1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 4 * 5 * Test code for seccomp bpf. 6 */ 7 8 #define _GNU_SOURCE 9 #include <sys/types.h> 10 11 /* 12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that, 13 * we need to use the kernel's siginfo.h file and trick glibc 14 * into accepting it. 15 */ 16 #if !__GLIBC_PREREQ(2, 26) 17 # include <asm/siginfo.h> 18 # define __have_siginfo_t 1 19 # define __have_sigval_t 1 20 # define __have_sigevent_t 1 21 #endif 22 23 #include <errno.h> 24 #include <linux/filter.h> 25 #include <sys/prctl.h> 26 #include <sys/ptrace.h> 27 #include <sys/user.h> 28 #include <linux/prctl.h> 29 #include <linux/ptrace.h> 30 #include <linux/seccomp.h> 31 #include <pthread.h> 32 #include <semaphore.h> 33 #include <signal.h> 34 #include <stddef.h> 35 #include <stdbool.h> 36 #include <string.h> 37 #include <time.h> 38 #include <limits.h> 39 #include <linux/elf.h> 40 #include <sys/uio.h> 41 #include <sys/utsname.h> 42 #include <sys/fcntl.h> 43 #include <sys/mman.h> 44 #include <sys/times.h> 45 #include <sys/socket.h> 46 #include <sys/ioctl.h> 47 #include <linux/kcmp.h> 48 #include <sys/resource.h> 49 50 #include <unistd.h> 51 #include <sys/syscall.h> 52 #include <poll.h> 53 54 #include "../kselftest_harness.h" 55 #include "../clone3/clone3_selftests.h" 56 57 /* Attempt to de-conflict with the selftests tree. */ 58 #ifndef SKIP 59 #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) 60 #endif 61 62 #ifndef PR_SET_PTRACER 63 # define PR_SET_PTRACER 0x59616d61 64 #endif 65 66 #ifndef PR_SET_NO_NEW_PRIVS 67 #define PR_SET_NO_NEW_PRIVS 38 68 #define PR_GET_NO_NEW_PRIVS 39 69 #endif 70 71 #ifndef PR_SECCOMP_EXT 72 #define PR_SECCOMP_EXT 43 73 #endif 74 75 #ifndef SECCOMP_EXT_ACT 76 #define SECCOMP_EXT_ACT 1 77 #endif 78 79 #ifndef SECCOMP_EXT_ACT_TSYNC 80 #define SECCOMP_EXT_ACT_TSYNC 1 81 #endif 82 83 #ifndef SECCOMP_MODE_STRICT 84 #define SECCOMP_MODE_STRICT 1 85 #endif 86 87 #ifndef SECCOMP_MODE_FILTER 88 #define SECCOMP_MODE_FILTER 2 89 #endif 90 91 #ifndef SECCOMP_RET_ALLOW 92 struct seccomp_data { 93 int nr; 94 __u32 arch; 95 __u64 instruction_pointer; 96 __u64 args[6]; 97 }; 98 #endif 99 100 #ifndef SECCOMP_RET_KILL_PROCESS 101 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */ 102 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */ 103 #endif 104 #ifndef SECCOMP_RET_KILL 105 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD 106 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ 107 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ 108 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ 109 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ 110 #endif 111 #ifndef SECCOMP_RET_LOG 112 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */ 113 #endif 114 115 #ifndef __NR_seccomp 116 # if defined(__i386__) 117 # define __NR_seccomp 354 118 # elif defined(__x86_64__) 119 # define __NR_seccomp 317 120 # elif defined(__arm__) 121 # define __NR_seccomp 383 122 # elif defined(__aarch64__) 123 # define __NR_seccomp 277 124 # elif defined(__riscv) 125 # define __NR_seccomp 277 126 # elif defined(__csky__) 127 # define __NR_seccomp 277 128 # elif defined(__hppa__) 129 # define __NR_seccomp 338 130 # elif defined(__powerpc__) 131 # define __NR_seccomp 358 132 # elif defined(__s390__) 133 # define __NR_seccomp 348 134 # elif defined(__xtensa__) 135 # define __NR_seccomp 337 136 # elif defined(__sh__) 137 # define __NR_seccomp 372 138 # else 139 # warning "seccomp syscall number unknown for this architecture" 140 # define __NR_seccomp 0xffff 141 # endif 142 #endif 143 144 #ifndef SECCOMP_SET_MODE_STRICT 145 #define SECCOMP_SET_MODE_STRICT 0 146 #endif 147 148 #ifndef SECCOMP_SET_MODE_FILTER 149 #define SECCOMP_SET_MODE_FILTER 1 150 #endif 151 152 #ifndef SECCOMP_GET_ACTION_AVAIL 153 #define SECCOMP_GET_ACTION_AVAIL 2 154 #endif 155 156 #ifndef SECCOMP_GET_NOTIF_SIZES 157 #define SECCOMP_GET_NOTIF_SIZES 3 158 #endif 159 160 #ifndef SECCOMP_FILTER_FLAG_TSYNC 161 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0) 162 #endif 163 164 #ifndef SECCOMP_FILTER_FLAG_LOG 165 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1) 166 #endif 167 168 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW 169 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2) 170 #endif 171 172 #ifndef PTRACE_SECCOMP_GET_METADATA 173 #define PTRACE_SECCOMP_GET_METADATA 0x420d 174 175 struct seccomp_metadata { 176 __u64 filter_off; /* Input: which filter */ 177 __u64 flags; /* Output: filter's flags */ 178 }; 179 #endif 180 181 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER 182 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3) 183 #endif 184 185 #ifndef SECCOMP_RET_USER_NOTIF 186 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U 187 188 #define SECCOMP_IOC_MAGIC '!' 189 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr) 190 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type) 191 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type) 192 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type) 193 194 /* Flags for seccomp notification fd ioctl. */ 195 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif) 196 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \ 197 struct seccomp_notif_resp) 198 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64) 199 200 struct seccomp_notif { 201 __u64 id; 202 __u32 pid; 203 __u32 flags; 204 struct seccomp_data data; 205 }; 206 207 struct seccomp_notif_resp { 208 __u64 id; 209 __s64 val; 210 __s32 error; 211 __u32 flags; 212 }; 213 214 struct seccomp_notif_sizes { 215 __u16 seccomp_notif; 216 __u16 seccomp_notif_resp; 217 __u16 seccomp_data; 218 }; 219 #endif 220 221 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD 222 /* On success, the return value is the remote process's added fd number */ 223 #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ 224 struct seccomp_notif_addfd) 225 226 /* valid flags for seccomp_notif_addfd */ 227 #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ 228 229 struct seccomp_notif_addfd { 230 __u64 id; 231 __u32 flags; 232 __u32 srcfd; 233 __u32 newfd; 234 __u32 newfd_flags; 235 }; 236 #endif 237 238 #ifndef SECCOMP_ADDFD_FLAG_SEND 239 #define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */ 240 #endif 241 242 struct seccomp_notif_addfd_small { 243 __u64 id; 244 char weird[4]; 245 }; 246 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \ 247 SECCOMP_IOW(3, struct seccomp_notif_addfd_small) 248 249 struct seccomp_notif_addfd_big { 250 union { 251 struct seccomp_notif_addfd addfd; 252 char buf[sizeof(struct seccomp_notif_addfd) + 8]; 253 }; 254 }; 255 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \ 256 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big) 257 258 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY 259 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 260 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2 261 #endif 262 263 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE 264 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001 265 #endif 266 267 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH 268 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4) 269 #endif 270 271 #ifndef seccomp 272 int seccomp(unsigned int op, unsigned int flags, void *args) 273 { 274 errno = 0; 275 return syscall(__NR_seccomp, op, flags, args); 276 } 277 #endif 278 279 #if __BYTE_ORDER == __LITTLE_ENDIAN 280 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) 281 #elif __BYTE_ORDER == __BIG_ENDIAN 282 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) 283 #else 284 #error "wut? Unknown __BYTE_ORDER?!" 285 #endif 286 287 #define SIBLING_EXIT_UNKILLED 0xbadbeef 288 #define SIBLING_EXIT_FAILURE 0xbadface 289 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed 290 291 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2) 292 { 293 #ifdef __NR_kcmp 294 errno = 0; 295 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2); 296 #else 297 errno = ENOSYS; 298 return -1; 299 #endif 300 } 301 302 /* Have TH_LOG report actual location filecmp() is used. */ 303 #define filecmp(pid1, pid2, fd1, fd2) ({ \ 304 int _ret; \ 305 \ 306 _ret = __filecmp(pid1, pid2, fd1, fd2); \ 307 if (_ret != 0) { \ 308 if (_ret < 0 && errno == ENOSYS) { \ 309 TH_LOG("kcmp() syscall missing (test is less accurate)");\ 310 _ret = 0; \ 311 } \ 312 } \ 313 _ret; }) 314 315 TEST(kcmp) 316 { 317 int ret; 318 319 ret = __filecmp(getpid(), getpid(), 1, 1); 320 EXPECT_EQ(ret, 0); 321 if (ret != 0 && errno == ENOSYS) 322 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)"); 323 } 324 325 TEST(mode_strict_support) 326 { 327 long ret; 328 329 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 330 ASSERT_EQ(0, ret) { 331 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 332 } 333 syscall(__NR_exit, 0); 334 } 335 336 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) 337 { 338 long ret; 339 340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 341 ASSERT_EQ(0, ret) { 342 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 343 } 344 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 345 NULL, NULL, NULL); 346 EXPECT_FALSE(true) { 347 TH_LOG("Unreachable!"); 348 } 349 } 350 351 /* Note! This doesn't test no new privs behavior */ 352 TEST(no_new_privs_support) 353 { 354 long ret; 355 356 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 357 EXPECT_EQ(0, ret) { 358 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 359 } 360 } 361 362 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */ 363 TEST(mode_filter_support) 364 { 365 long ret; 366 367 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 368 ASSERT_EQ(0, ret) { 369 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 370 } 371 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); 372 EXPECT_EQ(-1, ret); 373 EXPECT_EQ(EFAULT, errno) { 374 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); 375 } 376 } 377 378 TEST(mode_filter_without_nnp) 379 { 380 struct sock_filter filter[] = { 381 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 382 }; 383 struct sock_fprog prog = { 384 .len = (unsigned short)ARRAY_SIZE(filter), 385 .filter = filter, 386 }; 387 long ret; 388 389 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); 390 ASSERT_LE(0, ret) { 391 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); 392 } 393 errno = 0; 394 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 395 /* Succeeds with CAP_SYS_ADMIN, fails without */ 396 /* TODO(wad) check caps not euid */ 397 if (geteuid()) { 398 EXPECT_EQ(-1, ret); 399 EXPECT_EQ(EACCES, errno); 400 } else { 401 EXPECT_EQ(0, ret); 402 } 403 } 404 405 #define MAX_INSNS_PER_PATH 32768 406 407 TEST(filter_size_limits) 408 { 409 int i; 410 int count = BPF_MAXINSNS + 1; 411 struct sock_filter allow[] = { 412 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 413 }; 414 struct sock_filter *filter; 415 struct sock_fprog prog = { }; 416 long ret; 417 418 filter = calloc(count, sizeof(*filter)); 419 ASSERT_NE(NULL, filter); 420 421 for (i = 0; i < count; i++) 422 filter[i] = allow[0]; 423 424 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 425 ASSERT_EQ(0, ret); 426 427 prog.filter = filter; 428 prog.len = count; 429 430 /* Too many filter instructions in a single filter. */ 431 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 432 ASSERT_NE(0, ret) { 433 TH_LOG("Installing %d insn filter was allowed", prog.len); 434 } 435 436 /* One less is okay, though. */ 437 prog.len -= 1; 438 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 439 ASSERT_EQ(0, ret) { 440 TH_LOG("Installing %d insn filter wasn't allowed", prog.len); 441 } 442 } 443 444 TEST(filter_chain_limits) 445 { 446 int i; 447 int count = BPF_MAXINSNS; 448 struct sock_filter allow[] = { 449 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 450 }; 451 struct sock_filter *filter; 452 struct sock_fprog prog = { }; 453 long ret; 454 455 filter = calloc(count, sizeof(*filter)); 456 ASSERT_NE(NULL, filter); 457 458 for (i = 0; i < count; i++) 459 filter[i] = allow[0]; 460 461 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 462 ASSERT_EQ(0, ret); 463 464 prog.filter = filter; 465 prog.len = 1; 466 467 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 468 ASSERT_EQ(0, ret); 469 470 prog.len = count; 471 472 /* Too many total filter instructions. */ 473 for (i = 0; i < MAX_INSNS_PER_PATH; i++) { 474 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 475 if (ret != 0) 476 break; 477 } 478 ASSERT_NE(0, ret) { 479 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", 480 i, count, i * (count + 4)); 481 } 482 } 483 484 TEST(mode_filter_cannot_move_to_strict) 485 { 486 struct sock_filter filter[] = { 487 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 488 }; 489 struct sock_fprog prog = { 490 .len = (unsigned short)ARRAY_SIZE(filter), 491 .filter = filter, 492 }; 493 long ret; 494 495 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 496 ASSERT_EQ(0, ret); 497 498 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 499 ASSERT_EQ(0, ret); 500 501 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); 502 EXPECT_EQ(-1, ret); 503 EXPECT_EQ(EINVAL, errno); 504 } 505 506 507 TEST(mode_filter_get_seccomp) 508 { 509 struct sock_filter filter[] = { 510 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 511 }; 512 struct sock_fprog prog = { 513 .len = (unsigned short)ARRAY_SIZE(filter), 514 .filter = filter, 515 }; 516 long ret; 517 518 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 519 ASSERT_EQ(0, ret); 520 521 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 522 EXPECT_EQ(0, ret); 523 524 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 525 ASSERT_EQ(0, ret); 526 527 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 528 EXPECT_EQ(2, ret); 529 } 530 531 532 TEST(ALLOW_all) 533 { 534 struct sock_filter filter[] = { 535 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 536 }; 537 struct sock_fprog prog = { 538 .len = (unsigned short)ARRAY_SIZE(filter), 539 .filter = filter, 540 }; 541 long ret; 542 543 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 544 ASSERT_EQ(0, ret); 545 546 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 547 ASSERT_EQ(0, ret); 548 } 549 550 TEST(empty_prog) 551 { 552 struct sock_filter filter[] = { 553 }; 554 struct sock_fprog prog = { 555 .len = (unsigned short)ARRAY_SIZE(filter), 556 .filter = filter, 557 }; 558 long ret; 559 560 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 561 ASSERT_EQ(0, ret); 562 563 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 564 EXPECT_EQ(-1, ret); 565 EXPECT_EQ(EINVAL, errno); 566 } 567 568 TEST(log_all) 569 { 570 struct sock_filter filter[] = { 571 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 572 }; 573 struct sock_fprog prog = { 574 .len = (unsigned short)ARRAY_SIZE(filter), 575 .filter = filter, 576 }; 577 long ret; 578 pid_t parent = getppid(); 579 580 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 581 ASSERT_EQ(0, ret); 582 583 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 584 ASSERT_EQ(0, ret); 585 586 /* getppid() should succeed and be logged (no check for logging) */ 587 EXPECT_EQ(parent, syscall(__NR_getppid)); 588 } 589 590 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) 591 { 592 struct sock_filter filter[] = { 593 BPF_STMT(BPF_RET|BPF_K, 0x10000000U), 594 }; 595 struct sock_fprog prog = { 596 .len = (unsigned short)ARRAY_SIZE(filter), 597 .filter = filter, 598 }; 599 long ret; 600 601 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 602 ASSERT_EQ(0, ret); 603 604 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 605 ASSERT_EQ(0, ret); 606 EXPECT_EQ(0, syscall(__NR_getpid)) { 607 TH_LOG("getpid() shouldn't ever return"); 608 } 609 } 610 611 /* return code >= 0x80000000 is unused. */ 612 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) 613 { 614 struct sock_filter filter[] = { 615 BPF_STMT(BPF_RET|BPF_K, 0x90000000U), 616 }; 617 struct sock_fprog prog = { 618 .len = (unsigned short)ARRAY_SIZE(filter), 619 .filter = filter, 620 }; 621 long ret; 622 623 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 624 ASSERT_EQ(0, ret); 625 626 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 627 ASSERT_EQ(0, ret); 628 EXPECT_EQ(0, syscall(__NR_getpid)) { 629 TH_LOG("getpid() shouldn't ever return"); 630 } 631 } 632 633 TEST_SIGNAL(KILL_all, SIGSYS) 634 { 635 struct sock_filter filter[] = { 636 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 637 }; 638 struct sock_fprog prog = { 639 .len = (unsigned short)ARRAY_SIZE(filter), 640 .filter = filter, 641 }; 642 long ret; 643 644 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 645 ASSERT_EQ(0, ret); 646 647 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 648 ASSERT_EQ(0, ret); 649 } 650 651 TEST_SIGNAL(KILL_one, SIGSYS) 652 { 653 struct sock_filter filter[] = { 654 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 655 offsetof(struct seccomp_data, nr)), 656 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 657 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 658 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 659 }; 660 struct sock_fprog prog = { 661 .len = (unsigned short)ARRAY_SIZE(filter), 662 .filter = filter, 663 }; 664 long ret; 665 pid_t parent = getppid(); 666 667 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 668 ASSERT_EQ(0, ret); 669 670 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 671 ASSERT_EQ(0, ret); 672 673 EXPECT_EQ(parent, syscall(__NR_getppid)); 674 /* getpid() should never return. */ 675 EXPECT_EQ(0, syscall(__NR_getpid)); 676 } 677 678 TEST_SIGNAL(KILL_one_arg_one, SIGSYS) 679 { 680 void *fatal_address; 681 struct sock_filter filter[] = { 682 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 683 offsetof(struct seccomp_data, nr)), 684 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0), 685 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 686 /* Only both with lower 32-bit for now. */ 687 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), 688 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 689 (unsigned long)&fatal_address, 0, 1), 690 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 691 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 692 }; 693 struct sock_fprog prog = { 694 .len = (unsigned short)ARRAY_SIZE(filter), 695 .filter = filter, 696 }; 697 long ret; 698 pid_t parent = getppid(); 699 struct tms timebuf; 700 clock_t clock = times(&timebuf); 701 702 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 703 ASSERT_EQ(0, ret); 704 705 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 706 ASSERT_EQ(0, ret); 707 708 EXPECT_EQ(parent, syscall(__NR_getppid)); 709 EXPECT_LE(clock, syscall(__NR_times, &timebuf)); 710 /* times() should never return. */ 711 EXPECT_EQ(0, syscall(__NR_times, &fatal_address)); 712 } 713 714 TEST_SIGNAL(KILL_one_arg_six, SIGSYS) 715 { 716 #ifndef __NR_mmap2 717 int sysno = __NR_mmap; 718 #else 719 int sysno = __NR_mmap2; 720 #endif 721 struct sock_filter filter[] = { 722 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 723 offsetof(struct seccomp_data, nr)), 724 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0), 725 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 726 /* Only both with lower 32-bit for now. */ 727 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), 728 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), 729 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 730 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 731 }; 732 struct sock_fprog prog = { 733 .len = (unsigned short)ARRAY_SIZE(filter), 734 .filter = filter, 735 }; 736 long ret; 737 pid_t parent = getppid(); 738 int fd; 739 void *map1, *map2; 740 int page_size = sysconf(_SC_PAGESIZE); 741 742 ASSERT_LT(0, page_size); 743 744 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 745 ASSERT_EQ(0, ret); 746 747 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 748 ASSERT_EQ(0, ret); 749 750 fd = open("/dev/zero", O_RDONLY); 751 ASSERT_NE(-1, fd); 752 753 EXPECT_EQ(parent, syscall(__NR_getppid)); 754 map1 = (void *)syscall(sysno, 755 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size); 756 EXPECT_NE(MAP_FAILED, map1); 757 /* mmap2() should never return. */ 758 map2 = (void *)syscall(sysno, 759 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE); 760 EXPECT_EQ(MAP_FAILED, map2); 761 762 /* The test failed, so clean up the resources. */ 763 munmap(map1, page_size); 764 munmap(map2, page_size); 765 close(fd); 766 } 767 768 /* This is a thread task to die via seccomp filter violation. */ 769 void *kill_thread(void *data) 770 { 771 bool die = (bool)data; 772 773 if (die) { 774 prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 775 return (void *)SIBLING_EXIT_FAILURE; 776 } 777 778 return (void *)SIBLING_EXIT_UNKILLED; 779 } 780 781 enum kill_t { 782 KILL_THREAD, 783 KILL_PROCESS, 784 RET_UNKNOWN 785 }; 786 787 /* Prepare a thread that will kill itself or both of us. */ 788 void kill_thread_or_group(struct __test_metadata *_metadata, 789 enum kill_t kill_how) 790 { 791 pthread_t thread; 792 void *status; 793 /* Kill only when calling __NR_prctl. */ 794 struct sock_filter filter_thread[] = { 795 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 796 offsetof(struct seccomp_data, nr)), 797 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 798 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), 799 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 800 }; 801 struct sock_fprog prog_thread = { 802 .len = (unsigned short)ARRAY_SIZE(filter_thread), 803 .filter = filter_thread, 804 }; 805 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAAA; 806 struct sock_filter filter_process[] = { 807 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 808 offsetof(struct seccomp_data, nr)), 809 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 810 BPF_STMT(BPF_RET|BPF_K, kill), 811 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 812 }; 813 struct sock_fprog prog_process = { 814 .len = (unsigned short)ARRAY_SIZE(filter_process), 815 .filter = filter_process, 816 }; 817 818 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 819 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 820 } 821 822 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, 823 kill_how == KILL_THREAD ? &prog_thread 824 : &prog_process)); 825 826 /* 827 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS 828 * flag cannot be downgraded by a new filter. 829 */ 830 if (kill_how == KILL_PROCESS) 831 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread)); 832 833 /* Start a thread that will exit immediately. */ 834 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false)); 835 ASSERT_EQ(0, pthread_join(thread, &status)); 836 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status); 837 838 /* Start a thread that will die immediately. */ 839 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true)); 840 ASSERT_EQ(0, pthread_join(thread, &status)); 841 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status); 842 843 /* 844 * If we get here, only the spawned thread died. Let the parent know 845 * the whole process didn't die (i.e. this thread, the spawner, 846 * stayed running). 847 */ 848 exit(42); 849 } 850 851 TEST(KILL_thread) 852 { 853 int status; 854 pid_t child_pid; 855 856 child_pid = fork(); 857 ASSERT_LE(0, child_pid); 858 if (child_pid == 0) { 859 kill_thread_or_group(_metadata, KILL_THREAD); 860 _exit(38); 861 } 862 863 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 864 865 /* If only the thread was killed, we'll see exit 42. */ 866 ASSERT_TRUE(WIFEXITED(status)); 867 ASSERT_EQ(42, WEXITSTATUS(status)); 868 } 869 870 TEST(KILL_process) 871 { 872 int status; 873 pid_t child_pid; 874 875 child_pid = fork(); 876 ASSERT_LE(0, child_pid); 877 if (child_pid == 0) { 878 kill_thread_or_group(_metadata, KILL_PROCESS); 879 _exit(38); 880 } 881 882 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 883 884 /* If the entire process was killed, we'll see SIGSYS. */ 885 ASSERT_TRUE(WIFSIGNALED(status)); 886 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 887 } 888 889 TEST(KILL_unknown) 890 { 891 int status; 892 pid_t child_pid; 893 894 child_pid = fork(); 895 ASSERT_LE(0, child_pid); 896 if (child_pid == 0) { 897 kill_thread_or_group(_metadata, RET_UNKNOWN); 898 _exit(38); 899 } 900 901 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 902 903 /* If the entire process was killed, we'll see SIGSYS. */ 904 EXPECT_TRUE(WIFSIGNALED(status)) { 905 TH_LOG("Unknown SECCOMP_RET is only killing the thread?"); 906 } 907 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 908 } 909 910 /* TODO(wad) add 64-bit versus 32-bit arg tests. */ 911 TEST(arg_out_of_range) 912 { 913 struct sock_filter filter[] = { 914 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), 915 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 916 }; 917 struct sock_fprog prog = { 918 .len = (unsigned short)ARRAY_SIZE(filter), 919 .filter = filter, 920 }; 921 long ret; 922 923 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 924 ASSERT_EQ(0, ret); 925 926 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 927 EXPECT_EQ(-1, ret); 928 EXPECT_EQ(EINVAL, errno); 929 } 930 931 #define ERRNO_FILTER(name, errno) \ 932 struct sock_filter _read_filter_##name[] = { \ 933 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \ 934 offsetof(struct seccomp_data, nr)), \ 935 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \ 936 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \ 937 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \ 938 }; \ 939 struct sock_fprog prog_##name = { \ 940 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \ 941 .filter = _read_filter_##name, \ 942 } 943 944 /* Make sure basic errno values are correctly passed through a filter. */ 945 TEST(ERRNO_valid) 946 { 947 ERRNO_FILTER(valid, E2BIG); 948 long ret; 949 pid_t parent = getppid(); 950 951 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 952 ASSERT_EQ(0, ret); 953 954 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid); 955 ASSERT_EQ(0, ret); 956 957 EXPECT_EQ(parent, syscall(__NR_getppid)); 958 EXPECT_EQ(-1, read(0, NULL, 0)); 959 EXPECT_EQ(E2BIG, errno); 960 } 961 962 /* Make sure an errno of zero is correctly handled by the arch code. */ 963 TEST(ERRNO_zero) 964 { 965 ERRNO_FILTER(zero, 0); 966 long ret; 967 pid_t parent = getppid(); 968 969 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 970 ASSERT_EQ(0, ret); 971 972 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero); 973 ASSERT_EQ(0, ret); 974 975 EXPECT_EQ(parent, syscall(__NR_getppid)); 976 /* "errno" of 0 is ok. */ 977 EXPECT_EQ(0, read(0, NULL, 0)); 978 } 979 980 /* 981 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller. 982 * This tests that the errno value gets capped correctly, fixed by 983 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO"). 984 */ 985 TEST(ERRNO_capped) 986 { 987 ERRNO_FILTER(capped, 4096); 988 long ret; 989 pid_t parent = getppid(); 990 991 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 992 ASSERT_EQ(0, ret); 993 994 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped); 995 ASSERT_EQ(0, ret); 996 997 EXPECT_EQ(parent, syscall(__NR_getppid)); 998 EXPECT_EQ(-1, read(0, NULL, 0)); 999 EXPECT_EQ(4095, errno); 1000 } 1001 1002 /* 1003 * Filters are processed in reverse order: last applied is executed first. 1004 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the 1005 * SECCOMP_RET_DATA mask results will follow the most recently applied 1006 * matching filter return (and not the lowest or highest value). 1007 */ 1008 TEST(ERRNO_order) 1009 { 1010 ERRNO_FILTER(first, 11); 1011 ERRNO_FILTER(second, 13); 1012 ERRNO_FILTER(third, 12); 1013 long ret; 1014 pid_t parent = getppid(); 1015 1016 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1017 ASSERT_EQ(0, ret); 1018 1019 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first); 1020 ASSERT_EQ(0, ret); 1021 1022 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second); 1023 ASSERT_EQ(0, ret); 1024 1025 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third); 1026 ASSERT_EQ(0, ret); 1027 1028 EXPECT_EQ(parent, syscall(__NR_getppid)); 1029 EXPECT_EQ(-1, read(0, NULL, 0)); 1030 EXPECT_EQ(12, errno); 1031 } 1032 1033 FIXTURE(TRAP) { 1034 struct sock_fprog prog; 1035 }; 1036 1037 FIXTURE_SETUP(TRAP) 1038 { 1039 struct sock_filter filter[] = { 1040 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1041 offsetof(struct seccomp_data, nr)), 1042 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 1043 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 1044 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1045 }; 1046 1047 memset(&self->prog, 0, sizeof(self->prog)); 1048 self->prog.filter = malloc(sizeof(filter)); 1049 ASSERT_NE(NULL, self->prog.filter); 1050 memcpy(self->prog.filter, filter, sizeof(filter)); 1051 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1052 } 1053 1054 FIXTURE_TEARDOWN(TRAP) 1055 { 1056 if (self->prog.filter) 1057 free(self->prog.filter); 1058 } 1059 1060 TEST_F_SIGNAL(TRAP, dfl, SIGSYS) 1061 { 1062 long ret; 1063 1064 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1065 ASSERT_EQ(0, ret); 1066 1067 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1068 ASSERT_EQ(0, ret); 1069 syscall(__NR_getpid); 1070 } 1071 1072 /* Ensure that SIGSYS overrides SIG_IGN */ 1073 TEST_F_SIGNAL(TRAP, ign, SIGSYS) 1074 { 1075 long ret; 1076 1077 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1078 ASSERT_EQ(0, ret); 1079 1080 signal(SIGSYS, SIG_IGN); 1081 1082 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1083 ASSERT_EQ(0, ret); 1084 syscall(__NR_getpid); 1085 } 1086 1087 static siginfo_t TRAP_info; 1088 static volatile int TRAP_nr; 1089 static void TRAP_action(int nr, siginfo_t *info, void *void_context) 1090 { 1091 memcpy(&TRAP_info, info, sizeof(TRAP_info)); 1092 TRAP_nr = nr; 1093 } 1094 1095 TEST_F(TRAP, handler) 1096 { 1097 int ret, test; 1098 struct sigaction act; 1099 sigset_t mask; 1100 1101 memset(&act, 0, sizeof(act)); 1102 sigemptyset(&mask); 1103 sigaddset(&mask, SIGSYS); 1104 1105 act.sa_sigaction = &TRAP_action; 1106 act.sa_flags = SA_SIGINFO; 1107 ret = sigaction(SIGSYS, &act, NULL); 1108 ASSERT_EQ(0, ret) { 1109 TH_LOG("sigaction failed"); 1110 } 1111 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); 1112 ASSERT_EQ(0, ret) { 1113 TH_LOG("sigprocmask failed"); 1114 } 1115 1116 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1117 ASSERT_EQ(0, ret); 1118 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1119 ASSERT_EQ(0, ret); 1120 TRAP_nr = 0; 1121 memset(&TRAP_info, 0, sizeof(TRAP_info)); 1122 /* Expect the registers to be rolled back. (nr = error) may vary 1123 * based on arch. */ 1124 ret = syscall(__NR_getpid); 1125 /* Silence gcc warning about volatile. */ 1126 test = TRAP_nr; 1127 EXPECT_EQ(SIGSYS, test); 1128 struct local_sigsys { 1129 void *_call_addr; /* calling user insn */ 1130 int _syscall; /* triggering system call number */ 1131 unsigned int _arch; /* AUDIT_ARCH_* of syscall */ 1132 } *sigsys = (struct local_sigsys *) 1133 #ifdef si_syscall 1134 &(TRAP_info.si_call_addr); 1135 #else 1136 &TRAP_info.si_pid; 1137 #endif 1138 EXPECT_EQ(__NR_getpid, sigsys->_syscall); 1139 /* Make sure arch is non-zero. */ 1140 EXPECT_NE(0, sigsys->_arch); 1141 EXPECT_NE(0, (unsigned long)sigsys->_call_addr); 1142 } 1143 1144 FIXTURE(precedence) { 1145 struct sock_fprog allow; 1146 struct sock_fprog log; 1147 struct sock_fprog trace; 1148 struct sock_fprog error; 1149 struct sock_fprog trap; 1150 struct sock_fprog kill; 1151 }; 1152 1153 FIXTURE_SETUP(precedence) 1154 { 1155 struct sock_filter allow_insns[] = { 1156 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1157 }; 1158 struct sock_filter log_insns[] = { 1159 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1160 offsetof(struct seccomp_data, nr)), 1161 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1162 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1163 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 1164 }; 1165 struct sock_filter trace_insns[] = { 1166 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1167 offsetof(struct seccomp_data, nr)), 1168 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1169 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1170 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), 1171 }; 1172 struct sock_filter error_insns[] = { 1173 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1174 offsetof(struct seccomp_data, nr)), 1175 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1176 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1177 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), 1178 }; 1179 struct sock_filter trap_insns[] = { 1180 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1181 offsetof(struct seccomp_data, nr)), 1182 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1183 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1184 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 1185 }; 1186 struct sock_filter kill_insns[] = { 1187 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1188 offsetof(struct seccomp_data, nr)), 1189 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1190 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1191 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1192 }; 1193 1194 memset(self, 0, sizeof(*self)); 1195 #define FILTER_ALLOC(_x) \ 1196 self->_x.filter = malloc(sizeof(_x##_insns)); \ 1197 ASSERT_NE(NULL, self->_x.filter); \ 1198 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ 1199 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) 1200 FILTER_ALLOC(allow); 1201 FILTER_ALLOC(log); 1202 FILTER_ALLOC(trace); 1203 FILTER_ALLOC(error); 1204 FILTER_ALLOC(trap); 1205 FILTER_ALLOC(kill); 1206 } 1207 1208 FIXTURE_TEARDOWN(precedence) 1209 { 1210 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) 1211 FILTER_FREE(allow); 1212 FILTER_FREE(log); 1213 FILTER_FREE(trace); 1214 FILTER_FREE(error); 1215 FILTER_FREE(trap); 1216 FILTER_FREE(kill); 1217 } 1218 1219 TEST_F(precedence, allow_ok) 1220 { 1221 pid_t parent, res = 0; 1222 long ret; 1223 1224 parent = getppid(); 1225 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1226 ASSERT_EQ(0, ret); 1227 1228 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1229 ASSERT_EQ(0, ret); 1230 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1231 ASSERT_EQ(0, ret); 1232 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1233 ASSERT_EQ(0, ret); 1234 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1235 ASSERT_EQ(0, ret); 1236 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1237 ASSERT_EQ(0, ret); 1238 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1239 ASSERT_EQ(0, ret); 1240 /* Should work just fine. */ 1241 res = syscall(__NR_getppid); 1242 EXPECT_EQ(parent, res); 1243 } 1244 1245 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) 1246 { 1247 pid_t parent, res = 0; 1248 long ret; 1249 1250 parent = getppid(); 1251 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1252 ASSERT_EQ(0, ret); 1253 1254 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1255 ASSERT_EQ(0, ret); 1256 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1257 ASSERT_EQ(0, ret); 1258 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1259 ASSERT_EQ(0, ret); 1260 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1261 ASSERT_EQ(0, ret); 1262 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1263 ASSERT_EQ(0, ret); 1264 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1265 ASSERT_EQ(0, ret); 1266 /* Should work just fine. */ 1267 res = syscall(__NR_getppid); 1268 EXPECT_EQ(parent, res); 1269 /* getpid() should never return. */ 1270 res = syscall(__NR_getpid); 1271 EXPECT_EQ(0, res); 1272 } 1273 1274 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) 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->kill); 1286 ASSERT_EQ(0, ret); 1287 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1288 ASSERT_EQ(0, ret); 1289 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1290 ASSERT_EQ(0, ret); 1291 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1292 ASSERT_EQ(0, ret); 1293 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1294 ASSERT_EQ(0, ret); 1295 /* Should work just fine. */ 1296 EXPECT_EQ(parent, syscall(__NR_getppid)); 1297 /* getpid() should never return. */ 1298 EXPECT_EQ(0, syscall(__NR_getpid)); 1299 } 1300 1301 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) 1302 { 1303 pid_t parent; 1304 long ret; 1305 1306 parent = getppid(); 1307 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1308 ASSERT_EQ(0, ret); 1309 1310 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1311 ASSERT_EQ(0, ret); 1312 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1313 ASSERT_EQ(0, ret); 1314 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1315 ASSERT_EQ(0, ret); 1316 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1317 ASSERT_EQ(0, ret); 1318 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1319 ASSERT_EQ(0, ret); 1320 /* Should work just fine. */ 1321 EXPECT_EQ(parent, syscall(__NR_getppid)); 1322 /* getpid() should never return. */ 1323 EXPECT_EQ(0, syscall(__NR_getpid)); 1324 } 1325 1326 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) 1327 { 1328 pid_t parent; 1329 long ret; 1330 1331 parent = getppid(); 1332 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1333 ASSERT_EQ(0, ret); 1334 1335 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1336 ASSERT_EQ(0, ret); 1337 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1338 ASSERT_EQ(0, ret); 1339 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1340 ASSERT_EQ(0, ret); 1341 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1342 ASSERT_EQ(0, ret); 1343 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1344 ASSERT_EQ(0, ret); 1345 /* Should work just fine. */ 1346 EXPECT_EQ(parent, syscall(__NR_getppid)); 1347 /* getpid() should never return. */ 1348 EXPECT_EQ(0, syscall(__NR_getpid)); 1349 } 1350 1351 TEST_F(precedence, errno_is_third) 1352 { 1353 pid_t parent; 1354 long ret; 1355 1356 parent = getppid(); 1357 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1358 ASSERT_EQ(0, ret); 1359 1360 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1361 ASSERT_EQ(0, ret); 1362 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1363 ASSERT_EQ(0, ret); 1364 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1365 ASSERT_EQ(0, ret); 1366 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1367 ASSERT_EQ(0, ret); 1368 /* Should work just fine. */ 1369 EXPECT_EQ(parent, syscall(__NR_getppid)); 1370 EXPECT_EQ(0, syscall(__NR_getpid)); 1371 } 1372 1373 TEST_F(precedence, errno_is_third_in_any_order) 1374 { 1375 pid_t parent; 1376 long ret; 1377 1378 parent = getppid(); 1379 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1380 ASSERT_EQ(0, ret); 1381 1382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1383 ASSERT_EQ(0, ret); 1384 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1385 ASSERT_EQ(0, ret); 1386 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1387 ASSERT_EQ(0, ret); 1388 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1389 ASSERT_EQ(0, ret); 1390 /* Should work just fine. */ 1391 EXPECT_EQ(parent, syscall(__NR_getppid)); 1392 EXPECT_EQ(0, syscall(__NR_getpid)); 1393 } 1394 1395 TEST_F(precedence, trace_is_fourth) 1396 { 1397 pid_t parent; 1398 long ret; 1399 1400 parent = getppid(); 1401 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1402 ASSERT_EQ(0, ret); 1403 1404 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1405 ASSERT_EQ(0, ret); 1406 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1407 ASSERT_EQ(0, ret); 1408 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1409 ASSERT_EQ(0, ret); 1410 /* Should work just fine. */ 1411 EXPECT_EQ(parent, syscall(__NR_getppid)); 1412 /* No ptracer */ 1413 EXPECT_EQ(-1, syscall(__NR_getpid)); 1414 } 1415 1416 TEST_F(precedence, trace_is_fourth_in_any_order) 1417 { 1418 pid_t parent; 1419 long ret; 1420 1421 parent = getppid(); 1422 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1423 ASSERT_EQ(0, ret); 1424 1425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1426 ASSERT_EQ(0, ret); 1427 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1428 ASSERT_EQ(0, ret); 1429 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1430 ASSERT_EQ(0, ret); 1431 /* Should work just fine. */ 1432 EXPECT_EQ(parent, syscall(__NR_getppid)); 1433 /* No ptracer */ 1434 EXPECT_EQ(-1, syscall(__NR_getpid)); 1435 } 1436 1437 TEST_F(precedence, log_is_fifth) 1438 { 1439 pid_t mypid, parent; 1440 long ret; 1441 1442 mypid = getpid(); 1443 parent = getppid(); 1444 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1445 ASSERT_EQ(0, ret); 1446 1447 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1448 ASSERT_EQ(0, ret); 1449 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1450 ASSERT_EQ(0, ret); 1451 /* Should work just fine. */ 1452 EXPECT_EQ(parent, syscall(__NR_getppid)); 1453 /* Should also work just fine */ 1454 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1455 } 1456 1457 TEST_F(precedence, log_is_fifth_in_any_order) 1458 { 1459 pid_t mypid, parent; 1460 long ret; 1461 1462 mypid = getpid(); 1463 parent = getppid(); 1464 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1465 ASSERT_EQ(0, ret); 1466 1467 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1468 ASSERT_EQ(0, ret); 1469 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1470 ASSERT_EQ(0, ret); 1471 /* Should work just fine. */ 1472 EXPECT_EQ(parent, syscall(__NR_getppid)); 1473 /* Should also work just fine */ 1474 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1475 } 1476 1477 #ifndef PTRACE_O_TRACESECCOMP 1478 #define PTRACE_O_TRACESECCOMP 0x00000080 1479 #endif 1480 1481 /* Catch the Ubuntu 12.04 value error. */ 1482 #if PTRACE_EVENT_SECCOMP != 7 1483 #undef PTRACE_EVENT_SECCOMP 1484 #endif 1485 1486 #ifndef PTRACE_EVENT_SECCOMP 1487 #define PTRACE_EVENT_SECCOMP 7 1488 #endif 1489 1490 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP) 1491 bool tracer_running; 1492 void tracer_stop(int sig) 1493 { 1494 tracer_running = false; 1495 } 1496 1497 typedef void tracer_func_t(struct __test_metadata *_metadata, 1498 pid_t tracee, int status, void *args); 1499 1500 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, 1501 tracer_func_t tracer_func, void *args, bool ptrace_syscall) 1502 { 1503 int ret = -1; 1504 struct sigaction action = { 1505 .sa_handler = tracer_stop, 1506 }; 1507 1508 /* Allow external shutdown. */ 1509 tracer_running = true; 1510 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); 1511 1512 errno = 0; 1513 while (ret == -1 && errno != EINVAL) 1514 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); 1515 ASSERT_EQ(0, ret) { 1516 kill(tracee, SIGKILL); 1517 } 1518 /* Wait for attach stop */ 1519 wait(NULL); 1520 1521 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ? 1522 PTRACE_O_TRACESYSGOOD : 1523 PTRACE_O_TRACESECCOMP); 1524 ASSERT_EQ(0, ret) { 1525 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); 1526 kill(tracee, SIGKILL); 1527 } 1528 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1529 tracee, NULL, 0); 1530 ASSERT_EQ(0, ret); 1531 1532 /* Unblock the tracee */ 1533 ASSERT_EQ(1, write(fd, "A", 1)); 1534 ASSERT_EQ(0, close(fd)); 1535 1536 /* Run until we're shut down. Must assert to stop execution. */ 1537 while (tracer_running) { 1538 int status; 1539 1540 if (wait(&status) != tracee) 1541 continue; 1542 if (WIFSIGNALED(status) || WIFEXITED(status)) 1543 /* Child is dead. Time to go. */ 1544 return; 1545 1546 /* Check if this is a seccomp event. */ 1547 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status)); 1548 1549 tracer_func(_metadata, tracee, status, args); 1550 1551 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1552 tracee, NULL, 0); 1553 ASSERT_EQ(0, ret); 1554 } 1555 /* Directly report the status of our test harness results. */ 1556 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 1557 } 1558 1559 /* Common tracer setup/teardown functions. */ 1560 void cont_handler(int num) 1561 { } 1562 pid_t setup_trace_fixture(struct __test_metadata *_metadata, 1563 tracer_func_t func, void *args, bool ptrace_syscall) 1564 { 1565 char sync; 1566 int pipefd[2]; 1567 pid_t tracer_pid; 1568 pid_t tracee = getpid(); 1569 1570 /* Setup a pipe for clean synchronization. */ 1571 ASSERT_EQ(0, pipe(pipefd)); 1572 1573 /* Fork a child which we'll promote to tracer */ 1574 tracer_pid = fork(); 1575 ASSERT_LE(0, tracer_pid); 1576 signal(SIGALRM, cont_handler); 1577 if (tracer_pid == 0) { 1578 close(pipefd[0]); 1579 start_tracer(_metadata, pipefd[1], tracee, func, args, 1580 ptrace_syscall); 1581 syscall(__NR_exit, 0); 1582 } 1583 close(pipefd[1]); 1584 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); 1585 read(pipefd[0], &sync, 1); 1586 close(pipefd[0]); 1587 1588 return tracer_pid; 1589 } 1590 1591 void teardown_trace_fixture(struct __test_metadata *_metadata, 1592 pid_t tracer) 1593 { 1594 if (tracer) { 1595 int status; 1596 /* 1597 * Extract the exit code from the other process and 1598 * adopt it for ourselves in case its asserts failed. 1599 */ 1600 ASSERT_EQ(0, kill(tracer, SIGUSR1)); 1601 ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); 1602 if (WEXITSTATUS(status)) 1603 _metadata->passed = 0; 1604 } 1605 } 1606 1607 /* "poke" tracer arguments and function. */ 1608 struct tracer_args_poke_t { 1609 unsigned long poke_addr; 1610 }; 1611 1612 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, 1613 void *args) 1614 { 1615 int ret; 1616 unsigned long msg; 1617 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; 1618 1619 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1620 EXPECT_EQ(0, ret); 1621 /* If this fails, don't try to recover. */ 1622 ASSERT_EQ(0x1001, msg) { 1623 kill(tracee, SIGKILL); 1624 } 1625 /* 1626 * Poke in the message. 1627 * Registers are not touched to try to keep this relatively arch 1628 * agnostic. 1629 */ 1630 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); 1631 EXPECT_EQ(0, ret); 1632 } 1633 1634 FIXTURE(TRACE_poke) { 1635 struct sock_fprog prog; 1636 pid_t tracer; 1637 long poked; 1638 struct tracer_args_poke_t tracer_args; 1639 }; 1640 1641 FIXTURE_SETUP(TRACE_poke) 1642 { 1643 struct sock_filter filter[] = { 1644 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1645 offsetof(struct seccomp_data, nr)), 1646 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 1647 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), 1648 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1649 }; 1650 1651 self->poked = 0; 1652 memset(&self->prog, 0, sizeof(self->prog)); 1653 self->prog.filter = malloc(sizeof(filter)); 1654 ASSERT_NE(NULL, self->prog.filter); 1655 memcpy(self->prog.filter, filter, sizeof(filter)); 1656 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1657 1658 /* Set up tracer args. */ 1659 self->tracer_args.poke_addr = (unsigned long)&self->poked; 1660 1661 /* Launch tracer. */ 1662 self->tracer = setup_trace_fixture(_metadata, tracer_poke, 1663 &self->tracer_args, false); 1664 } 1665 1666 FIXTURE_TEARDOWN(TRACE_poke) 1667 { 1668 teardown_trace_fixture(_metadata, self->tracer); 1669 if (self->prog.filter) 1670 free(self->prog.filter); 1671 } 1672 1673 TEST_F(TRACE_poke, read_has_side_effects) 1674 { 1675 ssize_t ret; 1676 1677 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1678 ASSERT_EQ(0, ret); 1679 1680 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1681 ASSERT_EQ(0, ret); 1682 1683 EXPECT_EQ(0, self->poked); 1684 ret = read(-1, NULL, 0); 1685 EXPECT_EQ(-1, ret); 1686 EXPECT_EQ(0x1001, self->poked); 1687 } 1688 1689 TEST_F(TRACE_poke, getpid_runs_normally) 1690 { 1691 long ret; 1692 1693 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1694 ASSERT_EQ(0, ret); 1695 1696 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1697 ASSERT_EQ(0, ret); 1698 1699 EXPECT_EQ(0, self->poked); 1700 EXPECT_NE(0, syscall(__NR_getpid)); 1701 EXPECT_EQ(0, self->poked); 1702 } 1703 1704 #if defined(__x86_64__) 1705 # define ARCH_REGS struct user_regs_struct 1706 # define SYSCALL_NUM(_regs) (_regs).orig_rax 1707 # define SYSCALL_RET(_regs) (_regs).rax 1708 #elif defined(__i386__) 1709 # define ARCH_REGS struct user_regs_struct 1710 # define SYSCALL_NUM(_regs) (_regs).orig_eax 1711 # define SYSCALL_RET(_regs) (_regs).eax 1712 #elif defined(__arm__) 1713 # define ARCH_REGS struct pt_regs 1714 # define SYSCALL_NUM(_regs) (_regs).ARM_r7 1715 # ifndef PTRACE_SET_SYSCALL 1716 # define PTRACE_SET_SYSCALL 23 1717 # endif 1718 # define SYSCALL_NUM_SET(_regs, _nr) \ 1719 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr)) 1720 # define SYSCALL_RET(_regs) (_regs).ARM_r0 1721 #elif defined(__aarch64__) 1722 # define ARCH_REGS struct user_pt_regs 1723 # define SYSCALL_NUM(_regs) (_regs).regs[8] 1724 # ifndef NT_ARM_SYSTEM_CALL 1725 # define NT_ARM_SYSTEM_CALL 0x404 1726 # endif 1727 # define SYSCALL_NUM_SET(_regs, _nr) \ 1728 do { \ 1729 struct iovec __v; \ 1730 typeof(_nr) __nr = (_nr); \ 1731 __v.iov_base = &__nr; \ 1732 __v.iov_len = sizeof(__nr); \ 1733 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \ 1734 NT_ARM_SYSTEM_CALL, &__v)); \ 1735 } while (0) 1736 # define SYSCALL_RET(_regs) (_regs).regs[0] 1737 #elif defined(__riscv) && __riscv_xlen == 64 1738 # define ARCH_REGS struct user_regs_struct 1739 # define SYSCALL_NUM(_regs) (_regs).a7 1740 # define SYSCALL_RET(_regs) (_regs).a0 1741 #elif defined(__csky__) 1742 # define ARCH_REGS struct pt_regs 1743 # if defined(__CSKYABIV2__) 1744 # define SYSCALL_NUM(_regs) (_regs).regs[3] 1745 # else 1746 # define SYSCALL_NUM(_regs) (_regs).regs[9] 1747 # endif 1748 # define SYSCALL_RET(_regs) (_regs).a0 1749 #elif defined(__hppa__) 1750 # define ARCH_REGS struct user_regs_struct 1751 # define SYSCALL_NUM(_regs) (_regs).gr[20] 1752 # define SYSCALL_RET(_regs) (_regs).gr[28] 1753 #elif defined(__powerpc__) 1754 # define ARCH_REGS struct pt_regs 1755 # define SYSCALL_NUM(_regs) (_regs).gpr[0] 1756 # define SYSCALL_RET(_regs) (_regs).gpr[3] 1757 # define SYSCALL_RET_SET(_regs, _val) \ 1758 do { \ 1759 typeof(_val) _result = (_val); \ 1760 if ((_regs.trap & 0xfff0) == 0x3000) { \ 1761 /* \ 1762 * scv 0 system call uses -ve result \ 1763 * for error, so no need to adjust. \ 1764 */ \ 1765 SYSCALL_RET(_regs) = _result; \ 1766 } else { \ 1767 /* \ 1768 * A syscall error is signaled by the \ 1769 * CR0 SO bit and the code is stored as \ 1770 * a positive value. \ 1771 */ \ 1772 if (_result < 0) { \ 1773 SYSCALL_RET(_regs) = -_result; \ 1774 (_regs).ccr |= 0x10000000; \ 1775 } else { \ 1776 SYSCALL_RET(_regs) = _result; \ 1777 (_regs).ccr &= ~0x10000000; \ 1778 } \ 1779 } \ 1780 } while (0) 1781 # define SYSCALL_RET_SET_ON_PTRACE_EXIT 1782 #elif defined(__s390__) 1783 # define ARCH_REGS s390_regs 1784 # define SYSCALL_NUM(_regs) (_regs).gprs[2] 1785 # define SYSCALL_RET_SET(_regs, _val) \ 1786 TH_LOG("Can't modify syscall return on this architecture") 1787 #elif defined(__mips__) 1788 # include <asm/unistd_nr_n32.h> 1789 # include <asm/unistd_nr_n64.h> 1790 # include <asm/unistd_nr_o32.h> 1791 # define ARCH_REGS struct pt_regs 1792 # define SYSCALL_NUM(_regs) \ 1793 ({ \ 1794 typeof((_regs).regs[2]) _nr; \ 1795 if ((_regs).regs[2] == __NR_O32_Linux) \ 1796 _nr = (_regs).regs[4]; \ 1797 else \ 1798 _nr = (_regs).regs[2]; \ 1799 _nr; \ 1800 }) 1801 # define SYSCALL_NUM_SET(_regs, _nr) \ 1802 do { \ 1803 if ((_regs).regs[2] == __NR_O32_Linux) \ 1804 (_regs).regs[4] = _nr; \ 1805 else \ 1806 (_regs).regs[2] = _nr; \ 1807 } while (0) 1808 # define SYSCALL_RET_SET(_regs, _val) \ 1809 TH_LOG("Can't modify syscall return on this architecture") 1810 #elif defined(__xtensa__) 1811 # define ARCH_REGS struct user_pt_regs 1812 # define SYSCALL_NUM(_regs) (_regs).syscall 1813 /* 1814 * On xtensa syscall return value is in the register 1815 * a2 of the current window which is not fixed. 1816 */ 1817 #define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2] 1818 #elif defined(__sh__) 1819 # define ARCH_REGS struct pt_regs 1820 # define SYSCALL_NUM(_regs) (_regs).regs[3] 1821 # define SYSCALL_RET(_regs) (_regs).regs[0] 1822 #else 1823 # error "Do not know how to find your architecture's registers and syscalls" 1824 #endif 1825 1826 /* 1827 * Most architectures can change the syscall by just updating the 1828 * associated register. This is the default if not defined above. 1829 */ 1830 #ifndef SYSCALL_NUM_SET 1831 # define SYSCALL_NUM_SET(_regs, _nr) \ 1832 do { \ 1833 SYSCALL_NUM(_regs) = (_nr); \ 1834 } while (0) 1835 #endif 1836 /* 1837 * Most architectures can change the syscall return value by just 1838 * writing to the SYSCALL_RET register. This is the default if not 1839 * defined above. If an architecture cannot set the return value 1840 * (for example when the syscall and return value register is 1841 * shared), report it with TH_LOG() in an arch-specific definition 1842 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined. 1843 */ 1844 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET) 1845 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch" 1846 #endif 1847 #ifndef SYSCALL_RET_SET 1848 # define SYSCALL_RET_SET(_regs, _val) \ 1849 do { \ 1850 SYSCALL_RET(_regs) = (_val); \ 1851 } while (0) 1852 #endif 1853 1854 /* When the syscall return can't be changed, stub out the tests for it. */ 1855 #ifndef SYSCALL_RET 1856 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action) 1857 #else 1858 # define EXPECT_SYSCALL_RETURN(val, action) \ 1859 do { \ 1860 errno = 0; \ 1861 if (val < 0) { \ 1862 EXPECT_EQ(-1, action); \ 1863 EXPECT_EQ(-(val), errno); \ 1864 } else { \ 1865 EXPECT_EQ(val, action); \ 1866 } \ 1867 } while (0) 1868 #endif 1869 1870 /* 1871 * Some architectures (e.g. powerpc) can only set syscall 1872 * return values on syscall exit during ptrace. 1873 */ 1874 const bool ptrace_entry_set_syscall_nr = true; 1875 const bool ptrace_entry_set_syscall_ret = 1876 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT 1877 true; 1878 #else 1879 false; 1880 #endif 1881 1882 /* 1883 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for 1884 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). 1885 */ 1886 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__) 1887 # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs)) 1888 # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs)) 1889 #else 1890 # define ARCH_GETREGS(_regs) ({ \ 1891 struct iovec __v; \ 1892 __v.iov_base = &(_regs); \ 1893 __v.iov_len = sizeof(_regs); \ 1894 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \ 1895 }) 1896 # define ARCH_SETREGS(_regs) ({ \ 1897 struct iovec __v; \ 1898 __v.iov_base = &(_regs); \ 1899 __v.iov_len = sizeof(_regs); \ 1900 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \ 1901 }) 1902 #endif 1903 1904 /* Architecture-specific syscall fetching routine. */ 1905 int get_syscall(struct __test_metadata *_metadata, pid_t tracee) 1906 { 1907 ARCH_REGS regs; 1908 1909 EXPECT_EQ(0, ARCH_GETREGS(regs)) { 1910 return -1; 1911 } 1912 1913 return SYSCALL_NUM(regs); 1914 } 1915 1916 /* Architecture-specific syscall changing routine. */ 1917 void __change_syscall(struct __test_metadata *_metadata, 1918 pid_t tracee, long *syscall, long *ret) 1919 { 1920 ARCH_REGS orig, regs; 1921 1922 /* Do not get/set registers if we have nothing to do. */ 1923 if (!syscall && !ret) 1924 return; 1925 1926 EXPECT_EQ(0, ARCH_GETREGS(regs)) { 1927 return; 1928 } 1929 orig = regs; 1930 1931 if (syscall) 1932 SYSCALL_NUM_SET(regs, *syscall); 1933 1934 if (ret) 1935 SYSCALL_RET_SET(regs, *ret); 1936 1937 /* Flush any register changes made. */ 1938 if (memcmp(&orig, ®s, sizeof(orig)) != 0) 1939 EXPECT_EQ(0, ARCH_SETREGS(regs)); 1940 } 1941 1942 /* Change only syscall number. */ 1943 void change_syscall_nr(struct __test_metadata *_metadata, 1944 pid_t tracee, long syscall) 1945 { 1946 __change_syscall(_metadata, tracee, &syscall, NULL); 1947 } 1948 1949 /* Change syscall return value (and set syscall number to -1). */ 1950 void change_syscall_ret(struct __test_metadata *_metadata, 1951 pid_t tracee, long ret) 1952 { 1953 long syscall = -1; 1954 1955 __change_syscall(_metadata, tracee, &syscall, &ret); 1956 } 1957 1958 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee, 1959 int status, void *args) 1960 { 1961 int ret; 1962 unsigned long msg; 1963 1964 /* Make sure we got the right message. */ 1965 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1966 EXPECT_EQ(0, ret); 1967 1968 /* Validate and take action on expected syscalls. */ 1969 switch (msg) { 1970 case 0x1002: 1971 /* change getpid to getppid. */ 1972 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee)); 1973 change_syscall_nr(_metadata, tracee, __NR_getppid); 1974 break; 1975 case 0x1003: 1976 /* skip gettid with valid return code. */ 1977 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee)); 1978 change_syscall_ret(_metadata, tracee, 45000); 1979 break; 1980 case 0x1004: 1981 /* skip openat with error. */ 1982 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee)); 1983 change_syscall_ret(_metadata, tracee, -ESRCH); 1984 break; 1985 case 0x1005: 1986 /* do nothing (allow getppid) */ 1987 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee)); 1988 break; 1989 default: 1990 EXPECT_EQ(0, msg) { 1991 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); 1992 kill(tracee, SIGKILL); 1993 } 1994 } 1995 1996 } 1997 1998 FIXTURE(TRACE_syscall) { 1999 struct sock_fprog prog; 2000 pid_t tracer, mytid, mypid, parent; 2001 long syscall_nr; 2002 }; 2003 2004 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee, 2005 int status, void *args) 2006 { 2007 int ret; 2008 unsigned long msg; 2009 static bool entry; 2010 long syscall_nr_val, syscall_ret_val; 2011 long *syscall_nr = NULL, *syscall_ret = NULL; 2012 FIXTURE_DATA(TRACE_syscall) *self = args; 2013 2014 /* 2015 * The traditional way to tell PTRACE_SYSCALL entry/exit 2016 * is by counting. 2017 */ 2018 entry = !entry; 2019 2020 /* Make sure we got an appropriate message. */ 2021 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 2022 EXPECT_EQ(0, ret); 2023 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY 2024 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg); 2025 2026 /* 2027 * Some architectures only support setting return values during 2028 * syscall exit under ptrace, and on exit the syscall number may 2029 * no longer be available. Therefore, save the initial sycall 2030 * number here, so it can be examined during both entry and exit 2031 * phases. 2032 */ 2033 if (entry) 2034 self->syscall_nr = get_syscall(_metadata, tracee); 2035 2036 /* 2037 * Depending on the architecture's syscall setting abilities, we 2038 * pick which things to set during this phase (entry or exit). 2039 */ 2040 if (entry == ptrace_entry_set_syscall_nr) 2041 syscall_nr = &syscall_nr_val; 2042 if (entry == ptrace_entry_set_syscall_ret) 2043 syscall_ret = &syscall_ret_val; 2044 2045 /* Now handle the actual rewriting cases. */ 2046 switch (self->syscall_nr) { 2047 case __NR_getpid: 2048 syscall_nr_val = __NR_getppid; 2049 /* Never change syscall return for this case. */ 2050 syscall_ret = NULL; 2051 break; 2052 case __NR_gettid: 2053 syscall_nr_val = -1; 2054 syscall_ret_val = 45000; 2055 break; 2056 case __NR_openat: 2057 syscall_nr_val = -1; 2058 syscall_ret_val = -ESRCH; 2059 break; 2060 default: 2061 /* Unhandled, do nothing. */ 2062 return; 2063 } 2064 2065 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret); 2066 } 2067 2068 FIXTURE_VARIANT(TRACE_syscall) { 2069 /* 2070 * All of the SECCOMP_RET_TRACE behaviors can be tested with either 2071 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL. 2072 * This indicates if we should use SECCOMP_RET_TRACE (false), or 2073 * ptrace (true). 2074 */ 2075 bool use_ptrace; 2076 }; 2077 2078 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) { 2079 .use_ptrace = true, 2080 }; 2081 2082 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) { 2083 .use_ptrace = false, 2084 }; 2085 2086 FIXTURE_SETUP(TRACE_syscall) 2087 { 2088 struct sock_filter filter[] = { 2089 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2090 offsetof(struct seccomp_data, nr)), 2091 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 2092 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), 2093 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), 2094 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), 2095 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1), 2096 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), 2097 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2098 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005), 2099 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2100 }; 2101 struct sock_fprog prog = { 2102 .len = (unsigned short)ARRAY_SIZE(filter), 2103 .filter = filter, 2104 }; 2105 long ret; 2106 2107 /* Prepare some testable syscall results. */ 2108 self->mytid = syscall(__NR_gettid); 2109 ASSERT_GT(self->mytid, 0); 2110 ASSERT_NE(self->mytid, 1) { 2111 TH_LOG("Running this test as init is not supported. :)"); 2112 } 2113 2114 self->mypid = getpid(); 2115 ASSERT_GT(self->mypid, 0); 2116 ASSERT_EQ(self->mytid, self->mypid); 2117 2118 self->parent = getppid(); 2119 ASSERT_GT(self->parent, 0); 2120 ASSERT_NE(self->parent, self->mypid); 2121 2122 /* Launch tracer. */ 2123 self->tracer = setup_trace_fixture(_metadata, 2124 variant->use_ptrace ? tracer_ptrace 2125 : tracer_seccomp, 2126 self, variant->use_ptrace); 2127 2128 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2129 ASSERT_EQ(0, ret); 2130 2131 if (variant->use_ptrace) 2132 return; 2133 2134 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2135 ASSERT_EQ(0, ret); 2136 } 2137 2138 FIXTURE_TEARDOWN(TRACE_syscall) 2139 { 2140 teardown_trace_fixture(_metadata, self->tracer); 2141 } 2142 2143 TEST(negative_ENOSYS) 2144 { 2145 /* 2146 * There should be no difference between an "internal" skip 2147 * and userspace asking for syscall "-1". 2148 */ 2149 errno = 0; 2150 EXPECT_EQ(-1, syscall(-1)); 2151 EXPECT_EQ(errno, ENOSYS); 2152 /* And no difference for "still not valid but not -1". */ 2153 errno = 0; 2154 EXPECT_EQ(-1, syscall(-101)); 2155 EXPECT_EQ(errno, ENOSYS); 2156 } 2157 2158 TEST_F(TRACE_syscall, negative_ENOSYS) 2159 { 2160 negative_ENOSYS(_metadata); 2161 } 2162 2163 TEST_F(TRACE_syscall, syscall_allowed) 2164 { 2165 /* getppid works as expected (no changes). */ 2166 EXPECT_EQ(self->parent, syscall(__NR_getppid)); 2167 EXPECT_NE(self->mypid, syscall(__NR_getppid)); 2168 } 2169 2170 TEST_F(TRACE_syscall, syscall_redirected) 2171 { 2172 /* getpid has been redirected to getppid as expected. */ 2173 EXPECT_EQ(self->parent, syscall(__NR_getpid)); 2174 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 2175 } 2176 2177 TEST_F(TRACE_syscall, syscall_errno) 2178 { 2179 /* Tracer should skip the open syscall, resulting in ESRCH. */ 2180 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat)); 2181 } 2182 2183 TEST_F(TRACE_syscall, syscall_faked) 2184 { 2185 /* Tracer skips the gettid syscall and store altered return value. */ 2186 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid)); 2187 } 2188 2189 TEST_F(TRACE_syscall, skip_after) 2190 { 2191 struct sock_filter filter[] = { 2192 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2193 offsetof(struct seccomp_data, nr)), 2194 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2195 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 2196 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2197 }; 2198 struct sock_fprog prog = { 2199 .len = (unsigned short)ARRAY_SIZE(filter), 2200 .filter = filter, 2201 }; 2202 long ret; 2203 2204 /* Install additional "errno on getppid" filter. */ 2205 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2206 ASSERT_EQ(0, ret); 2207 2208 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 2209 errno = 0; 2210 EXPECT_EQ(-1, syscall(__NR_getpid)); 2211 EXPECT_EQ(EPERM, errno); 2212 } 2213 2214 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS) 2215 { 2216 struct sock_filter filter[] = { 2217 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2218 offsetof(struct seccomp_data, nr)), 2219 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2220 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2221 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2222 }; 2223 struct sock_fprog prog = { 2224 .len = (unsigned short)ARRAY_SIZE(filter), 2225 .filter = filter, 2226 }; 2227 long ret; 2228 2229 /* Install additional "death on getppid" filter. */ 2230 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2231 ASSERT_EQ(0, ret); 2232 2233 /* Tracer will redirect getpid to getppid, and we should die. */ 2234 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 2235 } 2236 2237 TEST(seccomp_syscall) 2238 { 2239 struct sock_filter filter[] = { 2240 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2241 }; 2242 struct sock_fprog prog = { 2243 .len = (unsigned short)ARRAY_SIZE(filter), 2244 .filter = filter, 2245 }; 2246 long ret; 2247 2248 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2249 ASSERT_EQ(0, ret) { 2250 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2251 } 2252 2253 /* Reject insane operation. */ 2254 ret = seccomp(-1, 0, &prog); 2255 ASSERT_NE(ENOSYS, errno) { 2256 TH_LOG("Kernel does not support seccomp syscall!"); 2257 } 2258 EXPECT_EQ(EINVAL, errno) { 2259 TH_LOG("Did not reject crazy op value!"); 2260 } 2261 2262 /* Reject strict with flags or pointer. */ 2263 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); 2264 EXPECT_EQ(EINVAL, errno) { 2265 TH_LOG("Did not reject mode strict with flags!"); 2266 } 2267 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); 2268 EXPECT_EQ(EINVAL, errno) { 2269 TH_LOG("Did not reject mode strict with uargs!"); 2270 } 2271 2272 /* Reject insane args for filter. */ 2273 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); 2274 EXPECT_EQ(EINVAL, errno) { 2275 TH_LOG("Did not reject crazy filter flags!"); 2276 } 2277 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); 2278 EXPECT_EQ(EFAULT, errno) { 2279 TH_LOG("Did not reject NULL filter!"); 2280 } 2281 2282 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2283 EXPECT_EQ(0, errno) { 2284 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", 2285 strerror(errno)); 2286 } 2287 } 2288 2289 TEST(seccomp_syscall_mode_lock) 2290 { 2291 struct sock_filter filter[] = { 2292 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2293 }; 2294 struct sock_fprog prog = { 2295 .len = (unsigned short)ARRAY_SIZE(filter), 2296 .filter = filter, 2297 }; 2298 long ret; 2299 2300 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2301 ASSERT_EQ(0, ret) { 2302 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2303 } 2304 2305 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2306 ASSERT_NE(ENOSYS, errno) { 2307 TH_LOG("Kernel does not support seccomp syscall!"); 2308 } 2309 EXPECT_EQ(0, ret) { 2310 TH_LOG("Could not install filter!"); 2311 } 2312 2313 /* Make sure neither entry point will switch to strict. */ 2314 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); 2315 EXPECT_EQ(EINVAL, errno) { 2316 TH_LOG("Switched to mode strict!"); 2317 } 2318 2319 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); 2320 EXPECT_EQ(EINVAL, errno) { 2321 TH_LOG("Switched to mode strict!"); 2322 } 2323 } 2324 2325 /* 2326 * Test detection of known and unknown filter flags. Userspace needs to be able 2327 * to check if a filter flag is supported by the current kernel and a good way 2328 * of doing that is by attempting to enter filter mode, with the flag bit in 2329 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates 2330 * that the flag is valid and EINVAL indicates that the flag is invalid. 2331 */ 2332 TEST(detect_seccomp_filter_flags) 2333 { 2334 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC, 2335 SECCOMP_FILTER_FLAG_LOG, 2336 SECCOMP_FILTER_FLAG_SPEC_ALLOW, 2337 SECCOMP_FILTER_FLAG_NEW_LISTENER, 2338 SECCOMP_FILTER_FLAG_TSYNC_ESRCH }; 2339 unsigned int exclusive[] = { 2340 SECCOMP_FILTER_FLAG_TSYNC, 2341 SECCOMP_FILTER_FLAG_NEW_LISTENER }; 2342 unsigned int flag, all_flags, exclusive_mask; 2343 int i; 2344 long ret; 2345 2346 /* Test detection of individual known-good filter flags */ 2347 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) { 2348 int bits = 0; 2349 2350 flag = flags[i]; 2351 /* Make sure the flag is a single bit! */ 2352 while (flag) { 2353 if (flag & 0x1) 2354 bits ++; 2355 flag >>= 1; 2356 } 2357 ASSERT_EQ(1, bits); 2358 flag = flags[i]; 2359 2360 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2361 ASSERT_NE(ENOSYS, errno) { 2362 TH_LOG("Kernel does not support seccomp syscall!"); 2363 } 2364 EXPECT_EQ(-1, ret); 2365 EXPECT_EQ(EFAULT, errno) { 2366 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!", 2367 flag); 2368 } 2369 2370 all_flags |= flag; 2371 } 2372 2373 /* 2374 * Test detection of all known-good filter flags combined. But 2375 * for the exclusive flags we need to mask them out and try them 2376 * individually for the "all flags" testing. 2377 */ 2378 exclusive_mask = 0; 2379 for (i = 0; i < ARRAY_SIZE(exclusive); i++) 2380 exclusive_mask |= exclusive[i]; 2381 for (i = 0; i < ARRAY_SIZE(exclusive); i++) { 2382 flag = all_flags & ~exclusive_mask; 2383 flag |= exclusive[i]; 2384 2385 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2386 EXPECT_EQ(-1, ret); 2387 EXPECT_EQ(EFAULT, errno) { 2388 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!", 2389 flag); 2390 } 2391 } 2392 2393 /* Test detection of an unknown filter flags, without exclusives. */ 2394 flag = -1; 2395 flag &= ~exclusive_mask; 2396 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2397 EXPECT_EQ(-1, ret); 2398 EXPECT_EQ(EINVAL, errno) { 2399 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!", 2400 flag); 2401 } 2402 2403 /* 2404 * Test detection of an unknown filter flag that may simply need to be 2405 * added to this test 2406 */ 2407 flag = flags[ARRAY_SIZE(flags) - 1] << 1; 2408 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2409 EXPECT_EQ(-1, ret); 2410 EXPECT_EQ(EINVAL, errno) { 2411 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?", 2412 flag); 2413 } 2414 } 2415 2416 TEST(TSYNC_first) 2417 { 2418 struct sock_filter filter[] = { 2419 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2420 }; 2421 struct sock_fprog prog = { 2422 .len = (unsigned short)ARRAY_SIZE(filter), 2423 .filter = filter, 2424 }; 2425 long ret; 2426 2427 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2428 ASSERT_EQ(0, ret) { 2429 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2430 } 2431 2432 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2433 &prog); 2434 ASSERT_NE(ENOSYS, errno) { 2435 TH_LOG("Kernel does not support seccomp syscall!"); 2436 } 2437 EXPECT_EQ(0, ret) { 2438 TH_LOG("Could not install initial filter with TSYNC!"); 2439 } 2440 } 2441 2442 #define TSYNC_SIBLINGS 2 2443 struct tsync_sibling { 2444 pthread_t tid; 2445 pid_t system_tid; 2446 sem_t *started; 2447 pthread_cond_t *cond; 2448 pthread_mutex_t *mutex; 2449 int diverge; 2450 int num_waits; 2451 struct sock_fprog *prog; 2452 struct __test_metadata *metadata; 2453 }; 2454 2455 /* 2456 * To avoid joining joined threads (which is not allowed by Bionic), 2457 * make sure we both successfully join and clear the tid to skip a 2458 * later join attempt during fixture teardown. Any remaining threads 2459 * will be directly killed during teardown. 2460 */ 2461 #define PTHREAD_JOIN(tid, status) \ 2462 do { \ 2463 int _rc = pthread_join(tid, status); \ 2464 if (_rc) { \ 2465 TH_LOG("pthread_join of tid %u failed: %d\n", \ 2466 (unsigned int)tid, _rc); \ 2467 } else { \ 2468 tid = 0; \ 2469 } \ 2470 } while (0) 2471 2472 FIXTURE(TSYNC) { 2473 struct sock_fprog root_prog, apply_prog; 2474 struct tsync_sibling sibling[TSYNC_SIBLINGS]; 2475 sem_t started; 2476 pthread_cond_t cond; 2477 pthread_mutex_t mutex; 2478 int sibling_count; 2479 }; 2480 2481 FIXTURE_SETUP(TSYNC) 2482 { 2483 struct sock_filter root_filter[] = { 2484 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2485 }; 2486 struct sock_filter apply_filter[] = { 2487 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2488 offsetof(struct seccomp_data, nr)), 2489 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 2490 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2491 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2492 }; 2493 2494 memset(&self->root_prog, 0, sizeof(self->root_prog)); 2495 memset(&self->apply_prog, 0, sizeof(self->apply_prog)); 2496 memset(&self->sibling, 0, sizeof(self->sibling)); 2497 self->root_prog.filter = malloc(sizeof(root_filter)); 2498 ASSERT_NE(NULL, self->root_prog.filter); 2499 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); 2500 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); 2501 2502 self->apply_prog.filter = malloc(sizeof(apply_filter)); 2503 ASSERT_NE(NULL, self->apply_prog.filter); 2504 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); 2505 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); 2506 2507 self->sibling_count = 0; 2508 pthread_mutex_init(&self->mutex, NULL); 2509 pthread_cond_init(&self->cond, NULL); 2510 sem_init(&self->started, 0, 0); 2511 self->sibling[0].tid = 0; 2512 self->sibling[0].cond = &self->cond; 2513 self->sibling[0].started = &self->started; 2514 self->sibling[0].mutex = &self->mutex; 2515 self->sibling[0].diverge = 0; 2516 self->sibling[0].num_waits = 1; 2517 self->sibling[0].prog = &self->root_prog; 2518 self->sibling[0].metadata = _metadata; 2519 self->sibling[1].tid = 0; 2520 self->sibling[1].cond = &self->cond; 2521 self->sibling[1].started = &self->started; 2522 self->sibling[1].mutex = &self->mutex; 2523 self->sibling[1].diverge = 0; 2524 self->sibling[1].prog = &self->root_prog; 2525 self->sibling[1].num_waits = 1; 2526 self->sibling[1].metadata = _metadata; 2527 } 2528 2529 FIXTURE_TEARDOWN(TSYNC) 2530 { 2531 int sib = 0; 2532 2533 if (self->root_prog.filter) 2534 free(self->root_prog.filter); 2535 if (self->apply_prog.filter) 2536 free(self->apply_prog.filter); 2537 2538 for ( ; sib < self->sibling_count; ++sib) { 2539 struct tsync_sibling *s = &self->sibling[sib]; 2540 2541 if (!s->tid) 2542 continue; 2543 /* 2544 * If a thread is still running, it may be stuck, so hit 2545 * it over the head really hard. 2546 */ 2547 pthread_kill(s->tid, 9); 2548 } 2549 pthread_mutex_destroy(&self->mutex); 2550 pthread_cond_destroy(&self->cond); 2551 sem_destroy(&self->started); 2552 } 2553 2554 void *tsync_sibling(void *data) 2555 { 2556 long ret = 0; 2557 struct tsync_sibling *me = data; 2558 2559 me->system_tid = syscall(__NR_gettid); 2560 2561 pthread_mutex_lock(me->mutex); 2562 if (me->diverge) { 2563 /* Just re-apply the root prog to fork the tree */ 2564 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 2565 me->prog, 0, 0); 2566 } 2567 sem_post(me->started); 2568 /* Return outside of started so parent notices failures. */ 2569 if (ret) { 2570 pthread_mutex_unlock(me->mutex); 2571 return (void *)SIBLING_EXIT_FAILURE; 2572 } 2573 do { 2574 pthread_cond_wait(me->cond, me->mutex); 2575 me->num_waits = me->num_waits - 1; 2576 } while (me->num_waits); 2577 pthread_mutex_unlock(me->mutex); 2578 2579 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); 2580 if (!ret) 2581 return (void *)SIBLING_EXIT_NEWPRIVS; 2582 read(0, NULL, 0); 2583 return (void *)SIBLING_EXIT_UNKILLED; 2584 } 2585 2586 void tsync_start_sibling(struct tsync_sibling *sibling) 2587 { 2588 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); 2589 } 2590 2591 TEST_F(TSYNC, siblings_fail_prctl) 2592 { 2593 long ret; 2594 void *status; 2595 struct sock_filter filter[] = { 2596 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2597 offsetof(struct seccomp_data, nr)), 2598 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 2599 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), 2600 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2601 }; 2602 struct sock_fprog prog = { 2603 .len = (unsigned short)ARRAY_SIZE(filter), 2604 .filter = filter, 2605 }; 2606 2607 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2608 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2609 } 2610 2611 /* Check prctl failure detection by requesting sib 0 diverge. */ 2612 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2613 ASSERT_NE(ENOSYS, errno) { 2614 TH_LOG("Kernel does not support seccomp syscall!"); 2615 } 2616 ASSERT_EQ(0, ret) { 2617 TH_LOG("setting filter failed"); 2618 } 2619 2620 self->sibling[0].diverge = 1; 2621 tsync_start_sibling(&self->sibling[0]); 2622 tsync_start_sibling(&self->sibling[1]); 2623 2624 while (self->sibling_count < TSYNC_SIBLINGS) { 2625 sem_wait(&self->started); 2626 self->sibling_count++; 2627 } 2628 2629 /* Signal the threads to clean up*/ 2630 pthread_mutex_lock(&self->mutex); 2631 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2632 TH_LOG("cond broadcast non-zero"); 2633 } 2634 pthread_mutex_unlock(&self->mutex); 2635 2636 /* Ensure diverging sibling failed to call prctl. */ 2637 PTHREAD_JOIN(self->sibling[0].tid, &status); 2638 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); 2639 PTHREAD_JOIN(self->sibling[1].tid, &status); 2640 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2641 } 2642 2643 TEST_F(TSYNC, two_siblings_with_ancestor) 2644 { 2645 long ret; 2646 void *status; 2647 2648 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2649 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2650 } 2651 2652 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2653 ASSERT_NE(ENOSYS, errno) { 2654 TH_LOG("Kernel does not support seccomp syscall!"); 2655 } 2656 ASSERT_EQ(0, ret) { 2657 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2658 } 2659 tsync_start_sibling(&self->sibling[0]); 2660 tsync_start_sibling(&self->sibling[1]); 2661 2662 while (self->sibling_count < TSYNC_SIBLINGS) { 2663 sem_wait(&self->started); 2664 self->sibling_count++; 2665 } 2666 2667 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2668 &self->apply_prog); 2669 ASSERT_EQ(0, ret) { 2670 TH_LOG("Could install filter on all threads!"); 2671 } 2672 /* Tell the siblings to test the policy */ 2673 pthread_mutex_lock(&self->mutex); 2674 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2675 TH_LOG("cond broadcast non-zero"); 2676 } 2677 pthread_mutex_unlock(&self->mutex); 2678 /* Ensure they are both killed and don't exit cleanly. */ 2679 PTHREAD_JOIN(self->sibling[0].tid, &status); 2680 EXPECT_EQ(0x0, (long)status); 2681 PTHREAD_JOIN(self->sibling[1].tid, &status); 2682 EXPECT_EQ(0x0, (long)status); 2683 } 2684 2685 TEST_F(TSYNC, two_sibling_want_nnp) 2686 { 2687 void *status; 2688 2689 /* start siblings before any prctl() operations */ 2690 tsync_start_sibling(&self->sibling[0]); 2691 tsync_start_sibling(&self->sibling[1]); 2692 while (self->sibling_count < TSYNC_SIBLINGS) { 2693 sem_wait(&self->started); 2694 self->sibling_count++; 2695 } 2696 2697 /* Tell the siblings to test no policy */ 2698 pthread_mutex_lock(&self->mutex); 2699 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2700 TH_LOG("cond broadcast non-zero"); 2701 } 2702 pthread_mutex_unlock(&self->mutex); 2703 2704 /* Ensure they are both upset about lacking nnp. */ 2705 PTHREAD_JOIN(self->sibling[0].tid, &status); 2706 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2707 PTHREAD_JOIN(self->sibling[1].tid, &status); 2708 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2709 } 2710 2711 TEST_F(TSYNC, two_siblings_with_no_filter) 2712 { 2713 long ret; 2714 void *status; 2715 2716 /* start siblings before any prctl() operations */ 2717 tsync_start_sibling(&self->sibling[0]); 2718 tsync_start_sibling(&self->sibling[1]); 2719 while (self->sibling_count < TSYNC_SIBLINGS) { 2720 sem_wait(&self->started); 2721 self->sibling_count++; 2722 } 2723 2724 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2725 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2726 } 2727 2728 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2729 &self->apply_prog); 2730 ASSERT_NE(ENOSYS, errno) { 2731 TH_LOG("Kernel does not support seccomp syscall!"); 2732 } 2733 ASSERT_EQ(0, ret) { 2734 TH_LOG("Could install filter on all threads!"); 2735 } 2736 2737 /* Tell the siblings to test the policy */ 2738 pthread_mutex_lock(&self->mutex); 2739 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2740 TH_LOG("cond broadcast non-zero"); 2741 } 2742 pthread_mutex_unlock(&self->mutex); 2743 2744 /* Ensure they are both killed and don't exit cleanly. */ 2745 PTHREAD_JOIN(self->sibling[0].tid, &status); 2746 EXPECT_EQ(0x0, (long)status); 2747 PTHREAD_JOIN(self->sibling[1].tid, &status); 2748 EXPECT_EQ(0x0, (long)status); 2749 } 2750 2751 TEST_F(TSYNC, two_siblings_with_one_divergence) 2752 { 2753 long ret; 2754 void *status; 2755 2756 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2757 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2758 } 2759 2760 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2761 ASSERT_NE(ENOSYS, errno) { 2762 TH_LOG("Kernel does not support seccomp syscall!"); 2763 } 2764 ASSERT_EQ(0, ret) { 2765 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2766 } 2767 self->sibling[0].diverge = 1; 2768 tsync_start_sibling(&self->sibling[0]); 2769 tsync_start_sibling(&self->sibling[1]); 2770 2771 while (self->sibling_count < TSYNC_SIBLINGS) { 2772 sem_wait(&self->started); 2773 self->sibling_count++; 2774 } 2775 2776 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2777 &self->apply_prog); 2778 ASSERT_EQ(self->sibling[0].system_tid, ret) { 2779 TH_LOG("Did not fail on diverged sibling."); 2780 } 2781 2782 /* Wake the threads */ 2783 pthread_mutex_lock(&self->mutex); 2784 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2785 TH_LOG("cond broadcast non-zero"); 2786 } 2787 pthread_mutex_unlock(&self->mutex); 2788 2789 /* Ensure they are both unkilled. */ 2790 PTHREAD_JOIN(self->sibling[0].tid, &status); 2791 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2792 PTHREAD_JOIN(self->sibling[1].tid, &status); 2793 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2794 } 2795 2796 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err) 2797 { 2798 long ret, flags; 2799 void *status; 2800 2801 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2802 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2803 } 2804 2805 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2806 ASSERT_NE(ENOSYS, errno) { 2807 TH_LOG("Kernel does not support seccomp syscall!"); 2808 } 2809 ASSERT_EQ(0, ret) { 2810 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2811 } 2812 self->sibling[0].diverge = 1; 2813 tsync_start_sibling(&self->sibling[0]); 2814 tsync_start_sibling(&self->sibling[1]); 2815 2816 while (self->sibling_count < TSYNC_SIBLINGS) { 2817 sem_wait(&self->started); 2818 self->sibling_count++; 2819 } 2820 2821 flags = SECCOMP_FILTER_FLAG_TSYNC | \ 2822 SECCOMP_FILTER_FLAG_TSYNC_ESRCH; 2823 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog); 2824 ASSERT_EQ(ESRCH, errno) { 2825 TH_LOG("Did not return ESRCH for diverged sibling."); 2826 } 2827 ASSERT_EQ(-1, ret) { 2828 TH_LOG("Did not fail on diverged sibling."); 2829 } 2830 2831 /* Wake the threads */ 2832 pthread_mutex_lock(&self->mutex); 2833 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2834 TH_LOG("cond broadcast non-zero"); 2835 } 2836 pthread_mutex_unlock(&self->mutex); 2837 2838 /* Ensure they are both unkilled. */ 2839 PTHREAD_JOIN(self->sibling[0].tid, &status); 2840 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2841 PTHREAD_JOIN(self->sibling[1].tid, &status); 2842 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2843 } 2844 2845 TEST_F(TSYNC, two_siblings_not_under_filter) 2846 { 2847 long ret, sib; 2848 void *status; 2849 struct timespec delay = { .tv_nsec = 100000000 }; 2850 2851 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2852 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2853 } 2854 2855 /* 2856 * Sibling 0 will have its own seccomp policy 2857 * and Sibling 1 will not be under seccomp at 2858 * all. Sibling 1 will enter seccomp and 0 2859 * will cause failure. 2860 */ 2861 self->sibling[0].diverge = 1; 2862 tsync_start_sibling(&self->sibling[0]); 2863 tsync_start_sibling(&self->sibling[1]); 2864 2865 while (self->sibling_count < TSYNC_SIBLINGS) { 2866 sem_wait(&self->started); 2867 self->sibling_count++; 2868 } 2869 2870 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2871 ASSERT_NE(ENOSYS, errno) { 2872 TH_LOG("Kernel does not support seccomp syscall!"); 2873 } 2874 ASSERT_EQ(0, ret) { 2875 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2876 } 2877 2878 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2879 &self->apply_prog); 2880 ASSERT_EQ(ret, self->sibling[0].system_tid) { 2881 TH_LOG("Did not fail on diverged sibling."); 2882 } 2883 sib = 1; 2884 if (ret == self->sibling[0].system_tid) 2885 sib = 0; 2886 2887 pthread_mutex_lock(&self->mutex); 2888 2889 /* Increment the other siblings num_waits so we can clean up 2890 * the one we just saw. 2891 */ 2892 self->sibling[!sib].num_waits += 1; 2893 2894 /* Signal the thread to clean up*/ 2895 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2896 TH_LOG("cond broadcast non-zero"); 2897 } 2898 pthread_mutex_unlock(&self->mutex); 2899 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2900 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2901 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2902 while (!kill(self->sibling[sib].system_tid, 0)) 2903 nanosleep(&delay, NULL); 2904 /* Switch to the remaining sibling */ 2905 sib = !sib; 2906 2907 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2908 &self->apply_prog); 2909 ASSERT_EQ(0, ret) { 2910 TH_LOG("Expected the remaining sibling to sync"); 2911 }; 2912 2913 pthread_mutex_lock(&self->mutex); 2914 2915 /* If remaining sibling didn't have a chance to wake up during 2916 * the first broadcast, manually reduce the num_waits now. 2917 */ 2918 if (self->sibling[sib].num_waits > 1) 2919 self->sibling[sib].num_waits = 1; 2920 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2921 TH_LOG("cond broadcast non-zero"); 2922 } 2923 pthread_mutex_unlock(&self->mutex); 2924 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2925 EXPECT_EQ(0, (long)status); 2926 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2927 while (!kill(self->sibling[sib].system_tid, 0)) 2928 nanosleep(&delay, NULL); 2929 2930 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2931 &self->apply_prog); 2932 ASSERT_EQ(0, ret); /* just us chickens */ 2933 } 2934 2935 /* Make sure restarted syscalls are seen directly as "restart_syscall". */ 2936 TEST(syscall_restart) 2937 { 2938 long ret; 2939 unsigned long msg; 2940 pid_t child_pid; 2941 int pipefd[2]; 2942 int status; 2943 siginfo_t info = { }; 2944 struct sock_filter filter[] = { 2945 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2946 offsetof(struct seccomp_data, nr)), 2947 2948 #ifdef __NR_sigreturn 2949 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0), 2950 #endif 2951 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0), 2952 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0), 2953 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0), 2954 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0), 2955 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0), 2956 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), 2957 2958 /* Allow __NR_write for easy logging. */ 2959 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), 2960 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2961 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2962 /* The nanosleep jump target. */ 2963 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), 2964 /* The restart_syscall jump target. */ 2965 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), 2966 }; 2967 struct sock_fprog prog = { 2968 .len = (unsigned short)ARRAY_SIZE(filter), 2969 .filter = filter, 2970 }; 2971 #if defined(__arm__) 2972 struct utsname utsbuf; 2973 #endif 2974 2975 ASSERT_EQ(0, pipe(pipefd)); 2976 2977 child_pid = fork(); 2978 ASSERT_LE(0, child_pid); 2979 if (child_pid == 0) { 2980 /* Child uses EXPECT not ASSERT to deliver status correctly. */ 2981 char buf = ' '; 2982 struct timespec timeout = { }; 2983 2984 /* Attach parent as tracer and stop. */ 2985 EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); 2986 EXPECT_EQ(0, raise(SIGSTOP)); 2987 2988 EXPECT_EQ(0, close(pipefd[1])); 2989 2990 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2991 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2992 } 2993 2994 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2995 EXPECT_EQ(0, ret) { 2996 TH_LOG("Failed to install filter!"); 2997 } 2998 2999 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 3000 TH_LOG("Failed to read() sync from parent"); 3001 } 3002 EXPECT_EQ('.', buf) { 3003 TH_LOG("Failed to get sync data from read()"); 3004 } 3005 3006 /* Start nanosleep to be interrupted. */ 3007 timeout.tv_sec = 1; 3008 errno = 0; 3009 EXPECT_EQ(0, nanosleep(&timeout, NULL)) { 3010 TH_LOG("Call to nanosleep() failed (errno %d)", errno); 3011 } 3012 3013 /* Read final sync from parent. */ 3014 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 3015 TH_LOG("Failed final read() from parent"); 3016 } 3017 EXPECT_EQ('!', buf) { 3018 TH_LOG("Failed to get final data from read()"); 3019 } 3020 3021 /* Directly report the status of our test harness results. */ 3022 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS 3023 : EXIT_FAILURE); 3024 } 3025 EXPECT_EQ(0, close(pipefd[0])); 3026 3027 /* Attach to child, setup options, and release. */ 3028 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3029 ASSERT_EQ(true, WIFSTOPPED(status)); 3030 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, 3031 PTRACE_O_TRACESECCOMP)); 3032 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3033 ASSERT_EQ(1, write(pipefd[1], ".", 1)); 3034 3035 /* Wait for nanosleep() to start. */ 3036 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3037 ASSERT_EQ(true, WIFSTOPPED(status)); 3038 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 3039 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 3040 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 3041 ASSERT_EQ(0x100, msg); 3042 ret = get_syscall(_metadata, child_pid); 3043 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep); 3044 3045 /* Might as well check siginfo for sanity while we're here. */ 3046 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 3047 ASSERT_EQ(SIGTRAP, info.si_signo); 3048 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); 3049 EXPECT_EQ(0, info.si_errno); 3050 EXPECT_EQ(getuid(), info.si_uid); 3051 /* Verify signal delivery came from child (seccomp-triggered). */ 3052 EXPECT_EQ(child_pid, info.si_pid); 3053 3054 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */ 3055 ASSERT_EQ(0, kill(child_pid, SIGSTOP)); 3056 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3057 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3058 ASSERT_EQ(true, WIFSTOPPED(status)); 3059 ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); 3060 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 3061 /* 3062 * There is no siginfo on SIGSTOP any more, so we can't verify 3063 * signal delivery came from parent now (getpid() == info.si_pid). 3064 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com 3065 * At least verify the SIGSTOP via PTRACE_GETSIGINFO. 3066 */ 3067 EXPECT_EQ(SIGSTOP, info.si_signo); 3068 3069 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ 3070 ASSERT_EQ(0, kill(child_pid, SIGCONT)); 3071 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3072 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3073 ASSERT_EQ(true, WIFSTOPPED(status)); 3074 ASSERT_EQ(SIGCONT, WSTOPSIG(status)); 3075 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3076 3077 /* Wait for restart_syscall() to start. */ 3078 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3079 ASSERT_EQ(true, WIFSTOPPED(status)); 3080 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 3081 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 3082 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 3083 3084 ASSERT_EQ(0x200, msg); 3085 ret = get_syscall(_metadata, child_pid); 3086 #if defined(__arm__) 3087 /* 3088 * FIXME: 3089 * - native ARM registers do NOT expose true syscall. 3090 * - compat ARM registers on ARM64 DO expose true syscall. 3091 */ 3092 ASSERT_EQ(0, uname(&utsbuf)); 3093 if (strncmp(utsbuf.machine, "arm", 3) == 0) { 3094 EXPECT_EQ(__NR_nanosleep, ret); 3095 } else 3096 #endif 3097 { 3098 EXPECT_EQ(__NR_restart_syscall, ret); 3099 } 3100 3101 /* Write again to end test. */ 3102 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3103 ASSERT_EQ(1, write(pipefd[1], "!", 1)); 3104 EXPECT_EQ(0, close(pipefd[1])); 3105 3106 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3107 if (WIFSIGNALED(status) || WEXITSTATUS(status)) 3108 _metadata->passed = 0; 3109 } 3110 3111 TEST_SIGNAL(filter_flag_log, SIGSYS) 3112 { 3113 struct sock_filter allow_filter[] = { 3114 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3115 }; 3116 struct sock_filter kill_filter[] = { 3117 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3118 offsetof(struct seccomp_data, nr)), 3119 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 3120 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 3121 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3122 }; 3123 struct sock_fprog allow_prog = { 3124 .len = (unsigned short)ARRAY_SIZE(allow_filter), 3125 .filter = allow_filter, 3126 }; 3127 struct sock_fprog kill_prog = { 3128 .len = (unsigned short)ARRAY_SIZE(kill_filter), 3129 .filter = kill_filter, 3130 }; 3131 long ret; 3132 pid_t parent = getppid(); 3133 3134 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3135 ASSERT_EQ(0, ret); 3136 3137 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */ 3138 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG, 3139 &allow_prog); 3140 ASSERT_NE(ENOSYS, errno) { 3141 TH_LOG("Kernel does not support seccomp syscall!"); 3142 } 3143 EXPECT_NE(0, ret) { 3144 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!"); 3145 } 3146 EXPECT_EQ(EINVAL, errno) { 3147 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!"); 3148 } 3149 3150 /* Verify that a simple, permissive filter can be added with no flags */ 3151 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog); 3152 EXPECT_EQ(0, ret); 3153 3154 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */ 3155 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 3156 &allow_prog); 3157 ASSERT_NE(EINVAL, errno) { 3158 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!"); 3159 } 3160 EXPECT_EQ(0, ret); 3161 3162 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */ 3163 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 3164 &kill_prog); 3165 EXPECT_EQ(0, ret); 3166 3167 EXPECT_EQ(parent, syscall(__NR_getppid)); 3168 /* getpid() should never return. */ 3169 EXPECT_EQ(0, syscall(__NR_getpid)); 3170 } 3171 3172 TEST(get_action_avail) 3173 { 3174 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP, 3175 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE, 3176 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW }; 3177 __u32 unknown_action = 0x10000000U; 3178 int i; 3179 long ret; 3180 3181 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]); 3182 ASSERT_NE(ENOSYS, errno) { 3183 TH_LOG("Kernel does not support seccomp syscall!"); 3184 } 3185 ASSERT_NE(EINVAL, errno) { 3186 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!"); 3187 } 3188 EXPECT_EQ(ret, 0); 3189 3190 for (i = 0; i < ARRAY_SIZE(actions); i++) { 3191 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]); 3192 EXPECT_EQ(ret, 0) { 3193 TH_LOG("Expected action (0x%X) not available!", 3194 actions[i]); 3195 } 3196 } 3197 3198 /* Check that an unknown action is handled properly (EOPNOTSUPP) */ 3199 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action); 3200 EXPECT_EQ(ret, -1); 3201 EXPECT_EQ(errno, EOPNOTSUPP); 3202 } 3203 3204 TEST(get_metadata) 3205 { 3206 pid_t pid; 3207 int pipefd[2]; 3208 char buf; 3209 struct seccomp_metadata md; 3210 long ret; 3211 3212 /* Only real root can get metadata. */ 3213 if (geteuid()) { 3214 SKIP(return, "get_metadata requires real root"); 3215 return; 3216 } 3217 3218 ASSERT_EQ(0, pipe(pipefd)); 3219 3220 pid = fork(); 3221 ASSERT_GE(pid, 0); 3222 if (pid == 0) { 3223 struct sock_filter filter[] = { 3224 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3225 }; 3226 struct sock_fprog prog = { 3227 .len = (unsigned short)ARRAY_SIZE(filter), 3228 .filter = filter, 3229 }; 3230 3231 /* one with log, one without */ 3232 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 3233 SECCOMP_FILTER_FLAG_LOG, &prog)); 3234 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog)); 3235 3236 EXPECT_EQ(0, close(pipefd[0])); 3237 ASSERT_EQ(1, write(pipefd[1], "1", 1)); 3238 ASSERT_EQ(0, close(pipefd[1])); 3239 3240 while (1) 3241 sleep(100); 3242 } 3243 3244 ASSERT_EQ(0, close(pipefd[1])); 3245 ASSERT_EQ(1, read(pipefd[0], &buf, 1)); 3246 3247 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid)); 3248 ASSERT_EQ(pid, waitpid(pid, NULL, 0)); 3249 3250 /* Past here must not use ASSERT or child process is never killed. */ 3251 3252 md.filter_off = 0; 3253 errno = 0; 3254 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); 3255 EXPECT_EQ(sizeof(md), ret) { 3256 if (errno == EINVAL) 3257 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)"); 3258 } 3259 3260 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG); 3261 EXPECT_EQ(md.filter_off, 0); 3262 3263 md.filter_off = 1; 3264 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); 3265 EXPECT_EQ(sizeof(md), ret); 3266 EXPECT_EQ(md.flags, 0); 3267 EXPECT_EQ(md.filter_off, 1); 3268 3269 skip: 3270 ASSERT_EQ(0, kill(pid, SIGKILL)); 3271 } 3272 3273 static int user_notif_syscall(int nr, unsigned int flags) 3274 { 3275 struct sock_filter filter[] = { 3276 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3277 offsetof(struct seccomp_data, nr)), 3278 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1), 3279 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF), 3280 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3281 }; 3282 3283 struct sock_fprog prog = { 3284 .len = (unsigned short)ARRAY_SIZE(filter), 3285 .filter = filter, 3286 }; 3287 3288 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog); 3289 } 3290 3291 #define USER_NOTIF_MAGIC INT_MAX 3292 TEST(user_notification_basic) 3293 { 3294 pid_t pid; 3295 long ret; 3296 int status, listener; 3297 struct seccomp_notif req = {}; 3298 struct seccomp_notif_resp resp = {}; 3299 struct pollfd pollfd; 3300 3301 struct sock_filter filter[] = { 3302 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3303 }; 3304 struct sock_fprog prog = { 3305 .len = (unsigned short)ARRAY_SIZE(filter), 3306 .filter = filter, 3307 }; 3308 3309 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3310 ASSERT_EQ(0, ret) { 3311 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3312 } 3313 3314 pid = fork(); 3315 ASSERT_GE(pid, 0); 3316 3317 /* Check that we get -ENOSYS with no listener attached */ 3318 if (pid == 0) { 3319 if (user_notif_syscall(__NR_getppid, 0) < 0) 3320 exit(1); 3321 ret = syscall(__NR_getppid); 3322 exit(ret >= 0 || errno != ENOSYS); 3323 } 3324 3325 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3326 EXPECT_EQ(true, WIFEXITED(status)); 3327 EXPECT_EQ(0, WEXITSTATUS(status)); 3328 3329 /* Add some no-op filters for grins. */ 3330 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3331 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3332 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3333 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3334 3335 /* Check that the basic notification machinery works */ 3336 listener = user_notif_syscall(__NR_getppid, 3337 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3338 ASSERT_GE(listener, 0); 3339 3340 /* Installing a second listener in the chain should EBUSY */ 3341 EXPECT_EQ(user_notif_syscall(__NR_getppid, 3342 SECCOMP_FILTER_FLAG_NEW_LISTENER), 3343 -1); 3344 EXPECT_EQ(errno, EBUSY); 3345 3346 pid = fork(); 3347 ASSERT_GE(pid, 0); 3348 3349 if (pid == 0) { 3350 ret = syscall(__NR_getppid); 3351 exit(ret != USER_NOTIF_MAGIC); 3352 } 3353 3354 pollfd.fd = listener; 3355 pollfd.events = POLLIN | POLLOUT; 3356 3357 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3358 EXPECT_EQ(pollfd.revents, POLLIN); 3359 3360 /* Test that we can't pass garbage to the kernel. */ 3361 memset(&req, 0, sizeof(req)); 3362 req.pid = -1; 3363 errno = 0; 3364 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req); 3365 EXPECT_EQ(-1, ret); 3366 EXPECT_EQ(EINVAL, errno); 3367 3368 if (ret) { 3369 req.pid = 0; 3370 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3371 } 3372 3373 pollfd.fd = listener; 3374 pollfd.events = POLLIN | POLLOUT; 3375 3376 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3377 EXPECT_EQ(pollfd.revents, POLLOUT); 3378 3379 EXPECT_EQ(req.data.nr, __NR_getppid); 3380 3381 resp.id = req.id; 3382 resp.error = 0; 3383 resp.val = USER_NOTIF_MAGIC; 3384 3385 /* check that we make sure flags == 0 */ 3386 resp.flags = 1; 3387 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3388 EXPECT_EQ(errno, EINVAL); 3389 3390 resp.flags = 0; 3391 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3392 3393 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3394 EXPECT_EQ(true, WIFEXITED(status)); 3395 EXPECT_EQ(0, WEXITSTATUS(status)); 3396 } 3397 3398 TEST(user_notification_with_tsync) 3399 { 3400 int ret; 3401 unsigned int flags; 3402 3403 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3404 ASSERT_EQ(0, ret) { 3405 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3406 } 3407 3408 /* these were exclusive */ 3409 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER | 3410 SECCOMP_FILTER_FLAG_TSYNC; 3411 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags)); 3412 ASSERT_EQ(EINVAL, errno); 3413 3414 /* but now they're not */ 3415 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH; 3416 ret = user_notif_syscall(__NR_getppid, flags); 3417 close(ret); 3418 ASSERT_LE(0, ret); 3419 } 3420 3421 TEST(user_notification_kill_in_middle) 3422 { 3423 pid_t pid; 3424 long ret; 3425 int listener; 3426 struct seccomp_notif req = {}; 3427 struct seccomp_notif_resp resp = {}; 3428 3429 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3430 ASSERT_EQ(0, ret) { 3431 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3432 } 3433 3434 listener = user_notif_syscall(__NR_getppid, 3435 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3436 ASSERT_GE(listener, 0); 3437 3438 /* 3439 * Check that nothing bad happens when we kill the task in the middle 3440 * of a syscall. 3441 */ 3442 pid = fork(); 3443 ASSERT_GE(pid, 0); 3444 3445 if (pid == 0) { 3446 ret = syscall(__NR_getppid); 3447 exit(ret != USER_NOTIF_MAGIC); 3448 } 3449 3450 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3451 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0); 3452 3453 EXPECT_EQ(kill(pid, SIGKILL), 0); 3454 EXPECT_EQ(waitpid(pid, NULL, 0), pid); 3455 3456 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1); 3457 3458 resp.id = req.id; 3459 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp); 3460 EXPECT_EQ(ret, -1); 3461 EXPECT_EQ(errno, ENOENT); 3462 } 3463 3464 static int handled = -1; 3465 3466 static void signal_handler(int signal) 3467 { 3468 if (write(handled, "c", 1) != 1) 3469 perror("write from signal"); 3470 } 3471 3472 TEST(user_notification_signal) 3473 { 3474 pid_t pid; 3475 long ret; 3476 int status, listener, sk_pair[2]; 3477 struct seccomp_notif req = {}; 3478 struct seccomp_notif_resp resp = {}; 3479 char c; 3480 3481 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3482 ASSERT_EQ(0, ret) { 3483 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3484 } 3485 3486 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); 3487 3488 listener = user_notif_syscall(__NR_gettid, 3489 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3490 ASSERT_GE(listener, 0); 3491 3492 pid = fork(); 3493 ASSERT_GE(pid, 0); 3494 3495 if (pid == 0) { 3496 close(sk_pair[0]); 3497 handled = sk_pair[1]; 3498 if (signal(SIGUSR1, signal_handler) == SIG_ERR) { 3499 perror("signal"); 3500 exit(1); 3501 } 3502 /* 3503 * ERESTARTSYS behavior is a bit hard to test, because we need 3504 * to rely on a signal that has not yet been handled. Let's at 3505 * least check that the error code gets propagated through, and 3506 * hope that it doesn't break when there is actually a signal :) 3507 */ 3508 ret = syscall(__NR_gettid); 3509 exit(!(ret == -1 && errno == 512)); 3510 } 3511 3512 close(sk_pair[1]); 3513 3514 memset(&req, 0, sizeof(req)); 3515 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3516 3517 EXPECT_EQ(kill(pid, SIGUSR1), 0); 3518 3519 /* 3520 * Make sure the signal really is delivered, which means we're not 3521 * stuck in the user notification code any more and the notification 3522 * should be dead. 3523 */ 3524 EXPECT_EQ(read(sk_pair[0], &c, 1), 1); 3525 3526 resp.id = req.id; 3527 resp.error = -EPERM; 3528 resp.val = 0; 3529 3530 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3531 EXPECT_EQ(errno, ENOENT); 3532 3533 memset(&req, 0, sizeof(req)); 3534 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3535 3536 resp.id = req.id; 3537 resp.error = -512; /* -ERESTARTSYS */ 3538 resp.val = 0; 3539 3540 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3541 3542 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3543 EXPECT_EQ(true, WIFEXITED(status)); 3544 EXPECT_EQ(0, WEXITSTATUS(status)); 3545 } 3546 3547 TEST(user_notification_closed_listener) 3548 { 3549 pid_t pid; 3550 long ret; 3551 int status, listener; 3552 3553 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3554 ASSERT_EQ(0, ret) { 3555 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3556 } 3557 3558 listener = user_notif_syscall(__NR_getppid, 3559 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3560 ASSERT_GE(listener, 0); 3561 3562 /* 3563 * Check that we get an ENOSYS when the listener is closed. 3564 */ 3565 pid = fork(); 3566 ASSERT_GE(pid, 0); 3567 if (pid == 0) { 3568 close(listener); 3569 ret = syscall(__NR_getppid); 3570 exit(ret != -1 && errno != ENOSYS); 3571 } 3572 3573 close(listener); 3574 3575 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3576 EXPECT_EQ(true, WIFEXITED(status)); 3577 EXPECT_EQ(0, WEXITSTATUS(status)); 3578 } 3579 3580 /* 3581 * Check that a pid in a child namespace still shows up as valid in ours. 3582 */ 3583 TEST(user_notification_child_pid_ns) 3584 { 3585 pid_t pid; 3586 int status, listener; 3587 struct seccomp_notif req = {}; 3588 struct seccomp_notif_resp resp = {}; 3589 3590 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) { 3591 if (errno == EINVAL) 3592 SKIP(return, "kernel missing CLONE_NEWUSER support"); 3593 }; 3594 3595 listener = user_notif_syscall(__NR_getppid, 3596 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3597 ASSERT_GE(listener, 0); 3598 3599 pid = fork(); 3600 ASSERT_GE(pid, 0); 3601 3602 if (pid == 0) 3603 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3604 3605 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3606 EXPECT_EQ(req.pid, pid); 3607 3608 resp.id = req.id; 3609 resp.error = 0; 3610 resp.val = USER_NOTIF_MAGIC; 3611 3612 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3613 3614 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3615 EXPECT_EQ(true, WIFEXITED(status)); 3616 EXPECT_EQ(0, WEXITSTATUS(status)); 3617 close(listener); 3618 } 3619 3620 /* 3621 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e. 3622 * invalid. 3623 */ 3624 TEST(user_notification_sibling_pid_ns) 3625 { 3626 pid_t pid, pid2; 3627 int status, listener; 3628 struct seccomp_notif req = {}; 3629 struct seccomp_notif_resp resp = {}; 3630 3631 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) { 3632 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3633 } 3634 3635 listener = user_notif_syscall(__NR_getppid, 3636 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3637 ASSERT_GE(listener, 0); 3638 3639 pid = fork(); 3640 ASSERT_GE(pid, 0); 3641 3642 if (pid == 0) { 3643 ASSERT_EQ(unshare(CLONE_NEWPID), 0); 3644 3645 pid2 = fork(); 3646 ASSERT_GE(pid2, 0); 3647 3648 if (pid2 == 0) 3649 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3650 3651 EXPECT_EQ(waitpid(pid2, &status, 0), pid2); 3652 EXPECT_EQ(true, WIFEXITED(status)); 3653 EXPECT_EQ(0, WEXITSTATUS(status)); 3654 exit(WEXITSTATUS(status)); 3655 } 3656 3657 /* Create the sibling ns, and sibling in it. */ 3658 ASSERT_EQ(unshare(CLONE_NEWPID), 0) { 3659 if (errno == EPERM) 3660 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); 3661 } 3662 ASSERT_EQ(errno, 0); 3663 3664 pid2 = fork(); 3665 ASSERT_GE(pid2, 0); 3666 3667 if (pid2 == 0) { 3668 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3669 /* 3670 * The pid should be 0, i.e. the task is in some namespace that 3671 * we can't "see". 3672 */ 3673 EXPECT_EQ(req.pid, 0); 3674 3675 resp.id = req.id; 3676 resp.error = 0; 3677 resp.val = USER_NOTIF_MAGIC; 3678 3679 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3680 exit(0); 3681 } 3682 3683 close(listener); 3684 3685 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3686 EXPECT_EQ(true, WIFEXITED(status)); 3687 EXPECT_EQ(0, WEXITSTATUS(status)); 3688 3689 EXPECT_EQ(waitpid(pid2, &status, 0), pid2); 3690 EXPECT_EQ(true, WIFEXITED(status)); 3691 EXPECT_EQ(0, WEXITSTATUS(status)); 3692 } 3693 3694 TEST(user_notification_fault_recv) 3695 { 3696 pid_t pid; 3697 int status, listener; 3698 struct seccomp_notif req = {}; 3699 struct seccomp_notif_resp resp = {}; 3700 3701 ASSERT_EQ(unshare(CLONE_NEWUSER), 0); 3702 3703 listener = user_notif_syscall(__NR_getppid, 3704 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3705 ASSERT_GE(listener, 0); 3706 3707 pid = fork(); 3708 ASSERT_GE(pid, 0); 3709 3710 if (pid == 0) 3711 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3712 3713 /* Do a bad recv() */ 3714 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1); 3715 EXPECT_EQ(errno, EFAULT); 3716 3717 /* We should still be able to receive this notification, though. */ 3718 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3719 EXPECT_EQ(req.pid, pid); 3720 3721 resp.id = req.id; 3722 resp.error = 0; 3723 resp.val = USER_NOTIF_MAGIC; 3724 3725 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3726 3727 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3728 EXPECT_EQ(true, WIFEXITED(status)); 3729 EXPECT_EQ(0, WEXITSTATUS(status)); 3730 } 3731 3732 TEST(seccomp_get_notif_sizes) 3733 { 3734 struct seccomp_notif_sizes sizes; 3735 3736 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0); 3737 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif)); 3738 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp)); 3739 } 3740 3741 TEST(user_notification_continue) 3742 { 3743 pid_t pid; 3744 long ret; 3745 int status, listener; 3746 struct seccomp_notif req = {}; 3747 struct seccomp_notif_resp resp = {}; 3748 struct pollfd pollfd; 3749 3750 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3751 ASSERT_EQ(0, ret) { 3752 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3753 } 3754 3755 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3756 ASSERT_GE(listener, 0); 3757 3758 pid = fork(); 3759 ASSERT_GE(pid, 0); 3760 3761 if (pid == 0) { 3762 int dup_fd, pipe_fds[2]; 3763 pid_t self; 3764 3765 ASSERT_GE(pipe(pipe_fds), 0); 3766 3767 dup_fd = dup(pipe_fds[0]); 3768 ASSERT_GE(dup_fd, 0); 3769 EXPECT_NE(pipe_fds[0], dup_fd); 3770 3771 self = getpid(); 3772 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0); 3773 exit(0); 3774 } 3775 3776 pollfd.fd = listener; 3777 pollfd.events = POLLIN | POLLOUT; 3778 3779 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3780 EXPECT_EQ(pollfd.revents, POLLIN); 3781 3782 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3783 3784 pollfd.fd = listener; 3785 pollfd.events = POLLIN | POLLOUT; 3786 3787 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3788 EXPECT_EQ(pollfd.revents, POLLOUT); 3789 3790 EXPECT_EQ(req.data.nr, __NR_dup); 3791 3792 resp.id = req.id; 3793 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE; 3794 3795 /* 3796 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other 3797 * args be set to 0. 3798 */ 3799 resp.error = 0; 3800 resp.val = USER_NOTIF_MAGIC; 3801 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3802 EXPECT_EQ(errno, EINVAL); 3803 3804 resp.error = USER_NOTIF_MAGIC; 3805 resp.val = 0; 3806 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3807 EXPECT_EQ(errno, EINVAL); 3808 3809 resp.error = 0; 3810 resp.val = 0; 3811 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) { 3812 if (errno == EINVAL) 3813 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE"); 3814 } 3815 3816 skip: 3817 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3818 EXPECT_EQ(true, WIFEXITED(status)); 3819 EXPECT_EQ(0, WEXITSTATUS(status)) { 3820 if (WEXITSTATUS(status) == 2) { 3821 SKIP(return, "Kernel does not support kcmp() syscall"); 3822 return; 3823 } 3824 } 3825 } 3826 3827 TEST(user_notification_filter_empty) 3828 { 3829 pid_t pid; 3830 long ret; 3831 int status; 3832 struct pollfd pollfd; 3833 struct __clone_args args = { 3834 .flags = CLONE_FILES, 3835 .exit_signal = SIGCHLD, 3836 }; 3837 3838 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3839 ASSERT_EQ(0, ret) { 3840 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3841 } 3842 3843 pid = sys_clone3(&args, sizeof(args)); 3844 ASSERT_GE(pid, 0); 3845 3846 if (pid == 0) { 3847 int listener; 3848 3849 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3850 if (listener < 0) 3851 _exit(EXIT_FAILURE); 3852 3853 if (dup2(listener, 200) != 200) 3854 _exit(EXIT_FAILURE); 3855 3856 close(listener); 3857 3858 _exit(EXIT_SUCCESS); 3859 } 3860 3861 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3862 EXPECT_EQ(true, WIFEXITED(status)); 3863 EXPECT_EQ(0, WEXITSTATUS(status)); 3864 3865 /* 3866 * The seccomp filter has become unused so we should be notified once 3867 * the kernel gets around to cleaning up task struct. 3868 */ 3869 pollfd.fd = 200; 3870 pollfd.events = POLLHUP; 3871 3872 EXPECT_GT(poll(&pollfd, 1, 2000), 0); 3873 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); 3874 } 3875 3876 static void *do_thread(void *data) 3877 { 3878 return NULL; 3879 } 3880 3881 TEST(user_notification_filter_empty_threaded) 3882 { 3883 pid_t pid; 3884 long ret; 3885 int status; 3886 struct pollfd pollfd; 3887 struct __clone_args args = { 3888 .flags = CLONE_FILES, 3889 .exit_signal = SIGCHLD, 3890 }; 3891 3892 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3893 ASSERT_EQ(0, ret) { 3894 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3895 } 3896 3897 pid = sys_clone3(&args, sizeof(args)); 3898 ASSERT_GE(pid, 0); 3899 3900 if (pid == 0) { 3901 pid_t pid1, pid2; 3902 int listener, status; 3903 pthread_t thread; 3904 3905 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3906 if (listener < 0) 3907 _exit(EXIT_FAILURE); 3908 3909 if (dup2(listener, 200) != 200) 3910 _exit(EXIT_FAILURE); 3911 3912 close(listener); 3913 3914 pid1 = fork(); 3915 if (pid1 < 0) 3916 _exit(EXIT_FAILURE); 3917 3918 if (pid1 == 0) 3919 _exit(EXIT_SUCCESS); 3920 3921 pid2 = fork(); 3922 if (pid2 < 0) 3923 _exit(EXIT_FAILURE); 3924 3925 if (pid2 == 0) 3926 _exit(EXIT_SUCCESS); 3927 3928 if (pthread_create(&thread, NULL, do_thread, NULL) || 3929 pthread_join(thread, NULL)) 3930 _exit(EXIT_FAILURE); 3931 3932 if (pthread_create(&thread, NULL, do_thread, NULL) || 3933 pthread_join(thread, NULL)) 3934 _exit(EXIT_FAILURE); 3935 3936 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) || 3937 WEXITSTATUS(status)) 3938 _exit(EXIT_FAILURE); 3939 3940 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) || 3941 WEXITSTATUS(status)) 3942 _exit(EXIT_FAILURE); 3943 3944 exit(EXIT_SUCCESS); 3945 } 3946 3947 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3948 EXPECT_EQ(true, WIFEXITED(status)); 3949 EXPECT_EQ(0, WEXITSTATUS(status)); 3950 3951 /* 3952 * The seccomp filter has become unused so we should be notified once 3953 * the kernel gets around to cleaning up task struct. 3954 */ 3955 pollfd.fd = 200; 3956 pollfd.events = POLLHUP; 3957 3958 EXPECT_GT(poll(&pollfd, 1, 2000), 0); 3959 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); 3960 } 3961 3962 TEST(user_notification_addfd) 3963 { 3964 pid_t pid; 3965 long ret; 3966 int status, listener, memfd, fd, nextfd; 3967 struct seccomp_notif_addfd addfd = {}; 3968 struct seccomp_notif_addfd_small small = {}; 3969 struct seccomp_notif_addfd_big big = {}; 3970 struct seccomp_notif req = {}; 3971 struct seccomp_notif_resp resp = {}; 3972 /* 100 ms */ 3973 struct timespec delay = { .tv_nsec = 100000000 }; 3974 3975 /* There may be arbitrary already-open fds at test start. */ 3976 memfd = memfd_create("test", 0); 3977 ASSERT_GE(memfd, 0); 3978 nextfd = memfd + 1; 3979 3980 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3981 ASSERT_EQ(0, ret) { 3982 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3983 } 3984 3985 /* fd: 4 */ 3986 /* Check that the basic notification machinery works */ 3987 listener = user_notif_syscall(__NR_getppid, 3988 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3989 ASSERT_EQ(listener, nextfd++); 3990 3991 pid = fork(); 3992 ASSERT_GE(pid, 0); 3993 3994 if (pid == 0) { 3995 /* fds will be added and this value is expected */ 3996 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) 3997 exit(1); 3998 3999 /* Atomic addfd+send is received here. Check it is a valid fd */ 4000 if (fcntl(syscall(__NR_getppid), F_GETFD) == -1) 4001 exit(1); 4002 4003 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 4004 } 4005 4006 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4007 4008 addfd.srcfd = memfd; 4009 addfd.newfd = 0; 4010 addfd.id = req.id; 4011 addfd.flags = 0x0; 4012 4013 /* Verify bad newfd_flags cannot be set */ 4014 addfd.newfd_flags = ~O_CLOEXEC; 4015 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4016 EXPECT_EQ(errno, EINVAL); 4017 addfd.newfd_flags = O_CLOEXEC; 4018 4019 /* Verify bad flags cannot be set */ 4020 addfd.flags = 0xff; 4021 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4022 EXPECT_EQ(errno, EINVAL); 4023 addfd.flags = 0; 4024 4025 /* Verify that remote_fd cannot be set without setting flags */ 4026 addfd.newfd = 1; 4027 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4028 EXPECT_EQ(errno, EINVAL); 4029 addfd.newfd = 0; 4030 4031 /* Verify small size cannot be set */ 4032 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1); 4033 EXPECT_EQ(errno, EINVAL); 4034 4035 /* Verify we can't send bits filled in unknown buffer area */ 4036 memset(&big, 0xAA, sizeof(big)); 4037 big.addfd = addfd; 4038 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1); 4039 EXPECT_EQ(errno, E2BIG); 4040 4041 4042 /* Verify we can set an arbitrary remote fd */ 4043 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4044 EXPECT_EQ(fd, nextfd++); 4045 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4046 4047 /* Verify we can set an arbitrary remote fd with large size */ 4048 memset(&big, 0x0, sizeof(big)); 4049 big.addfd = addfd; 4050 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); 4051 EXPECT_EQ(fd, nextfd++); 4052 4053 /* Verify we can set a specific remote fd */ 4054 addfd.newfd = 42; 4055 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; 4056 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4057 EXPECT_EQ(fd, 42); 4058 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4059 4060 /* Resume syscall */ 4061 resp.id = req.id; 4062 resp.error = 0; 4063 resp.val = USER_NOTIF_MAGIC; 4064 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4065 4066 /* 4067 * This sets the ID of the ADD FD to the last request plus 1. The 4068 * notification ID increments 1 per notification. 4069 */ 4070 addfd.id = req.id + 1; 4071 4072 /* This spins until the underlying notification is generated */ 4073 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && 4074 errno != -EINPROGRESS) 4075 nanosleep(&delay, NULL); 4076 4077 memset(&req, 0, sizeof(req)); 4078 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4079 ASSERT_EQ(addfd.id, req.id); 4080 4081 /* Verify we can do an atomic addfd and send */ 4082 addfd.newfd = 0; 4083 addfd.flags = SECCOMP_ADDFD_FLAG_SEND; 4084 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4085 /* 4086 * Child has earlier "low" fds and now 42, so we expect the next 4087 * lowest available fd to be assigned here. 4088 */ 4089 EXPECT_EQ(fd, nextfd++); 4090 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4091 4092 /* 4093 * This sets the ID of the ADD FD to the last request plus 1. The 4094 * notification ID increments 1 per notification. 4095 */ 4096 addfd.id = req.id + 1; 4097 4098 /* This spins until the underlying notification is generated */ 4099 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && 4100 errno != -EINPROGRESS) 4101 nanosleep(&delay, NULL); 4102 4103 memset(&req, 0, sizeof(req)); 4104 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4105 ASSERT_EQ(addfd.id, req.id); 4106 4107 resp.id = req.id; 4108 resp.error = 0; 4109 resp.val = USER_NOTIF_MAGIC; 4110 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4111 4112 /* Wait for child to finish. */ 4113 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4114 EXPECT_EQ(true, WIFEXITED(status)); 4115 EXPECT_EQ(0, WEXITSTATUS(status)); 4116 4117 close(memfd); 4118 } 4119 4120 TEST(user_notification_addfd_rlimit) 4121 { 4122 pid_t pid; 4123 long ret; 4124 int status, listener, memfd; 4125 struct seccomp_notif_addfd addfd = {}; 4126 struct seccomp_notif req = {}; 4127 struct seccomp_notif_resp resp = {}; 4128 const struct rlimit lim = { 4129 .rlim_cur = 0, 4130 .rlim_max = 0, 4131 }; 4132 4133 memfd = memfd_create("test", 0); 4134 ASSERT_GE(memfd, 0); 4135 4136 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4137 ASSERT_EQ(0, ret) { 4138 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4139 } 4140 4141 /* Check that the basic notification machinery works */ 4142 listener = user_notif_syscall(__NR_getppid, 4143 SECCOMP_FILTER_FLAG_NEW_LISTENER); 4144 ASSERT_GE(listener, 0); 4145 4146 pid = fork(); 4147 ASSERT_GE(pid, 0); 4148 4149 if (pid == 0) 4150 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 4151 4152 4153 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4154 4155 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0); 4156 4157 addfd.srcfd = memfd; 4158 addfd.newfd_flags = O_CLOEXEC; 4159 addfd.newfd = 0; 4160 addfd.id = req.id; 4161 addfd.flags = 0; 4162 4163 /* Should probably spot check /proc/sys/fs/file-nr */ 4164 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4165 EXPECT_EQ(errno, EMFILE); 4166 4167 addfd.flags = SECCOMP_ADDFD_FLAG_SEND; 4168 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4169 EXPECT_EQ(errno, EMFILE); 4170 4171 addfd.newfd = 100; 4172 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; 4173 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4174 EXPECT_EQ(errno, EBADF); 4175 4176 resp.id = req.id; 4177 resp.error = 0; 4178 resp.val = USER_NOTIF_MAGIC; 4179 4180 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4181 4182 /* Wait for child to finish. */ 4183 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4184 EXPECT_EQ(true, WIFEXITED(status)); 4185 EXPECT_EQ(0, WEXITSTATUS(status)); 4186 4187 close(memfd); 4188 } 4189 4190 /* 4191 * TODO: 4192 * - expand NNP testing 4193 * - better arch-specific TRACE and TRAP handlers. 4194 * - endianness checking when appropriate 4195 * - 64-bit arg prodding 4196 * - arch value testing (x86 modes especially) 4197 * - verify that FILTER_FLAG_LOG filters generate log messages 4198 * - verify that RET_LOG generates log messages 4199 */ 4200 4201 TEST_HARNESS_MAIN 4202