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