1 /* 2 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 3 * Use of this source code is governed by the GPLv2 license. 4 * 5 * Test code for seccomp bpf. 6 */ 7 8 #include <sys/types.h> 9 10 /* 11 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that, 12 * we need to use the kernel's siginfo.h file and trick glibc 13 * into accepting it. 14 */ 15 #if !__GLIBC_PREREQ(2, 26) 16 # include <asm/siginfo.h> 17 # define __have_siginfo_t 1 18 # define __have_sigval_t 1 19 # define __have_sigevent_t 1 20 #endif 21 22 #include <errno.h> 23 #include <linux/filter.h> 24 #include <sys/prctl.h> 25 #include <sys/ptrace.h> 26 #include <sys/user.h> 27 #include <linux/prctl.h> 28 #include <linux/ptrace.h> 29 #include <linux/seccomp.h> 30 #include <pthread.h> 31 #include <semaphore.h> 32 #include <signal.h> 33 #include <stddef.h> 34 #include <stdbool.h> 35 #include <string.h> 36 #include <time.h> 37 #include <linux/elf.h> 38 #include <sys/uio.h> 39 #include <sys/utsname.h> 40 #include <sys/fcntl.h> 41 #include <sys/mman.h> 42 #include <sys/times.h> 43 44 #define _GNU_SOURCE 45 #include <unistd.h> 46 #include <sys/syscall.h> 47 48 #include "../kselftest_harness.h" 49 50 #ifndef PR_SET_PTRACER 51 # define PR_SET_PTRACER 0x59616d61 52 #endif 53 54 #ifndef PR_SET_NO_NEW_PRIVS 55 #define PR_SET_NO_NEW_PRIVS 38 56 #define PR_GET_NO_NEW_PRIVS 39 57 #endif 58 59 #ifndef PR_SECCOMP_EXT 60 #define PR_SECCOMP_EXT 43 61 #endif 62 63 #ifndef SECCOMP_EXT_ACT 64 #define SECCOMP_EXT_ACT 1 65 #endif 66 67 #ifndef SECCOMP_EXT_ACT_TSYNC 68 #define SECCOMP_EXT_ACT_TSYNC 1 69 #endif 70 71 #ifndef SECCOMP_MODE_STRICT 72 #define SECCOMP_MODE_STRICT 1 73 #endif 74 75 #ifndef SECCOMP_MODE_FILTER 76 #define SECCOMP_MODE_FILTER 2 77 #endif 78 79 #ifndef SECCOMP_RET_ALLOW 80 struct seccomp_data { 81 int nr; 82 __u32 arch; 83 __u64 instruction_pointer; 84 __u64 args[6]; 85 }; 86 #endif 87 88 #ifndef SECCOMP_RET_KILL_PROCESS 89 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */ 90 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */ 91 #endif 92 #ifndef SECCOMP_RET_KILL 93 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD 94 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ 95 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ 96 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ 97 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ 98 #endif 99 #ifndef SECCOMP_RET_LOG 100 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */ 101 #endif 102 103 #ifndef __NR_seccomp 104 # if defined(__i386__) 105 # define __NR_seccomp 354 106 # elif defined(__x86_64__) 107 # define __NR_seccomp 317 108 # elif defined(__arm__) 109 # define __NR_seccomp 383 110 # elif defined(__aarch64__) 111 # define __NR_seccomp 277 112 # elif defined(__hppa__) 113 # define __NR_seccomp 338 114 # elif defined(__powerpc__) 115 # define __NR_seccomp 358 116 # elif defined(__s390__) 117 # define __NR_seccomp 348 118 # else 119 # warning "seccomp syscall number unknown for this architecture" 120 # define __NR_seccomp 0xffff 121 # endif 122 #endif 123 124 #ifndef SECCOMP_SET_MODE_STRICT 125 #define SECCOMP_SET_MODE_STRICT 0 126 #endif 127 128 #ifndef SECCOMP_SET_MODE_FILTER 129 #define SECCOMP_SET_MODE_FILTER 1 130 #endif 131 132 #ifndef SECCOMP_GET_ACTION_AVAIL 133 #define SECCOMP_GET_ACTION_AVAIL 2 134 #endif 135 136 #ifndef SECCOMP_FILTER_FLAG_TSYNC 137 #define SECCOMP_FILTER_FLAG_TSYNC 1 138 #endif 139 140 #ifndef SECCOMP_FILTER_FLAG_LOG 141 #define SECCOMP_FILTER_FLAG_LOG 2 142 #endif 143 144 #ifndef seccomp 145 int seccomp(unsigned int op, unsigned int flags, void *args) 146 { 147 errno = 0; 148 return syscall(__NR_seccomp, op, flags, args); 149 } 150 #endif 151 152 #if __BYTE_ORDER == __LITTLE_ENDIAN 153 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) 154 #elif __BYTE_ORDER == __BIG_ENDIAN 155 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) 156 #else 157 #error "wut? Unknown __BYTE_ORDER?!" 158 #endif 159 160 #define SIBLING_EXIT_UNKILLED 0xbadbeef 161 #define SIBLING_EXIT_FAILURE 0xbadface 162 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed 163 164 TEST(mode_strict_support) 165 { 166 long ret; 167 168 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 169 ASSERT_EQ(0, ret) { 170 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 171 } 172 syscall(__NR_exit, 0); 173 } 174 175 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) 176 { 177 long ret; 178 179 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 180 ASSERT_EQ(0, ret) { 181 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 182 } 183 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 184 NULL, NULL, NULL); 185 EXPECT_FALSE(true) { 186 TH_LOG("Unreachable!"); 187 } 188 } 189 190 /* Note! This doesn't test no new privs behavior */ 191 TEST(no_new_privs_support) 192 { 193 long ret; 194 195 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 196 EXPECT_EQ(0, ret) { 197 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 198 } 199 } 200 201 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */ 202 TEST(mode_filter_support) 203 { 204 long ret; 205 206 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 207 ASSERT_EQ(0, ret) { 208 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 209 } 210 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); 211 EXPECT_EQ(-1, ret); 212 EXPECT_EQ(EFAULT, errno) { 213 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); 214 } 215 } 216 217 TEST(mode_filter_without_nnp) 218 { 219 struct sock_filter filter[] = { 220 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 221 }; 222 struct sock_fprog prog = { 223 .len = (unsigned short)ARRAY_SIZE(filter), 224 .filter = filter, 225 }; 226 long ret; 227 228 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); 229 ASSERT_LE(0, ret) { 230 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); 231 } 232 errno = 0; 233 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 234 /* Succeeds with CAP_SYS_ADMIN, fails without */ 235 /* TODO(wad) check caps not euid */ 236 if (geteuid()) { 237 EXPECT_EQ(-1, ret); 238 EXPECT_EQ(EACCES, errno); 239 } else { 240 EXPECT_EQ(0, ret); 241 } 242 } 243 244 #define MAX_INSNS_PER_PATH 32768 245 246 TEST(filter_size_limits) 247 { 248 int i; 249 int count = BPF_MAXINSNS + 1; 250 struct sock_filter allow[] = { 251 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 252 }; 253 struct sock_filter *filter; 254 struct sock_fprog prog = { }; 255 long ret; 256 257 filter = calloc(count, sizeof(*filter)); 258 ASSERT_NE(NULL, filter); 259 260 for (i = 0; i < count; i++) 261 filter[i] = allow[0]; 262 263 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 264 ASSERT_EQ(0, ret); 265 266 prog.filter = filter; 267 prog.len = count; 268 269 /* Too many filter instructions in a single filter. */ 270 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 271 ASSERT_NE(0, ret) { 272 TH_LOG("Installing %d insn filter was allowed", prog.len); 273 } 274 275 /* One less is okay, though. */ 276 prog.len -= 1; 277 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 278 ASSERT_EQ(0, ret) { 279 TH_LOG("Installing %d insn filter wasn't allowed", prog.len); 280 } 281 } 282 283 TEST(filter_chain_limits) 284 { 285 int i; 286 int count = BPF_MAXINSNS; 287 struct sock_filter allow[] = { 288 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 289 }; 290 struct sock_filter *filter; 291 struct sock_fprog prog = { }; 292 long ret; 293 294 filter = calloc(count, sizeof(*filter)); 295 ASSERT_NE(NULL, filter); 296 297 for (i = 0; i < count; i++) 298 filter[i] = allow[0]; 299 300 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 301 ASSERT_EQ(0, ret); 302 303 prog.filter = filter; 304 prog.len = 1; 305 306 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 307 ASSERT_EQ(0, ret); 308 309 prog.len = count; 310 311 /* Too many total filter instructions. */ 312 for (i = 0; i < MAX_INSNS_PER_PATH; i++) { 313 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 314 if (ret != 0) 315 break; 316 } 317 ASSERT_NE(0, ret) { 318 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", 319 i, count, i * (count + 4)); 320 } 321 } 322 323 TEST(mode_filter_cannot_move_to_strict) 324 { 325 struct sock_filter filter[] = { 326 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 327 }; 328 struct sock_fprog prog = { 329 .len = (unsigned short)ARRAY_SIZE(filter), 330 .filter = filter, 331 }; 332 long ret; 333 334 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 335 ASSERT_EQ(0, ret); 336 337 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 338 ASSERT_EQ(0, ret); 339 340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); 341 EXPECT_EQ(-1, ret); 342 EXPECT_EQ(EINVAL, errno); 343 } 344 345 346 TEST(mode_filter_get_seccomp) 347 { 348 struct sock_filter filter[] = { 349 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 350 }; 351 struct sock_fprog prog = { 352 .len = (unsigned short)ARRAY_SIZE(filter), 353 .filter = filter, 354 }; 355 long ret; 356 357 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 358 ASSERT_EQ(0, ret); 359 360 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 361 EXPECT_EQ(0, ret); 362 363 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 364 ASSERT_EQ(0, ret); 365 366 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 367 EXPECT_EQ(2, ret); 368 } 369 370 371 TEST(ALLOW_all) 372 { 373 struct sock_filter filter[] = { 374 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 375 }; 376 struct sock_fprog prog = { 377 .len = (unsigned short)ARRAY_SIZE(filter), 378 .filter = filter, 379 }; 380 long ret; 381 382 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 383 ASSERT_EQ(0, ret); 384 385 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 386 ASSERT_EQ(0, ret); 387 } 388 389 TEST(empty_prog) 390 { 391 struct sock_filter filter[] = { 392 }; 393 struct sock_fprog prog = { 394 .len = (unsigned short)ARRAY_SIZE(filter), 395 .filter = filter, 396 }; 397 long ret; 398 399 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 400 ASSERT_EQ(0, ret); 401 402 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 403 EXPECT_EQ(-1, ret); 404 EXPECT_EQ(EINVAL, errno); 405 } 406 407 TEST(log_all) 408 { 409 struct sock_filter filter[] = { 410 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 411 }; 412 struct sock_fprog prog = { 413 .len = (unsigned short)ARRAY_SIZE(filter), 414 .filter = filter, 415 }; 416 long ret; 417 pid_t parent = getppid(); 418 419 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 420 ASSERT_EQ(0, ret); 421 422 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 423 ASSERT_EQ(0, ret); 424 425 /* getppid() should succeed and be logged (no check for logging) */ 426 EXPECT_EQ(parent, syscall(__NR_getppid)); 427 } 428 429 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) 430 { 431 struct sock_filter filter[] = { 432 BPF_STMT(BPF_RET|BPF_K, 0x10000000U), 433 }; 434 struct sock_fprog prog = { 435 .len = (unsigned short)ARRAY_SIZE(filter), 436 .filter = filter, 437 }; 438 long ret; 439 440 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 441 ASSERT_EQ(0, ret); 442 443 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 444 ASSERT_EQ(0, ret); 445 EXPECT_EQ(0, syscall(__NR_getpid)) { 446 TH_LOG("getpid() shouldn't ever return"); 447 } 448 } 449 450 /* return code >= 0x80000000 is unused. */ 451 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) 452 { 453 struct sock_filter filter[] = { 454 BPF_STMT(BPF_RET|BPF_K, 0x90000000U), 455 }; 456 struct sock_fprog prog = { 457 .len = (unsigned short)ARRAY_SIZE(filter), 458 .filter = filter, 459 }; 460 long ret; 461 462 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 463 ASSERT_EQ(0, ret); 464 465 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 466 ASSERT_EQ(0, ret); 467 EXPECT_EQ(0, syscall(__NR_getpid)) { 468 TH_LOG("getpid() shouldn't ever return"); 469 } 470 } 471 472 TEST_SIGNAL(KILL_all, SIGSYS) 473 { 474 struct sock_filter filter[] = { 475 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 476 }; 477 struct sock_fprog prog = { 478 .len = (unsigned short)ARRAY_SIZE(filter), 479 .filter = filter, 480 }; 481 long ret; 482 483 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 484 ASSERT_EQ(0, ret); 485 486 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 487 ASSERT_EQ(0, ret); 488 } 489 490 TEST_SIGNAL(KILL_one, SIGSYS) 491 { 492 struct sock_filter filter[] = { 493 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 494 offsetof(struct seccomp_data, nr)), 495 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 496 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 497 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 498 }; 499 struct sock_fprog prog = { 500 .len = (unsigned short)ARRAY_SIZE(filter), 501 .filter = filter, 502 }; 503 long ret; 504 pid_t parent = getppid(); 505 506 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 507 ASSERT_EQ(0, ret); 508 509 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 510 ASSERT_EQ(0, ret); 511 512 EXPECT_EQ(parent, syscall(__NR_getppid)); 513 /* getpid() should never return. */ 514 EXPECT_EQ(0, syscall(__NR_getpid)); 515 } 516 517 TEST_SIGNAL(KILL_one_arg_one, SIGSYS) 518 { 519 void *fatal_address; 520 struct sock_filter filter[] = { 521 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 522 offsetof(struct seccomp_data, nr)), 523 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0), 524 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 525 /* Only both with lower 32-bit for now. */ 526 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), 527 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 528 (unsigned long)&fatal_address, 0, 1), 529 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 530 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 531 }; 532 struct sock_fprog prog = { 533 .len = (unsigned short)ARRAY_SIZE(filter), 534 .filter = filter, 535 }; 536 long ret; 537 pid_t parent = getppid(); 538 struct tms timebuf; 539 clock_t clock = times(&timebuf); 540 541 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 542 ASSERT_EQ(0, ret); 543 544 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 545 ASSERT_EQ(0, ret); 546 547 EXPECT_EQ(parent, syscall(__NR_getppid)); 548 EXPECT_LE(clock, syscall(__NR_times, &timebuf)); 549 /* times() should never return. */ 550 EXPECT_EQ(0, syscall(__NR_times, &fatal_address)); 551 } 552 553 TEST_SIGNAL(KILL_one_arg_six, SIGSYS) 554 { 555 #ifndef __NR_mmap2 556 int sysno = __NR_mmap; 557 #else 558 int sysno = __NR_mmap2; 559 #endif 560 struct sock_filter filter[] = { 561 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 562 offsetof(struct seccomp_data, nr)), 563 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0), 564 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 565 /* Only both with lower 32-bit for now. */ 566 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), 567 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), 568 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 569 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 570 }; 571 struct sock_fprog prog = { 572 .len = (unsigned short)ARRAY_SIZE(filter), 573 .filter = filter, 574 }; 575 long ret; 576 pid_t parent = getppid(); 577 int fd; 578 void *map1, *map2; 579 int page_size = sysconf(_SC_PAGESIZE); 580 581 ASSERT_LT(0, page_size); 582 583 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 584 ASSERT_EQ(0, ret); 585 586 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 587 ASSERT_EQ(0, ret); 588 589 fd = open("/dev/zero", O_RDONLY); 590 ASSERT_NE(-1, fd); 591 592 EXPECT_EQ(parent, syscall(__NR_getppid)); 593 map1 = (void *)syscall(sysno, 594 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size); 595 EXPECT_NE(MAP_FAILED, map1); 596 /* mmap2() should never return. */ 597 map2 = (void *)syscall(sysno, 598 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE); 599 EXPECT_EQ(MAP_FAILED, map2); 600 601 /* The test failed, so clean up the resources. */ 602 munmap(map1, page_size); 603 munmap(map2, page_size); 604 close(fd); 605 } 606 607 /* This is a thread task to die via seccomp filter violation. */ 608 void *kill_thread(void *data) 609 { 610 bool die = (bool)data; 611 612 if (die) { 613 prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 614 return (void *)SIBLING_EXIT_FAILURE; 615 } 616 617 return (void *)SIBLING_EXIT_UNKILLED; 618 } 619 620 /* Prepare a thread that will kill itself or both of us. */ 621 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process) 622 { 623 pthread_t thread; 624 void *status; 625 /* Kill only when calling __NR_prctl. */ 626 struct sock_filter filter_thread[] = { 627 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 628 offsetof(struct seccomp_data, nr)), 629 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 630 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), 631 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 632 }; 633 struct sock_fprog prog_thread = { 634 .len = (unsigned short)ARRAY_SIZE(filter_thread), 635 .filter = filter_thread, 636 }; 637 struct sock_filter filter_process[] = { 638 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 639 offsetof(struct seccomp_data, nr)), 640 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 641 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS), 642 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 643 }; 644 struct sock_fprog prog_process = { 645 .len = (unsigned short)ARRAY_SIZE(filter_process), 646 .filter = filter_process, 647 }; 648 649 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 650 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 651 } 652 653 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, 654 kill_process ? &prog_process : &prog_thread)); 655 656 /* 657 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS 658 * flag cannot be downgraded by a new filter. 659 */ 660 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread)); 661 662 /* Start a thread that will exit immediately. */ 663 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false)); 664 ASSERT_EQ(0, pthread_join(thread, &status)); 665 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status); 666 667 /* Start a thread that will die immediately. */ 668 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true)); 669 ASSERT_EQ(0, pthread_join(thread, &status)); 670 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status); 671 672 /* 673 * If we get here, only the spawned thread died. Let the parent know 674 * the whole process didn't die (i.e. this thread, the spawner, 675 * stayed running). 676 */ 677 exit(42); 678 } 679 680 TEST(KILL_thread) 681 { 682 int status; 683 pid_t child_pid; 684 685 child_pid = fork(); 686 ASSERT_LE(0, child_pid); 687 if (child_pid == 0) { 688 kill_thread_or_group(_metadata, false); 689 _exit(38); 690 } 691 692 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 693 694 /* If only the thread was killed, we'll see exit 42. */ 695 ASSERT_TRUE(WIFEXITED(status)); 696 ASSERT_EQ(42, WEXITSTATUS(status)); 697 } 698 699 TEST(KILL_process) 700 { 701 int status; 702 pid_t child_pid; 703 704 child_pid = fork(); 705 ASSERT_LE(0, child_pid); 706 if (child_pid == 0) { 707 kill_thread_or_group(_metadata, true); 708 _exit(38); 709 } 710 711 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 712 713 /* If the entire process was killed, we'll see SIGSYS. */ 714 ASSERT_TRUE(WIFSIGNALED(status)); 715 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 716 } 717 718 /* TODO(wad) add 64-bit versus 32-bit arg tests. */ 719 TEST(arg_out_of_range) 720 { 721 struct sock_filter filter[] = { 722 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), 723 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 724 }; 725 struct sock_fprog prog = { 726 .len = (unsigned short)ARRAY_SIZE(filter), 727 .filter = filter, 728 }; 729 long ret; 730 731 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 732 ASSERT_EQ(0, ret); 733 734 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 735 EXPECT_EQ(-1, ret); 736 EXPECT_EQ(EINVAL, errno); 737 } 738 739 #define ERRNO_FILTER(name, errno) \ 740 struct sock_filter _read_filter_##name[] = { \ 741 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \ 742 offsetof(struct seccomp_data, nr)), \ 743 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \ 744 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \ 745 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \ 746 }; \ 747 struct sock_fprog prog_##name = { \ 748 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \ 749 .filter = _read_filter_##name, \ 750 } 751 752 /* Make sure basic errno values are correctly passed through a filter. */ 753 TEST(ERRNO_valid) 754 { 755 ERRNO_FILTER(valid, E2BIG); 756 long ret; 757 pid_t parent = getppid(); 758 759 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 760 ASSERT_EQ(0, ret); 761 762 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid); 763 ASSERT_EQ(0, ret); 764 765 EXPECT_EQ(parent, syscall(__NR_getppid)); 766 EXPECT_EQ(-1, read(0, NULL, 0)); 767 EXPECT_EQ(E2BIG, errno); 768 } 769 770 /* Make sure an errno of zero is correctly handled by the arch code. */ 771 TEST(ERRNO_zero) 772 { 773 ERRNO_FILTER(zero, 0); 774 long ret; 775 pid_t parent = getppid(); 776 777 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 778 ASSERT_EQ(0, ret); 779 780 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero); 781 ASSERT_EQ(0, ret); 782 783 EXPECT_EQ(parent, syscall(__NR_getppid)); 784 /* "errno" of 0 is ok. */ 785 EXPECT_EQ(0, read(0, NULL, 0)); 786 } 787 788 /* 789 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller. 790 * This tests that the errno value gets capped correctly, fixed by 791 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO"). 792 */ 793 TEST(ERRNO_capped) 794 { 795 ERRNO_FILTER(capped, 4096); 796 long ret; 797 pid_t parent = getppid(); 798 799 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 800 ASSERT_EQ(0, ret); 801 802 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped); 803 ASSERT_EQ(0, ret); 804 805 EXPECT_EQ(parent, syscall(__NR_getppid)); 806 EXPECT_EQ(-1, read(0, NULL, 0)); 807 EXPECT_EQ(4095, errno); 808 } 809 810 /* 811 * Filters are processed in reverse order: last applied is executed first. 812 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the 813 * SECCOMP_RET_DATA mask results will follow the most recently applied 814 * matching filter return (and not the lowest or highest value). 815 */ 816 TEST(ERRNO_order) 817 { 818 ERRNO_FILTER(first, 11); 819 ERRNO_FILTER(second, 13); 820 ERRNO_FILTER(third, 12); 821 long ret; 822 pid_t parent = getppid(); 823 824 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 825 ASSERT_EQ(0, ret); 826 827 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first); 828 ASSERT_EQ(0, ret); 829 830 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second); 831 ASSERT_EQ(0, ret); 832 833 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third); 834 ASSERT_EQ(0, ret); 835 836 EXPECT_EQ(parent, syscall(__NR_getppid)); 837 EXPECT_EQ(-1, read(0, NULL, 0)); 838 EXPECT_EQ(12, errno); 839 } 840 841 FIXTURE_DATA(TRAP) { 842 struct sock_fprog prog; 843 }; 844 845 FIXTURE_SETUP(TRAP) 846 { 847 struct sock_filter filter[] = { 848 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 849 offsetof(struct seccomp_data, nr)), 850 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 851 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 852 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 853 }; 854 855 memset(&self->prog, 0, sizeof(self->prog)); 856 self->prog.filter = malloc(sizeof(filter)); 857 ASSERT_NE(NULL, self->prog.filter); 858 memcpy(self->prog.filter, filter, sizeof(filter)); 859 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 860 } 861 862 FIXTURE_TEARDOWN(TRAP) 863 { 864 if (self->prog.filter) 865 free(self->prog.filter); 866 } 867 868 TEST_F_SIGNAL(TRAP, dfl, SIGSYS) 869 { 870 long ret; 871 872 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 873 ASSERT_EQ(0, ret); 874 875 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 876 ASSERT_EQ(0, ret); 877 syscall(__NR_getpid); 878 } 879 880 /* Ensure that SIGSYS overrides SIG_IGN */ 881 TEST_F_SIGNAL(TRAP, ign, SIGSYS) 882 { 883 long ret; 884 885 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 886 ASSERT_EQ(0, ret); 887 888 signal(SIGSYS, SIG_IGN); 889 890 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 891 ASSERT_EQ(0, ret); 892 syscall(__NR_getpid); 893 } 894 895 static siginfo_t TRAP_info; 896 static volatile int TRAP_nr; 897 static void TRAP_action(int nr, siginfo_t *info, void *void_context) 898 { 899 memcpy(&TRAP_info, info, sizeof(TRAP_info)); 900 TRAP_nr = nr; 901 } 902 903 TEST_F(TRAP, handler) 904 { 905 int ret, test; 906 struct sigaction act; 907 sigset_t mask; 908 909 memset(&act, 0, sizeof(act)); 910 sigemptyset(&mask); 911 sigaddset(&mask, SIGSYS); 912 913 act.sa_sigaction = &TRAP_action; 914 act.sa_flags = SA_SIGINFO; 915 ret = sigaction(SIGSYS, &act, NULL); 916 ASSERT_EQ(0, ret) { 917 TH_LOG("sigaction failed"); 918 } 919 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); 920 ASSERT_EQ(0, ret) { 921 TH_LOG("sigprocmask failed"); 922 } 923 924 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 925 ASSERT_EQ(0, ret); 926 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 927 ASSERT_EQ(0, ret); 928 TRAP_nr = 0; 929 memset(&TRAP_info, 0, sizeof(TRAP_info)); 930 /* Expect the registers to be rolled back. (nr = error) may vary 931 * based on arch. */ 932 ret = syscall(__NR_getpid); 933 /* Silence gcc warning about volatile. */ 934 test = TRAP_nr; 935 EXPECT_EQ(SIGSYS, test); 936 struct local_sigsys { 937 void *_call_addr; /* calling user insn */ 938 int _syscall; /* triggering system call number */ 939 unsigned int _arch; /* AUDIT_ARCH_* of syscall */ 940 } *sigsys = (struct local_sigsys *) 941 #ifdef si_syscall 942 &(TRAP_info.si_call_addr); 943 #else 944 &TRAP_info.si_pid; 945 #endif 946 EXPECT_EQ(__NR_getpid, sigsys->_syscall); 947 /* Make sure arch is non-zero. */ 948 EXPECT_NE(0, sigsys->_arch); 949 EXPECT_NE(0, (unsigned long)sigsys->_call_addr); 950 } 951 952 FIXTURE_DATA(precedence) { 953 struct sock_fprog allow; 954 struct sock_fprog log; 955 struct sock_fprog trace; 956 struct sock_fprog error; 957 struct sock_fprog trap; 958 struct sock_fprog kill; 959 }; 960 961 FIXTURE_SETUP(precedence) 962 { 963 struct sock_filter allow_insns[] = { 964 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 965 }; 966 struct sock_filter log_insns[] = { 967 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 968 offsetof(struct seccomp_data, nr)), 969 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 970 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 971 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 972 }; 973 struct sock_filter trace_insns[] = { 974 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 975 offsetof(struct seccomp_data, nr)), 976 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 977 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 978 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), 979 }; 980 struct sock_filter error_insns[] = { 981 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 982 offsetof(struct seccomp_data, nr)), 983 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 984 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 985 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), 986 }; 987 struct sock_filter trap_insns[] = { 988 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 989 offsetof(struct seccomp_data, nr)), 990 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 991 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 992 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 993 }; 994 struct sock_filter kill_insns[] = { 995 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 996 offsetof(struct seccomp_data, nr)), 997 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 998 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 999 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1000 }; 1001 1002 memset(self, 0, sizeof(*self)); 1003 #define FILTER_ALLOC(_x) \ 1004 self->_x.filter = malloc(sizeof(_x##_insns)); \ 1005 ASSERT_NE(NULL, self->_x.filter); \ 1006 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ 1007 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) 1008 FILTER_ALLOC(allow); 1009 FILTER_ALLOC(log); 1010 FILTER_ALLOC(trace); 1011 FILTER_ALLOC(error); 1012 FILTER_ALLOC(trap); 1013 FILTER_ALLOC(kill); 1014 } 1015 1016 FIXTURE_TEARDOWN(precedence) 1017 { 1018 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) 1019 FILTER_FREE(allow); 1020 FILTER_FREE(log); 1021 FILTER_FREE(trace); 1022 FILTER_FREE(error); 1023 FILTER_FREE(trap); 1024 FILTER_FREE(kill); 1025 } 1026 1027 TEST_F(precedence, allow_ok) 1028 { 1029 pid_t parent, res = 0; 1030 long ret; 1031 1032 parent = getppid(); 1033 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1034 ASSERT_EQ(0, ret); 1035 1036 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1037 ASSERT_EQ(0, ret); 1038 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1039 ASSERT_EQ(0, ret); 1040 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1041 ASSERT_EQ(0, ret); 1042 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1043 ASSERT_EQ(0, ret); 1044 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1045 ASSERT_EQ(0, ret); 1046 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1047 ASSERT_EQ(0, ret); 1048 /* Should work just fine. */ 1049 res = syscall(__NR_getppid); 1050 EXPECT_EQ(parent, res); 1051 } 1052 1053 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) 1054 { 1055 pid_t parent, res = 0; 1056 long ret; 1057 1058 parent = getppid(); 1059 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1060 ASSERT_EQ(0, ret); 1061 1062 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1063 ASSERT_EQ(0, ret); 1064 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1065 ASSERT_EQ(0, ret); 1066 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1067 ASSERT_EQ(0, ret); 1068 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1069 ASSERT_EQ(0, ret); 1070 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1071 ASSERT_EQ(0, ret); 1072 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1073 ASSERT_EQ(0, ret); 1074 /* Should work just fine. */ 1075 res = syscall(__NR_getppid); 1076 EXPECT_EQ(parent, res); 1077 /* getpid() should never return. */ 1078 res = syscall(__NR_getpid); 1079 EXPECT_EQ(0, res); 1080 } 1081 1082 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) 1083 { 1084 pid_t parent; 1085 long ret; 1086 1087 parent = getppid(); 1088 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1089 ASSERT_EQ(0, ret); 1090 1091 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1092 ASSERT_EQ(0, ret); 1093 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1094 ASSERT_EQ(0, ret); 1095 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1096 ASSERT_EQ(0, ret); 1097 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1098 ASSERT_EQ(0, ret); 1099 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1100 ASSERT_EQ(0, ret); 1101 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1102 ASSERT_EQ(0, ret); 1103 /* Should work just fine. */ 1104 EXPECT_EQ(parent, syscall(__NR_getppid)); 1105 /* getpid() should never return. */ 1106 EXPECT_EQ(0, syscall(__NR_getpid)); 1107 } 1108 1109 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) 1110 { 1111 pid_t parent; 1112 long ret; 1113 1114 parent = getppid(); 1115 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1116 ASSERT_EQ(0, ret); 1117 1118 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1119 ASSERT_EQ(0, ret); 1120 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1121 ASSERT_EQ(0, ret); 1122 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1123 ASSERT_EQ(0, ret); 1124 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1125 ASSERT_EQ(0, ret); 1126 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1127 ASSERT_EQ(0, ret); 1128 /* Should work just fine. */ 1129 EXPECT_EQ(parent, syscall(__NR_getppid)); 1130 /* getpid() should never return. */ 1131 EXPECT_EQ(0, syscall(__NR_getpid)); 1132 } 1133 1134 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) 1135 { 1136 pid_t parent; 1137 long ret; 1138 1139 parent = getppid(); 1140 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1141 ASSERT_EQ(0, ret); 1142 1143 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1144 ASSERT_EQ(0, ret); 1145 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1146 ASSERT_EQ(0, ret); 1147 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1148 ASSERT_EQ(0, ret); 1149 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1150 ASSERT_EQ(0, ret); 1151 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1152 ASSERT_EQ(0, ret); 1153 /* Should work just fine. */ 1154 EXPECT_EQ(parent, syscall(__NR_getppid)); 1155 /* getpid() should never return. */ 1156 EXPECT_EQ(0, syscall(__NR_getpid)); 1157 } 1158 1159 TEST_F(precedence, errno_is_third) 1160 { 1161 pid_t parent; 1162 long ret; 1163 1164 parent = getppid(); 1165 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1166 ASSERT_EQ(0, ret); 1167 1168 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1169 ASSERT_EQ(0, ret); 1170 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1171 ASSERT_EQ(0, ret); 1172 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1173 ASSERT_EQ(0, ret); 1174 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1175 ASSERT_EQ(0, ret); 1176 /* Should work just fine. */ 1177 EXPECT_EQ(parent, syscall(__NR_getppid)); 1178 EXPECT_EQ(0, syscall(__NR_getpid)); 1179 } 1180 1181 TEST_F(precedence, errno_is_third_in_any_order) 1182 { 1183 pid_t parent; 1184 long ret; 1185 1186 parent = getppid(); 1187 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1188 ASSERT_EQ(0, ret); 1189 1190 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1191 ASSERT_EQ(0, ret); 1192 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1193 ASSERT_EQ(0, ret); 1194 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1195 ASSERT_EQ(0, ret); 1196 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1197 ASSERT_EQ(0, ret); 1198 /* Should work just fine. */ 1199 EXPECT_EQ(parent, syscall(__NR_getppid)); 1200 EXPECT_EQ(0, syscall(__NR_getpid)); 1201 } 1202 1203 TEST_F(precedence, trace_is_fourth) 1204 { 1205 pid_t parent; 1206 long ret; 1207 1208 parent = getppid(); 1209 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1210 ASSERT_EQ(0, ret); 1211 1212 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1213 ASSERT_EQ(0, ret); 1214 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1215 ASSERT_EQ(0, ret); 1216 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1217 ASSERT_EQ(0, ret); 1218 /* Should work just fine. */ 1219 EXPECT_EQ(parent, syscall(__NR_getppid)); 1220 /* No ptracer */ 1221 EXPECT_EQ(-1, syscall(__NR_getpid)); 1222 } 1223 1224 TEST_F(precedence, trace_is_fourth_in_any_order) 1225 { 1226 pid_t parent; 1227 long ret; 1228 1229 parent = getppid(); 1230 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1231 ASSERT_EQ(0, ret); 1232 1233 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1234 ASSERT_EQ(0, ret); 1235 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1236 ASSERT_EQ(0, ret); 1237 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1238 ASSERT_EQ(0, ret); 1239 /* Should work just fine. */ 1240 EXPECT_EQ(parent, syscall(__NR_getppid)); 1241 /* No ptracer */ 1242 EXPECT_EQ(-1, syscall(__NR_getpid)); 1243 } 1244 1245 TEST_F(precedence, log_is_fifth) 1246 { 1247 pid_t mypid, parent; 1248 long ret; 1249 1250 mypid = getpid(); 1251 parent = getppid(); 1252 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1253 ASSERT_EQ(0, ret); 1254 1255 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1256 ASSERT_EQ(0, ret); 1257 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1258 ASSERT_EQ(0, ret); 1259 /* Should work just fine. */ 1260 EXPECT_EQ(parent, syscall(__NR_getppid)); 1261 /* Should also work just fine */ 1262 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1263 } 1264 1265 TEST_F(precedence, log_is_fifth_in_any_order) 1266 { 1267 pid_t mypid, parent; 1268 long ret; 1269 1270 mypid = getpid(); 1271 parent = getppid(); 1272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1273 ASSERT_EQ(0, ret); 1274 1275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1276 ASSERT_EQ(0, ret); 1277 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1278 ASSERT_EQ(0, ret); 1279 /* Should work just fine. */ 1280 EXPECT_EQ(parent, syscall(__NR_getppid)); 1281 /* Should also work just fine */ 1282 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1283 } 1284 1285 #ifndef PTRACE_O_TRACESECCOMP 1286 #define PTRACE_O_TRACESECCOMP 0x00000080 1287 #endif 1288 1289 /* Catch the Ubuntu 12.04 value error. */ 1290 #if PTRACE_EVENT_SECCOMP != 7 1291 #undef PTRACE_EVENT_SECCOMP 1292 #endif 1293 1294 #ifndef PTRACE_EVENT_SECCOMP 1295 #define PTRACE_EVENT_SECCOMP 7 1296 #endif 1297 1298 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP) 1299 bool tracer_running; 1300 void tracer_stop(int sig) 1301 { 1302 tracer_running = false; 1303 } 1304 1305 typedef void tracer_func_t(struct __test_metadata *_metadata, 1306 pid_t tracee, int status, void *args); 1307 1308 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, 1309 tracer_func_t tracer_func, void *args, bool ptrace_syscall) 1310 { 1311 int ret = -1; 1312 struct sigaction action = { 1313 .sa_handler = tracer_stop, 1314 }; 1315 1316 /* Allow external shutdown. */ 1317 tracer_running = true; 1318 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); 1319 1320 errno = 0; 1321 while (ret == -1 && errno != EINVAL) 1322 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); 1323 ASSERT_EQ(0, ret) { 1324 kill(tracee, SIGKILL); 1325 } 1326 /* Wait for attach stop */ 1327 wait(NULL); 1328 1329 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ? 1330 PTRACE_O_TRACESYSGOOD : 1331 PTRACE_O_TRACESECCOMP); 1332 ASSERT_EQ(0, ret) { 1333 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); 1334 kill(tracee, SIGKILL); 1335 } 1336 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1337 tracee, NULL, 0); 1338 ASSERT_EQ(0, ret); 1339 1340 /* Unblock the tracee */ 1341 ASSERT_EQ(1, write(fd, "A", 1)); 1342 ASSERT_EQ(0, close(fd)); 1343 1344 /* Run until we're shut down. Must assert to stop execution. */ 1345 while (tracer_running) { 1346 int status; 1347 1348 if (wait(&status) != tracee) 1349 continue; 1350 if (WIFSIGNALED(status) || WIFEXITED(status)) 1351 /* Child is dead. Time to go. */ 1352 return; 1353 1354 /* Check if this is a seccomp event. */ 1355 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status)); 1356 1357 tracer_func(_metadata, tracee, status, args); 1358 1359 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1360 tracee, NULL, 0); 1361 ASSERT_EQ(0, ret); 1362 } 1363 /* Directly report the status of our test harness results. */ 1364 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 1365 } 1366 1367 /* Common tracer setup/teardown functions. */ 1368 void cont_handler(int num) 1369 { } 1370 pid_t setup_trace_fixture(struct __test_metadata *_metadata, 1371 tracer_func_t func, void *args, bool ptrace_syscall) 1372 { 1373 char sync; 1374 int pipefd[2]; 1375 pid_t tracer_pid; 1376 pid_t tracee = getpid(); 1377 1378 /* Setup a pipe for clean synchronization. */ 1379 ASSERT_EQ(0, pipe(pipefd)); 1380 1381 /* Fork a child which we'll promote to tracer */ 1382 tracer_pid = fork(); 1383 ASSERT_LE(0, tracer_pid); 1384 signal(SIGALRM, cont_handler); 1385 if (tracer_pid == 0) { 1386 close(pipefd[0]); 1387 start_tracer(_metadata, pipefd[1], tracee, func, args, 1388 ptrace_syscall); 1389 syscall(__NR_exit, 0); 1390 } 1391 close(pipefd[1]); 1392 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); 1393 read(pipefd[0], &sync, 1); 1394 close(pipefd[0]); 1395 1396 return tracer_pid; 1397 } 1398 void teardown_trace_fixture(struct __test_metadata *_metadata, 1399 pid_t tracer) 1400 { 1401 if (tracer) { 1402 int status; 1403 /* 1404 * Extract the exit code from the other process and 1405 * adopt it for ourselves in case its asserts failed. 1406 */ 1407 ASSERT_EQ(0, kill(tracer, SIGUSR1)); 1408 ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); 1409 if (WEXITSTATUS(status)) 1410 _metadata->passed = 0; 1411 } 1412 } 1413 1414 /* "poke" tracer arguments and function. */ 1415 struct tracer_args_poke_t { 1416 unsigned long poke_addr; 1417 }; 1418 1419 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, 1420 void *args) 1421 { 1422 int ret; 1423 unsigned long msg; 1424 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; 1425 1426 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1427 EXPECT_EQ(0, ret); 1428 /* If this fails, don't try to recover. */ 1429 ASSERT_EQ(0x1001, msg) { 1430 kill(tracee, SIGKILL); 1431 } 1432 /* 1433 * Poke in the message. 1434 * Registers are not touched to try to keep this relatively arch 1435 * agnostic. 1436 */ 1437 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); 1438 EXPECT_EQ(0, ret); 1439 } 1440 1441 FIXTURE_DATA(TRACE_poke) { 1442 struct sock_fprog prog; 1443 pid_t tracer; 1444 long poked; 1445 struct tracer_args_poke_t tracer_args; 1446 }; 1447 1448 FIXTURE_SETUP(TRACE_poke) 1449 { 1450 struct sock_filter filter[] = { 1451 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1452 offsetof(struct seccomp_data, nr)), 1453 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 1454 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), 1455 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1456 }; 1457 1458 self->poked = 0; 1459 memset(&self->prog, 0, sizeof(self->prog)); 1460 self->prog.filter = malloc(sizeof(filter)); 1461 ASSERT_NE(NULL, self->prog.filter); 1462 memcpy(self->prog.filter, filter, sizeof(filter)); 1463 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1464 1465 /* Set up tracer args. */ 1466 self->tracer_args.poke_addr = (unsigned long)&self->poked; 1467 1468 /* Launch tracer. */ 1469 self->tracer = setup_trace_fixture(_metadata, tracer_poke, 1470 &self->tracer_args, false); 1471 } 1472 1473 FIXTURE_TEARDOWN(TRACE_poke) 1474 { 1475 teardown_trace_fixture(_metadata, self->tracer); 1476 if (self->prog.filter) 1477 free(self->prog.filter); 1478 } 1479 1480 TEST_F(TRACE_poke, read_has_side_effects) 1481 { 1482 ssize_t ret; 1483 1484 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1485 ASSERT_EQ(0, ret); 1486 1487 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1488 ASSERT_EQ(0, ret); 1489 1490 EXPECT_EQ(0, self->poked); 1491 ret = read(-1, NULL, 0); 1492 EXPECT_EQ(-1, ret); 1493 EXPECT_EQ(0x1001, self->poked); 1494 } 1495 1496 TEST_F(TRACE_poke, getpid_runs_normally) 1497 { 1498 long ret; 1499 1500 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1501 ASSERT_EQ(0, ret); 1502 1503 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1504 ASSERT_EQ(0, ret); 1505 1506 EXPECT_EQ(0, self->poked); 1507 EXPECT_NE(0, syscall(__NR_getpid)); 1508 EXPECT_EQ(0, self->poked); 1509 } 1510 1511 #if defined(__x86_64__) 1512 # define ARCH_REGS struct user_regs_struct 1513 # define SYSCALL_NUM orig_rax 1514 # define SYSCALL_RET rax 1515 #elif defined(__i386__) 1516 # define ARCH_REGS struct user_regs_struct 1517 # define SYSCALL_NUM orig_eax 1518 # define SYSCALL_RET eax 1519 #elif defined(__arm__) 1520 # define ARCH_REGS struct pt_regs 1521 # define SYSCALL_NUM ARM_r7 1522 # define SYSCALL_RET ARM_r0 1523 #elif defined(__aarch64__) 1524 # define ARCH_REGS struct user_pt_regs 1525 # define SYSCALL_NUM regs[8] 1526 # define SYSCALL_RET regs[0] 1527 #elif defined(__hppa__) 1528 # define ARCH_REGS struct user_regs_struct 1529 # define SYSCALL_NUM gr[20] 1530 # define SYSCALL_RET gr[28] 1531 #elif defined(__powerpc__) 1532 # define ARCH_REGS struct pt_regs 1533 # define SYSCALL_NUM gpr[0] 1534 # define SYSCALL_RET gpr[3] 1535 #elif defined(__s390__) 1536 # define ARCH_REGS s390_regs 1537 # define SYSCALL_NUM gprs[2] 1538 # define SYSCALL_RET gprs[2] 1539 #elif defined(__mips__) 1540 # define ARCH_REGS struct pt_regs 1541 # define SYSCALL_NUM regs[2] 1542 # define SYSCALL_SYSCALL_NUM regs[4] 1543 # define SYSCALL_RET regs[2] 1544 # define SYSCALL_NUM_RET_SHARE_REG 1545 #else 1546 # error "Do not know how to find your architecture's registers and syscalls" 1547 #endif 1548 1549 /* When the syscall return can't be changed, stub out the tests for it. */ 1550 #ifdef SYSCALL_NUM_RET_SHARE_REG 1551 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action) 1552 #else 1553 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(val, action) 1554 #endif 1555 1556 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for 1557 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). 1558 */ 1559 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__) 1560 #define HAVE_GETREGS 1561 #endif 1562 1563 /* Architecture-specific syscall fetching routine. */ 1564 int get_syscall(struct __test_metadata *_metadata, pid_t tracee) 1565 { 1566 ARCH_REGS regs; 1567 #ifdef HAVE_GETREGS 1568 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, ®s)) { 1569 TH_LOG("PTRACE_GETREGS failed"); 1570 return -1; 1571 } 1572 #else 1573 struct iovec iov; 1574 1575 iov.iov_base = ®s; 1576 iov.iov_len = sizeof(regs); 1577 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) { 1578 TH_LOG("PTRACE_GETREGSET failed"); 1579 return -1; 1580 } 1581 #endif 1582 1583 #if defined(__mips__) 1584 if (regs.SYSCALL_NUM == __NR_O32_Linux) 1585 return regs.SYSCALL_SYSCALL_NUM; 1586 #endif 1587 return regs.SYSCALL_NUM; 1588 } 1589 1590 /* Architecture-specific syscall changing routine. */ 1591 void change_syscall(struct __test_metadata *_metadata, 1592 pid_t tracee, int syscall) 1593 { 1594 int ret; 1595 ARCH_REGS regs; 1596 #ifdef HAVE_GETREGS 1597 ret = ptrace(PTRACE_GETREGS, tracee, 0, ®s); 1598 #else 1599 struct iovec iov; 1600 iov.iov_base = ®s; 1601 iov.iov_len = sizeof(regs); 1602 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov); 1603 #endif 1604 EXPECT_EQ(0, ret) {} 1605 1606 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \ 1607 defined(__s390__) || defined(__hppa__) 1608 { 1609 regs.SYSCALL_NUM = syscall; 1610 } 1611 #elif defined(__mips__) 1612 { 1613 if (regs.SYSCALL_NUM == __NR_O32_Linux) 1614 regs.SYSCALL_SYSCALL_NUM = syscall; 1615 else 1616 regs.SYSCALL_NUM = syscall; 1617 } 1618 1619 #elif defined(__arm__) 1620 # ifndef PTRACE_SET_SYSCALL 1621 # define PTRACE_SET_SYSCALL 23 1622 # endif 1623 { 1624 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall); 1625 EXPECT_EQ(0, ret); 1626 } 1627 1628 #elif defined(__aarch64__) 1629 # ifndef NT_ARM_SYSTEM_CALL 1630 # define NT_ARM_SYSTEM_CALL 0x404 1631 # endif 1632 { 1633 iov.iov_base = &syscall; 1634 iov.iov_len = sizeof(syscall); 1635 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL, 1636 &iov); 1637 EXPECT_EQ(0, ret); 1638 } 1639 1640 #else 1641 ASSERT_EQ(1, 0) { 1642 TH_LOG("How is the syscall changed on this architecture?"); 1643 } 1644 #endif 1645 1646 /* If syscall is skipped, change return value. */ 1647 if (syscall == -1) 1648 #ifdef SYSCALL_NUM_RET_SHARE_REG 1649 TH_LOG("Can't modify syscall return on this architecture"); 1650 #else 1651 regs.SYSCALL_RET = EPERM; 1652 #endif 1653 1654 #ifdef HAVE_GETREGS 1655 ret = ptrace(PTRACE_SETREGS, tracee, 0, ®s); 1656 #else 1657 iov.iov_base = ®s; 1658 iov.iov_len = sizeof(regs); 1659 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov); 1660 #endif 1661 EXPECT_EQ(0, ret); 1662 } 1663 1664 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee, 1665 int status, void *args) 1666 { 1667 int ret; 1668 unsigned long msg; 1669 1670 /* Make sure we got the right message. */ 1671 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1672 EXPECT_EQ(0, ret); 1673 1674 /* Validate and take action on expected syscalls. */ 1675 switch (msg) { 1676 case 0x1002: 1677 /* change getpid to getppid. */ 1678 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee)); 1679 change_syscall(_metadata, tracee, __NR_getppid); 1680 break; 1681 case 0x1003: 1682 /* skip gettid. */ 1683 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee)); 1684 change_syscall(_metadata, tracee, -1); 1685 break; 1686 case 0x1004: 1687 /* do nothing (allow getppid) */ 1688 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee)); 1689 break; 1690 default: 1691 EXPECT_EQ(0, msg) { 1692 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); 1693 kill(tracee, SIGKILL); 1694 } 1695 } 1696 1697 } 1698 1699 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee, 1700 int status, void *args) 1701 { 1702 int ret, nr; 1703 unsigned long msg; 1704 static bool entry; 1705 1706 /* Make sure we got an empty message. */ 1707 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1708 EXPECT_EQ(0, ret); 1709 EXPECT_EQ(0, msg); 1710 1711 /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */ 1712 entry = !entry; 1713 if (!entry) 1714 return; 1715 1716 nr = get_syscall(_metadata, tracee); 1717 1718 if (nr == __NR_getpid) 1719 change_syscall(_metadata, tracee, __NR_getppid); 1720 if (nr == __NR_open) 1721 change_syscall(_metadata, tracee, -1); 1722 } 1723 1724 FIXTURE_DATA(TRACE_syscall) { 1725 struct sock_fprog prog; 1726 pid_t tracer, mytid, mypid, parent; 1727 }; 1728 1729 FIXTURE_SETUP(TRACE_syscall) 1730 { 1731 struct sock_filter filter[] = { 1732 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1733 offsetof(struct seccomp_data, nr)), 1734 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 1735 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), 1736 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), 1737 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), 1738 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1739 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), 1740 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1741 }; 1742 1743 memset(&self->prog, 0, sizeof(self->prog)); 1744 self->prog.filter = malloc(sizeof(filter)); 1745 ASSERT_NE(NULL, self->prog.filter); 1746 memcpy(self->prog.filter, filter, sizeof(filter)); 1747 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1748 1749 /* Prepare some testable syscall results. */ 1750 self->mytid = syscall(__NR_gettid); 1751 ASSERT_GT(self->mytid, 0); 1752 ASSERT_NE(self->mytid, 1) { 1753 TH_LOG("Running this test as init is not supported. :)"); 1754 } 1755 1756 self->mypid = getpid(); 1757 ASSERT_GT(self->mypid, 0); 1758 ASSERT_EQ(self->mytid, self->mypid); 1759 1760 self->parent = getppid(); 1761 ASSERT_GT(self->parent, 0); 1762 ASSERT_NE(self->parent, self->mypid); 1763 1764 /* Launch tracer. */ 1765 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL, 1766 false); 1767 } 1768 1769 FIXTURE_TEARDOWN(TRACE_syscall) 1770 { 1771 teardown_trace_fixture(_metadata, self->tracer); 1772 if (self->prog.filter) 1773 free(self->prog.filter); 1774 } 1775 1776 TEST_F(TRACE_syscall, ptrace_syscall_redirected) 1777 { 1778 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ 1779 teardown_trace_fixture(_metadata, self->tracer); 1780 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, 1781 true); 1782 1783 /* Tracer will redirect getpid to getppid. */ 1784 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1785 } 1786 1787 TEST_F(TRACE_syscall, ptrace_syscall_dropped) 1788 { 1789 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ 1790 teardown_trace_fixture(_metadata, self->tracer); 1791 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, 1792 true); 1793 1794 /* Tracer should skip the open syscall, resulting in EPERM. */ 1795 EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_open)); 1796 } 1797 1798 TEST_F(TRACE_syscall, syscall_allowed) 1799 { 1800 long ret; 1801 1802 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1803 ASSERT_EQ(0, ret); 1804 1805 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1806 ASSERT_EQ(0, ret); 1807 1808 /* getppid works as expected (no changes). */ 1809 EXPECT_EQ(self->parent, syscall(__NR_getppid)); 1810 EXPECT_NE(self->mypid, syscall(__NR_getppid)); 1811 } 1812 1813 TEST_F(TRACE_syscall, syscall_redirected) 1814 { 1815 long ret; 1816 1817 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1818 ASSERT_EQ(0, ret); 1819 1820 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1821 ASSERT_EQ(0, ret); 1822 1823 /* getpid has been redirected to getppid as expected. */ 1824 EXPECT_EQ(self->parent, syscall(__NR_getpid)); 1825 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1826 } 1827 1828 TEST_F(TRACE_syscall, syscall_dropped) 1829 { 1830 long ret; 1831 1832 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1833 ASSERT_EQ(0, ret); 1834 1835 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1836 ASSERT_EQ(0, ret); 1837 1838 /* gettid has been skipped and an altered return value stored. */ 1839 EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_gettid)); 1840 EXPECT_NE(self->mytid, syscall(__NR_gettid)); 1841 } 1842 1843 TEST_F(TRACE_syscall, skip_after_RET_TRACE) 1844 { 1845 struct sock_filter filter[] = { 1846 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1847 offsetof(struct seccomp_data, nr)), 1848 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1849 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 1850 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1851 }; 1852 struct sock_fprog prog = { 1853 .len = (unsigned short)ARRAY_SIZE(filter), 1854 .filter = filter, 1855 }; 1856 long ret; 1857 1858 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1859 ASSERT_EQ(0, ret); 1860 1861 /* Install fixture filter. */ 1862 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1863 ASSERT_EQ(0, ret); 1864 1865 /* Install "errno on getppid" filter. */ 1866 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1867 ASSERT_EQ(0, ret); 1868 1869 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 1870 errno = 0; 1871 EXPECT_EQ(-1, syscall(__NR_getpid)); 1872 EXPECT_EQ(EPERM, errno); 1873 } 1874 1875 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS) 1876 { 1877 struct sock_filter filter[] = { 1878 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1879 offsetof(struct seccomp_data, nr)), 1880 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1881 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1882 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1883 }; 1884 struct sock_fprog prog = { 1885 .len = (unsigned short)ARRAY_SIZE(filter), 1886 .filter = filter, 1887 }; 1888 long ret; 1889 1890 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1891 ASSERT_EQ(0, ret); 1892 1893 /* Install fixture filter. */ 1894 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1895 ASSERT_EQ(0, ret); 1896 1897 /* Install "death on getppid" filter. */ 1898 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1899 ASSERT_EQ(0, ret); 1900 1901 /* Tracer will redirect getpid to getppid, and we should die. */ 1902 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1903 } 1904 1905 TEST_F(TRACE_syscall, skip_after_ptrace) 1906 { 1907 struct sock_filter filter[] = { 1908 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1909 offsetof(struct seccomp_data, nr)), 1910 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1911 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 1912 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1913 }; 1914 struct sock_fprog prog = { 1915 .len = (unsigned short)ARRAY_SIZE(filter), 1916 .filter = filter, 1917 }; 1918 long ret; 1919 1920 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ 1921 teardown_trace_fixture(_metadata, self->tracer); 1922 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, 1923 true); 1924 1925 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1926 ASSERT_EQ(0, ret); 1927 1928 /* Install "errno on getppid" filter. */ 1929 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1930 ASSERT_EQ(0, ret); 1931 1932 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 1933 EXPECT_EQ(-1, syscall(__NR_getpid)); 1934 EXPECT_EQ(EPERM, errno); 1935 } 1936 1937 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS) 1938 { 1939 struct sock_filter filter[] = { 1940 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1941 offsetof(struct seccomp_data, nr)), 1942 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1943 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1944 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1945 }; 1946 struct sock_fprog prog = { 1947 .len = (unsigned short)ARRAY_SIZE(filter), 1948 .filter = filter, 1949 }; 1950 long ret; 1951 1952 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ 1953 teardown_trace_fixture(_metadata, self->tracer); 1954 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, 1955 true); 1956 1957 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1958 ASSERT_EQ(0, ret); 1959 1960 /* Install "death on getppid" filter. */ 1961 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1962 ASSERT_EQ(0, ret); 1963 1964 /* Tracer will redirect getpid to getppid, and we should die. */ 1965 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1966 } 1967 1968 TEST(seccomp_syscall) 1969 { 1970 struct sock_filter filter[] = { 1971 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1972 }; 1973 struct sock_fprog prog = { 1974 .len = (unsigned short)ARRAY_SIZE(filter), 1975 .filter = filter, 1976 }; 1977 long ret; 1978 1979 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1980 ASSERT_EQ(0, ret) { 1981 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 1982 } 1983 1984 /* Reject insane operation. */ 1985 ret = seccomp(-1, 0, &prog); 1986 ASSERT_NE(ENOSYS, errno) { 1987 TH_LOG("Kernel does not support seccomp syscall!"); 1988 } 1989 EXPECT_EQ(EINVAL, errno) { 1990 TH_LOG("Did not reject crazy op value!"); 1991 } 1992 1993 /* Reject strict with flags or pointer. */ 1994 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); 1995 EXPECT_EQ(EINVAL, errno) { 1996 TH_LOG("Did not reject mode strict with flags!"); 1997 } 1998 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); 1999 EXPECT_EQ(EINVAL, errno) { 2000 TH_LOG("Did not reject mode strict with uargs!"); 2001 } 2002 2003 /* Reject insane args for filter. */ 2004 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); 2005 EXPECT_EQ(EINVAL, errno) { 2006 TH_LOG("Did not reject crazy filter flags!"); 2007 } 2008 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); 2009 EXPECT_EQ(EFAULT, errno) { 2010 TH_LOG("Did not reject NULL filter!"); 2011 } 2012 2013 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2014 EXPECT_EQ(0, errno) { 2015 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", 2016 strerror(errno)); 2017 } 2018 } 2019 2020 TEST(seccomp_syscall_mode_lock) 2021 { 2022 struct sock_filter filter[] = { 2023 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2024 }; 2025 struct sock_fprog prog = { 2026 .len = (unsigned short)ARRAY_SIZE(filter), 2027 .filter = filter, 2028 }; 2029 long ret; 2030 2031 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2032 ASSERT_EQ(0, ret) { 2033 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2034 } 2035 2036 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2037 ASSERT_NE(ENOSYS, errno) { 2038 TH_LOG("Kernel does not support seccomp syscall!"); 2039 } 2040 EXPECT_EQ(0, ret) { 2041 TH_LOG("Could not install filter!"); 2042 } 2043 2044 /* Make sure neither entry point will switch to strict. */ 2045 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); 2046 EXPECT_EQ(EINVAL, errno) { 2047 TH_LOG("Switched to mode strict!"); 2048 } 2049 2050 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); 2051 EXPECT_EQ(EINVAL, errno) { 2052 TH_LOG("Switched to mode strict!"); 2053 } 2054 } 2055 2056 /* 2057 * Test detection of known and unknown filter flags. Userspace needs to be able 2058 * to check if a filter flag is supported by the current kernel and a good way 2059 * of doing that is by attempting to enter filter mode, with the flag bit in 2060 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates 2061 * that the flag is valid and EINVAL indicates that the flag is invalid. 2062 */ 2063 TEST(detect_seccomp_filter_flags) 2064 { 2065 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC, 2066 SECCOMP_FILTER_FLAG_LOG }; 2067 unsigned int flag, all_flags; 2068 int i; 2069 long ret; 2070 2071 /* Test detection of known-good filter flags */ 2072 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) { 2073 flag = flags[i]; 2074 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2075 ASSERT_NE(ENOSYS, errno) { 2076 TH_LOG("Kernel does not support seccomp syscall!"); 2077 } 2078 EXPECT_EQ(-1, ret); 2079 EXPECT_EQ(EFAULT, errno) { 2080 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!", 2081 flag); 2082 } 2083 2084 all_flags |= flag; 2085 } 2086 2087 /* Test detection of all known-good filter flags */ 2088 ret = seccomp(SECCOMP_SET_MODE_FILTER, all_flags, NULL); 2089 EXPECT_EQ(-1, ret); 2090 EXPECT_EQ(EFAULT, errno) { 2091 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!", 2092 all_flags); 2093 } 2094 2095 /* Test detection of an unknown filter flag */ 2096 flag = -1; 2097 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2098 EXPECT_EQ(-1, ret); 2099 EXPECT_EQ(EINVAL, errno) { 2100 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!", 2101 flag); 2102 } 2103 2104 /* 2105 * Test detection of an unknown filter flag that may simply need to be 2106 * added to this test 2107 */ 2108 flag = flags[ARRAY_SIZE(flags) - 1] << 1; 2109 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2110 EXPECT_EQ(-1, ret); 2111 EXPECT_EQ(EINVAL, errno) { 2112 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?", 2113 flag); 2114 } 2115 } 2116 2117 TEST(TSYNC_first) 2118 { 2119 struct sock_filter filter[] = { 2120 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2121 }; 2122 struct sock_fprog prog = { 2123 .len = (unsigned short)ARRAY_SIZE(filter), 2124 .filter = filter, 2125 }; 2126 long ret; 2127 2128 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2129 ASSERT_EQ(0, ret) { 2130 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2131 } 2132 2133 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2134 &prog); 2135 ASSERT_NE(ENOSYS, errno) { 2136 TH_LOG("Kernel does not support seccomp syscall!"); 2137 } 2138 EXPECT_EQ(0, ret) { 2139 TH_LOG("Could not install initial filter with TSYNC!"); 2140 } 2141 } 2142 2143 #define TSYNC_SIBLINGS 2 2144 struct tsync_sibling { 2145 pthread_t tid; 2146 pid_t system_tid; 2147 sem_t *started; 2148 pthread_cond_t *cond; 2149 pthread_mutex_t *mutex; 2150 int diverge; 2151 int num_waits; 2152 struct sock_fprog *prog; 2153 struct __test_metadata *metadata; 2154 }; 2155 2156 /* 2157 * To avoid joining joined threads (which is not allowed by Bionic), 2158 * make sure we both successfully join and clear the tid to skip a 2159 * later join attempt during fixture teardown. Any remaining threads 2160 * will be directly killed during teardown. 2161 */ 2162 #define PTHREAD_JOIN(tid, status) \ 2163 do { \ 2164 int _rc = pthread_join(tid, status); \ 2165 if (_rc) { \ 2166 TH_LOG("pthread_join of tid %u failed: %d\n", \ 2167 (unsigned int)tid, _rc); \ 2168 } else { \ 2169 tid = 0; \ 2170 } \ 2171 } while (0) 2172 2173 FIXTURE_DATA(TSYNC) { 2174 struct sock_fprog root_prog, apply_prog; 2175 struct tsync_sibling sibling[TSYNC_SIBLINGS]; 2176 sem_t started; 2177 pthread_cond_t cond; 2178 pthread_mutex_t mutex; 2179 int sibling_count; 2180 }; 2181 2182 FIXTURE_SETUP(TSYNC) 2183 { 2184 struct sock_filter root_filter[] = { 2185 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2186 }; 2187 struct sock_filter apply_filter[] = { 2188 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2189 offsetof(struct seccomp_data, nr)), 2190 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 2191 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2192 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2193 }; 2194 2195 memset(&self->root_prog, 0, sizeof(self->root_prog)); 2196 memset(&self->apply_prog, 0, sizeof(self->apply_prog)); 2197 memset(&self->sibling, 0, sizeof(self->sibling)); 2198 self->root_prog.filter = malloc(sizeof(root_filter)); 2199 ASSERT_NE(NULL, self->root_prog.filter); 2200 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); 2201 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); 2202 2203 self->apply_prog.filter = malloc(sizeof(apply_filter)); 2204 ASSERT_NE(NULL, self->apply_prog.filter); 2205 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); 2206 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); 2207 2208 self->sibling_count = 0; 2209 pthread_mutex_init(&self->mutex, NULL); 2210 pthread_cond_init(&self->cond, NULL); 2211 sem_init(&self->started, 0, 0); 2212 self->sibling[0].tid = 0; 2213 self->sibling[0].cond = &self->cond; 2214 self->sibling[0].started = &self->started; 2215 self->sibling[0].mutex = &self->mutex; 2216 self->sibling[0].diverge = 0; 2217 self->sibling[0].num_waits = 1; 2218 self->sibling[0].prog = &self->root_prog; 2219 self->sibling[0].metadata = _metadata; 2220 self->sibling[1].tid = 0; 2221 self->sibling[1].cond = &self->cond; 2222 self->sibling[1].started = &self->started; 2223 self->sibling[1].mutex = &self->mutex; 2224 self->sibling[1].diverge = 0; 2225 self->sibling[1].prog = &self->root_prog; 2226 self->sibling[1].num_waits = 1; 2227 self->sibling[1].metadata = _metadata; 2228 } 2229 2230 FIXTURE_TEARDOWN(TSYNC) 2231 { 2232 int sib = 0; 2233 2234 if (self->root_prog.filter) 2235 free(self->root_prog.filter); 2236 if (self->apply_prog.filter) 2237 free(self->apply_prog.filter); 2238 2239 for ( ; sib < self->sibling_count; ++sib) { 2240 struct tsync_sibling *s = &self->sibling[sib]; 2241 2242 if (!s->tid) 2243 continue; 2244 /* 2245 * If a thread is still running, it may be stuck, so hit 2246 * it over the head really hard. 2247 */ 2248 pthread_kill(s->tid, 9); 2249 } 2250 pthread_mutex_destroy(&self->mutex); 2251 pthread_cond_destroy(&self->cond); 2252 sem_destroy(&self->started); 2253 } 2254 2255 void *tsync_sibling(void *data) 2256 { 2257 long ret = 0; 2258 struct tsync_sibling *me = data; 2259 2260 me->system_tid = syscall(__NR_gettid); 2261 2262 pthread_mutex_lock(me->mutex); 2263 if (me->diverge) { 2264 /* Just re-apply the root prog to fork the tree */ 2265 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 2266 me->prog, 0, 0); 2267 } 2268 sem_post(me->started); 2269 /* Return outside of started so parent notices failures. */ 2270 if (ret) { 2271 pthread_mutex_unlock(me->mutex); 2272 return (void *)SIBLING_EXIT_FAILURE; 2273 } 2274 do { 2275 pthread_cond_wait(me->cond, me->mutex); 2276 me->num_waits = me->num_waits - 1; 2277 } while (me->num_waits); 2278 pthread_mutex_unlock(me->mutex); 2279 2280 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); 2281 if (!ret) 2282 return (void *)SIBLING_EXIT_NEWPRIVS; 2283 read(0, NULL, 0); 2284 return (void *)SIBLING_EXIT_UNKILLED; 2285 } 2286 2287 void tsync_start_sibling(struct tsync_sibling *sibling) 2288 { 2289 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); 2290 } 2291 2292 TEST_F(TSYNC, siblings_fail_prctl) 2293 { 2294 long ret; 2295 void *status; 2296 struct sock_filter filter[] = { 2297 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2298 offsetof(struct seccomp_data, nr)), 2299 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 2300 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), 2301 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2302 }; 2303 struct sock_fprog prog = { 2304 .len = (unsigned short)ARRAY_SIZE(filter), 2305 .filter = filter, 2306 }; 2307 2308 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2309 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2310 } 2311 2312 /* Check prctl failure detection by requesting sib 0 diverge. */ 2313 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2314 ASSERT_NE(ENOSYS, errno) { 2315 TH_LOG("Kernel does not support seccomp syscall!"); 2316 } 2317 ASSERT_EQ(0, ret) { 2318 TH_LOG("setting filter failed"); 2319 } 2320 2321 self->sibling[0].diverge = 1; 2322 tsync_start_sibling(&self->sibling[0]); 2323 tsync_start_sibling(&self->sibling[1]); 2324 2325 while (self->sibling_count < TSYNC_SIBLINGS) { 2326 sem_wait(&self->started); 2327 self->sibling_count++; 2328 } 2329 2330 /* Signal the threads to clean up*/ 2331 pthread_mutex_lock(&self->mutex); 2332 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2333 TH_LOG("cond broadcast non-zero"); 2334 } 2335 pthread_mutex_unlock(&self->mutex); 2336 2337 /* Ensure diverging sibling failed to call prctl. */ 2338 PTHREAD_JOIN(self->sibling[0].tid, &status); 2339 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); 2340 PTHREAD_JOIN(self->sibling[1].tid, &status); 2341 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2342 } 2343 2344 TEST_F(TSYNC, two_siblings_with_ancestor) 2345 { 2346 long ret; 2347 void *status; 2348 2349 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2350 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2351 } 2352 2353 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2354 ASSERT_NE(ENOSYS, errno) { 2355 TH_LOG("Kernel does not support seccomp syscall!"); 2356 } 2357 ASSERT_EQ(0, ret) { 2358 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2359 } 2360 tsync_start_sibling(&self->sibling[0]); 2361 tsync_start_sibling(&self->sibling[1]); 2362 2363 while (self->sibling_count < TSYNC_SIBLINGS) { 2364 sem_wait(&self->started); 2365 self->sibling_count++; 2366 } 2367 2368 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2369 &self->apply_prog); 2370 ASSERT_EQ(0, ret) { 2371 TH_LOG("Could install filter on all threads!"); 2372 } 2373 /* Tell the siblings to test the policy */ 2374 pthread_mutex_lock(&self->mutex); 2375 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2376 TH_LOG("cond broadcast non-zero"); 2377 } 2378 pthread_mutex_unlock(&self->mutex); 2379 /* Ensure they are both killed and don't exit cleanly. */ 2380 PTHREAD_JOIN(self->sibling[0].tid, &status); 2381 EXPECT_EQ(0x0, (long)status); 2382 PTHREAD_JOIN(self->sibling[1].tid, &status); 2383 EXPECT_EQ(0x0, (long)status); 2384 } 2385 2386 TEST_F(TSYNC, two_sibling_want_nnp) 2387 { 2388 void *status; 2389 2390 /* start siblings before any prctl() operations */ 2391 tsync_start_sibling(&self->sibling[0]); 2392 tsync_start_sibling(&self->sibling[1]); 2393 while (self->sibling_count < TSYNC_SIBLINGS) { 2394 sem_wait(&self->started); 2395 self->sibling_count++; 2396 } 2397 2398 /* Tell the siblings to test no policy */ 2399 pthread_mutex_lock(&self->mutex); 2400 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2401 TH_LOG("cond broadcast non-zero"); 2402 } 2403 pthread_mutex_unlock(&self->mutex); 2404 2405 /* Ensure they are both upset about lacking nnp. */ 2406 PTHREAD_JOIN(self->sibling[0].tid, &status); 2407 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2408 PTHREAD_JOIN(self->sibling[1].tid, &status); 2409 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2410 } 2411 2412 TEST_F(TSYNC, two_siblings_with_no_filter) 2413 { 2414 long ret; 2415 void *status; 2416 2417 /* start siblings before any prctl() operations */ 2418 tsync_start_sibling(&self->sibling[0]); 2419 tsync_start_sibling(&self->sibling[1]); 2420 while (self->sibling_count < TSYNC_SIBLINGS) { 2421 sem_wait(&self->started); 2422 self->sibling_count++; 2423 } 2424 2425 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2426 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2427 } 2428 2429 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2430 &self->apply_prog); 2431 ASSERT_NE(ENOSYS, errno) { 2432 TH_LOG("Kernel does not support seccomp syscall!"); 2433 } 2434 ASSERT_EQ(0, ret) { 2435 TH_LOG("Could install filter on all threads!"); 2436 } 2437 2438 /* Tell the siblings to test the policy */ 2439 pthread_mutex_lock(&self->mutex); 2440 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2441 TH_LOG("cond broadcast non-zero"); 2442 } 2443 pthread_mutex_unlock(&self->mutex); 2444 2445 /* Ensure they are both killed and don't exit cleanly. */ 2446 PTHREAD_JOIN(self->sibling[0].tid, &status); 2447 EXPECT_EQ(0x0, (long)status); 2448 PTHREAD_JOIN(self->sibling[1].tid, &status); 2449 EXPECT_EQ(0x0, (long)status); 2450 } 2451 2452 TEST_F(TSYNC, two_siblings_with_one_divergence) 2453 { 2454 long ret; 2455 void *status; 2456 2457 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2458 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2459 } 2460 2461 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2462 ASSERT_NE(ENOSYS, errno) { 2463 TH_LOG("Kernel does not support seccomp syscall!"); 2464 } 2465 ASSERT_EQ(0, ret) { 2466 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2467 } 2468 self->sibling[0].diverge = 1; 2469 tsync_start_sibling(&self->sibling[0]); 2470 tsync_start_sibling(&self->sibling[1]); 2471 2472 while (self->sibling_count < TSYNC_SIBLINGS) { 2473 sem_wait(&self->started); 2474 self->sibling_count++; 2475 } 2476 2477 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2478 &self->apply_prog); 2479 ASSERT_EQ(self->sibling[0].system_tid, ret) { 2480 TH_LOG("Did not fail on diverged sibling."); 2481 } 2482 2483 /* Wake the threads */ 2484 pthread_mutex_lock(&self->mutex); 2485 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2486 TH_LOG("cond broadcast non-zero"); 2487 } 2488 pthread_mutex_unlock(&self->mutex); 2489 2490 /* Ensure they are both unkilled. */ 2491 PTHREAD_JOIN(self->sibling[0].tid, &status); 2492 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2493 PTHREAD_JOIN(self->sibling[1].tid, &status); 2494 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2495 } 2496 2497 TEST_F(TSYNC, two_siblings_not_under_filter) 2498 { 2499 long ret, sib; 2500 void *status; 2501 2502 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2503 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2504 } 2505 2506 /* 2507 * Sibling 0 will have its own seccomp policy 2508 * and Sibling 1 will not be under seccomp at 2509 * all. Sibling 1 will enter seccomp and 0 2510 * will cause failure. 2511 */ 2512 self->sibling[0].diverge = 1; 2513 tsync_start_sibling(&self->sibling[0]); 2514 tsync_start_sibling(&self->sibling[1]); 2515 2516 while (self->sibling_count < TSYNC_SIBLINGS) { 2517 sem_wait(&self->started); 2518 self->sibling_count++; 2519 } 2520 2521 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2522 ASSERT_NE(ENOSYS, errno) { 2523 TH_LOG("Kernel does not support seccomp syscall!"); 2524 } 2525 ASSERT_EQ(0, ret) { 2526 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2527 } 2528 2529 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2530 &self->apply_prog); 2531 ASSERT_EQ(ret, self->sibling[0].system_tid) { 2532 TH_LOG("Did not fail on diverged sibling."); 2533 } 2534 sib = 1; 2535 if (ret == self->sibling[0].system_tid) 2536 sib = 0; 2537 2538 pthread_mutex_lock(&self->mutex); 2539 2540 /* Increment the other siblings num_waits so we can clean up 2541 * the one we just saw. 2542 */ 2543 self->sibling[!sib].num_waits += 1; 2544 2545 /* Signal the thread to clean up*/ 2546 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2547 TH_LOG("cond broadcast non-zero"); 2548 } 2549 pthread_mutex_unlock(&self->mutex); 2550 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2551 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2552 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2553 while (!kill(self->sibling[sib].system_tid, 0)) 2554 sleep(0.1); 2555 /* Switch to the remaining sibling */ 2556 sib = !sib; 2557 2558 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2559 &self->apply_prog); 2560 ASSERT_EQ(0, ret) { 2561 TH_LOG("Expected the remaining sibling to sync"); 2562 }; 2563 2564 pthread_mutex_lock(&self->mutex); 2565 2566 /* If remaining sibling didn't have a chance to wake up during 2567 * the first broadcast, manually reduce the num_waits now. 2568 */ 2569 if (self->sibling[sib].num_waits > 1) 2570 self->sibling[sib].num_waits = 1; 2571 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2572 TH_LOG("cond broadcast non-zero"); 2573 } 2574 pthread_mutex_unlock(&self->mutex); 2575 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2576 EXPECT_EQ(0, (long)status); 2577 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2578 while (!kill(self->sibling[sib].system_tid, 0)) 2579 sleep(0.1); 2580 2581 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2582 &self->apply_prog); 2583 ASSERT_EQ(0, ret); /* just us chickens */ 2584 } 2585 2586 /* Make sure restarted syscalls are seen directly as "restart_syscall". */ 2587 TEST(syscall_restart) 2588 { 2589 long ret; 2590 unsigned long msg; 2591 pid_t child_pid; 2592 int pipefd[2]; 2593 int status; 2594 siginfo_t info = { }; 2595 struct sock_filter filter[] = { 2596 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2597 offsetof(struct seccomp_data, nr)), 2598 2599 #ifdef __NR_sigreturn 2600 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0), 2601 #endif 2602 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0), 2603 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0), 2604 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0), 2605 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0), 2606 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), 2607 2608 /* Allow __NR_write for easy logging. */ 2609 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), 2610 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2611 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2612 /* The nanosleep jump target. */ 2613 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), 2614 /* The restart_syscall jump target. */ 2615 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), 2616 }; 2617 struct sock_fprog prog = { 2618 .len = (unsigned short)ARRAY_SIZE(filter), 2619 .filter = filter, 2620 }; 2621 #if defined(__arm__) 2622 struct utsname utsbuf; 2623 #endif 2624 2625 ASSERT_EQ(0, pipe(pipefd)); 2626 2627 child_pid = fork(); 2628 ASSERT_LE(0, child_pid); 2629 if (child_pid == 0) { 2630 /* Child uses EXPECT not ASSERT to deliver status correctly. */ 2631 char buf = ' '; 2632 struct timespec timeout = { }; 2633 2634 /* Attach parent as tracer and stop. */ 2635 EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); 2636 EXPECT_EQ(0, raise(SIGSTOP)); 2637 2638 EXPECT_EQ(0, close(pipefd[1])); 2639 2640 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2641 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2642 } 2643 2644 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2645 EXPECT_EQ(0, ret) { 2646 TH_LOG("Failed to install filter!"); 2647 } 2648 2649 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 2650 TH_LOG("Failed to read() sync from parent"); 2651 } 2652 EXPECT_EQ('.', buf) { 2653 TH_LOG("Failed to get sync data from read()"); 2654 } 2655 2656 /* Start nanosleep to be interrupted. */ 2657 timeout.tv_sec = 1; 2658 errno = 0; 2659 EXPECT_EQ(0, nanosleep(&timeout, NULL)) { 2660 TH_LOG("Call to nanosleep() failed (errno %d)", errno); 2661 } 2662 2663 /* Read final sync from parent. */ 2664 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 2665 TH_LOG("Failed final read() from parent"); 2666 } 2667 EXPECT_EQ('!', buf) { 2668 TH_LOG("Failed to get final data from read()"); 2669 } 2670 2671 /* Directly report the status of our test harness results. */ 2672 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS 2673 : EXIT_FAILURE); 2674 } 2675 EXPECT_EQ(0, close(pipefd[0])); 2676 2677 /* Attach to child, setup options, and release. */ 2678 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2679 ASSERT_EQ(true, WIFSTOPPED(status)); 2680 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, 2681 PTRACE_O_TRACESECCOMP)); 2682 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2683 ASSERT_EQ(1, write(pipefd[1], ".", 1)); 2684 2685 /* Wait for nanosleep() to start. */ 2686 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2687 ASSERT_EQ(true, WIFSTOPPED(status)); 2688 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 2689 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 2690 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 2691 ASSERT_EQ(0x100, msg); 2692 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid)); 2693 2694 /* Might as well check siginfo for sanity while we're here. */ 2695 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 2696 ASSERT_EQ(SIGTRAP, info.si_signo); 2697 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); 2698 EXPECT_EQ(0, info.si_errno); 2699 EXPECT_EQ(getuid(), info.si_uid); 2700 /* Verify signal delivery came from child (seccomp-triggered). */ 2701 EXPECT_EQ(child_pid, info.si_pid); 2702 2703 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */ 2704 ASSERT_EQ(0, kill(child_pid, SIGSTOP)); 2705 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2706 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2707 ASSERT_EQ(true, WIFSTOPPED(status)); 2708 ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); 2709 /* Verify signal delivery came from parent now. */ 2710 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 2711 EXPECT_EQ(getpid(), info.si_pid); 2712 2713 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ 2714 ASSERT_EQ(0, kill(child_pid, SIGCONT)); 2715 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2716 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2717 ASSERT_EQ(true, WIFSTOPPED(status)); 2718 ASSERT_EQ(SIGCONT, WSTOPSIG(status)); 2719 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2720 2721 /* Wait for restart_syscall() to start. */ 2722 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2723 ASSERT_EQ(true, WIFSTOPPED(status)); 2724 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 2725 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 2726 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 2727 2728 ASSERT_EQ(0x200, msg); 2729 ret = get_syscall(_metadata, child_pid); 2730 #if defined(__arm__) 2731 /* 2732 * FIXME: 2733 * - native ARM registers do NOT expose true syscall. 2734 * - compat ARM registers on ARM64 DO expose true syscall. 2735 */ 2736 ASSERT_EQ(0, uname(&utsbuf)); 2737 if (strncmp(utsbuf.machine, "arm", 3) == 0) { 2738 EXPECT_EQ(__NR_nanosleep, ret); 2739 } else 2740 #endif 2741 { 2742 EXPECT_EQ(__NR_restart_syscall, ret); 2743 } 2744 2745 /* Write again to end test. */ 2746 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2747 ASSERT_EQ(1, write(pipefd[1], "!", 1)); 2748 EXPECT_EQ(0, close(pipefd[1])); 2749 2750 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2751 if (WIFSIGNALED(status) || WEXITSTATUS(status)) 2752 _metadata->passed = 0; 2753 } 2754 2755 TEST_SIGNAL(filter_flag_log, SIGSYS) 2756 { 2757 struct sock_filter allow_filter[] = { 2758 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2759 }; 2760 struct sock_filter kill_filter[] = { 2761 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2762 offsetof(struct seccomp_data, nr)), 2763 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 2764 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2765 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2766 }; 2767 struct sock_fprog allow_prog = { 2768 .len = (unsigned short)ARRAY_SIZE(allow_filter), 2769 .filter = allow_filter, 2770 }; 2771 struct sock_fprog kill_prog = { 2772 .len = (unsigned short)ARRAY_SIZE(kill_filter), 2773 .filter = kill_filter, 2774 }; 2775 long ret; 2776 pid_t parent = getppid(); 2777 2778 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2779 ASSERT_EQ(0, ret); 2780 2781 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */ 2782 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG, 2783 &allow_prog); 2784 ASSERT_NE(ENOSYS, errno) { 2785 TH_LOG("Kernel does not support seccomp syscall!"); 2786 } 2787 EXPECT_NE(0, ret) { 2788 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!"); 2789 } 2790 EXPECT_EQ(EINVAL, errno) { 2791 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!"); 2792 } 2793 2794 /* Verify that a simple, permissive filter can be added with no flags */ 2795 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog); 2796 EXPECT_EQ(0, ret); 2797 2798 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */ 2799 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 2800 &allow_prog); 2801 ASSERT_NE(EINVAL, errno) { 2802 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!"); 2803 } 2804 EXPECT_EQ(0, ret); 2805 2806 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */ 2807 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 2808 &kill_prog); 2809 EXPECT_EQ(0, ret); 2810 2811 EXPECT_EQ(parent, syscall(__NR_getppid)); 2812 /* getpid() should never return. */ 2813 EXPECT_EQ(0, syscall(__NR_getpid)); 2814 } 2815 2816 TEST(get_action_avail) 2817 { 2818 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP, 2819 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE, 2820 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW }; 2821 __u32 unknown_action = 0x10000000U; 2822 int i; 2823 long ret; 2824 2825 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]); 2826 ASSERT_NE(ENOSYS, errno) { 2827 TH_LOG("Kernel does not support seccomp syscall!"); 2828 } 2829 ASSERT_NE(EINVAL, errno) { 2830 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!"); 2831 } 2832 EXPECT_EQ(ret, 0); 2833 2834 for (i = 0; i < ARRAY_SIZE(actions); i++) { 2835 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]); 2836 EXPECT_EQ(ret, 0) { 2837 TH_LOG("Expected action (0x%X) not available!", 2838 actions[i]); 2839 } 2840 } 2841 2842 /* Check that an unknown action is handled properly (EOPNOTSUPP) */ 2843 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action); 2844 EXPECT_EQ(ret, -1); 2845 EXPECT_EQ(errno, EOPNOTSUPP); 2846 } 2847 2848 /* 2849 * TODO: 2850 * - add microbenchmarks 2851 * - expand NNP testing 2852 * - better arch-specific TRACE and TRAP handlers. 2853 * - endianness checking when appropriate 2854 * - 64-bit arg prodding 2855 * - arch value testing (x86 modes especially) 2856 * - verify that FILTER_FLAG_LOG filters generate log messages 2857 * - verify that RET_LOG generates log messages 2858 * - ... 2859 */ 2860 2861 TEST_HARNESS_MAIN 2862