errno_is_third_in_any_order) 1370 { 1371 pid_t parent; 1372 long ret; 1373 1374 parent = getppid(); 1375 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1376 ASSERT_EQ(0, ret); 1377 1378 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1379 ASSERT_EQ(0, ret); 1380 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1381 ASSERT_EQ(0, ret); 1382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1383 ASSERT_EQ(0, ret); 1384 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1385 ASSERT_EQ(0, ret); 1386 /* Should work just fine. */ 1387 EXPECT_EQ(parent, syscall(__NR_getppid)); 1388 EXPECT_EQ(0, syscall(__NR_getpid)); 1389 } 1390 1391 TEST_F(precedence, trace_is_fourth) 1392 { 1393 pid_t parent; 1394 long ret; 1395 1396 parent = getppid(); 1397 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1398 ASSERT_EQ(0, ret); 1399 1400 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1401 ASSERT_EQ(0, ret); 1402 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1403 ASSERT_EQ(0, ret); 1404 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1405 ASSERT_EQ(0, ret); 1406 /* Should work just fine. */ 1407 EXPECT_EQ(parent, syscall(__NR_getppid)); 1408 /* No ptracer */ 1409 EXPECT_EQ(-1, syscall(__NR_getpid)); 1410 } 1411 1412 TEST_F(precedence, trace_is_fourth_in_any_order) 1413 { 1414 pid_t parent; 1415 long ret; 1416 1417 parent = getppid(); 1418 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1419 ASSERT_EQ(0, ret); 1420 1421 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1422 ASSERT_EQ(0, ret); 1423 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1424 ASSERT_EQ(0, ret); 1425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1426 ASSERT_EQ(0, ret); 1427 /* Should work just fine. */ 1428 EXPECT_EQ(parent, syscall(__NR_getppid)); 1429 /* No ptracer */ 1430 EXPECT_EQ(-1, syscall(__NR_getpid)); 1431 } 1432 1433 TEST_F(precedence, log_is_fifth) 1434 { 1435 pid_t mypid, parent; 1436 long ret; 1437 1438 mypid = getpid(); 1439 parent = getppid(); 1440 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1441 ASSERT_EQ(0, ret); 1442 1443 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1444 ASSERT_EQ(0, ret); 1445 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1446 ASSERT_EQ(0, ret); 1447 /* Should work just fine. */ 1448 EXPECT_EQ(parent, syscall(__NR_getppid)); 1449 /* Should also work just fine */ 1450 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1451 } 1452 1453 TEST_F(precedence, log_is_fifth_in_any_order) 1454 { 1455 pid_t mypid, parent; 1456 long ret; 1457 1458 mypid = getpid(); 1459 parent = getppid(); 1460 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1461 ASSERT_EQ(0, ret); 1462 1463 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1464 ASSERT_EQ(0, ret); 1465 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1466 ASSERT_EQ(0, ret); 1467 /* Should work just fine. */ 1468 EXPECT_EQ(parent, syscall(__NR_getppid)); 1469 /* Should also work just fine */ 1470 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1471 } 1472 1473 #ifndef PTRACE_O_TRACESECCOMP 1474 #define PTRACE_O_TRACESECCOMP 0x00000080 1475 #endif 1476 1477 /* Catch the Ubuntu 12.04 value error. */ 1478 #if PTRACE_EVENT_SECCOMP != 7 1479 #undef PTRACE_EVENT_SECCOMP 1480 #endif 1481 1482 #ifndef PTRACE_EVENT_SECCOMP 1483 #define PTRACE_EVENT_SECCOMP 7 1484 #endif 1485 1486 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP) 1487 bool tracer_running; 1488 void tracer_stop(int sig) 1489 { 1490 tracer_running = false; 1491 } 1492 1493 typedef void tracer_func_t(struct __test_metadata *_metadata, 1494 pid_t tracee, int status, void *args); 1495 1496 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, 1497 tracer_func_t tracer_func, void *args, bool ptrace_syscall) 1498 { 1499 int ret = -1; 1500 struct sigaction action = { 1501 .sa_handler = tracer_stop, 1502 }; 1503 1504 /* Allow external shutdown. */ 1505 tracer_running = true; 1506 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); 1507 1508 errno = 0; 1509 while (ret == -1 && errno != EINVAL) 1510 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); 1511 ASSERT_EQ(0, ret) { 1512 kill(tracee, SIGKILL); 1513 } 1514 /* Wait for attach stop */ 1515 wait(NULL); 1516 1517 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ? 1518 PTRACE_O_TRACESYSGOOD : 1519 PTRACE_O_TRACESECCOMP); 1520 ASSERT_EQ(0, ret) { 1521 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); 1522 kill(tracee, SIGKILL); 1523 } 1524 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1525 tracee, NULL, 0); 1526 ASSERT_EQ(0, ret); 1527 1528 /* Unblock the tracee */ 1529 ASSERT_EQ(1, write(fd, "A", 1)); 1530 ASSERT_EQ(0, close(fd)); 1531 1532 /* Run until we're shut down. Must assert to stop execution. */ 1533 while (tracer_running) { 1534 int status; 1535 1536 if (wait(&status) != tracee) 1537 continue; 1538 if (WIFSIGNALED(status) || WIFEXITED(status)) 1539 /* Child is dead. Time to go. */ 1540 return; 1541 1542 /* Check if this is a seccomp event. */ 1543 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status)); 1544 1545 tracer_func(_metadata, tracee, status, args); 1546 1547 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1548 tracee, NULL, 0); 1549 ASSERT_EQ(0, ret); 1550 } 1551 /* Directly report the status of our test harness results. */ 1552 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 1553 } 1554 1555 /* Common tracer setup/teardown functions. */ 1556 void cont_handler(int num) 1557 { } 1558 pid_t setup_trace_fixture(struct __test_metadata *_metadata, 1559 tracer_func_t func, void *args, bool ptrace_syscall) 1560 { 1561 char sync; 1562 int pipefd[2]; 1563 pid_t tracer_pid; 1564 pid_t tracee = getpid(); 1565 1566 /* Setup a pipe for clean synchronization. */ 1567 ASSERT_EQ(0, pipe(pipefd)); 1568 1569 /* Fork a child which we'll promote to tracer */ 1570 tracer_pid = fork(); 1571 ASSERT_LE(0, tracer_pid); 1572 signal(SIGALRM, cont_handler); 1573 if (tracer_pid == 0) { 1574 close(pipefd[0]); 1575 start_tracer(_metadata, pipefd[1], tracee, func, args, 1576 ptrace_syscall); 1577 syscall(__NR_exit, 0); 1578 } 1579 close(pipefd[1]); 1580 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); 1581 read(pipefd[0], &sync, 1); 1582 close(pipefd[0]); 1583 1584 return tracer_pid; 1585 } 1586 1587 void teardown_trace_fixture(struct __test_metadata *_metadata, 1588 pid_t tracer) 1589 { 1590 if (tracer) { 1591 int status; 1592 /* 1593 * Extract the exit code from the other process and 1594 * adopt it for ourselves in case its asserts failed. 1595 */ 1596 ASSERT_EQ(0, kill(tracer, SIGUSR1)); 1597 ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); 1598 if (WEXITSTATUS(status)) 1599 _metadata->passed = 0; 1600 } 1601 } 1602 1603 /* "poke" tracer arguments and function. */ 1604 struct tracer_args_poke_t { 1605 unsigned long poke_addr; 1606 }; 1607 1608 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, 1609 void *args) 1610 { 1611 int ret; 1612 unsigned long msg; 1613 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; 1614 1615 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1616 EXPECT_EQ(0, ret); 1617 /* If this fails, don't try to recover. */ 1618 ASSERT_EQ(0x1001, msg) { 1619 kill(tracee, SIGKILL); 1620 } 1621 /* 1622 * Poke in the message. 1623 * Registers are not touched to try to keep this relatively arch 1624 * agnostic. 1625 */ 1626 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); 1627 EXPECT_EQ(0, ret); 1628 } 1629 1630 FIXTURE(TRACE_poke) { 1631 struct sock_fprog prog; 1632 pid_t tracer; 1633 long poked; 1634 struct tracer_args_poke_t tracer_args; 1635 }; 1636 1637 FIXTURE_SETUP(TRACE_poke) 1638 { 1639 struct sock_filter filter[] = { 1640 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1641 offsetof(struct seccomp_data, nr)), 1642 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 1643 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), 1644 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1645 }; 1646 1647 self->poked = 0; 1648 memset(&self->prog, 0, sizeof(self->prog)); 1649 self->prog.filter = malloc(sizeof(filter)); 1650 ASSERT_NE(NULL, self->prog.filter); 1651 memcpy(self->prog.filter, filter, sizeof(filter)); 1652 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1653 1654 /* Set up tracer args. */ 1655 self->tracer_args.poke_addr = (unsigned long)&self->poked; 1656 1657 /* Launch tracer. */ 1658 self->tracer = setup_trace_fixture(_metadata, tracer_poke, 1659 &self->tracer_args, false); 1660 } 1661 1662 FIXTURE_TEARDOWN(TRACE_poke) 1663 { 1664 teardown_trace_fixture(_metadata, self->tracer); 1665 if (self->prog.filter) 1666 free(self->prog.filter); 1667 } 1668 1669 TEST_F(TRACE_poke, read_has_side_effects) 1670 { 1671 ssize_t ret; 1672 1673 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1674 ASSERT_EQ(0, ret); 1675 1676 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1677 ASSERT_EQ(0, ret); 1678 1679 EXPECT_EQ(0, self->poked); 1680 ret = read(-1, NULL, 0); 1681 EXPECT_EQ(-1, ret); 1682 EXPECT_EQ(0x1001, self->poked); 1683 } 1684 1685 TEST_F(TRACE_poke, getpid_runs_normally) 1686 { 1687 long ret; 1688 1689 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1690 ASSERT_EQ(0, ret); 1691 1692 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1693 ASSERT_EQ(0, ret); 1694 1695 EXPECT_EQ(0, self->poked); 1696 EXPECT_NE(0, syscall(__NR_getpid)); 1697 EXPECT_EQ(0, self->poked); 1698 } 1699 1700 #if defined(__x86_64__) 1701 # define ARCH_REGS struct user_regs_struct 1702 # define SYSCALL_NUM(_regs) (_regs).orig_rax 1703 # define SYSCALL_RET(_regs) (_regs).rax 1704 #elif defined(__i386__) 1705 # define ARCH_REGS struct user_regs_struct 1706 # define SYSCALL_NUM(_regs) (_regs).orig_eax 1707 # define SYSCALL_RET(_regs) (_regs).eax 1708 #elif defined(__arm__) 1709 # define ARCH_REGS struct pt_regs 1710 # define SYSCALL_NUM(_regs) (_regs).ARM_r7 1711 # ifndef PTRACE_SET_SYSCALL 1712 # define PTRACE_SET_SYSCALL 23 1713 # endif 1714 # define SYSCALL_NUM_SET(_regs, _nr) \ 1715 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr)) 1716 # define SYSCALL_RET(_regs) (_regs).ARM_r0 1717 #elif defined(__aarch64__) 1718 # define ARCH_REGS struct user_pt_regs 1719 # define SYSCALL_NUM(_regs) (_regs).regs[8] 1720 # ifndef NT_ARM_SYSTEM_CALL 1721 # define NT_ARM_SYSTEM_CALL 0x404 1722 # endif 1723 # define SYSCALL_NUM_SET(_regs, _nr) \ 1724 do { \ 1725 struct iovec __v; \ 1726 typeof(_nr) __nr = (_nr); \ 1727 __v.iov_base = &__nr; \ 1728 __v.iov_len = sizeof(__nr); \ 1729 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \ 1730 NT_ARM_SYSTEM_CALL, &__v)); \ 1731 } while (0) 1732 # define SYSCALL_RET(_regs) (_regs).regs[0] 1733 #elif defined(__riscv) && __riscv_xlen == 64 1734 # define ARCH_REGS struct user_regs_struct 1735 # define SYSCALL_NUM(_regs) (_regs).a7 1736 # define SYSCALL_RET(_regs) (_regs).a0 1737 #elif defined(__csky__) 1738 # define ARCH_REGS struct pt_regs 1739 # if defined(__CSKYABIV2__) 1740 # define SYSCALL_NUM(_regs) (_regs).regs[3] 1741 # else 1742 # define SYSCALL_NUM(_regs) (_regs).regs[9] 1743 # endif 1744 # define SYSCALL_RET(_regs) (_regs).a0 1745 #elif defined(__hppa__) 1746 # define ARCH_REGS struct user_regs_struct 1747 # define SYSCALL_NUM(_regs) (_regs).gr[20] 1748 # define SYSCALL_RET(_regs) (_regs).gr[28] 1749 #elif defined(__powerpc__) 1750 # define ARCH_REGS struct pt_regs 1751 # define SYSCALL_NUM(_regs) (_regs).gpr[0] 1752 # define SYSCALL_RET(_regs) (_regs).gpr[3] 1753 # define SYSCALL_RET_SET(_regs, _val) \ 1754 do { \ 1755 typeof(_val) _result = (_val); \ 1756 /* \ 1757 * A syscall error is signaled by CR0 SO bit \ 1758 * and the code is stored as a positive value. \ 1759 */ \ 1760 if (_result < 0) { \ 1761 SYSCALL_RET(_regs) = -_result; \ 1762 (_regs).ccr |= 0x10000000; \ 1763 } else { \ 1764 SYSCALL_RET(_regs) = _result; \ 1765 (_regs).ccr &= ~0x10000000; \ 1766 } \ 1767 } while (0) 1768 # define SYSCALL_RET_SET_ON_PTRACE_EXIT 1769 #elif defined(__s390__) 1770 # define ARCH_REGS s390_regs 1771 # define SYSCALL_NUM(_regs) (_regs).gprs[2] 1772 # define SYSCALL_RET_SET(_regs, _val) \ 1773 TH_LOG("Can't modify syscall return on this architecture") 1774 #elif defined(__mips__) 1775 # include <asm/unistd_nr_n32.h> 1776 # include <asm/unistd_nr_n64.h> 1777 # include <asm/unistd_nr_o32.h> 1778 # define ARCH_REGS struct pt_regs 1779 # define SYSCALL_NUM(_regs) \ 1780 ({ \ 1781 typeof((_regs).regs[2]) _nr; \ 1782 if ((_regs).regs[2] == __NR_O32_Linux) \ 1783 _nr = (_regs).regs[4]; \ 1784 else \ 1785 _nr = (_regs).regs[2]; \ 1786 _nr; \ 1787 }) 1788 # define SYSCALL_NUM_SET(_regs, _nr) \ 1789 do { \ 1790 if ((_regs).regs[2] == __NR_O32_Linux) \ 1791 (_regs).regs[4] = _nr; \ 1792 else \ 1793 (_regs).regs[2] = _nr; \ 1794 } while (0) 1795 # define SYSCALL_RET_SET(_regs, _val) \ 1796 TH_LOG("Can't modify syscall return on this architecture") 1797 #elif defined(__xtensa__) 1798 # define ARCH_REGS struct user_pt_regs 1799 # define SYSCALL_NUM(_regs) (_regs).syscall 1800 /* 1801 * On xtensa syscall return value is in the register 1802 * a2 of the current window which is not fixed. 1803 */ 1804 #define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2] 1805 #elif defined(__sh__) 1806 # define ARCH_REGS struct pt_regs 1807 # define SYSCALL_NUM(_regs) (_regs).regs[3] 1808 # define SYSCALL_RET(_regs) (_regs).regs[0] 1809 #else 1810 # error "Do not know how to find your architecture's registers and syscalls" 1811 #endif 1812 1813 /* 1814 * Most architectures can change the syscall by just updating the 1815 * associated register. This is the default if not defined above. 1816 */ 1817 #ifndef SYSCALL_NUM_SET 1818 # define SYSCALL_NUM_SET(_regs, _nr) \ 1819 do { \ 1820 SYSCALL_NUM(_regs) = (_nr); \ 1821 } while (0) 1822 #endif 1823 /* 1824 * Most architectures can change the syscall return value by just 1825 * writing to the SYSCALL_RET register. This is the default if not 1826 * defined above. If an architecture cannot set the return value 1827 * (for example when the syscall and return value register is 1828 * shared), report it with TH_LOG() in an arch-specific definition 1829 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined. 1830 */ 1831 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET) 1832 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch" 1833 #endif 1834 #ifndef SYSCALL_RET_SET 1835 # define SYSCALL_RET_SET(_regs, _val) \ 1836 do { \ 1837 SYSCALL_RET(_regs) = (_val); \ 1838 } while (0) 1839 #endif 1840 1841 /* When the syscall return can't be changed, stub out the tests for it. */ 1842 #ifndef SYSCALL_RET 1843 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action) 1844 #else 1845 # define EXPECT_SYSCALL_RETURN(val, action) \ 1846 do { \ 1847 errno = 0; \ 1848 if (val < 0) { \ 1849 EXPECT_EQ(-1, action); \ 1850 EXPECT_EQ(-(val), errno); \ 1851 } else { \ 1852 EXPECT_EQ(val, action); \ 1853 } \ 1854 } while (0) 1855 #endif 1856 1857 /* 1858 * Some architectures (e.g. powerpc) can only set syscall 1859 * return values on syscall exit during ptrace. 1860 */ 1861 const bool ptrace_entry_set_syscall_nr = true; 1862 const bool ptrace_entry_set_syscall_ret = 1863 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT 1864 true; 1865 #else 1866 false; 1867 #endif 1868 1869 /* 1870 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for 1871 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). 1872 */ 1873 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__) 1874 # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs)) 1875 # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs)) 1876 #else 1877 # define ARCH_GETREGS(_regs) ({ \ 1878 struct iovec __v; \ 1879 __v.iov_base = &(_regs); \ 1880 __v.iov_len = sizeof(_regs); \ 1881 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \ 1882 }) 1883 # define ARCH_SETREGS(_regs) ({ \ 1884 struct iovec __v; \ 1885 __v.iov_base = &(_regs); \ 1886 __v.iov_len = sizeof(_regs); \ 1887 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \ 1888 }) 1889 #endif 1890 1891 /* Architecture-specific syscall fetching routine. */ 1892 int get_syscall(struct __test_metadata *_metadata, pid_t tracee) 1893 { 1894 ARCH_REGS regs; 1895 1896 EXPECT_EQ(0, ARCH_GETREGS(regs)) { 1897 return -1; 1898 } 1899 1900 return SYSCALL_NUM(regs); 1901 } 1902 1903 /* Architecture-specific syscall changing routine. */ 1904 void __change_syscall(struct __test_metadata *_metadata, 1905 pid_t tracee, long *syscall, long *ret) 1906 { 1907 ARCH_REGS orig, regs; 1908 1909 /* Do not get/set registers if we have nothing to do. */ 1910 if (!syscall && !ret) 1911 return; 1912 1913 EXPECT_EQ(0, ARCH_GETREGS(regs)) { 1914 return; 1915 } 1916 orig = regs; 1917 1918 if (syscall) 1919 SYSCALL_NUM_SET(regs, *syscall); 1920 1921 if (ret) 1922 SYSCALL_RET_SET(regs, *ret); 1923 1924 /* Flush any register changes made. */ 1925 if (memcmp(&orig, ®s, sizeof(orig)) != 0) 1926 EXPECT_EQ(0, ARCH_SETREGS(regs)); 1927 } 1928 1929 /* Change only syscall number. */ 1930 void change_syscall_nr(struct __test_metadata *_metadata, 1931 pid_t tracee, long syscall) 1932 { 1933 __change_syscall(_metadata, tracee, &syscall, NULL); 1934 } 1935 1936 /* Change syscall return value (and set syscall number to -1). */ 1937 void change_syscall_ret(struct __test_metadata *_metadata, 1938 pid_t tracee, long ret) 1939 { 1940 long syscall = -1; 1941 1942 __change_syscall(_metadata, tracee, &syscall, &ret); 1943 } 1944 1945 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee, 1946 int status, void *args) 1947 { 1948 int ret; 1949 unsigned long msg; 1950 1951 /* Make sure we got the right message. */ 1952 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1953 EXPECT_EQ(0, ret); 1954 1955 /* Validate and take action on expected syscalls. */ 1956 switch (msg) { 1957 case 0x1002: 1958 /* change getpid to getppid. */ 1959 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee)); 1960 change_syscall_nr(_metadata, tracee, __NR_getppid); 1961 break; 1962 case 0x1003: 1963 /* skip gettid with valid return code. */ 1964 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee)); 1965 change_syscall_ret(_metadata, tracee, 45000); 1966 break; 1967 case 0x1004: 1968 /* skip openat with error. */ 1969 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee)); 1970 change_syscall_ret(_metadata, tracee, -ESRCH); 1971 break; 1972 case 0x1005: 1973 /* do nothing (allow getppid) */ 1974 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee)); 1975 break; 1976 default: 1977 EXPECT_EQ(0, msg) { 1978 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); 1979 kill(tracee, SIGKILL); 1980 } 1981 } 1982 1983 } 1984 1985 FIXTURE(TRACE_syscall) { 1986 struct sock_fprog prog; 1987 pid_t tracer, mytid, mypid, parent; 1988 long syscall_nr; 1989 }; 1990 1991 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee, 1992 int status, void *args) 1993 { 1994 int ret; 1995 unsigned long msg; 1996 static bool entry; 1997 long syscall_nr_val, syscall_ret_val; 1998 long *syscall_nr = NULL, *syscall_ret = NULL; 1999 FIXTURE_DATA(TRACE_syscall) *self = args; 2000 2001 /* 2002 * The traditional way to tell PTRACE_SYSCALL entry/exit 2003 * is by counting. 2004 */ 2005 entry = !entry; 2006 2007 /* Make sure we got an appropriate message. */ 2008 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 2009 EXPECT_EQ(0, ret); 2010 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY 2011 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg); 2012 2013 /* 2014 * Some architectures only support setting return values during 2015 * syscall exit under ptrace, and on exit the syscall number may 2016 * no longer be available. Therefore, save the initial sycall 2017 * number here, so it can be examined during both entry and exit 2018 * phases. 2019 */ 2020 if (entry) 2021 self->syscall_nr = get_syscall(_metadata, tracee); 2022 2023 /* 2024 * Depending on the architecture's syscall setting abilities, we 2025 * pick which things to set during this phase (entry or exit). 2026 */ 2027 if (entry == ptrace_entry_set_syscall_nr) 2028 syscall_nr = &syscall_nr_val; 2029 if (entry == ptrace_entry_set_syscall_ret) 2030 syscall_ret = &syscall_ret_val; 2031 2032 /* Now handle the actual rewriting cases. */ 2033 switch (self->syscall_nr) { 2034 case __NR_getpid: 2035 syscall_nr_val = __NR_getppid; 2036 /* Never change syscall return for this case. */ 2037 syscall_ret = NULL; 2038 break; 2039 case __NR_gettid: 2040 syscall_nr_val = -1; 2041 syscall_ret_val = 45000; 2042 break; 2043 case __NR_openat: 2044 syscall_nr_val = -1; 2045 syscall_ret_val = -ESRCH; 2046 break; 2047 default: 2048 /* Unhandled, do nothing. */ 2049 return; 2050 } 2051 2052 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret); 2053 } 2054 2055 FIXTURE_VARIANT(TRACE_syscall) { 2056 /* 2057 * All of the SECCOMP_RET_TRACE behaviors can be tested with either 2058 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL. 2059 * This indicates if we should use SECCOMP_RET_TRACE (false), or 2060 * ptrace (true). 2061 */ 2062 bool use_ptrace; 2063 }; 2064 2065 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) { 2066 .use_ptrace = true, 2067 }; 2068 2069 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) { 2070 .use_ptrace = false, 2071 }; 2072 2073 FIXTURE_SETUP(TRACE_syscall) 2074 { 2075 struct sock_filter filter[] = { 2076 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2077 offsetof(struct seccomp_data, nr)), 2078 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 2079 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), 2080 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), 2081 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), 2082 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1), 2083 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), 2084 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2085 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005), 2086 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2087 }; 2088 struct sock_fprog prog = { 2089 .len = (unsigned short)ARRAY_SIZE(filter), 2090 .filter = filter, 2091 }; 2092 long ret; 2093 2094 /* Prepare some testable syscall results. */ 2095 self->mytid = syscall(__NR_gettid); 2096 ASSERT_GT(self->mytid, 0); 2097 ASSERT_NE(self->mytid, 1) { 2098 TH_LOG("Running this test as init is not supported. :)"); 2099 } 2100 2101 self->mypid = getpid(); 2102 ASSERT_GT(self->mypid, 0); 2103 ASSERT_EQ(self->mytid, self->mypid); 2104 2105 self->parent = getppid(); 2106 ASSERT_GT(self->parent, 0); 2107 ASSERT_NE(self->parent, self->mypid); 2108 2109 /* Launch tracer. */ 2110 self->tracer = setup_trace_fixture(_metadata, 2111 variant->use_ptrace ? tracer_ptrace 2112 : tracer_seccomp, 2113 self, variant->use_ptrace); 2114 2115 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2116 ASSERT_EQ(0, ret); 2117 2118 if (variant->use_ptrace) 2119 return; 2120 2121 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2122 ASSERT_EQ(0, ret); 2123 } 2124 2125 FIXTURE_TEARDOWN(TRACE_syscall) 2126 { 2127 teardown_trace_fixture(_metadata, self->tracer); 2128 } 2129 2130 TEST(negative_ENOSYS) 2131 { 2132 /* 2133 * There should be no difference between an "internal" skip 2134 * and userspace asking for syscall "-1". 2135 */ 2136 errno = 0; 2137 EXPECT_EQ(-1, syscall(-1)); 2138 EXPECT_EQ(errno, ENOSYS); 2139 /* And no difference for "still not valid but not -1". */ 2140 errno = 0; 2141 EXPECT_EQ(-1, syscall(-101)); 2142 EXPECT_EQ(errno, ENOSYS); 2143 } 2144 2145 TEST_F(TRACE_syscall, negative_ENOSYS) 2146 { 2147 negative_ENOSYS(_metadata); 2148 } 2149 2150 TEST_F(TRACE_syscall, syscall_allowed) 2151 { 2152 /* getppid works as expected (no changes). */ 2153 EXPECT_EQ(self->parent, syscall(__NR_getppid)); 2154 EXPECT_NE(self->mypid, syscall(__NR_getppid)); 2155 } 2156 2157 TEST_F(TRACE_syscall, syscall_redirected) 2158 { 2159 /* getpid has been redirected to getppid as expected. */ 2160 EXPECT_EQ(self->parent, syscall(__NR_getpid)); 2161 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 2162 } 2163 2164 TEST_F(TRACE_syscall, syscall_errno) 2165 { 2166 /* Tracer should skip the open syscall, resulting in ESRCH. */ 2167 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat)); 2168 } 2169 2170 TEST_F(TRACE_syscall, syscall_faked) 2171 { 2172 /* Tracer skips the gettid syscall and store altered return value. */ 2173 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid)); 2174 } 2175 2176 TEST_F(TRACE_syscall, skip_after) 2177 { 2178 struct sock_filter filter[] = { 2179 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2180 offsetof(struct seccomp_data, nr)), 2181 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2182 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 2183 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2184 }; 2185 struct sock_fprog prog = { 2186 .len = (unsigned short)ARRAY_SIZE(filter), 2187 .filter = filter, 2188 }; 2189 long ret; 2190 2191 /* Install additional "errno on getppid" filter. */ 2192 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2193 ASSERT_EQ(0, ret); 2194 2195 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 2196 errno = 0; 2197 EXPECT_EQ(-1, syscall(__NR_getpid)); 2198 EXPECT_EQ(EPERM, errno); 2199 } 2200 2201 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS) 2202 { 2203 struct sock_filter filter[] = { 2204 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2205 offsetof(struct seccomp_data, nr)), 2206 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2207 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2208 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2209 }; 2210 struct sock_fprog prog = { 2211 .len = (unsigned short)ARRAY_SIZE(filter), 2212 .filter = filter, 2213 }; 2214 long ret; 2215 2216 /* Install additional "death on getppid" filter. */ 2217 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2218 ASSERT_EQ(0, ret); 2219 2220 /* Tracer will redirect getpid to getppid, and we should die. */ 2221 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 2222 } 2223 2224 TEST(seccomp_syscall) 2225 { 2226 struct sock_filter filter[] = { 2227 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2228 }; 2229 struct sock_fprog prog = { 2230 .len = (unsigned short)ARRAY_SIZE(filter), 2231 .filter = filter, 2232 }; 2233 long ret; 2234 2235 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2236 ASSERT_EQ(0, ret) { 2237 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2238 } 2239 2240 /* Reject insane operation. */ 2241 ret = seccomp(-1, 0, &prog); 2242 ASSERT_NE(ENOSYS, errno) { 2243 TH_LOG("Kernel does not support seccomp syscall!"); 2244 } 2245 EXPECT_EQ(EINVAL, errno) { 2246 TH_LOG("Did not reject crazy op value!"); 2247 } 2248 2249 /* Reject strict with flags or pointer. */ 2250 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); 2251 EXPECT_EQ(EINVAL, errno) { 2252 TH_LOG("Did not reject mode strict with flags!"); 2253 } 2254 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); 2255 EXPECT_EQ(EINVAL, errno) { 2256 TH_LOG("Did not reject mode strict with uargs!"); 2257 } 2258 2259 /* Reject insane args for filter. */ 2260 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); 2261 EXPECT_EQ(EINVAL, errno) { 2262 TH_LOG("Did not reject crazy filter flags!"); 2263 } 2264 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); 2265 EXPECT_EQ(EFAULT, errno) { 2266 TH_LOG("Did not reject NULL filter!"); 2267 } 2268 2269 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2270 EXPECT_EQ(0, errno) { 2271 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", 2272 strerror(errno)); 2273 } 2274 } 2275 2276 TEST(seccomp_syscall_mode_lock) 2277 { 2278 struct sock_filter filter[] = { 2279 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2280 }; 2281 struct sock_fprog prog = { 2282 .len = (unsigned short)ARRAY_SIZE(filter), 2283 .filter = filter, 2284 }; 2285 long ret; 2286 2287 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2288 ASSERT_EQ(0, ret) { 2289 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2290 } 2291 2292 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2293 ASSERT_NE(ENOSYS, errno) { 2294 TH_LOG("Kernel does not support seccomp syscall!"); 2295 } 2296 EXPECT_EQ(0, ret) { 2297 TH_LOG("Could not install filter!"); 2298 } 2299 2300 /* Make sure neither entry point will switch to strict. */ 2301 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); 2302 EXPECT_EQ(EINVAL, errno) { 2303 TH_LOG("Switched to mode strict!"); 2304 } 2305 2306 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); 2307 EXPECT_EQ(EINVAL, errno) { 2308 TH_LOG("Switched to mode strict!"); 2309 } 2310 } 2311 2312 /* 2313 * Test detection of known and unknown filter flags. Userspace needs to be able 2314 * to check if a filter flag is supported by the current kernel and a good way 2315 * of doing that is by attempting to enter filter mode, with the flag bit in 2316 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates 2317 * that the flag is valid and EINVAL indicates that the flag is invalid. 2318 */ 2319 TEST(detect_seccomp_filter_flags) 2320 { 2321 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC, 2322 SECCOMP_FILTER_FLAG_LOG, 2323 SECCOMP_FILTER_FLAG_SPEC_ALLOW, 2324 SECCOMP_FILTER_FLAG_NEW_LISTENER, 2325 SECCOMP_FILTER_FLAG_TSYNC_ESRCH }; 2326 unsigned int exclusive[] = { 2327 SECCOMP_FILTER_FLAG_TSYNC, 2328 SECCOMP_FILTER_FLAG_NEW_LISTENER }; 2329 unsigned int flag, all_flags, exclusive_mask; 2330 int i; 2331 long ret; 2332 2333 /* Test detection of individual known-good filter flags */ 2334 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) { 2335 int bits = 0; 2336 2337 flag = flags[i]; 2338 /* Make sure the flag is a single bit! */ 2339 while (flag) { 2340 if (flag & 0x1) 2341 bits ++; 2342 flag >>= 1; 2343 } 2344 ASSERT_EQ(1, bits); 2345 flag = flags[i]; 2346 2347 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2348 ASSERT_NE(ENOSYS, errno) { 2349 TH_LOG("Kernel does not support seccomp syscall!"); 2350 } 2351 EXPECT_EQ(-1, ret); 2352 EXPECT_EQ(EFAULT, errno) { 2353 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!", 2354 flag); 2355 } 2356 2357 all_flags |= flag; 2358 } 2359 2360 /* 2361 * Test detection of all known-good filter flags combined. But 2362 * for the exclusive flags we need to mask them out and try them 2363 * individually for the "all flags" testing. 2364 */ 2365 exclusive_mask = 0; 2366 for (i = 0; i < ARRAY_SIZE(exclusive); i++) 2367 exclusive_mask |= exclusive[i]; 2368 for (i = 0; i < ARRAY_SIZE(exclusive); i++) { 2369 flag = all_flags & ~exclusive_mask; 2370 flag |= exclusive[i]; 2371 2372 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2373 EXPECT_EQ(-1, ret); 2374 EXPECT_EQ(EFAULT, errno) { 2375 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!", 2376 flag); 2377 } 2378 } 2379 2380 /* Test detection of an unknown filter flags, without exclusives. */ 2381 flag = -1; 2382 flag &= ~exclusive_mask; 2383 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2384 EXPECT_EQ(-1, ret); 2385 EXPECT_EQ(EINVAL, errno) { 2386 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!", 2387 flag); 2388 } 2389 2390 /* 2391 * Test detection of an unknown filter flag that may simply need to be 2392 * added to this test 2393 */ 2394 flag = flags[ARRAY_SIZE(flags) - 1] << 1; 2395 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2396 EXPECT_EQ(-1, ret); 2397 EXPECT_EQ(EINVAL, errno) { 2398 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?", 2399 flag); 2400 } 2401 } 2402 2403 TEST(TSYNC_first) 2404 { 2405 struct sock_filter filter[] = { 2406 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2407 }; 2408 struct sock_fprog prog = { 2409 .len = (unsigned short)ARRAY_SIZE(filter), 2410 .filter = filter, 2411 }; 2412 long ret; 2413 2414 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2415 ASSERT_EQ(0, ret) { 2416 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2417 } 2418 2419 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2420 &prog); 2421 ASSERT_NE(ENOSYS, errno) { 2422 TH_LOG("Kernel does not support seccomp syscall!"); 2423 } 2424 EXPECT_EQ(0, ret) { 2425 TH_LOG("Could not install initial filter with TSYNC!"); 2426 } 2427 } 2428 2429 #define TSYNC_SIBLINGS 2 2430 struct tsync_sibling { 2431 pthread_t tid; 2432 pid_t system_tid; 2433 sem_t *started; 2434 pthread_cond_t *cond; 2435 pthread_mutex_t *mutex; 2436 int diverge; 2437 int num_waits; 2438 struct sock_fprog *prog; 2439 struct __test_metadata *metadata; 2440 }; 2441 2442 /* 2443 * To avoid joining joined threads (which is not allowed by Bionic), 2444 * make sure we both successfully join and clear the tid to skip a 2445 * later join attempt during fixture teardown. Any remaining threads 2446 * will be directly killed during teardown. 2447 */ 2448 #define PTHREAD_JOIN(tid, status) \ 2449 do { \ 2450 int _rc = pthread_join(tid, status); \ 2451 if (_rc) { \ 2452 TH_LOG("pthread_join of tid %u failed: %d\n", \ 2453 (unsigned int)tid, _rc); \ 2454 } else { \ 2455 tid = 0; \ 2456 } \ 2457 } while (0) 2458 2459 FIXTURE(TSYNC) { 2460 struct sock_fprog root_prog, apply_prog; 2461 struct tsync_sibling sibling[TSYNC_SIBLINGS]; 2462 sem_t started; 2463 pthread_cond_t cond; 2464 pthread_mutex_t mutex; 2465 int sibling_count; 2466 }; 2467 2468 FIXTURE_SETUP(TSYNC) 2469 { 2470 struct sock_filter root_filter[] = { 2471 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2472 }; 2473 struct sock_filter apply_filter[] = { 2474 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2475 offsetof(struct seccomp_data, nr)), 2476 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 2477 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2478 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2479 }; 2480 2481 memset(&self->root_prog, 0, sizeof(self->root_prog)); 2482 memset(&self->apply_prog, 0, sizeof(self->apply_prog)); 2483 memset(&self->sibling, 0, sizeof(self->sibling)); 2484 self->root_prog.filter = malloc(sizeof(root_filter)); 2485 ASSERT_NE(NULL, self->root_prog.filter); 2486 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); 2487 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); 2488 2489 self->apply_prog.filter = malloc(sizeof(apply_filter)); 2490 ASSERT_NE(NULL, self->apply_prog.filter); 2491 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); 2492 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); 2493 2494 self->sibling_count = 0; 2495 pthread_mutex_init(&self->mutex, NULL); 2496 pthread_cond_init(&self->cond, NULL); 2497 sem_init(&self->started, 0, 0); 2498 self->sibling[0].tid = 0; 2499 self->sibling[0].cond = &self->cond; 2500 self->sibling[0].started = &self->started; 2501 self->sibling[0].mutex = &self->mutex; 2502 self->sibling[0].diverge = 0; 2503 self->sibling[0].num_waits = 1; 2504 self->sibling[0].prog = &self->root_prog; 2505 self->sibling[0].metadata = _metadata; 2506 self->sibling[1].tid = 0; 2507 self->sibling[1].cond = &self->cond; 2508 self->sibling[1].started = &self->started; 2509 self->sibling[1].mutex = &self->mutex; 2510 self->sibling[1].diverge = 0; 2511 self->sibling[1].prog = &self->root_prog; 2512 self->sibling[1].num_waits = 1; 2513 self->sibling[1].metadata = _metadata; 2514 } 2515 2516 FIXTURE_TEARDOWN(TSYNC) 2517 { 2518 int sib = 0; 2519 2520 if (self->root_prog.filter) 2521 free(self->root_prog.filter); 2522 if (self->apply_prog.filter) 2523 free(self->apply_prog.filter); 2524 2525 for ( ; sib < self->sibling_count; ++sib) { 2526 struct tsync_sibling *s = &self->sibling[sib]; 2527 2528 if (!s->tid) 2529 continue; 2530 /* 2531 * If a thread is still running, it may be stuck, so hit 2532 * it over the head really hard. 2533 */ 2534 pthread_kill(s->tid, 9); 2535 } 2536 pthread_mutex_destroy(&self->mutex); 2537 pthread_cond_destroy(&self->cond); 2538 sem_destroy(&self->started); 2539 } 2540 2541 void *tsync_sibling(void *data) 2542 { 2543 long ret = 0; 2544 struct tsync_sibling *me = data; 2545 2546 me->system_tid = syscall(__NR_gettid); 2547 2548 pthread_mutex_lock(me->mutex); 2549 if (me->diverge) { 2550 /* Just re-apply the root prog to fork the tree */ 2551 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 2552 me->prog, 0, 0); 2553 } 2554 sem_post(me->started); 2555 /* Return outside of started so parent notices failures. */ 2556 if (ret) { 2557 pthread_mutex_unlock(me->mutex); 2558 return (void *)SIBLING_EXIT_FAILURE; 2559 } 2560 do { 2561 pthread_cond_wait(me->cond, me->mutex); 2562 me->num_waits = me->num_waits - 1; 2563 } while (me->num_waits); 2564 pthread_mutex_unlock(me->mutex); 2565 2566 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); 2567 if (!ret) 2568 return (void *)SIBLING_EXIT_NEWPRIVS; 2569 read(0, NULL, 0); 2570 return (void *)SIBLING_EXIT_UNKILLED; 2571 } 2572 2573 void tsync_start_sibling(struct tsync_sibling *sibling) 2574 { 2575 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); 2576 } 2577 2578 TEST_F(TSYNC, siblings_fail_prctl) 2579 { 2580 long ret; 2581 void *status; 2582 struct sock_filter filter[] = { 2583 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2584 offsetof(struct seccomp_data, nr)), 2585 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 2586 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), 2587 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2588 }; 2589 struct sock_fprog prog = { 2590 .len = (unsigned short)ARRAY_SIZE(filter), 2591 .filter = filter, 2592 }; 2593 2594 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2595 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2596 } 2597 2598 /* Check prctl failure detection by requesting sib 0 diverge. */ 2599 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2600 ASSERT_NE(ENOSYS, errno) { 2601 TH_LOG("Kernel does not support seccomp syscall!"); 2602 } 2603 ASSERT_EQ(0, ret) { 2604 TH_LOG("setting filter failed"); 2605 } 2606 2607 self->sibling[0].diverge = 1; 2608 tsync_start_sibling(&self->sibling[0]); 2609 tsync_start_sibling(&self->sibling[1]); 2610 2611 while (self->sibling_count < TSYNC_SIBLINGS) { 2612 sem_wait(&self->started); 2613 self->sibling_count++; 2614 } 2615 2616 /* Signal the threads to clean up*/ 2617 pthread_mutex_lock(&self->mutex); 2618 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2619 TH_LOG("cond broadcast non-zero"); 2620 } 2621 pthread_mutex_unlock(&self->mutex); 2622 2623 /* Ensure diverging sibling failed to call prctl. */ 2624 PTHREAD_JOIN(self->sibling[0].tid, &status); 2625 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); 2626 PTHREAD_JOIN(self->sibling[1].tid, &status); 2627 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2628 } 2629 2630 TEST_F(TSYNC, two_siblings_with_ancestor) 2631 { 2632 long ret; 2633 void *status; 2634 2635 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2636 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2637 } 2638 2639 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2640 ASSERT_NE(ENOSYS, errno) { 2641 TH_LOG("Kernel does not support seccomp syscall!"); 2642 } 2643 ASSERT_EQ(0, ret) { 2644 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2645 } 2646 tsync_start_sibling(&self->sibling[0]); 2647 tsync_start_sibling(&self->sibling[1]); 2648 2649 while (self->sibling_count < TSYNC_SIBLINGS) { 2650 sem_wait(&self->started); 2651 self->sibling_count++; 2652 } 2653 2654 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2655 &self->apply_prog); 2656 ASSERT_EQ(0, ret) { 2657 TH_LOG("Could install filter on all threads!"); 2658 } 2659 /* Tell the siblings to test the policy */ 2660 pthread_mutex_lock(&self->mutex); 2661 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2662 TH_LOG("cond broadcast non-zero"); 2663 } 2664 pthread_mutex_unlock(&self->mutex); 2665 /* Ensure they are both killed and don't exit cleanly. */ 2666 PTHREAD_JOIN(self->sibling[0].tid, &status); 2667 EXPECT_EQ(0x0, (long)status); 2668 PTHREAD_JOIN(self->sibling[1].tid, &status); 2669 EXPECT_EQ(0x0, (long)status); 2670 } 2671 2672 TEST_F(TSYNC, two_sibling_want_nnp) 2673 { 2674 void *status; 2675 2676 /* start siblings before any prctl() operations */ 2677 tsync_start_sibling(&self->sibling[0]); 2678 tsync_start_sibling(&self->sibling[1]); 2679 while (self->sibling_count < TSYNC_SIBLINGS) { 2680 sem_wait(&self->started); 2681 self->sibling_count++; 2682 } 2683 2684 /* Tell the siblings to test no policy */ 2685 pthread_mutex_lock(&self->mutex); 2686 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2687 TH_LOG("cond broadcast non-zero"); 2688 } 2689 pthread_mutex_unlock(&self->mutex); 2690 2691 /* Ensure they are both upset about lacking nnp. */ 2692 PTHREAD_JOIN(self->sibling[0].tid, &status); 2693 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2694 PTHREAD_JOIN(self->sibling[1].tid, &status); 2695 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2696 } 2697 2698 TEST_F(TSYNC, two_siblings_with_no_filter) 2699 { 2700 long ret; 2701 void *status; 2702 2703 /* start siblings before any prctl() operations */ 2704 tsync_start_sibling(&self->sibling[0]); 2705 tsync_start_sibling(&self->sibling[1]); 2706 while (self->sibling_count < TSYNC_SIBLINGS) { 2707 sem_wait(&self->started); 2708 self->sibling_count++; 2709 } 2710 2711 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2712 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2713 } 2714 2715 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2716 &self->apply_prog); 2717 ASSERT_NE(ENOSYS, errno) { 2718 TH_LOG("Kernel does not support seccomp syscall!"); 2719 } 2720 ASSERT_EQ(0, ret) { 2721 TH_LOG("Could install filter on all threads!"); 2722 } 2723 2724 /* Tell the siblings to test the policy */ 2725 pthread_mutex_lock(&self->mutex); 2726 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2727 TH_LOG("cond broadcast non-zero"); 2728 } 2729 pthread_mutex_unlock(&self->mutex); 2730 2731 /* Ensure they are both killed and don't exit cleanly. */ 2732 PTHREAD_JOIN(self->sibling[0].tid, &status); 2733 EXPECT_EQ(0x0, (long)status); 2734 PTHREAD_JOIN(self->sibling[1].tid, &status); 2735 EXPECT_EQ(0x0, (long)status); 2736 } 2737 2738 TEST_F(TSYNC, two_siblings_with_one_divergence) 2739 { 2740 long ret; 2741 void *status; 2742 2743 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2744 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2745 } 2746 2747 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2748 ASSERT_NE(ENOSYS, errno) { 2749 TH_LOG("Kernel does not support seccomp syscall!"); 2750 } 2751 ASSERT_EQ(0, ret) { 2752 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2753 } 2754 self->sibling[0].diverge = 1; 2755 tsync_start_sibling(&self->sibling[0]); 2756 tsync_start_sibling(&self->sibling[1]); 2757 2758 while (self->sibling_count < TSYNC_SIBLINGS) { 2759 sem_wait(&self->started); 2760 self->sibling_count++; 2761 } 2762 2763 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2764 &self->apply_prog); 2765 ASSERT_EQ(self->sibling[0].system_tid, ret) { 2766 TH_LOG("Did not fail on diverged sibling."); 2767 } 2768 2769 /* Wake the threads */ 2770 pthread_mutex_lock(&self->mutex); 2771 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2772 TH_LOG("cond broadcast non-zero"); 2773 } 2774 pthread_mutex_unlock(&self->mutex); 2775 2776 /* Ensure they are both unkilled. */ 2777 PTHREAD_JOIN(self->sibling[0].tid, &status); 2778 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2779 PTHREAD_JOIN(self->sibling[1].tid, &status); 2780 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2781 } 2782 2783 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err) 2784 { 2785 long ret, flags; 2786 void *status; 2787 2788 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2789 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2790 } 2791 2792 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2793 ASSERT_NE(ENOSYS, errno) { 2794 TH_LOG("Kernel does not support seccomp syscall!"); 2795 } 2796 ASSERT_EQ(0, ret) { 2797 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2798 } 2799 self->sibling[0].diverge = 1; 2800 tsync_start_sibling(&self->sibling[0]); 2801 tsync_start_sibling(&self->sibling[1]); 2802 2803 while (self->sibling_count < TSYNC_SIBLINGS) { 2804 sem_wait(&self->started); 2805 self->sibling_count++; 2806 } 2807 2808 flags = SECCOMP_FILTER_FLAG_TSYNC | \ 2809 SECCOMP_FILTER_FLAG_TSYNC_ESRCH; 2810 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog); 2811 ASSERT_EQ(ESRCH, errno) { 2812 TH_LOG("Did not return ESRCH for diverged sibling."); 2813 } 2814 ASSERT_EQ(-1, ret) { 2815 TH_LOG("Did not fail on diverged sibling."); 2816 } 2817 2818 /* Wake the threads */ 2819 pthread_mutex_lock(&self->mutex); 2820 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2821 TH_LOG("cond broadcast non-zero"); 2822 } 2823 pthread_mutex_unlock(&self->mutex); 2824 2825 /* Ensure they are both unkilled. */ 2826 PTHREAD_JOIN(self->sibling[0].tid, &status); 2827 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2828 PTHREAD_JOIN(self->sibling[1].tid, &status); 2829 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2830 } 2831 2832 TEST_F(TSYNC, two_siblings_not_under_filter) 2833 { 2834 long ret, sib; 2835 void *status; 2836 struct timespec delay = { .tv_nsec = 100000000 }; 2837 2838 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2839 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2840 } 2841 2842 /* 2843 * Sibling 0 will have its own seccomp policy 2844 * and Sibling 1 will not be under seccomp at 2845 * all. Sibling 1 will enter seccomp and 0 2846 * will cause failure. 2847 */ 2848 self->sibling[0].diverge = 1; 2849 tsync_start_sibling(&self->sibling[0]); 2850 tsync_start_sibling(&self->sibling[1]); 2851 2852 while (self->sibling_count < TSYNC_SIBLINGS) { 2853 sem_wait(&self->started); 2854 self->sibling_count++; 2855 } 2856 2857 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2858 ASSERT_NE(ENOSYS, errno) { 2859 TH_LOG("Kernel does not support seccomp syscall!"); 2860 } 2861 ASSERT_EQ(0, ret) { 2862 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2863 } 2864 2865 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2866 &self->apply_prog); 2867 ASSERT_EQ(ret, self->sibling[0].system_tid) { 2868 TH_LOG("Did not fail on diverged sibling."); 2869 } 2870 sib = 1; 2871 if (ret == self->sibling[0].system_tid) 2872 sib = 0; 2873 2874 pthread_mutex_lock(&self->mutex); 2875 2876 /* Increment the other siblings num_waits so we can clean up 2877 * the one we just saw. 2878 */ 2879 self->sibling[!sib].num_waits += 1; 2880 2881 /* Signal the thread to clean up*/ 2882 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2883 TH_LOG("cond broadcast non-zero"); 2884 } 2885 pthread_mutex_unlock(&self->mutex); 2886 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2887 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2888 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2889 while (!kill(self->sibling[sib].system_tid, 0)) 2890 nanosleep(&delay, NULL); 2891 /* Switch to the remaining sibling */ 2892 sib = !sib; 2893 2894 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2895 &self->apply_prog); 2896 ASSERT_EQ(0, ret) { 2897 TH_LOG("Expected the remaining sibling to sync"); 2898 }; 2899 2900 pthread_mutex_lock(&self->mutex); 2901 2902 /* If remaining sibling didn't have a chance to wake up during 2903 * the first broadcast, manually reduce the num_waits now. 2904 */ 2905 if (self->sibling[sib].num_waits > 1) 2906 self->sibling[sib].num_waits = 1; 2907 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2908 TH_LOG("cond broadcast non-zero"); 2909 } 2910 pthread_mutex_unlock(&self->mutex); 2911 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2912 EXPECT_EQ(0, (long)status); 2913 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2914 while (!kill(self->sibling[sib].system_tid, 0)) 2915 nanosleep(&delay, NULL); 2916 2917 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2918 &self->apply_prog); 2919 ASSERT_EQ(0, ret); /* just us chickens */ 2920 } 2921 2922 /* Make sure restarted syscalls are seen directly as "restart_syscall". */ 2923 TEST(syscall_restart) 2924 { 2925 long ret; 2926 unsigned long msg; 2927 pid_t child_pid; 2928 int pipefd[2]; 2929 int status; 2930 siginfo_t info = { }; 2931 struct sock_filter filter[] = { 2932 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2933 offsetof(struct seccomp_data, nr)), 2934 2935 #ifdef __NR_sigreturn 2936 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0), 2937 #endif 2938 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0), 2939 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0), 2940 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0), 2941 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0), 2942 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0), 2943 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), 2944 2945 /* Allow __NR_write for easy logging. */ 2946 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), 2947 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2948 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2949 /* The nanosleep jump target. */ 2950 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), 2951 /* The restart_syscall jump target. */ 2952 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), 2953 }; 2954 struct sock_fprog prog = { 2955 .len = (unsigned short)ARRAY_SIZE(filter), 2956 .filter = filter, 2957 }; 2958 #if defined(__arm__) 2959 struct utsname utsbuf; 2960 #endif 2961 2962 ASSERT_EQ(0, pipe(pipefd)); 2963 2964 child_pid = fork(); 2965 ASSERT_LE(0, child_pid); 2966 if (child_pid == 0) { 2967 /* Child uses EXPECT not ASSERT to deliver status correctly. */ 2968 char buf = ' '; 2969 struct timespec timeout = { }; 2970 2971 /* Attach parent as tracer and stop. */ 2972 EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); 2973 EXPECT_EQ(0, raise(SIGSTOP)); 2974 2975 EXPECT_EQ(0, close(pipefd[1])); 2976 2977 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2978 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2979 } 2980 2981 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2982 EXPECT_EQ(0, ret) { 2983 TH_LOG("Failed to install filter!"); 2984 } 2985 2986 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 2987 TH_LOG("Failed to read() sync from parent"); 2988 } 2989 EXPECT_EQ('.', buf) { 2990 TH_LOG("Failed to get sync data from read()"); 2991 } 2992 2993 /* Start nanosleep to be interrupted. */ 2994 timeout.tv_sec = 1; 2995 errno = 0; 2996 EXPECT_EQ(0, nanosleep(&timeout, NULL)) { 2997 TH_LOG("Call to nanosleep() failed (errno %d)", errno); 2998 } 2999 3000 /* Read final sync from parent. */ 3001 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 3002 TH_LOG("Failed final read() from parent"); 3003 } 3004 EXPECT_EQ('!', buf) { 3005 TH_LOG("Failed to get final data from read()"); 3006 } 3007 3008 /* Directly report the status of our test harness results. */ 3009 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS 3010 : EXIT_FAILURE); 3011 } 3012 EXPECT_EQ(0, close(pipefd[0])); 3013 3014 /* Attach to child, setup options, and release. */ 3015 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3016 ASSERT_EQ(true, WIFSTOPPED(status)); 3017 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, 3018 PTRACE_O_TRACESECCOMP)); 3019 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3020 ASSERT_EQ(1, write(pipefd[1], ".", 1)); 3021 3022 /* Wait for nanosleep() to start. */ 3023 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3024 ASSERT_EQ(true, WIFSTOPPED(status)); 3025 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 3026 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 3027 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 3028 ASSERT_EQ(0x100, msg); 3029 ret = get_syscall(_metadata, child_pid); 3030 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep); 3031 3032 /* Might as well check siginfo for sanity while we're here. */ 3033 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 3034 ASSERT_EQ(SIGTRAP, info.si_signo); 3035 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); 3036 EXPECT_EQ(0, info.si_errno); 3037 EXPECT_EQ(getuid(), info.si_uid); 3038 /* Verify signal delivery came from child (seccomp-triggered). */ 3039 EXPECT_EQ(child_pid, info.si_pid); 3040 3041 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */ 3042 ASSERT_EQ(0, kill(child_pid, SIGSTOP)); 3043 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3044 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3045 ASSERT_EQ(true, WIFSTOPPED(status)); 3046 ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); 3047 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 3048 /* 3049 * There is no siginfo on SIGSTOP any more, so we can't verify 3050 * signal delivery came from parent now (getpid() == info.si_pid). 3051 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com 3052 * At least verify the SIGSTOP via PTRACE_GETSIGINFO. 3053 */ 3054 EXPECT_EQ(SIGSTOP, info.si_signo); 3055 3056 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ 3057 ASSERT_EQ(0, kill(child_pid, SIGCONT)); 3058 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3059 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3060 ASSERT_EQ(true, WIFSTOPPED(status)); 3061 ASSERT_EQ(SIGCONT, WSTOPSIG(status)); 3062 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3063 3064 /* Wait for restart_syscall() to start. */ 3065 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3066 ASSERT_EQ(true, WIFSTOPPED(status)); 3067 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 3068 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 3069 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 3070 3071 ASSERT_EQ(0x200, msg); 3072 ret = get_syscall(_metadata, child_pid); 3073 #if defined(__arm__) 3074 /* 3075 * FIXME: 3076 * - native ARM registers do NOT expose true syscall. 3077 * - compat ARM registers on ARM64 DO expose true syscall. 3078 */ 3079 ASSERT_EQ(0, uname(&utsbuf)); 3080 if (strncmp(utsbuf.machine, "arm", 3) == 0) { 3081 EXPECT_EQ(__NR_nanosleep, ret); 3082 } else 3083 #endif 3084 { 3085 EXPECT_EQ(__NR_restart_syscall, ret); 3086 } 3087 3088 /* Write again to end test. */ 3089 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3090 ASSERT_EQ(1, write(pipefd[1], "!", 1)); 3091 EXPECT_EQ(0, close(pipefd[1])); 3092 3093 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3094 if (WIFSIGNALED(status) || WEXITSTATUS(status)) 3095 _metadata->passed = 0; 3096 } 3097 3098 TEST_SIGNAL(filter_flag_log, SIGSYS) 3099 { 3100 struct sock_filter allow_filter[] = { 3101 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3102 }; 3103 struct sock_filter kill_filter[] = { 3104 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3105 offsetof(struct seccomp_data, nr)), 3106 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 3107 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 3108 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3109 }; 3110 struct sock_fprog allow_prog = { 3111 .len = (unsigned short)ARRAY_SIZE(allow_filter), 3112 .filter = allow_filter, 3113 }; 3114 struct sock_fprog kill_prog = { 3115 .len = (unsigned short)ARRAY_SIZE(kill_filter), 3116 .filter = kill_filter, 3117 }; 3118 long ret; 3119 pid_t parent = getppid(); 3120 3121 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3122 ASSERT_EQ(0, ret); 3123 3124 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */ 3125 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG, 3126 &allow_prog); 3127 ASSERT_NE(ENOSYS, errno) { 3128 TH_LOG("Kernel does not support seccomp syscall!"); 3129 } 3130 EXPECT_NE(0, ret) { 3131 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!"); 3132 } 3133 EXPECT_EQ(EINVAL, errno) { 3134 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!"); 3135 } 3136 3137 /* Verify that a simple, permissive filter can be added with no flags */ 3138 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog); 3139 EXPECT_EQ(0, ret); 3140 3141 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */ 3142 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 3143 &allow_prog); 3144 ASSERT_NE(EINVAL, errno) { 3145 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!"); 3146 } 3147 EXPECT_EQ(0, ret); 3148 3149 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */ 3150 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 3151 &kill_prog); 3152 EXPECT_EQ(0, ret); 3153 3154 EXPECT_EQ(parent, syscall(__NR_getppid)); 3155 /* getpid() should never return. */ 3156 EXPECT_EQ(0, syscall(__NR_getpid)); 3157 } 3158 3159 TEST(get_action_avail) 3160 { 3161 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP, 3162 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE, 3163 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW }; 3164 __u32 unknown_action = 0x10000000U; 3165 int i; 3166 long ret; 3167 3168 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]); 3169 ASSERT_NE(ENOSYS, errno) { 3170 TH_LOG("Kernel does not support seccomp syscall!"); 3171 } 3172 ASSERT_NE(EINVAL, errno) { 3173 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!"); 3174 } 3175 EXPECT_EQ(ret, 0); 3176 3177 for (i = 0; i < ARRAY_SIZE(actions); i++) { 3178 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]); 3179 EXPECT_EQ(ret, 0) { 3180 TH_LOG("Expected action (0x%X) not available!", 3181 actions[i]); 3182 } 3183 } 3184 3185 /* Check that an unknown action is handled properly (EOPNOTSUPP) */ 3186 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action); 3187 EXPECT_EQ(ret, -1); 3188 EXPECT_EQ(errno, EOPNOTSUPP); 3189 } 3190 3191 TEST(get_metadata) 3192 { 3193 pid_t pid; 3194 int pipefd[2]; 3195 char buf; 3196 struct seccomp_metadata md; 3197 long ret; 3198 3199 /* Only real root can get metadata. */ 3200 if (geteuid()) { 3201 SKIP(return, "get_metadata requires real root"); 3202 return; 3203 } 3204 3205 ASSERT_EQ(0, pipe(pipefd)); 3206 3207 pid = fork(); 3208 ASSERT_GE(pid, 0); 3209 if (pid == 0) { 3210 struct sock_filter filter[] = { 3211 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3212 }; 3213 struct sock_fprog prog = { 3214 .len = (unsigned short)ARRAY_SIZE(filter), 3215 .filter = filter, 3216 }; 3217 3218 /* one with log, one without */ 3219 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 3220 SECCOMP_FILTER_FLAG_LOG, &prog)); 3221 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog)); 3222 3223 EXPECT_EQ(0, close(pipefd[0])); 3224 ASSERT_EQ(1, write(pipefd[1], "1", 1)); 3225 ASSERT_EQ(0, close(pipefd[1])); 3226 3227 while (1) 3228 sleep(100); 3229 } 3230 3231 ASSERT_EQ(0, close(pipefd[1])); 3232 ASSERT_EQ(1, read(pipefd[0], &buf, 1)); 3233 3234 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid)); 3235 ASSERT_EQ(pid, waitpid(pid, NULL, 0)); 3236 3237 /* Past here must not use ASSERT or child process is never killed. */ 3238 3239 md.filter_off = 0; 3240 errno = 0; 3241 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); 3242 EXPECT_EQ(sizeof(md), ret) { 3243 if (errno == EINVAL) 3244 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)"); 3245 } 3246 3247 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG); 3248 EXPECT_EQ(md.filter_off, 0); 3249 3250 md.filter_off = 1; 3251 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); 3252 EXPECT_EQ(sizeof(md), ret); 3253 EXPECT_EQ(md.flags, 0); 3254 EXPECT_EQ(md.filter_off, 1); 3255 3256 skip: 3257 ASSERT_EQ(0, kill(pid, SIGKILL)); 3258 } 3259 3260 static int user_notif_syscall(int nr, unsigned int flags) 3261 { 3262 struct sock_filter filter[] = { 3263 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3264 offsetof(struct seccomp_data, nr)), 3265 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1), 3266 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF), 3267 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3268 }; 3269 3270 struct sock_fprog prog = { 3271 .len = (unsigned short)ARRAY_SIZE(filter), 3272 .filter = filter, 3273 }; 3274 3275 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog); 3276 } 3277 3278 #define USER_NOTIF_MAGIC INT_MAX 3279 TEST(user_notification_basic) 3280 { 3281 pid_t pid; 3282 long ret; 3283 int status, listener; 3284 struct seccomp_notif req = {}; 3285 struct seccomp_notif_resp resp = {}; 3286 struct pollfd pollfd; 3287 3288 struct sock_filter filter[] = { 3289 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3290 }; 3291 struct sock_fprog prog = { 3292 .len = (unsigned short)ARRAY_SIZE(filter), 3293 .filter = filter, 3294 }; 3295 3296 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3297 ASSERT_EQ(0, ret) { 3298 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3299 } 3300 3301 pid = fork(); 3302 ASSERT_GE(pid, 0); 3303 3304 /* Check that we get -ENOSYS with no listener attached */ 3305 if (pid == 0) { 3306 if (user_notif_syscall(__NR_getppid, 0) < 0) 3307 exit(1); 3308 ret = syscall(__NR_getppid); 3309 exit(ret >= 0 || errno != ENOSYS); 3310 } 3311 3312 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3313 EXPECT_EQ(true, WIFEXITED(status)); 3314 EXPECT_EQ(0, WEXITSTATUS(status)); 3315 3316 /* Add some no-op filters for grins. */ 3317 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3318 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3319 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3320 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3321 3322 /* Check that the basic notification machinery works */ 3323 listener = user_notif_syscall(__NR_getppid, 3324 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3325 ASSERT_GE(listener, 0); 3326 3327 /* Installing a second listener in the chain should EBUSY */ 3328 EXPECT_EQ(user_notif_syscall(__NR_getppid, 3329 SECCOMP_FILTER_FLAG_NEW_LISTENER), 3330 -1); 3331 EXPECT_EQ(errno, EBUSY); 3332 3333 pid = fork(); 3334 ASSERT_GE(pid, 0); 3335 3336 if (pid == 0) { 3337 ret = syscall(__NR_getppid); 3338 exit(ret != USER_NOTIF_MAGIC); 3339 } 3340 3341 pollfd.fd = listener; 3342 pollfd.events = POLLIN | POLLOUT; 3343 3344 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3345 EXPECT_EQ(pollfd.revents, POLLIN); 3346 3347 /* Test that we can't pass garbage to the kernel. */ 3348 memset(&req, 0, sizeof(req)); 3349 req.pid = -1; 3350 errno = 0; 3351 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req); 3352 EXPECT_EQ(-1, ret); 3353 EXPECT_EQ(EINVAL, errno); 3354 3355 if (ret) { 3356 req.pid = 0; 3357 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3358 } 3359 3360 pollfd.fd = listener; 3361 pollfd.events = POLLIN | POLLOUT; 3362 3363 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3364 EXPECT_EQ(pollfd.revents, POLLOUT); 3365 3366 EXPECT_EQ(req.data.nr, __NR_getppid); 3367 3368 resp.id = req.id; 3369 resp.error = 0; 3370 resp.val = USER_NOTIF_MAGIC; 3371 3372 /* check that we make sure flags == 0 */ 3373 resp.flags = 1; 3374 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3375 EXPECT_EQ(errno, EINVAL); 3376 3377 resp.flags = 0; 3378 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3379 3380 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3381 EXPECT_EQ(true, WIFEXITED(status)); 3382 EXPECT_EQ(0, WEXITSTATUS(status)); 3383 } 3384 3385 TEST(user_notification_with_tsync) 3386 { 3387 int ret; 3388 unsigned int flags; 3389 3390 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3391 ASSERT_EQ(0, ret) { 3392 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3393 } 3394 3395 /* these were exclusive */ 3396 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER | 3397 SECCOMP_FILTER_FLAG_TSYNC; 3398 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags)); 3399 ASSERT_EQ(EINVAL, errno); 3400 3401 /* but now they're not */ 3402 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH; 3403 ret = user_notif_syscall(__NR_getppid, flags); 3404 close(ret); 3405 ASSERT_LE(0, ret); 3406 } 3407 3408 TEST(user_notification_kill_in_middle) 3409 { 3410 pid_t pid; 3411 long ret; 3412 int listener; 3413 struct seccomp_notif req = {}; 3414 struct seccomp_notif_resp resp = {}; 3415 3416 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3417 ASSERT_EQ(0, ret) { 3418 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3419 } 3420 3421 listener = user_notif_syscall(__NR_getppid, 3422 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3423 ASSERT_GE(listener, 0); 3424 3425 /* 3426 * Check that nothing bad happens when we kill the task in the middle 3427 * of a syscall. 3428 */ 3429 pid = fork(); 3430 ASSERT_GE(pid, 0); 3431 3432 if (pid == 0) { 3433 ret = syscall(__NR_getppid); 3434 exit(ret != USER_NOTIF_MAGIC); 3435 } 3436 3437 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3438 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0); 3439 3440 EXPECT_EQ(kill(pid, SIGKILL), 0); 3441 EXPECT_EQ(waitpid(pid, NULL, 0), pid); 3442 3443 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1); 3444 3445 resp.id = req.id; 3446 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp); 3447 EXPECT_EQ(ret, -1); 3448 EXPECT_EQ(errno, ENOENT); 3449 } 3450 3451 static int handled = -1; 3452 3453 static void signal_handler(int signal) 3454 { 3455 if (write(handled, "c", 1) != 1) 3456 perror("write from signal"); 3457 } 3458 3459 TEST(user_notification_signal) 3460 { 3461 pid_t pid; 3462 long ret; 3463 int status, listener, sk_pair[2]; 3464 struct seccomp_notif req = {}; 3465 struct seccomp_notif_resp resp = {}; 3466 char c; 3467 3468 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3469 ASSERT_EQ(0, ret) { 3470 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3471 } 3472 3473 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); 3474 3475 listener = user_notif_syscall(__NR_gettid, 3476 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3477 ASSERT_GE(listener, 0); 3478 3479 pid = fork(); 3480 ASSERT_GE(pid, 0); 3481 3482 if (pid == 0) { 3483 close(sk_pair[0]); 3484 handled = sk_pair[1]; 3485 if (signal(SIGUSR1, signal_handler) == SIG_ERR) { 3486 perror("signal"); 3487 exit(1); 3488 } 3489 /* 3490 * ERESTARTSYS behavior is a bit hard to test, because we need 3491 * to rely on a signal that has not yet been handled. Let's at 3492 * least check that the error code gets propagated through, and 3493 * hope that it doesn't break when there is actually a signal :) 3494 */ 3495 ret = syscall(__NR_gettid); 3496 exit(!(ret == -1 && errno == 512)); 3497 } 3498 3499 close(sk_pair[1]); 3500 3501 memset(&req, 0, sizeof(req)); 3502 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3503 3504 EXPECT_EQ(kill(pid, SIGUSR1), 0); 3505 3506 /* 3507 * Make sure the signal really is delivered, which means we're not 3508 * stuck in the user notification code any more and the notification 3509 * should be dead. 3510 */ 3511 EXPECT_EQ(read(sk_pair[0], &c, 1), 1); 3512 3513 resp.id = req.id; 3514 resp.error = -EPERM; 3515 resp.val = 0; 3516 3517 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3518 EXPECT_EQ(errno, ENOENT); 3519 3520 memset(&req, 0, sizeof(req)); 3521 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3522 3523 resp.id = req.id; 3524 resp.error = -512; /* -ERESTARTSYS */ 3525 resp.val = 0; 3526 3527 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3528 3529 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3530 EXPECT_EQ(true, WIFEXITED(status)); 3531 EXPECT_EQ(0, WEXITSTATUS(status)); 3532 } 3533 3534 TEST(user_notification_closed_listener) 3535 { 3536 pid_t pid; 3537 long ret; 3538 int status, listener; 3539 3540 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3541 ASSERT_EQ(0, ret) { 3542 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3543 } 3544 3545 listener = user_notif_syscall(__NR_getppid, 3546 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3547 ASSERT_GE(listener, 0); 3548 3549 /* 3550 * Check that we get an ENOSYS when the listener is closed. 3551 */ 3552 pid = fork(); 3553 ASSERT_GE(pid, 0); 3554 if (pid == 0) { 3555 close(listener); 3556 ret = syscall(__NR_getppid); 3557 exit(ret != -1 && errno != ENOSYS); 3558 } 3559 3560 close(listener); 3561 3562 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3563 EXPECT_EQ(true, WIFEXITED(status)); 3564 EXPECT_EQ(0, WEXITSTATUS(status)); 3565 } 3566 3567 /* 3568 * Check that a pid in a child namespace still shows up as valid in ours. 3569 */ 3570 TEST(user_notification_child_pid_ns) 3571 { 3572 pid_t pid; 3573 int status, listener; 3574 struct seccomp_notif req = {}; 3575 struct seccomp_notif_resp resp = {}; 3576 3577 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) { 3578 if (errno == EINVAL) 3579 SKIP(return, "kernel missing CLONE_NEWUSER support"); 3580 }; 3581 3582 listener = user_notif_syscall(__NR_getppid, 3583 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3584 ASSERT_GE(listener, 0); 3585 3586 pid = fork(); 3587 ASSERT_GE(pid, 0); 3588 3589 if (pid == 0) 3590 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3591 3592 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3593 EXPECT_EQ(req.pid, pid); 3594 3595 resp.id = req.id; 3596 resp.error = 0; 3597 resp.val = USER_NOTIF_MAGIC; 3598 3599 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3600 3601 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3602 EXPECT_EQ(true, WIFEXITED(status)); 3603 EXPECT_EQ(0, WEXITSTATUS(status)); 3604 close(listener); 3605 } 3606 3607 /* 3608 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e. 3609 * invalid. 3610 */ 3611 TEST(user_notification_sibling_pid_ns) 3612 { 3613 pid_t pid, pid2; 3614 int status, listener; 3615 struct seccomp_notif req = {}; 3616 struct seccomp_notif_resp resp = {}; 3617 3618 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) { 3619 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3620 } 3621 3622 listener = user_notif_syscall(__NR_getppid, 3623 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3624 ASSERT_GE(listener, 0); 3625 3626 pid = fork(); 3627 ASSERT_GE(pid, 0); 3628 3629 if (pid == 0) { 3630 ASSERT_EQ(unshare(CLONE_NEWPID), 0); 3631 3632 pid2 = fork(); 3633 ASSERT_GE(pid2, 0); 3634 3635 if (pid2 == 0) 3636 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3637 3638 EXPECT_EQ(waitpid(pid2, &status, 0), pid2); 3639 EXPECT_EQ(true, WIFEXITED(status)); 3640 EXPECT_EQ(0, WEXITSTATUS(status)); 3641 exit(WEXITSTATUS(status)); 3642 } 3643 3644 /* Create the sibling ns, and sibling in it. */ 3645 ASSERT_EQ(unshare(CLONE_NEWPID), 0) { 3646 if (errno == EPERM) 3647 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); 3648 } 3649 ASSERT_EQ(errno, 0); 3650 3651 pid2 = fork(); 3652 ASSERT_GE(pid2, 0); 3653 3654 if (pid2 == 0) { 3655 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3656 /* 3657 * The pid should be 0, i.e. the task is in some namespace that 3658 * we can't "see". 3659 */ 3660 EXPECT_EQ(req.pid, 0); 3661 3662 resp.id = req.id; 3663 resp.error = 0; 3664 resp.val = USER_NOTIF_MAGIC; 3665 3666 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3667 exit(0); 3668 } 3669 3670 close(listener); 3671 3672 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3673 EXPECT_EQ(true, WIFEXITED(status)); 3674 EXPECT_EQ(0, WEXITSTATUS(status)); 3675 3676 EXPECT_EQ(waitpid(pid2, &status, 0), pid2); 3677 EXPECT_EQ(true, WIFEXITED(status)); 3678 EXPECT_EQ(0, WEXITSTATUS(status)); 3679 } 3680 3681 TEST(user_notification_fault_recv) 3682 { 3683 pid_t pid; 3684 int status, listener; 3685 struct seccomp_notif req = {}; 3686 struct seccomp_notif_resp resp = {}; 3687 3688 ASSERT_EQ(unshare(CLONE_NEWUSER), 0); 3689 3690 listener = user_notif_syscall(__NR_getppid, 3691 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3692 ASSERT_GE(listener, 0); 3693 3694 pid = fork(); 3695 ASSERT_GE(pid, 0); 3696 3697 if (pid == 0) 3698 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3699 3700 /* Do a bad recv() */ 3701 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1); 3702 EXPECT_EQ(errno, EFAULT); 3703 3704 /* We should still be able to receive this notification, though. */ 3705 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3706 EXPECT_EQ(req.pid, pid); 3707 3708 resp.id = req.id; 3709 resp.error = 0; 3710 resp.val = USER_NOTIF_MAGIC; 3711 3712 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3713 3714 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3715 EXPECT_EQ(true, WIFEXITED(status)); 3716 EXPECT_EQ(0, WEXITSTATUS(status)); 3717 } 3718 3719 TEST(seccomp_get_notif_sizes) 3720 { 3721 struct seccomp_notif_sizes sizes; 3722 3723 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0); 3724 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif)); 3725 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp)); 3726 } 3727 3728 TEST(user_notification_continue) 3729 { 3730 pid_t pid; 3731 long ret; 3732 int status, listener; 3733 struct seccomp_notif req = {}; 3734 struct seccomp_notif_resp resp = {}; 3735 struct pollfd pollfd; 3736 3737 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3738 ASSERT_EQ(0, ret) { 3739 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3740 } 3741 3742 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3743 ASSERT_GE(listener, 0); 3744 3745 pid = fork(); 3746 ASSERT_GE(pid, 0); 3747 3748 if (pid == 0) { 3749 int dup_fd, pipe_fds[2]; 3750 pid_t self; 3751 3752 ASSERT_GE(pipe(pipe_fds), 0); 3753 3754 dup_fd = dup(pipe_fds[0]); 3755 ASSERT_GE(dup_fd, 0); 3756 EXPECT_NE(pipe_fds[0], dup_fd); 3757 3758 self = getpid(); 3759 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0); 3760 exit(0); 3761 } 3762 3763 pollfd.fd = listener; 3764 pollfd.events = POLLIN | POLLOUT; 3765 3766 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3767 EXPECT_EQ(pollfd.revents, POLLIN); 3768 3769 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3770 3771 pollfd.fd = listener; 3772 pollfd.events = POLLIN | POLLOUT; 3773 3774 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3775 EXPECT_EQ(pollfd.revents, POLLOUT); 3776 3777 EXPECT_EQ(req.data.nr, __NR_dup); 3778 3779 resp.id = req.id; 3780 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE; 3781 3782 /* 3783 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other 3784 * args be set to 0. 3785 */ 3786 resp.error = 0; 3787 resp.val = USER_NOTIF_MAGIC; 3788 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3789 EXPECT_EQ(errno, EINVAL); 3790 3791 resp.error = USER_NOTIF_MAGIC; 3792 resp.val = 0; 3793 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3794 EXPECT_EQ(errno, EINVAL); 3795 3796 resp.error = 0; 3797 resp.val = 0; 3798 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) { 3799 if (errno == EINVAL) 3800 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE"); 3801 } 3802 3803 skip: 3804 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3805 EXPECT_EQ(true, WIFEXITED(status)); 3806 EXPECT_EQ(0, WEXITSTATUS(status)) { 3807 if (WEXITSTATUS(status) == 2) { 3808 SKIP(return, "Kernel does not support kcmp() syscall"); 3809 return; 3810 } 3811 } 3812 } 3813 3814 TEST(user_notification_filter_empty) 3815 { 3816 pid_t pid; 3817 long ret; 3818 int status; 3819 struct pollfd pollfd; 3820 struct __clone_args args = { 3821 .flags = CLONE_FILES, 3822 .exit_signal = SIGCHLD, 3823 }; 3824 3825 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3826 ASSERT_EQ(0, ret) { 3827 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3828 } 3829 3830 pid = sys_clone3(&args, sizeof(args)); 3831 ASSERT_GE(pid, 0); 3832 3833 if (pid == 0) { 3834 int listener; 3835 3836 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3837 if (listener < 0) 3838 _exit(EXIT_FAILURE); 3839 3840 if (dup2(listener, 200) != 200) 3841 _exit(EXIT_FAILURE); 3842 3843 close(listener); 3844 3845 _exit(EXIT_SUCCESS); 3846 } 3847 3848 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3849 EXPECT_EQ(true, WIFEXITED(status)); 3850 EXPECT_EQ(0, WEXITSTATUS(status)); 3851 3852 /* 3853 * The seccomp filter has become unused so we should be notified once 3854 * the kernel gets around to cleaning up task struct. 3855 */ 3856 pollfd.fd = 200; 3857 pollfd.events = POLLHUP; 3858 3859 EXPECT_GT(poll(&pollfd, 1, 2000), 0); 3860 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); 3861 } 3862 3863 static void *do_thread(void *data) 3864 { 3865 return NULL; 3866 } 3867 3868 TEST(user_notification_filter_empty_threaded) 3869 { 3870 pid_t pid; 3871 long ret; 3872 int status; 3873 struct pollfd pollfd; 3874 struct __clone_args args = { 3875 .flags = CLONE_FILES, 3876 .exit_signal = SIGCHLD, 3877 }; 3878 3879 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3880 ASSERT_EQ(0, ret) { 3881 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3882 } 3883 3884 pid = sys_clone3(&args, sizeof(args)); 3885 ASSERT_GE(pid, 0); 3886 3887 if (pid == 0) { 3888 pid_t pid1, pid2; 3889 int listener, status; 3890 pthread_t thread; 3891 3892 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3893 if (listener < 0) 3894 _exit(EXIT_FAILURE); 3895 3896 if (dup2(listener, 200) != 200) 3897 _exit(EXIT_FAILURE); 3898 3899 close(listener); 3900 3901 pid1 = fork(); 3902 if (pid1 < 0) 3903 _exit(EXIT_FAILURE); 3904 3905 if (pid1 == 0) 3906 _exit(EXIT_SUCCESS); 3907 3908 pid2 = fork(); 3909 if (pid2 < 0) 3910 _exit(EXIT_FAILURE); 3911 3912 if (pid2 == 0) 3913 _exit(EXIT_SUCCESS); 3914 3915 if (pthread_create(&thread, NULL, do_thread, NULL) || 3916 pthread_join(thread, NULL)) 3917 _exit(EXIT_FAILURE); 3918 3919 if (pthread_create(&thread, NULL, do_thread, NULL) || 3920 pthread_join(thread, NULL)) 3921 _exit(EXIT_FAILURE); 3922 3923 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) || 3924 WEXITSTATUS(status)) 3925 _exit(EXIT_FAILURE); 3926 3927 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) || 3928 WEXITSTATUS(status)) 3929 _exit(EXIT_FAILURE); 3930 3931 exit(EXIT_SUCCESS); 3932 } 3933 3934 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3935 EXPECT_EQ(true, WIFEXITED(status)); 3936 EXPECT_EQ(0, WEXITSTATUS(status)); 3937 3938 /* 3939 * The seccomp filter has become unused so we should be notified once 3940 * the kernel gets around to cleaning up task struct. 3941 */ 3942 pollfd.fd = 200; 3943 pollfd.events = POLLHUP; 3944 3945 EXPECT_GT(poll(&pollfd, 1, 2000), 0); 3946 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); 3947 } 3948 3949 TEST(user_notification_addfd) 3950 { 3951 pid_t pid; 3952 long ret; 3953 int status, listener, memfd, fd; 3954 struct seccomp_notif_addfd addfd = {}; 3955 struct seccomp_notif_addfd_small small = {}; 3956 struct seccomp_notif_addfd_big big = {}; 3957 struct seccomp_notif req = {}; 3958 struct seccomp_notif_resp resp = {}; 3959 /* 100 ms */ 3960 struct timespec delay = { .tv_nsec = 100000000 }; 3961 3962 memfd = memfd_create("test", 0); 3963 ASSERT_GE(memfd, 0); 3964 3965 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3966 ASSERT_EQ(0, ret) { 3967 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3968 } 3969 3970 /* Check that the basic notification machinery works */ 3971 listener = user_notif_syscall(__NR_getppid, 3972 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3973 ASSERT_GE(listener, 0); 3974 3975 pid = fork(); 3976 ASSERT_GE(pid, 0); 3977 3978 if (pid == 0) { 3979 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) 3980 exit(1); 3981 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3982 } 3983 3984 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3985 3986 addfd.srcfd = memfd; 3987 addfd.newfd = 0; 3988 addfd.id = req.id; 3989 addfd.flags = 0x0; 3990 3991 /* Verify bad newfd_flags cannot be set */ 3992 addfd.newfd_flags = ~O_CLOEXEC; 3993 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 3994 EXPECT_EQ(errno, EINVAL); 3995 addfd.newfd_flags = O_CLOEXEC; 3996 3997 /* Verify bad flags cannot be set */ 3998 addfd.flags = 0xff; 3999 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4000 EXPECT_EQ(errno, EINVAL); 4001 addfd.flags = 0; 4002 4003 /* Verify that remote_fd cannot be set without setting flags */ 4004 addfd.newfd = 1; 4005 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4006 EXPECT_EQ(errno, EINVAL); 4007 addfd.newfd = 0; 4008 4009 /* Verify small size cannot be set */ 4010 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1); 4011 EXPECT_EQ(errno, EINVAL); 4012 4013 /* Verify we can't send bits filled in unknown buffer area */ 4014 memset(&big, 0xAA, sizeof(big)); 4015 big.addfd = addfd; 4016 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1); 4017 EXPECT_EQ(errno, E2BIG); 4018 4019 4020 /* Verify we can set an arbitrary remote fd */ 4021 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4022 /* 4023 * The child has fds 0(stdin), 1(stdout), 2(stderr), 3(memfd), 4024 * 4(listener), so the newly allocated fd should be 5. 4025 */ 4026 EXPECT_EQ(fd, 5); 4027 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4028 4029 /* Verify we can set an arbitrary remote fd with large size */ 4030 memset(&big, 0x0, sizeof(big)); 4031 big.addfd = addfd; 4032 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); 4033 EXPECT_EQ(fd, 6); 4034 4035 /* Verify we can set a specific remote fd */ 4036 addfd.newfd = 42; 4037 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; 4038 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4039 EXPECT_EQ(fd, 42); 4040 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4041 4042 /* Resume syscall */ 4043 resp.id = req.id; 4044 resp.error = 0; 4045 resp.val = USER_NOTIF_MAGIC; 4046 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4047 4048 /* 4049 * This sets the ID of the ADD FD to the last request plus 1. The 4050 * notification ID increments 1 per notification. 4051 */ 4052 addfd.id = req.id + 1; 4053 4054 /* This spins until the underlying notification is generated */ 4055 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && 4056 errno != -EINPROGRESS) 4057 nanosleep(&delay, NULL); 4058 4059 memset(&req, 0, sizeof(req)); 4060 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4061 ASSERT_EQ(addfd.id, req.id); 4062 4063 resp.id = req.id; 4064 resp.error = 0; 4065 resp.val = USER_NOTIF_MAGIC; 4066 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4067 4068 /* Wait for child to finish. */ 4069 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4070 EXPECT_EQ(true, WIFEXITED(status)); 4071 EXPECT_EQ(0, WEXITSTATUS(status)); 4072 4073 close(memfd); 4074 } 4075 4076 TEST(user_notification_addfd_rlimit) 4077 { 4078 pid_t pid; 4079 long ret; 4080 int status, listener, memfd; 4081 struct seccomp_notif_addfd addfd = {}; 4082 struct seccomp_notif req = {}; 4083 struct seccomp_notif_resp resp = {}; 4084 const struct rlimit lim = { 4085 .rlim_cur = 0, 4086 .rlim_max = 0, 4087 }; 4088 4089 memfd = memfd_create("test", 0); 4090 ASSERT_GE(memfd, 0); 4091 4092 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4093 ASSERT_EQ(0, ret) { 4094 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4095 } 4096 4097 /* Check that the basic notification machinery works */ 4098 listener = user_notif_syscall(__NR_getppid, 4099 SECCOMP_FILTER_FLAG_NEW_LISTENER); 4100 ASSERT_GE(listener, 0); 4101 4102 pid = fork(); 4103 ASSERT_GE(pid, 0); 4104 4105 if (pid == 0) 4106 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 4107 4108 4109 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4110 4111 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0); 4112 4113 addfd.srcfd = memfd; 4114 addfd.newfd_flags = O_CLOEXEC; 4115 addfd.newfd = 0; 4116 addfd.id = req.id; 4117 addfd.flags = 0; 4118 4119 /* Should probably spot check /proc/sys/fs/file-nr */ 4120 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4121 EXPECT_EQ(errno, EMFILE); 4122 4123 addfd.newfd = 100; 4124 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; 4125 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4126 EXPECT_EQ(errno, EBADF); 4127 4128 resp.id = req.id; 4129 resp.error = 0; 4130 resp.val = USER_NOTIF_MAGIC; 4131 4132 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4133 4134 /* Wait for child to finish. */ 4135 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4136 EXPECT_EQ(true, WIFEXITED(status)); 4137 EXPECT_EQ(0, WEXITSTATUS(status)); 4138 4139 close(memfd); 4140 } 4141 4142 /* 4143 * TODO: 4144 * - expand NNP testing 4145 * - better arch-specific TRACE and TRAP handlers. 4146 * - endianness checking when appropriate 4147 * - 64-bit arg prodding 4148 * - arch value testing (x86 modes especially) 4149 * - verify that FILTER_FLAG_LOG filters generate log messages 4150 * - verify that RET_LOG generates log messages 4151 */ 4152 4153 TEST_HARNESS_MAIN 4154