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