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 #include <asm/siginfo.h> 10 #define __have_siginfo_t 1 11 #define __have_sigval_t 1 12 #define __have_sigevent_t 1 13 14 #include <errno.h> 15 #include <linux/filter.h> 16 #include <sys/prctl.h> 17 #include <sys/ptrace.h> 18 #include <sys/user.h> 19 #include <linux/prctl.h> 20 #include <linux/ptrace.h> 21 #include <linux/seccomp.h> 22 #include <pthread.h> 23 #include <semaphore.h> 24 #include <signal.h> 25 #include <stddef.h> 26 #include <stdbool.h> 27 #include <string.h> 28 #include <time.h> 29 #include <linux/elf.h> 30 #include <sys/uio.h> 31 #include <sys/utsname.h> 32 #include <sys/fcntl.h> 33 #include <sys/mman.h> 34 #include <sys/times.h> 35 36 #define _GNU_SOURCE 37 #include <unistd.h> 38 #include <sys/syscall.h> 39 40 #include "test_harness.h" 41 42 #ifndef PR_SET_PTRACER 43 # define PR_SET_PTRACER 0x59616d61 44 #endif 45 46 #ifndef PR_SET_NO_NEW_PRIVS 47 #define PR_SET_NO_NEW_PRIVS 38 48 #define PR_GET_NO_NEW_PRIVS 39 49 #endif 50 51 #ifndef PR_SECCOMP_EXT 52 #define PR_SECCOMP_EXT 43 53 #endif 54 55 #ifndef SECCOMP_EXT_ACT 56 #define SECCOMP_EXT_ACT 1 57 #endif 58 59 #ifndef SECCOMP_EXT_ACT_TSYNC 60 #define SECCOMP_EXT_ACT_TSYNC 1 61 #endif 62 63 #ifndef SECCOMP_MODE_STRICT 64 #define SECCOMP_MODE_STRICT 1 65 #endif 66 67 #ifndef SECCOMP_MODE_FILTER 68 #define SECCOMP_MODE_FILTER 2 69 #endif 70 71 #ifndef SECCOMP_RET_KILL 72 #define SECCOMP_RET_KILL 0x00000000U /* kill the task immediately */ 73 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ 74 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ 75 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ 76 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ 77 78 /* Masks for the return value sections. */ 79 #define SECCOMP_RET_ACTION 0x7fff0000U 80 #define SECCOMP_RET_DATA 0x0000ffffU 81 82 struct seccomp_data { 83 int nr; 84 __u32 arch; 85 __u64 instruction_pointer; 86 __u64 args[6]; 87 }; 88 #endif 89 90 #if __BYTE_ORDER == __LITTLE_ENDIAN 91 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) 92 #elif __BYTE_ORDER == __BIG_ENDIAN 93 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) 94 #else 95 #error "wut? Unknown __BYTE_ORDER?!" 96 #endif 97 98 #define SIBLING_EXIT_UNKILLED 0xbadbeef 99 #define SIBLING_EXIT_FAILURE 0xbadface 100 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed 101 102 TEST(mode_strict_support) 103 { 104 long ret; 105 106 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 107 ASSERT_EQ(0, ret) { 108 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 109 } 110 syscall(__NR_exit, 1); 111 } 112 113 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) 114 { 115 long ret; 116 117 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 118 ASSERT_EQ(0, ret) { 119 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 120 } 121 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 122 NULL, NULL, NULL); 123 EXPECT_FALSE(true) { 124 TH_LOG("Unreachable!"); 125 } 126 } 127 128 /* Note! This doesn't test no new privs behavior */ 129 TEST(no_new_privs_support) 130 { 131 long ret; 132 133 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 134 EXPECT_EQ(0, ret) { 135 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 136 } 137 } 138 139 /* Tests kernel support by checking for a copy_from_user() fault on * NULL. */ 140 TEST(mode_filter_support) 141 { 142 long ret; 143 144 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 145 ASSERT_EQ(0, ret) { 146 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 147 } 148 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); 149 EXPECT_EQ(-1, ret); 150 EXPECT_EQ(EFAULT, errno) { 151 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); 152 } 153 } 154 155 TEST(mode_filter_without_nnp) 156 { 157 struct sock_filter filter[] = { 158 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 159 }; 160 struct sock_fprog prog = { 161 .len = (unsigned short)ARRAY_SIZE(filter), 162 .filter = filter, 163 }; 164 long ret; 165 166 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); 167 ASSERT_LE(0, ret) { 168 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); 169 } 170 errno = 0; 171 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 172 /* Succeeds with CAP_SYS_ADMIN, fails without */ 173 /* TODO(wad) check caps not euid */ 174 if (geteuid()) { 175 EXPECT_EQ(-1, ret); 176 EXPECT_EQ(EACCES, errno); 177 } else { 178 EXPECT_EQ(0, ret); 179 } 180 } 181 182 #define MAX_INSNS_PER_PATH 32768 183 184 TEST(filter_size_limits) 185 { 186 int i; 187 int count = BPF_MAXINSNS + 1; 188 struct sock_filter allow[] = { 189 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 190 }; 191 struct sock_filter *filter; 192 struct sock_fprog prog = { }; 193 long ret; 194 195 filter = calloc(count, sizeof(*filter)); 196 ASSERT_NE(NULL, filter); 197 198 for (i = 0; i < count; i++) 199 filter[i] = allow[0]; 200 201 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 202 ASSERT_EQ(0, ret); 203 204 prog.filter = filter; 205 prog.len = count; 206 207 /* Too many filter instructions in a single filter. */ 208 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 209 ASSERT_NE(0, ret) { 210 TH_LOG("Installing %d insn filter was allowed", prog.len); 211 } 212 213 /* One less is okay, though. */ 214 prog.len -= 1; 215 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 216 ASSERT_EQ(0, ret) { 217 TH_LOG("Installing %d insn filter wasn't allowed", prog.len); 218 } 219 } 220 221 TEST(filter_chain_limits) 222 { 223 int i; 224 int count = BPF_MAXINSNS; 225 struct sock_filter allow[] = { 226 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 227 }; 228 struct sock_filter *filter; 229 struct sock_fprog prog = { }; 230 long ret; 231 232 filter = calloc(count, sizeof(*filter)); 233 ASSERT_NE(NULL, filter); 234 235 for (i = 0; i < count; i++) 236 filter[i] = allow[0]; 237 238 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 239 ASSERT_EQ(0, ret); 240 241 prog.filter = filter; 242 prog.len = 1; 243 244 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 245 ASSERT_EQ(0, ret); 246 247 prog.len = count; 248 249 /* Too many total filter instructions. */ 250 for (i = 0; i < MAX_INSNS_PER_PATH; i++) { 251 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 252 if (ret != 0) 253 break; 254 } 255 ASSERT_NE(0, ret) { 256 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", 257 i, count, i * (count + 4)); 258 } 259 } 260 261 TEST(mode_filter_cannot_move_to_strict) 262 { 263 struct sock_filter filter[] = { 264 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 265 }; 266 struct sock_fprog prog = { 267 .len = (unsigned short)ARRAY_SIZE(filter), 268 .filter = filter, 269 }; 270 long ret; 271 272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 273 ASSERT_EQ(0, ret); 274 275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 276 ASSERT_EQ(0, ret); 277 278 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); 279 EXPECT_EQ(-1, ret); 280 EXPECT_EQ(EINVAL, errno); 281 } 282 283 284 TEST(mode_filter_get_seccomp) 285 { 286 struct sock_filter filter[] = { 287 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 288 }; 289 struct sock_fprog prog = { 290 .len = (unsigned short)ARRAY_SIZE(filter), 291 .filter = filter, 292 }; 293 long ret; 294 295 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 296 ASSERT_EQ(0, ret); 297 298 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 299 EXPECT_EQ(0, ret); 300 301 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 302 ASSERT_EQ(0, ret); 303 304 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 305 EXPECT_EQ(2, ret); 306 } 307 308 309 TEST(ALLOW_all) 310 { 311 struct sock_filter filter[] = { 312 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 313 }; 314 struct sock_fprog prog = { 315 .len = (unsigned short)ARRAY_SIZE(filter), 316 .filter = filter, 317 }; 318 long ret; 319 320 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 321 ASSERT_EQ(0, ret); 322 323 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 324 ASSERT_EQ(0, ret); 325 } 326 327 TEST(empty_prog) 328 { 329 struct sock_filter filter[] = { 330 }; 331 struct sock_fprog prog = { 332 .len = (unsigned short)ARRAY_SIZE(filter), 333 .filter = filter, 334 }; 335 long ret; 336 337 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 338 ASSERT_EQ(0, ret); 339 340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 341 EXPECT_EQ(-1, ret); 342 EXPECT_EQ(EINVAL, errno); 343 } 344 345 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) 346 { 347 struct sock_filter filter[] = { 348 BPF_STMT(BPF_RET|BPF_K, 0x10000000U), 349 }; 350 struct sock_fprog prog = { 351 .len = (unsigned short)ARRAY_SIZE(filter), 352 .filter = filter, 353 }; 354 long ret; 355 356 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 357 ASSERT_EQ(0, ret); 358 359 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 360 ASSERT_EQ(0, ret); 361 EXPECT_EQ(0, syscall(__NR_getpid)) { 362 TH_LOG("getpid() shouldn't ever return"); 363 } 364 } 365 366 /* return code >= 0x80000000 is unused. */ 367 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) 368 { 369 struct sock_filter filter[] = { 370 BPF_STMT(BPF_RET|BPF_K, 0x90000000U), 371 }; 372 struct sock_fprog prog = { 373 .len = (unsigned short)ARRAY_SIZE(filter), 374 .filter = filter, 375 }; 376 long ret; 377 378 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 379 ASSERT_EQ(0, ret); 380 381 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 382 ASSERT_EQ(0, ret); 383 EXPECT_EQ(0, syscall(__NR_getpid)) { 384 TH_LOG("getpid() shouldn't ever return"); 385 } 386 } 387 388 TEST_SIGNAL(KILL_all, SIGSYS) 389 { 390 struct sock_filter filter[] = { 391 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 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 ASSERT_EQ(0, ret); 404 } 405 406 TEST_SIGNAL(KILL_one, SIGSYS) 407 { 408 struct sock_filter filter[] = { 409 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 410 offsetof(struct seccomp_data, nr)), 411 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 412 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 413 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 414 }; 415 struct sock_fprog prog = { 416 .len = (unsigned short)ARRAY_SIZE(filter), 417 .filter = filter, 418 }; 419 long ret; 420 pid_t parent = getppid(); 421 422 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 423 ASSERT_EQ(0, ret); 424 425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 426 ASSERT_EQ(0, ret); 427 428 EXPECT_EQ(parent, syscall(__NR_getppid)); 429 /* getpid() should never return. */ 430 EXPECT_EQ(0, syscall(__NR_getpid)); 431 } 432 433 TEST_SIGNAL(KILL_one_arg_one, SIGSYS) 434 { 435 void *fatal_address; 436 struct sock_filter filter[] = { 437 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 438 offsetof(struct seccomp_data, nr)), 439 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0), 440 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 441 /* Only both with lower 32-bit for now. */ 442 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), 443 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 444 (unsigned long)&fatal_address, 0, 1), 445 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 446 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 447 }; 448 struct sock_fprog prog = { 449 .len = (unsigned short)ARRAY_SIZE(filter), 450 .filter = filter, 451 }; 452 long ret; 453 pid_t parent = getppid(); 454 struct tms timebuf; 455 clock_t clock = times(&timebuf); 456 457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 458 ASSERT_EQ(0, ret); 459 460 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 461 ASSERT_EQ(0, ret); 462 463 EXPECT_EQ(parent, syscall(__NR_getppid)); 464 EXPECT_LE(clock, syscall(__NR_times, &timebuf)); 465 /* times() should never return. */ 466 EXPECT_EQ(0, syscall(__NR_times, &fatal_address)); 467 } 468 469 TEST_SIGNAL(KILL_one_arg_six, SIGSYS) 470 { 471 #ifndef __NR_mmap2 472 int sysno = __NR_mmap; 473 #else 474 int sysno = __NR_mmap2; 475 #endif 476 struct sock_filter filter[] = { 477 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 478 offsetof(struct seccomp_data, nr)), 479 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0), 480 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 481 /* Only both with lower 32-bit for now. */ 482 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), 483 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), 484 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 485 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 486 }; 487 struct sock_fprog prog = { 488 .len = (unsigned short)ARRAY_SIZE(filter), 489 .filter = filter, 490 }; 491 long ret; 492 pid_t parent = getppid(); 493 int fd; 494 void *map1, *map2; 495 int page_size = sysconf(_SC_PAGESIZE); 496 497 ASSERT_LT(0, page_size); 498 499 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 500 ASSERT_EQ(0, ret); 501 502 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 503 ASSERT_EQ(0, ret); 504 505 fd = open("/dev/zero", O_RDONLY); 506 ASSERT_NE(-1, fd); 507 508 EXPECT_EQ(parent, syscall(__NR_getppid)); 509 map1 = (void *)syscall(sysno, 510 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size); 511 EXPECT_NE(MAP_FAILED, map1); 512 /* mmap2() should never return. */ 513 map2 = (void *)syscall(sysno, 514 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE); 515 EXPECT_EQ(MAP_FAILED, map2); 516 517 /* The test failed, so clean up the resources. */ 518 munmap(map1, page_size); 519 munmap(map2, page_size); 520 close(fd); 521 } 522 523 /* TODO(wad) add 64-bit versus 32-bit arg tests. */ 524 TEST(arg_out_of_range) 525 { 526 struct sock_filter filter[] = { 527 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), 528 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 529 }; 530 struct sock_fprog prog = { 531 .len = (unsigned short)ARRAY_SIZE(filter), 532 .filter = filter, 533 }; 534 long ret; 535 536 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 537 ASSERT_EQ(0, ret); 538 539 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 540 EXPECT_EQ(-1, ret); 541 EXPECT_EQ(EINVAL, errno); 542 } 543 544 TEST(ERRNO_valid) 545 { 546 struct sock_filter filter[] = { 547 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 548 offsetof(struct seccomp_data, nr)), 549 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 550 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | E2BIG), 551 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 552 }; 553 struct sock_fprog prog = { 554 .len = (unsigned short)ARRAY_SIZE(filter), 555 .filter = filter, 556 }; 557 long ret; 558 pid_t parent = getppid(); 559 560 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 561 ASSERT_EQ(0, ret); 562 563 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 564 ASSERT_EQ(0, ret); 565 566 EXPECT_EQ(parent, syscall(__NR_getppid)); 567 EXPECT_EQ(-1, read(0, NULL, 0)); 568 EXPECT_EQ(E2BIG, errno); 569 } 570 571 TEST(ERRNO_zero) 572 { 573 struct sock_filter filter[] = { 574 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 575 offsetof(struct seccomp_data, nr)), 576 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 577 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 0), 578 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 579 }; 580 struct sock_fprog prog = { 581 .len = (unsigned short)ARRAY_SIZE(filter), 582 .filter = filter, 583 }; 584 long ret; 585 pid_t parent = getppid(); 586 587 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 588 ASSERT_EQ(0, ret); 589 590 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 591 ASSERT_EQ(0, ret); 592 593 EXPECT_EQ(parent, syscall(__NR_getppid)); 594 /* "errno" of 0 is ok. */ 595 EXPECT_EQ(0, read(0, NULL, 0)); 596 } 597 598 TEST(ERRNO_capped) 599 { 600 struct sock_filter filter[] = { 601 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 602 offsetof(struct seccomp_data, nr)), 603 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 604 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 4096), 605 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 606 }; 607 struct sock_fprog prog = { 608 .len = (unsigned short)ARRAY_SIZE(filter), 609 .filter = filter, 610 }; 611 long ret; 612 pid_t parent = getppid(); 613 614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 615 ASSERT_EQ(0, ret); 616 617 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 618 ASSERT_EQ(0, ret); 619 620 EXPECT_EQ(parent, syscall(__NR_getppid)); 621 EXPECT_EQ(-1, read(0, NULL, 0)); 622 EXPECT_EQ(4095, errno); 623 } 624 625 FIXTURE_DATA(TRAP) { 626 struct sock_fprog prog; 627 }; 628 629 FIXTURE_SETUP(TRAP) 630 { 631 struct sock_filter filter[] = { 632 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 633 offsetof(struct seccomp_data, nr)), 634 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 635 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 636 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 637 }; 638 639 memset(&self->prog, 0, sizeof(self->prog)); 640 self->prog.filter = malloc(sizeof(filter)); 641 ASSERT_NE(NULL, self->prog.filter); 642 memcpy(self->prog.filter, filter, sizeof(filter)); 643 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 644 } 645 646 FIXTURE_TEARDOWN(TRAP) 647 { 648 if (self->prog.filter) 649 free(self->prog.filter); 650 } 651 652 TEST_F_SIGNAL(TRAP, dfl, SIGSYS) 653 { 654 long ret; 655 656 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 657 ASSERT_EQ(0, ret); 658 659 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 660 ASSERT_EQ(0, ret); 661 syscall(__NR_getpid); 662 } 663 664 /* Ensure that SIGSYS overrides SIG_IGN */ 665 TEST_F_SIGNAL(TRAP, ign, SIGSYS) 666 { 667 long ret; 668 669 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 670 ASSERT_EQ(0, ret); 671 672 signal(SIGSYS, SIG_IGN); 673 674 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 675 ASSERT_EQ(0, ret); 676 syscall(__NR_getpid); 677 } 678 679 static struct siginfo TRAP_info; 680 static volatile int TRAP_nr; 681 static void TRAP_action(int nr, siginfo_t *info, void *void_context) 682 { 683 memcpy(&TRAP_info, info, sizeof(TRAP_info)); 684 TRAP_nr = nr; 685 } 686 687 TEST_F(TRAP, handler) 688 { 689 int ret, test; 690 struct sigaction act; 691 sigset_t mask; 692 693 memset(&act, 0, sizeof(act)); 694 sigemptyset(&mask); 695 sigaddset(&mask, SIGSYS); 696 697 act.sa_sigaction = &TRAP_action; 698 act.sa_flags = SA_SIGINFO; 699 ret = sigaction(SIGSYS, &act, NULL); 700 ASSERT_EQ(0, ret) { 701 TH_LOG("sigaction failed"); 702 } 703 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); 704 ASSERT_EQ(0, ret) { 705 TH_LOG("sigprocmask failed"); 706 } 707 708 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 709 ASSERT_EQ(0, ret); 710 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 711 ASSERT_EQ(0, ret); 712 TRAP_nr = 0; 713 memset(&TRAP_info, 0, sizeof(TRAP_info)); 714 /* Expect the registers to be rolled back. (nr = error) may vary 715 * based on arch. */ 716 ret = syscall(__NR_getpid); 717 /* Silence gcc warning about volatile. */ 718 test = TRAP_nr; 719 EXPECT_EQ(SIGSYS, test); 720 struct local_sigsys { 721 void *_call_addr; /* calling user insn */ 722 int _syscall; /* triggering system call number */ 723 unsigned int _arch; /* AUDIT_ARCH_* of syscall */ 724 } *sigsys = (struct local_sigsys *) 725 #ifdef si_syscall 726 &(TRAP_info.si_call_addr); 727 #else 728 &TRAP_info.si_pid; 729 #endif 730 EXPECT_EQ(__NR_getpid, sigsys->_syscall); 731 /* Make sure arch is non-zero. */ 732 EXPECT_NE(0, sigsys->_arch); 733 EXPECT_NE(0, (unsigned long)sigsys->_call_addr); 734 } 735 736 FIXTURE_DATA(precedence) { 737 struct sock_fprog allow; 738 struct sock_fprog trace; 739 struct sock_fprog error; 740 struct sock_fprog trap; 741 struct sock_fprog kill; 742 }; 743 744 FIXTURE_SETUP(precedence) 745 { 746 struct sock_filter allow_insns[] = { 747 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 748 }; 749 struct sock_filter trace_insns[] = { 750 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 751 offsetof(struct seccomp_data, nr)), 752 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 754 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), 755 }; 756 struct sock_filter error_insns[] = { 757 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 758 offsetof(struct seccomp_data, nr)), 759 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 760 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 761 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), 762 }; 763 struct sock_filter trap_insns[] = { 764 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 765 offsetof(struct seccomp_data, nr)), 766 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 767 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 768 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 769 }; 770 struct sock_filter kill_insns[] = { 771 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 772 offsetof(struct seccomp_data, nr)), 773 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 774 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 775 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 776 }; 777 778 memset(self, 0, sizeof(*self)); 779 #define FILTER_ALLOC(_x) \ 780 self->_x.filter = malloc(sizeof(_x##_insns)); \ 781 ASSERT_NE(NULL, self->_x.filter); \ 782 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ 783 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) 784 FILTER_ALLOC(allow); 785 FILTER_ALLOC(trace); 786 FILTER_ALLOC(error); 787 FILTER_ALLOC(trap); 788 FILTER_ALLOC(kill); 789 } 790 791 FIXTURE_TEARDOWN(precedence) 792 { 793 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) 794 FILTER_FREE(allow); 795 FILTER_FREE(trace); 796 FILTER_FREE(error); 797 FILTER_FREE(trap); 798 FILTER_FREE(kill); 799 } 800 801 TEST_F(precedence, allow_ok) 802 { 803 pid_t parent, res = 0; 804 long ret; 805 806 parent = getppid(); 807 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 808 ASSERT_EQ(0, ret); 809 810 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 811 ASSERT_EQ(0, ret); 812 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 813 ASSERT_EQ(0, ret); 814 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 815 ASSERT_EQ(0, ret); 816 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 817 ASSERT_EQ(0, ret); 818 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 819 ASSERT_EQ(0, ret); 820 /* Should work just fine. */ 821 res = syscall(__NR_getppid); 822 EXPECT_EQ(parent, res); 823 } 824 825 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) 826 { 827 pid_t parent, res = 0; 828 long ret; 829 830 parent = getppid(); 831 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 832 ASSERT_EQ(0, ret); 833 834 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 835 ASSERT_EQ(0, ret); 836 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 837 ASSERT_EQ(0, ret); 838 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 839 ASSERT_EQ(0, ret); 840 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 841 ASSERT_EQ(0, ret); 842 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 843 ASSERT_EQ(0, ret); 844 /* Should work just fine. */ 845 res = syscall(__NR_getppid); 846 EXPECT_EQ(parent, res); 847 /* getpid() should never return. */ 848 res = syscall(__NR_getpid); 849 EXPECT_EQ(0, res); 850 } 851 852 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) 853 { 854 pid_t parent; 855 long ret; 856 857 parent = getppid(); 858 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 859 ASSERT_EQ(0, ret); 860 861 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 862 ASSERT_EQ(0, ret); 863 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 864 ASSERT_EQ(0, ret); 865 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 866 ASSERT_EQ(0, ret); 867 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 868 ASSERT_EQ(0, ret); 869 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 870 ASSERT_EQ(0, ret); 871 /* Should work just fine. */ 872 EXPECT_EQ(parent, syscall(__NR_getppid)); 873 /* getpid() should never return. */ 874 EXPECT_EQ(0, syscall(__NR_getpid)); 875 } 876 877 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) 878 { 879 pid_t parent; 880 long ret; 881 882 parent = getppid(); 883 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 884 ASSERT_EQ(0, ret); 885 886 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 887 ASSERT_EQ(0, ret); 888 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 889 ASSERT_EQ(0, ret); 890 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 891 ASSERT_EQ(0, ret); 892 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 893 ASSERT_EQ(0, ret); 894 /* Should work just fine. */ 895 EXPECT_EQ(parent, syscall(__NR_getppid)); 896 /* getpid() should never return. */ 897 EXPECT_EQ(0, syscall(__NR_getpid)); 898 } 899 900 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) 901 { 902 pid_t parent; 903 long ret; 904 905 parent = getppid(); 906 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 907 ASSERT_EQ(0, ret); 908 909 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 910 ASSERT_EQ(0, ret); 911 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 912 ASSERT_EQ(0, ret); 913 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 914 ASSERT_EQ(0, ret); 915 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 916 ASSERT_EQ(0, ret); 917 /* Should work just fine. */ 918 EXPECT_EQ(parent, syscall(__NR_getppid)); 919 /* getpid() should never return. */ 920 EXPECT_EQ(0, syscall(__NR_getpid)); 921 } 922 923 TEST_F(precedence, errno_is_third) 924 { 925 pid_t parent; 926 long ret; 927 928 parent = getppid(); 929 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 930 ASSERT_EQ(0, ret); 931 932 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 933 ASSERT_EQ(0, ret); 934 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 935 ASSERT_EQ(0, ret); 936 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 937 ASSERT_EQ(0, ret); 938 /* Should work just fine. */ 939 EXPECT_EQ(parent, syscall(__NR_getppid)); 940 EXPECT_EQ(0, syscall(__NR_getpid)); 941 } 942 943 TEST_F(precedence, errno_is_third_in_any_order) 944 { 945 pid_t parent; 946 long ret; 947 948 parent = getppid(); 949 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 950 ASSERT_EQ(0, ret); 951 952 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 953 ASSERT_EQ(0, ret); 954 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 955 ASSERT_EQ(0, ret); 956 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 957 ASSERT_EQ(0, ret); 958 /* Should work just fine. */ 959 EXPECT_EQ(parent, syscall(__NR_getppid)); 960 EXPECT_EQ(0, syscall(__NR_getpid)); 961 } 962 963 TEST_F(precedence, trace_is_fourth) 964 { 965 pid_t parent; 966 long ret; 967 968 parent = getppid(); 969 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 970 ASSERT_EQ(0, ret); 971 972 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 973 ASSERT_EQ(0, ret); 974 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 975 ASSERT_EQ(0, ret); 976 /* Should work just fine. */ 977 EXPECT_EQ(parent, syscall(__NR_getppid)); 978 /* No ptracer */ 979 EXPECT_EQ(-1, syscall(__NR_getpid)); 980 } 981 982 TEST_F(precedence, trace_is_fourth_in_any_order) 983 { 984 pid_t parent; 985 long ret; 986 987 parent = getppid(); 988 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 989 ASSERT_EQ(0, ret); 990 991 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 992 ASSERT_EQ(0, ret); 993 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 994 ASSERT_EQ(0, ret); 995 /* Should work just fine. */ 996 EXPECT_EQ(parent, syscall(__NR_getppid)); 997 /* No ptracer */ 998 EXPECT_EQ(-1, syscall(__NR_getpid)); 999 } 1000 1001 #ifndef PTRACE_O_TRACESECCOMP 1002 #define PTRACE_O_TRACESECCOMP 0x00000080 1003 #endif 1004 1005 /* Catch the Ubuntu 12.04 value error. */ 1006 #if PTRACE_EVENT_SECCOMP != 7 1007 #undef PTRACE_EVENT_SECCOMP 1008 #endif 1009 1010 #ifndef PTRACE_EVENT_SECCOMP 1011 #define PTRACE_EVENT_SECCOMP 7 1012 #endif 1013 1014 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP) 1015 bool tracer_running; 1016 void tracer_stop(int sig) 1017 { 1018 tracer_running = false; 1019 } 1020 1021 typedef void tracer_func_t(struct __test_metadata *_metadata, 1022 pid_t tracee, int status, void *args); 1023 1024 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, 1025 tracer_func_t tracer_func, void *args, bool ptrace_syscall) 1026 { 1027 int ret = -1; 1028 struct sigaction action = { 1029 .sa_handler = tracer_stop, 1030 }; 1031 1032 /* Allow external shutdown. */ 1033 tracer_running = true; 1034 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); 1035 1036 errno = 0; 1037 while (ret == -1 && errno != EINVAL) 1038 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); 1039 ASSERT_EQ(0, ret) { 1040 kill(tracee, SIGKILL); 1041 } 1042 /* Wait for attach stop */ 1043 wait(NULL); 1044 1045 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ? 1046 PTRACE_O_TRACESYSGOOD : 1047 PTRACE_O_TRACESECCOMP); 1048 ASSERT_EQ(0, ret) { 1049 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); 1050 kill(tracee, SIGKILL); 1051 } 1052 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1053 tracee, NULL, 0); 1054 ASSERT_EQ(0, ret); 1055 1056 /* Unblock the tracee */ 1057 ASSERT_EQ(1, write(fd, "A", 1)); 1058 ASSERT_EQ(0, close(fd)); 1059 1060 /* Run until we're shut down. Must assert to stop execution. */ 1061 while (tracer_running) { 1062 int status; 1063 1064 if (wait(&status) != tracee) 1065 continue; 1066 if (WIFSIGNALED(status) || WIFEXITED(status)) 1067 /* Child is dead. Time to go. */ 1068 return; 1069 1070 /* Check if this is a seccomp event. */ 1071 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status)); 1072 1073 tracer_func(_metadata, tracee, status, args); 1074 1075 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1076 tracee, NULL, 0); 1077 ASSERT_EQ(0, ret); 1078 } 1079 /* Directly report the status of our test harness results. */ 1080 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 1081 } 1082 1083 /* Common tracer setup/teardown functions. */ 1084 void cont_handler(int num) 1085 { } 1086 pid_t setup_trace_fixture(struct __test_metadata *_metadata, 1087 tracer_func_t func, void *args, bool ptrace_syscall) 1088 { 1089 char sync; 1090 int pipefd[2]; 1091 pid_t tracer_pid; 1092 pid_t tracee = getpid(); 1093 1094 /* Setup a pipe for clean synchronization. */ 1095 ASSERT_EQ(0, pipe(pipefd)); 1096 1097 /* Fork a child which we'll promote to tracer */ 1098 tracer_pid = fork(); 1099 ASSERT_LE(0, tracer_pid); 1100 signal(SIGALRM, cont_handler); 1101 if (tracer_pid == 0) { 1102 close(pipefd[0]); 1103 start_tracer(_metadata, pipefd[1], tracee, func, args, 1104 ptrace_syscall); 1105 syscall(__NR_exit, 0); 1106 } 1107 close(pipefd[1]); 1108 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); 1109 read(pipefd[0], &sync, 1); 1110 close(pipefd[0]); 1111 1112 return tracer_pid; 1113 } 1114 void teardown_trace_fixture(struct __test_metadata *_metadata, 1115 pid_t tracer) 1116 { 1117 if (tracer) { 1118 int status; 1119 /* 1120 * Extract the exit code from the other process and 1121 * adopt it for ourselves in case its asserts failed. 1122 */ 1123 ASSERT_EQ(0, kill(tracer, SIGUSR1)); 1124 ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); 1125 if (WEXITSTATUS(status)) 1126 _metadata->passed = 0; 1127 } 1128 } 1129 1130 /* "poke" tracer arguments and function. */ 1131 struct tracer_args_poke_t { 1132 unsigned long poke_addr; 1133 }; 1134 1135 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, 1136 void *args) 1137 { 1138 int ret; 1139 unsigned long msg; 1140 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; 1141 1142 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1143 EXPECT_EQ(0, ret); 1144 /* If this fails, don't try to recover. */ 1145 ASSERT_EQ(0x1001, msg) { 1146 kill(tracee, SIGKILL); 1147 } 1148 /* 1149 * Poke in the message. 1150 * Registers are not touched to try to keep this relatively arch 1151 * agnostic. 1152 */ 1153 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); 1154 EXPECT_EQ(0, ret); 1155 } 1156 1157 FIXTURE_DATA(TRACE_poke) { 1158 struct sock_fprog prog; 1159 pid_t tracer; 1160 long poked; 1161 struct tracer_args_poke_t tracer_args; 1162 }; 1163 1164 FIXTURE_SETUP(TRACE_poke) 1165 { 1166 struct sock_filter filter[] = { 1167 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1168 offsetof(struct seccomp_data, nr)), 1169 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 1170 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), 1171 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1172 }; 1173 1174 self->poked = 0; 1175 memset(&self->prog, 0, sizeof(self->prog)); 1176 self->prog.filter = malloc(sizeof(filter)); 1177 ASSERT_NE(NULL, self->prog.filter); 1178 memcpy(self->prog.filter, filter, sizeof(filter)); 1179 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1180 1181 /* Set up tracer args. */ 1182 self->tracer_args.poke_addr = (unsigned long)&self->poked; 1183 1184 /* Launch tracer. */ 1185 self->tracer = setup_trace_fixture(_metadata, tracer_poke, 1186 &self->tracer_args, false); 1187 } 1188 1189 FIXTURE_TEARDOWN(TRACE_poke) 1190 { 1191 teardown_trace_fixture(_metadata, self->tracer); 1192 if (self->prog.filter) 1193 free(self->prog.filter); 1194 } 1195 1196 TEST_F(TRACE_poke, read_has_side_effects) 1197 { 1198 ssize_t ret; 1199 1200 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1201 ASSERT_EQ(0, ret); 1202 1203 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1204 ASSERT_EQ(0, ret); 1205 1206 EXPECT_EQ(0, self->poked); 1207 ret = read(-1, NULL, 0); 1208 EXPECT_EQ(-1, ret); 1209 EXPECT_EQ(0x1001, self->poked); 1210 } 1211 1212 TEST_F(TRACE_poke, getpid_runs_normally) 1213 { 1214 long ret; 1215 1216 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1217 ASSERT_EQ(0, ret); 1218 1219 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1220 ASSERT_EQ(0, ret); 1221 1222 EXPECT_EQ(0, self->poked); 1223 EXPECT_NE(0, syscall(__NR_getpid)); 1224 EXPECT_EQ(0, self->poked); 1225 } 1226 1227 #if defined(__x86_64__) 1228 # define ARCH_REGS struct user_regs_struct 1229 # define SYSCALL_NUM orig_rax 1230 # define SYSCALL_RET rax 1231 #elif defined(__i386__) 1232 # define ARCH_REGS struct user_regs_struct 1233 # define SYSCALL_NUM orig_eax 1234 # define SYSCALL_RET eax 1235 #elif defined(__arm__) 1236 # define ARCH_REGS struct pt_regs 1237 # define SYSCALL_NUM ARM_r7 1238 # define SYSCALL_RET ARM_r0 1239 #elif defined(__aarch64__) 1240 # define ARCH_REGS struct user_pt_regs 1241 # define SYSCALL_NUM regs[8] 1242 # define SYSCALL_RET regs[0] 1243 #elif defined(__hppa__) 1244 # define ARCH_REGS struct user_regs_struct 1245 # define SYSCALL_NUM gr[20] 1246 # define SYSCALL_RET gr[28] 1247 #elif defined(__powerpc__) 1248 # define ARCH_REGS struct pt_regs 1249 # define SYSCALL_NUM gpr[0] 1250 # define SYSCALL_RET gpr[3] 1251 #elif defined(__s390__) 1252 # define ARCH_REGS s390_regs 1253 # define SYSCALL_NUM gprs[2] 1254 # define SYSCALL_RET gprs[2] 1255 #elif defined(__mips__) 1256 # define ARCH_REGS struct pt_regs 1257 # define SYSCALL_NUM regs[2] 1258 # define SYSCALL_SYSCALL_NUM regs[4] 1259 # define SYSCALL_RET regs[2] 1260 # define SYSCALL_NUM_RET_SHARE_REG 1261 #else 1262 # error "Do not know how to find your architecture's registers and syscalls" 1263 #endif 1264 1265 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for 1266 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). 1267 */ 1268 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__) 1269 #define HAVE_GETREGS 1270 #endif 1271 1272 /* Architecture-specific syscall fetching routine. */ 1273 int get_syscall(struct __test_metadata *_metadata, pid_t tracee) 1274 { 1275 ARCH_REGS regs; 1276 #ifdef HAVE_GETREGS 1277 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, ®s)) { 1278 TH_LOG("PTRACE_GETREGS failed"); 1279 return -1; 1280 } 1281 #else 1282 struct iovec iov; 1283 1284 iov.iov_base = ®s; 1285 iov.iov_len = sizeof(regs); 1286 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) { 1287 TH_LOG("PTRACE_GETREGSET failed"); 1288 return -1; 1289 } 1290 #endif 1291 1292 #if defined(__mips__) 1293 if (regs.SYSCALL_NUM == __NR_O32_Linux) 1294 return regs.SYSCALL_SYSCALL_NUM; 1295 #endif 1296 return regs.SYSCALL_NUM; 1297 } 1298 1299 /* Architecture-specific syscall changing routine. */ 1300 void change_syscall(struct __test_metadata *_metadata, 1301 pid_t tracee, int syscall) 1302 { 1303 int ret; 1304 ARCH_REGS regs; 1305 #ifdef HAVE_GETREGS 1306 ret = ptrace(PTRACE_GETREGS, tracee, 0, ®s); 1307 #else 1308 struct iovec iov; 1309 iov.iov_base = ®s; 1310 iov.iov_len = sizeof(regs); 1311 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov); 1312 #endif 1313 EXPECT_EQ(0, ret); 1314 1315 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \ 1316 defined(__s390__) || defined(__hppa__) 1317 { 1318 regs.SYSCALL_NUM = syscall; 1319 } 1320 #elif defined(__mips__) 1321 { 1322 if (regs.SYSCALL_NUM == __NR_O32_Linux) 1323 regs.SYSCALL_SYSCALL_NUM = syscall; 1324 else 1325 regs.SYSCALL_NUM = syscall; 1326 } 1327 1328 #elif defined(__arm__) 1329 # ifndef PTRACE_SET_SYSCALL 1330 # define PTRACE_SET_SYSCALL 23 1331 # endif 1332 { 1333 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall); 1334 EXPECT_EQ(0, ret); 1335 } 1336 1337 #elif defined(__aarch64__) 1338 # ifndef NT_ARM_SYSTEM_CALL 1339 # define NT_ARM_SYSTEM_CALL 0x404 1340 # endif 1341 { 1342 iov.iov_base = &syscall; 1343 iov.iov_len = sizeof(syscall); 1344 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL, 1345 &iov); 1346 EXPECT_EQ(0, ret); 1347 } 1348 1349 #else 1350 ASSERT_EQ(1, 0) { 1351 TH_LOG("How is the syscall changed on this architecture?"); 1352 } 1353 #endif 1354 1355 /* If syscall is skipped, change return value. */ 1356 if (syscall == -1) 1357 #ifdef SYSCALL_NUM_RET_SHARE_REG 1358 TH_LOG("Can't modify syscall return on this architecture"); 1359 #else 1360 regs.SYSCALL_RET = 1; 1361 #endif 1362 1363 #ifdef HAVE_GETREGS 1364 ret = ptrace(PTRACE_SETREGS, tracee, 0, ®s); 1365 #else 1366 iov.iov_base = ®s; 1367 iov.iov_len = sizeof(regs); 1368 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov); 1369 #endif 1370 EXPECT_EQ(0, ret); 1371 } 1372 1373 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee, 1374 int status, void *args) 1375 { 1376 int ret; 1377 unsigned long msg; 1378 1379 /* Make sure we got the right message. */ 1380 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1381 EXPECT_EQ(0, ret); 1382 1383 /* Validate and take action on expected syscalls. */ 1384 switch (msg) { 1385 case 0x1002: 1386 /* change getpid to getppid. */ 1387 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee)); 1388 change_syscall(_metadata, tracee, __NR_getppid); 1389 break; 1390 case 0x1003: 1391 /* skip gettid. */ 1392 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee)); 1393 change_syscall(_metadata, tracee, -1); 1394 break; 1395 case 0x1004: 1396 /* do nothing (allow getppid) */ 1397 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee)); 1398 break; 1399 default: 1400 EXPECT_EQ(0, msg) { 1401 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); 1402 kill(tracee, SIGKILL); 1403 } 1404 } 1405 1406 } 1407 1408 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee, 1409 int status, void *args) 1410 { 1411 int ret, nr; 1412 unsigned long msg; 1413 static bool entry; 1414 1415 /* Make sure we got an empty message. */ 1416 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1417 EXPECT_EQ(0, ret); 1418 EXPECT_EQ(0, msg); 1419 1420 /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */ 1421 entry = !entry; 1422 if (!entry) 1423 return; 1424 1425 nr = get_syscall(_metadata, tracee); 1426 1427 if (nr == __NR_getpid) 1428 change_syscall(_metadata, tracee, __NR_getppid); 1429 } 1430 1431 FIXTURE_DATA(TRACE_syscall) { 1432 struct sock_fprog prog; 1433 pid_t tracer, mytid, mypid, parent; 1434 }; 1435 1436 FIXTURE_SETUP(TRACE_syscall) 1437 { 1438 struct sock_filter filter[] = { 1439 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1440 offsetof(struct seccomp_data, nr)), 1441 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 1442 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), 1443 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), 1444 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), 1445 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1446 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), 1447 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1448 }; 1449 1450 memset(&self->prog, 0, sizeof(self->prog)); 1451 self->prog.filter = malloc(sizeof(filter)); 1452 ASSERT_NE(NULL, self->prog.filter); 1453 memcpy(self->prog.filter, filter, sizeof(filter)); 1454 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1455 1456 /* Prepare some testable syscall results. */ 1457 self->mytid = syscall(__NR_gettid); 1458 ASSERT_GT(self->mytid, 0); 1459 ASSERT_NE(self->mytid, 1) { 1460 TH_LOG("Running this test as init is not supported. :)"); 1461 } 1462 1463 self->mypid = getpid(); 1464 ASSERT_GT(self->mypid, 0); 1465 ASSERT_EQ(self->mytid, self->mypid); 1466 1467 self->parent = getppid(); 1468 ASSERT_GT(self->parent, 0); 1469 ASSERT_NE(self->parent, self->mypid); 1470 1471 /* Launch tracer. */ 1472 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL, 1473 false); 1474 } 1475 1476 FIXTURE_TEARDOWN(TRACE_syscall) 1477 { 1478 teardown_trace_fixture(_metadata, self->tracer); 1479 if (self->prog.filter) 1480 free(self->prog.filter); 1481 } 1482 1483 TEST_F(TRACE_syscall, syscall_allowed) 1484 { 1485 long ret; 1486 1487 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1488 ASSERT_EQ(0, ret); 1489 1490 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1491 ASSERT_EQ(0, ret); 1492 1493 /* getppid works as expected (no changes). */ 1494 EXPECT_EQ(self->parent, syscall(__NR_getppid)); 1495 EXPECT_NE(self->mypid, syscall(__NR_getppid)); 1496 } 1497 1498 TEST_F(TRACE_syscall, syscall_redirected) 1499 { 1500 long ret; 1501 1502 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1503 ASSERT_EQ(0, ret); 1504 1505 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1506 ASSERT_EQ(0, ret); 1507 1508 /* getpid has been redirected to getppid as expected. */ 1509 EXPECT_EQ(self->parent, syscall(__NR_getpid)); 1510 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1511 } 1512 1513 TEST_F(TRACE_syscall, syscall_dropped) 1514 { 1515 long ret; 1516 1517 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1518 ASSERT_EQ(0, ret); 1519 1520 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1521 ASSERT_EQ(0, ret); 1522 1523 #ifdef SYSCALL_NUM_RET_SHARE_REG 1524 /* gettid has been skipped */ 1525 EXPECT_EQ(-1, syscall(__NR_gettid)); 1526 #else 1527 /* gettid has been skipped and an altered return value stored. */ 1528 EXPECT_EQ(1, syscall(__NR_gettid)); 1529 #endif 1530 EXPECT_NE(self->mytid, syscall(__NR_gettid)); 1531 } 1532 1533 TEST_F(TRACE_syscall, skip_after_RET_TRACE) 1534 { 1535 struct sock_filter filter[] = { 1536 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1537 offsetof(struct seccomp_data, nr)), 1538 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1539 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 1540 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1541 }; 1542 struct sock_fprog prog = { 1543 .len = (unsigned short)ARRAY_SIZE(filter), 1544 .filter = filter, 1545 }; 1546 long ret; 1547 1548 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1549 ASSERT_EQ(0, ret); 1550 1551 /* Install fixture filter. */ 1552 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1553 ASSERT_EQ(0, ret); 1554 1555 /* Install "errno on getppid" filter. */ 1556 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1557 ASSERT_EQ(0, ret); 1558 1559 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 1560 EXPECT_EQ(-1, syscall(__NR_getpid)); 1561 EXPECT_EQ(EPERM, errno); 1562 } 1563 1564 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS) 1565 { 1566 struct sock_filter filter[] = { 1567 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1568 offsetof(struct seccomp_data, nr)), 1569 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1570 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1571 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1572 }; 1573 struct sock_fprog prog = { 1574 .len = (unsigned short)ARRAY_SIZE(filter), 1575 .filter = filter, 1576 }; 1577 long ret; 1578 1579 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1580 ASSERT_EQ(0, ret); 1581 1582 /* Install fixture filter. */ 1583 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1584 ASSERT_EQ(0, ret); 1585 1586 /* Install "death on getppid" filter. */ 1587 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1588 ASSERT_EQ(0, ret); 1589 1590 /* Tracer will redirect getpid to getppid, and we should die. */ 1591 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1592 } 1593 1594 TEST_F(TRACE_syscall, skip_after_ptrace) 1595 { 1596 struct sock_filter filter[] = { 1597 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1598 offsetof(struct seccomp_data, nr)), 1599 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1600 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 1601 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1602 }; 1603 struct sock_fprog prog = { 1604 .len = (unsigned short)ARRAY_SIZE(filter), 1605 .filter = filter, 1606 }; 1607 long ret; 1608 1609 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ 1610 teardown_trace_fixture(_metadata, self->tracer); 1611 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, 1612 true); 1613 1614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1615 ASSERT_EQ(0, ret); 1616 1617 /* Install "errno on getppid" filter. */ 1618 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1619 ASSERT_EQ(0, ret); 1620 1621 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 1622 EXPECT_EQ(-1, syscall(__NR_getpid)); 1623 EXPECT_EQ(EPERM, errno); 1624 } 1625 1626 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS) 1627 { 1628 struct sock_filter filter[] = { 1629 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1630 offsetof(struct seccomp_data, nr)), 1631 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 1632 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1633 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1634 }; 1635 struct sock_fprog prog = { 1636 .len = (unsigned short)ARRAY_SIZE(filter), 1637 .filter = filter, 1638 }; 1639 long ret; 1640 1641 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ 1642 teardown_trace_fixture(_metadata, self->tracer); 1643 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, 1644 true); 1645 1646 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1647 ASSERT_EQ(0, ret); 1648 1649 /* Install "death on getppid" filter. */ 1650 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 1651 ASSERT_EQ(0, ret); 1652 1653 /* Tracer will redirect getpid to getppid, and we should die. */ 1654 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 1655 } 1656 1657 #ifndef __NR_seccomp 1658 # if defined(__i386__) 1659 # define __NR_seccomp 354 1660 # elif defined(__x86_64__) 1661 # define __NR_seccomp 317 1662 # elif defined(__arm__) 1663 # define __NR_seccomp 383 1664 # elif defined(__aarch64__) 1665 # define __NR_seccomp 277 1666 # elif defined(__hppa__) 1667 # define __NR_seccomp 338 1668 # elif defined(__powerpc__) 1669 # define __NR_seccomp 358 1670 # elif defined(__s390__) 1671 # define __NR_seccomp 348 1672 # else 1673 # warning "seccomp syscall number unknown for this architecture" 1674 # define __NR_seccomp 0xffff 1675 # endif 1676 #endif 1677 1678 #ifndef SECCOMP_SET_MODE_STRICT 1679 #define SECCOMP_SET_MODE_STRICT 0 1680 #endif 1681 1682 #ifndef SECCOMP_SET_MODE_FILTER 1683 #define SECCOMP_SET_MODE_FILTER 1 1684 #endif 1685 1686 #ifndef SECCOMP_FILTER_FLAG_TSYNC 1687 #define SECCOMP_FILTER_FLAG_TSYNC 1 1688 #endif 1689 1690 #ifndef seccomp 1691 int seccomp(unsigned int op, unsigned int flags, void *args) 1692 { 1693 errno = 0; 1694 return syscall(__NR_seccomp, op, flags, args); 1695 } 1696 #endif 1697 1698 TEST(seccomp_syscall) 1699 { 1700 struct sock_filter filter[] = { 1701 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1702 }; 1703 struct sock_fprog prog = { 1704 .len = (unsigned short)ARRAY_SIZE(filter), 1705 .filter = filter, 1706 }; 1707 long ret; 1708 1709 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1710 ASSERT_EQ(0, ret) { 1711 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 1712 } 1713 1714 /* Reject insane operation. */ 1715 ret = seccomp(-1, 0, &prog); 1716 ASSERT_NE(ENOSYS, errno) { 1717 TH_LOG("Kernel does not support seccomp syscall!"); 1718 } 1719 EXPECT_EQ(EINVAL, errno) { 1720 TH_LOG("Did not reject crazy op value!"); 1721 } 1722 1723 /* Reject strict with flags or pointer. */ 1724 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); 1725 EXPECT_EQ(EINVAL, errno) { 1726 TH_LOG("Did not reject mode strict with flags!"); 1727 } 1728 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); 1729 EXPECT_EQ(EINVAL, errno) { 1730 TH_LOG("Did not reject mode strict with uargs!"); 1731 } 1732 1733 /* Reject insane args for filter. */ 1734 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); 1735 EXPECT_EQ(EINVAL, errno) { 1736 TH_LOG("Did not reject crazy filter flags!"); 1737 } 1738 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); 1739 EXPECT_EQ(EFAULT, errno) { 1740 TH_LOG("Did not reject NULL filter!"); 1741 } 1742 1743 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 1744 EXPECT_EQ(0, errno) { 1745 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", 1746 strerror(errno)); 1747 } 1748 } 1749 1750 TEST(seccomp_syscall_mode_lock) 1751 { 1752 struct sock_filter filter[] = { 1753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1754 }; 1755 struct sock_fprog prog = { 1756 .len = (unsigned short)ARRAY_SIZE(filter), 1757 .filter = filter, 1758 }; 1759 long ret; 1760 1761 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 1762 ASSERT_EQ(0, ret) { 1763 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 1764 } 1765 1766 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 1767 ASSERT_NE(ENOSYS, errno) { 1768 TH_LOG("Kernel does not support seccomp syscall!"); 1769 } 1770 EXPECT_EQ(0, ret) { 1771 TH_LOG("Could not install filter!"); 1772 } 1773 1774 /* Make sure neither entry point will switch to strict. */ 1775 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); 1776 EXPECT_EQ(EINVAL, errno) { 1777 TH_LOG("Switched to mode strict!"); 1778 } 1779 1780 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); 1781 EXPECT_EQ(EINVAL, errno) { 1782 TH_LOG("Switched to mode strict!"); 1783 } 1784 } 1785 1786 TEST(TSYNC_first) 1787 { 1788 struct sock_filter filter[] = { 1789 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1790 }; 1791 struct sock_fprog prog = { 1792 .len = (unsigned short)ARRAY_SIZE(filter), 1793 .filter = filter, 1794 }; 1795 long ret; 1796 1797 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 1798 ASSERT_EQ(0, ret) { 1799 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 1800 } 1801 1802 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 1803 &prog); 1804 ASSERT_NE(ENOSYS, errno) { 1805 TH_LOG("Kernel does not support seccomp syscall!"); 1806 } 1807 EXPECT_EQ(0, ret) { 1808 TH_LOG("Could not install initial filter with TSYNC!"); 1809 } 1810 } 1811 1812 #define TSYNC_SIBLINGS 2 1813 struct tsync_sibling { 1814 pthread_t tid; 1815 pid_t system_tid; 1816 sem_t *started; 1817 pthread_cond_t *cond; 1818 pthread_mutex_t *mutex; 1819 int diverge; 1820 int num_waits; 1821 struct sock_fprog *prog; 1822 struct __test_metadata *metadata; 1823 }; 1824 1825 FIXTURE_DATA(TSYNC) { 1826 struct sock_fprog root_prog, apply_prog; 1827 struct tsync_sibling sibling[TSYNC_SIBLINGS]; 1828 sem_t started; 1829 pthread_cond_t cond; 1830 pthread_mutex_t mutex; 1831 int sibling_count; 1832 }; 1833 1834 FIXTURE_SETUP(TSYNC) 1835 { 1836 struct sock_filter root_filter[] = { 1837 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1838 }; 1839 struct sock_filter apply_filter[] = { 1840 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1841 offsetof(struct seccomp_data, nr)), 1842 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 1843 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1844 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1845 }; 1846 1847 memset(&self->root_prog, 0, sizeof(self->root_prog)); 1848 memset(&self->apply_prog, 0, sizeof(self->apply_prog)); 1849 memset(&self->sibling, 0, sizeof(self->sibling)); 1850 self->root_prog.filter = malloc(sizeof(root_filter)); 1851 ASSERT_NE(NULL, self->root_prog.filter); 1852 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); 1853 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); 1854 1855 self->apply_prog.filter = malloc(sizeof(apply_filter)); 1856 ASSERT_NE(NULL, self->apply_prog.filter); 1857 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); 1858 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); 1859 1860 self->sibling_count = 0; 1861 pthread_mutex_init(&self->mutex, NULL); 1862 pthread_cond_init(&self->cond, NULL); 1863 sem_init(&self->started, 0, 0); 1864 self->sibling[0].tid = 0; 1865 self->sibling[0].cond = &self->cond; 1866 self->sibling[0].started = &self->started; 1867 self->sibling[0].mutex = &self->mutex; 1868 self->sibling[0].diverge = 0; 1869 self->sibling[0].num_waits = 1; 1870 self->sibling[0].prog = &self->root_prog; 1871 self->sibling[0].metadata = _metadata; 1872 self->sibling[1].tid = 0; 1873 self->sibling[1].cond = &self->cond; 1874 self->sibling[1].started = &self->started; 1875 self->sibling[1].mutex = &self->mutex; 1876 self->sibling[1].diverge = 0; 1877 self->sibling[1].prog = &self->root_prog; 1878 self->sibling[1].num_waits = 1; 1879 self->sibling[1].metadata = _metadata; 1880 } 1881 1882 FIXTURE_TEARDOWN(TSYNC) 1883 { 1884 int sib = 0; 1885 1886 if (self->root_prog.filter) 1887 free(self->root_prog.filter); 1888 if (self->apply_prog.filter) 1889 free(self->apply_prog.filter); 1890 1891 for ( ; sib < self->sibling_count; ++sib) { 1892 struct tsync_sibling *s = &self->sibling[sib]; 1893 void *status; 1894 1895 if (!s->tid) 1896 continue; 1897 if (pthread_kill(s->tid, 0)) { 1898 pthread_cancel(s->tid); 1899 pthread_join(s->tid, &status); 1900 } 1901 } 1902 pthread_mutex_destroy(&self->mutex); 1903 pthread_cond_destroy(&self->cond); 1904 sem_destroy(&self->started); 1905 } 1906 1907 void *tsync_sibling(void *data) 1908 { 1909 long ret = 0; 1910 struct tsync_sibling *me = data; 1911 1912 me->system_tid = syscall(__NR_gettid); 1913 1914 pthread_mutex_lock(me->mutex); 1915 if (me->diverge) { 1916 /* Just re-apply the root prog to fork the tree */ 1917 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 1918 me->prog, 0, 0); 1919 } 1920 sem_post(me->started); 1921 /* Return outside of started so parent notices failures. */ 1922 if (ret) { 1923 pthread_mutex_unlock(me->mutex); 1924 return (void *)SIBLING_EXIT_FAILURE; 1925 } 1926 do { 1927 pthread_cond_wait(me->cond, me->mutex); 1928 me->num_waits = me->num_waits - 1; 1929 } while (me->num_waits); 1930 pthread_mutex_unlock(me->mutex); 1931 1932 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); 1933 if (!ret) 1934 return (void *)SIBLING_EXIT_NEWPRIVS; 1935 read(0, NULL, 0); 1936 return (void *)SIBLING_EXIT_UNKILLED; 1937 } 1938 1939 void tsync_start_sibling(struct tsync_sibling *sibling) 1940 { 1941 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); 1942 } 1943 1944 TEST_F(TSYNC, siblings_fail_prctl) 1945 { 1946 long ret; 1947 void *status; 1948 struct sock_filter filter[] = { 1949 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1950 offsetof(struct seccomp_data, nr)), 1951 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 1952 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), 1953 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1954 }; 1955 struct sock_fprog prog = { 1956 .len = (unsigned short)ARRAY_SIZE(filter), 1957 .filter = filter, 1958 }; 1959 1960 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 1961 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 1962 } 1963 1964 /* Check prctl failure detection by requesting sib 0 diverge. */ 1965 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 1966 ASSERT_NE(ENOSYS, errno) { 1967 TH_LOG("Kernel does not support seccomp syscall!"); 1968 } 1969 ASSERT_EQ(0, ret) { 1970 TH_LOG("setting filter failed"); 1971 } 1972 1973 self->sibling[0].diverge = 1; 1974 tsync_start_sibling(&self->sibling[0]); 1975 tsync_start_sibling(&self->sibling[1]); 1976 1977 while (self->sibling_count < TSYNC_SIBLINGS) { 1978 sem_wait(&self->started); 1979 self->sibling_count++; 1980 } 1981 1982 /* Signal the threads to clean up*/ 1983 pthread_mutex_lock(&self->mutex); 1984 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 1985 TH_LOG("cond broadcast non-zero"); 1986 } 1987 pthread_mutex_unlock(&self->mutex); 1988 1989 /* Ensure diverging sibling failed to call prctl. */ 1990 pthread_join(self->sibling[0].tid, &status); 1991 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); 1992 pthread_join(self->sibling[1].tid, &status); 1993 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 1994 } 1995 1996 TEST_F(TSYNC, two_siblings_with_ancestor) 1997 { 1998 long ret; 1999 void *status; 2000 2001 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2002 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2003 } 2004 2005 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2006 ASSERT_NE(ENOSYS, errno) { 2007 TH_LOG("Kernel does not support seccomp syscall!"); 2008 } 2009 ASSERT_EQ(0, ret) { 2010 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2011 } 2012 tsync_start_sibling(&self->sibling[0]); 2013 tsync_start_sibling(&self->sibling[1]); 2014 2015 while (self->sibling_count < TSYNC_SIBLINGS) { 2016 sem_wait(&self->started); 2017 self->sibling_count++; 2018 } 2019 2020 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2021 &self->apply_prog); 2022 ASSERT_EQ(0, ret) { 2023 TH_LOG("Could install filter on all threads!"); 2024 } 2025 /* Tell the siblings to test the policy */ 2026 pthread_mutex_lock(&self->mutex); 2027 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2028 TH_LOG("cond broadcast non-zero"); 2029 } 2030 pthread_mutex_unlock(&self->mutex); 2031 /* Ensure they are both killed and don't exit cleanly. */ 2032 pthread_join(self->sibling[0].tid, &status); 2033 EXPECT_EQ(0x0, (long)status); 2034 pthread_join(self->sibling[1].tid, &status); 2035 EXPECT_EQ(0x0, (long)status); 2036 } 2037 2038 TEST_F(TSYNC, two_sibling_want_nnp) 2039 { 2040 void *status; 2041 2042 /* start siblings before any prctl() operations */ 2043 tsync_start_sibling(&self->sibling[0]); 2044 tsync_start_sibling(&self->sibling[1]); 2045 while (self->sibling_count < TSYNC_SIBLINGS) { 2046 sem_wait(&self->started); 2047 self->sibling_count++; 2048 } 2049 2050 /* Tell the siblings to test no policy */ 2051 pthread_mutex_lock(&self->mutex); 2052 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2053 TH_LOG("cond broadcast non-zero"); 2054 } 2055 pthread_mutex_unlock(&self->mutex); 2056 2057 /* Ensure they are both upset about lacking nnp. */ 2058 pthread_join(self->sibling[0].tid, &status); 2059 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2060 pthread_join(self->sibling[1].tid, &status); 2061 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2062 } 2063 2064 TEST_F(TSYNC, two_siblings_with_no_filter) 2065 { 2066 long ret; 2067 void *status; 2068 2069 /* start siblings before any prctl() operations */ 2070 tsync_start_sibling(&self->sibling[0]); 2071 tsync_start_sibling(&self->sibling[1]); 2072 while (self->sibling_count < TSYNC_SIBLINGS) { 2073 sem_wait(&self->started); 2074 self->sibling_count++; 2075 } 2076 2077 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2078 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2079 } 2080 2081 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2082 &self->apply_prog); 2083 ASSERT_NE(ENOSYS, errno) { 2084 TH_LOG("Kernel does not support seccomp syscall!"); 2085 } 2086 ASSERT_EQ(0, ret) { 2087 TH_LOG("Could install filter on all threads!"); 2088 } 2089 2090 /* Tell the siblings to test the policy */ 2091 pthread_mutex_lock(&self->mutex); 2092 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2093 TH_LOG("cond broadcast non-zero"); 2094 } 2095 pthread_mutex_unlock(&self->mutex); 2096 2097 /* Ensure they are both killed and don't exit cleanly. */ 2098 pthread_join(self->sibling[0].tid, &status); 2099 EXPECT_EQ(0x0, (long)status); 2100 pthread_join(self->sibling[1].tid, &status); 2101 EXPECT_EQ(0x0, (long)status); 2102 } 2103 2104 TEST_F(TSYNC, two_siblings_with_one_divergence) 2105 { 2106 long ret; 2107 void *status; 2108 2109 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2110 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2111 } 2112 2113 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2114 ASSERT_NE(ENOSYS, errno) { 2115 TH_LOG("Kernel does not support seccomp syscall!"); 2116 } 2117 ASSERT_EQ(0, ret) { 2118 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2119 } 2120 self->sibling[0].diverge = 1; 2121 tsync_start_sibling(&self->sibling[0]); 2122 tsync_start_sibling(&self->sibling[1]); 2123 2124 while (self->sibling_count < TSYNC_SIBLINGS) { 2125 sem_wait(&self->started); 2126 self->sibling_count++; 2127 } 2128 2129 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2130 &self->apply_prog); 2131 ASSERT_EQ(self->sibling[0].system_tid, ret) { 2132 TH_LOG("Did not fail on diverged sibling."); 2133 } 2134 2135 /* Wake the threads */ 2136 pthread_mutex_lock(&self->mutex); 2137 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2138 TH_LOG("cond broadcast non-zero"); 2139 } 2140 pthread_mutex_unlock(&self->mutex); 2141 2142 /* Ensure they are both unkilled. */ 2143 pthread_join(self->sibling[0].tid, &status); 2144 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2145 pthread_join(self->sibling[1].tid, &status); 2146 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2147 } 2148 2149 TEST_F(TSYNC, two_siblings_not_under_filter) 2150 { 2151 long ret, sib; 2152 void *status; 2153 2154 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2155 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2156 } 2157 2158 /* 2159 * Sibling 0 will have its own seccomp policy 2160 * and Sibling 1 will not be under seccomp at 2161 * all. Sibling 1 will enter seccomp and 0 2162 * will cause failure. 2163 */ 2164 self->sibling[0].diverge = 1; 2165 tsync_start_sibling(&self->sibling[0]); 2166 tsync_start_sibling(&self->sibling[1]); 2167 2168 while (self->sibling_count < TSYNC_SIBLINGS) { 2169 sem_wait(&self->started); 2170 self->sibling_count++; 2171 } 2172 2173 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2174 ASSERT_NE(ENOSYS, errno) { 2175 TH_LOG("Kernel does not support seccomp syscall!"); 2176 } 2177 ASSERT_EQ(0, ret) { 2178 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2179 } 2180 2181 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2182 &self->apply_prog); 2183 ASSERT_EQ(ret, self->sibling[0].system_tid) { 2184 TH_LOG("Did not fail on diverged sibling."); 2185 } 2186 sib = 1; 2187 if (ret == self->sibling[0].system_tid) 2188 sib = 0; 2189 2190 pthread_mutex_lock(&self->mutex); 2191 2192 /* Increment the other siblings num_waits so we can clean up 2193 * the one we just saw. 2194 */ 2195 self->sibling[!sib].num_waits += 1; 2196 2197 /* Signal the thread to clean up*/ 2198 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2199 TH_LOG("cond broadcast non-zero"); 2200 } 2201 pthread_mutex_unlock(&self->mutex); 2202 pthread_join(self->sibling[sib].tid, &status); 2203 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2204 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2205 while (!kill(self->sibling[sib].system_tid, 0)) 2206 sleep(0.1); 2207 /* Switch to the remaining sibling */ 2208 sib = !sib; 2209 2210 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2211 &self->apply_prog); 2212 ASSERT_EQ(0, ret) { 2213 TH_LOG("Expected the remaining sibling to sync"); 2214 }; 2215 2216 pthread_mutex_lock(&self->mutex); 2217 2218 /* If remaining sibling didn't have a chance to wake up during 2219 * the first broadcast, manually reduce the num_waits now. 2220 */ 2221 if (self->sibling[sib].num_waits > 1) 2222 self->sibling[sib].num_waits = 1; 2223 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2224 TH_LOG("cond broadcast non-zero"); 2225 } 2226 pthread_mutex_unlock(&self->mutex); 2227 pthread_join(self->sibling[sib].tid, &status); 2228 EXPECT_EQ(0, (long)status); 2229 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2230 while (!kill(self->sibling[sib].system_tid, 0)) 2231 sleep(0.1); 2232 2233 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2234 &self->apply_prog); 2235 ASSERT_EQ(0, ret); /* just us chickens */ 2236 } 2237 2238 /* Make sure restarted syscalls are seen directly as "restart_syscall". */ 2239 TEST(syscall_restart) 2240 { 2241 long ret; 2242 unsigned long msg; 2243 pid_t child_pid; 2244 int pipefd[2]; 2245 int status; 2246 siginfo_t info = { }; 2247 struct sock_filter filter[] = { 2248 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2249 offsetof(struct seccomp_data, nr)), 2250 2251 #ifdef __NR_sigreturn 2252 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0), 2253 #endif 2254 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0), 2255 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0), 2256 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0), 2257 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0), 2258 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), 2259 2260 /* Allow __NR_write for easy logging. */ 2261 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), 2262 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2263 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2264 /* The nanosleep jump target. */ 2265 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), 2266 /* The restart_syscall jump target. */ 2267 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), 2268 }; 2269 struct sock_fprog prog = { 2270 .len = (unsigned short)ARRAY_SIZE(filter), 2271 .filter = filter, 2272 }; 2273 #if defined(__arm__) 2274 struct utsname utsbuf; 2275 #endif 2276 2277 ASSERT_EQ(0, pipe(pipefd)); 2278 2279 child_pid = fork(); 2280 ASSERT_LE(0, child_pid); 2281 if (child_pid == 0) { 2282 /* Child uses EXPECT not ASSERT to deliver status correctly. */ 2283 char buf = ' '; 2284 struct timespec timeout = { }; 2285 2286 /* Attach parent as tracer and stop. */ 2287 EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); 2288 EXPECT_EQ(0, raise(SIGSTOP)); 2289 2290 EXPECT_EQ(0, close(pipefd[1])); 2291 2292 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2293 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2294 } 2295 2296 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2297 EXPECT_EQ(0, ret) { 2298 TH_LOG("Failed to install filter!"); 2299 } 2300 2301 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 2302 TH_LOG("Failed to read() sync from parent"); 2303 } 2304 EXPECT_EQ('.', buf) { 2305 TH_LOG("Failed to get sync data from read()"); 2306 } 2307 2308 /* Start nanosleep to be interrupted. */ 2309 timeout.tv_sec = 1; 2310 errno = 0; 2311 EXPECT_EQ(0, nanosleep(&timeout, NULL)) { 2312 TH_LOG("Call to nanosleep() failed (errno %d)", errno); 2313 } 2314 2315 /* Read final sync from parent. */ 2316 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 2317 TH_LOG("Failed final read() from parent"); 2318 } 2319 EXPECT_EQ('!', buf) { 2320 TH_LOG("Failed to get final data from read()"); 2321 } 2322 2323 /* Directly report the status of our test harness results. */ 2324 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS 2325 : EXIT_FAILURE); 2326 } 2327 EXPECT_EQ(0, close(pipefd[0])); 2328 2329 /* Attach to child, setup options, and release. */ 2330 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2331 ASSERT_EQ(true, WIFSTOPPED(status)); 2332 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, 2333 PTRACE_O_TRACESECCOMP)); 2334 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2335 ASSERT_EQ(1, write(pipefd[1], ".", 1)); 2336 2337 /* Wait for nanosleep() to start. */ 2338 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2339 ASSERT_EQ(true, WIFSTOPPED(status)); 2340 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 2341 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 2342 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 2343 ASSERT_EQ(0x100, msg); 2344 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid)); 2345 2346 /* Might as well check siginfo for sanity while we're here. */ 2347 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 2348 ASSERT_EQ(SIGTRAP, info.si_signo); 2349 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); 2350 EXPECT_EQ(0, info.si_errno); 2351 EXPECT_EQ(getuid(), info.si_uid); 2352 /* Verify signal delivery came from child (seccomp-triggered). */ 2353 EXPECT_EQ(child_pid, info.si_pid); 2354 2355 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */ 2356 ASSERT_EQ(0, kill(child_pid, SIGSTOP)); 2357 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2358 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2359 ASSERT_EQ(true, WIFSTOPPED(status)); 2360 ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); 2361 /* Verify signal delivery came from parent now. */ 2362 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 2363 EXPECT_EQ(getpid(), info.si_pid); 2364 2365 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ 2366 ASSERT_EQ(0, kill(child_pid, SIGCONT)); 2367 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2368 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2369 ASSERT_EQ(true, WIFSTOPPED(status)); 2370 ASSERT_EQ(SIGCONT, WSTOPSIG(status)); 2371 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2372 2373 /* Wait for restart_syscall() to start. */ 2374 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2375 ASSERT_EQ(true, WIFSTOPPED(status)); 2376 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 2377 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 2378 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 2379 2380 ASSERT_EQ(0x200, msg); 2381 ret = get_syscall(_metadata, child_pid); 2382 #if defined(__arm__) 2383 /* 2384 * FIXME: 2385 * - native ARM registers do NOT expose true syscall. 2386 * - compat ARM registers on ARM64 DO expose true syscall. 2387 */ 2388 ASSERT_EQ(0, uname(&utsbuf)); 2389 if (strncmp(utsbuf.machine, "arm", 3) == 0) { 2390 EXPECT_EQ(__NR_nanosleep, ret); 2391 } else 2392 #endif 2393 { 2394 EXPECT_EQ(__NR_restart_syscall, ret); 2395 } 2396 2397 /* Write again to end test. */ 2398 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 2399 ASSERT_EQ(1, write(pipefd[1], "!", 1)); 2400 EXPECT_EQ(0, close(pipefd[1])); 2401 2402 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 2403 if (WIFSIGNALED(status) || WEXITSTATUS(status)) 2404 _metadata->passed = 0; 2405 } 2406 2407 /* 2408 * TODO: 2409 * - add microbenchmarks 2410 * - expand NNP testing 2411 * - better arch-specific TRACE and TRAP handlers. 2412 * - endianness checking when appropriate 2413 * - 64-bit arg prodding 2414 * - arch value testing (x86 modes especially) 2415 * - ... 2416 */ 2417 2418 TEST_HARNESS_MAIN 2419