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#include <sys/capability.h> 50 51#include <unistd.h> 52#include <sys/syscall.h> 53#include <poll.h> 54 55#include "../kselftest_harness.h" 56#include "../clone3/clone3_selftests.h" 57 58/* Attempt to de-conflict with the selftests tree. */ 59#ifndef SKIP 60#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) 61#endif 62 63#define MIN(X, Y) ((X) < (Y) ? (X) : (Y)) 64 65#ifndef PR_SET_PTRACER 66# define PR_SET_PTRACER 0x59616d61 67#endif 68 69#ifndef PR_SET_NO_NEW_PRIVS 70#define PR_SET_NO_NEW_PRIVS 38 71#define PR_GET_NO_NEW_PRIVS 39 72#endif 73 74#ifndef PR_SECCOMP_EXT 75#define PR_SECCOMP_EXT 43 76#endif 77 78#ifndef SECCOMP_EXT_ACT 79#define SECCOMP_EXT_ACT 1 80#endif 81 82#ifndef SECCOMP_EXT_ACT_TSYNC 83#define SECCOMP_EXT_ACT_TSYNC 1 84#endif 85 86#ifndef SECCOMP_MODE_STRICT 87#define SECCOMP_MODE_STRICT 1 88#endif 89 90#ifndef SECCOMP_MODE_FILTER 91#define SECCOMP_MODE_FILTER 2 92#endif 93 94#ifndef SECCOMP_RET_ALLOW 95struct seccomp_data { 96 int nr; 97 __u32 arch; 98 __u64 instruction_pointer; 99 __u64 args[6]; 100}; 101#endif 102 103#ifndef SECCOMP_RET_KILL_PROCESS 104#define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */ 105#define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */ 106#endif 107#ifndef SECCOMP_RET_KILL 108#define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD 109#define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ 110#define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ 111#define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ 112#define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ 113#endif 114#ifndef SECCOMP_RET_LOG 115#define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */ 116#endif 117 118#ifndef __NR_seccomp 119# if defined(__i386__) 120# define __NR_seccomp 354 121# elif defined(__x86_64__) 122# define __NR_seccomp 317 123# elif defined(__arm__) 124# define __NR_seccomp 383 125# elif defined(__aarch64__) 126# define __NR_seccomp 277 127# elif defined(__riscv) 128# define __NR_seccomp 277 129# elif defined(__csky__) 130# define __NR_seccomp 277 131# elif defined(__loongarch__) 132# define __NR_seccomp 277 133# elif defined(__hppa__) 134# define __NR_seccomp 338 135# elif defined(__powerpc__) 136# define __NR_seccomp 358 137# elif defined(__s390__) 138# define __NR_seccomp 348 139# elif defined(__xtensa__) 140# define __NR_seccomp 337 141# elif defined(__sh__) 142# define __NR_seccomp 372 143# elif defined(__mc68000__) 144# define __NR_seccomp 380 145# else 146# warning "seccomp syscall number unknown for this architecture" 147# define __NR_seccomp 0xffff 148# endif 149#endif 150 151#ifndef SECCOMP_SET_MODE_STRICT 152#define SECCOMP_SET_MODE_STRICT 0 153#endif 154 155#ifndef SECCOMP_SET_MODE_FILTER 156#define SECCOMP_SET_MODE_FILTER 1 157#endif 158 159#ifndef SECCOMP_GET_ACTION_AVAIL 160#define SECCOMP_GET_ACTION_AVAIL 2 161#endif 162 163#ifndef SECCOMP_GET_NOTIF_SIZES 164#define SECCOMP_GET_NOTIF_SIZES 3 165#endif 166 167#ifndef SECCOMP_FILTER_FLAG_TSYNC 168#define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0) 169#endif 170 171#ifndef SECCOMP_FILTER_FLAG_LOG 172#define SECCOMP_FILTER_FLAG_LOG (1UL << 1) 173#endif 174 175#ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW 176#define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2) 177#endif 178 179#ifndef PTRACE_SECCOMP_GET_METADATA 180#define PTRACE_SECCOMP_GET_METADATA 0x420d 181 182struct seccomp_metadata { 183 __u64 filter_off; /* Input: which filter */ 184 __u64 flags; /* Output: filter's flags */ 185}; 186#endif 187 188#ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER 189#define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3) 190#endif 191 192#ifndef SECCOMP_RET_USER_NOTIF 193#define SECCOMP_RET_USER_NOTIF 0x7fc00000U 194 195#define SECCOMP_IOC_MAGIC '!' 196#define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr) 197#define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type) 198#define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type) 199#define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type) 200 201/* Flags for seccomp notification fd ioctl. */ 202#define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif) 203#define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \ 204 struct seccomp_notif_resp) 205#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64) 206 207struct seccomp_notif { 208 __u64 id; 209 __u32 pid; 210 __u32 flags; 211 struct seccomp_data data; 212}; 213 214struct seccomp_notif_resp { 215 __u64 id; 216 __s64 val; 217 __s32 error; 218 __u32 flags; 219}; 220 221struct seccomp_notif_sizes { 222 __u16 seccomp_notif; 223 __u16 seccomp_notif_resp; 224 __u16 seccomp_data; 225}; 226#endif 227 228#ifndef SECCOMP_IOCTL_NOTIF_ADDFD 229/* On success, the return value is the remote process's added fd number */ 230#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ 231 struct seccomp_notif_addfd) 232 233/* valid flags for seccomp_notif_addfd */ 234#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ 235 236struct seccomp_notif_addfd { 237 __u64 id; 238 __u32 flags; 239 __u32 srcfd; 240 __u32 newfd; 241 __u32 newfd_flags; 242}; 243#endif 244 245#ifndef SECCOMP_ADDFD_FLAG_SEND 246#define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */ 247#endif 248 249struct seccomp_notif_addfd_small { 250 __u64 id; 251 char weird[4]; 252}; 253#define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \ 254 SECCOMP_IOW(3, struct seccomp_notif_addfd_small) 255 256struct seccomp_notif_addfd_big { 257 union { 258 struct seccomp_notif_addfd addfd; 259 char buf[sizeof(struct seccomp_notif_addfd) + 8]; 260 }; 261}; 262#define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \ 263 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big) 264 265#ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY 266#define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 267#define PTRACE_EVENTMSG_SYSCALL_EXIT 2 268#endif 269 270#ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE 271#define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001 272#endif 273 274#ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH 275#define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4) 276#endif 277 278#ifndef SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV 279#define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5) 280#endif 281 282#ifndef seccomp 283int seccomp(unsigned int op, unsigned int flags, void *args) 284{ 285 errno = 0; 286 return syscall(__NR_seccomp, op, flags, args); 287} 288#endif 289 290#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ 291#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) 292#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ 293#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) 294#else 295#error "wut? Unknown __BYTE_ORDER__?!" 296#endif 297 298#define SIBLING_EXIT_UNKILLED 0xbadbeef 299#define SIBLING_EXIT_FAILURE 0xbadface 300#define SIBLING_EXIT_NEWPRIVS 0xbadfeed 301 302static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2) 303{ 304#ifdef __NR_kcmp 305 errno = 0; 306 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2); 307#else 308 errno = ENOSYS; 309 return -1; 310#endif 311} 312 313/* Have TH_LOG report actual location filecmp() is used. */ 314#define filecmp(pid1, pid2, fd1, fd2) ({ \ 315 int _ret; \ 316 \ 317 _ret = __filecmp(pid1, pid2, fd1, fd2); \ 318 if (_ret != 0) { \ 319 if (_ret < 0 && errno == ENOSYS) { \ 320 TH_LOG("kcmp() syscall missing (test is less accurate)");\ 321 _ret = 0; \ 322 } \ 323 } \ 324 _ret; }) 325 326TEST(kcmp) 327{ 328 int ret; 329 330 ret = __filecmp(getpid(), getpid(), 1, 1); 331 EXPECT_EQ(ret, 0); 332 if (ret != 0 && errno == ENOSYS) 333 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)"); 334} 335 336TEST(mode_strict_support) 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_exit, 0); 345} 346 347TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) 348{ 349 long ret; 350 351 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); 352 ASSERT_EQ(0, ret) { 353 TH_LOG("Kernel does not support CONFIG_SECCOMP"); 354 } 355 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 356 NULL, NULL, NULL); 357 EXPECT_FALSE(true) { 358 TH_LOG("Unreachable!"); 359 } 360} 361 362/* Note! This doesn't test no new privs behavior */ 363TEST(no_new_privs_support) 364{ 365 long ret; 366 367 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 368 EXPECT_EQ(0, ret) { 369 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 370 } 371} 372 373/* Tests kernel support by checking for a copy_from_user() fault on NULL. */ 374TEST(mode_filter_support) 375{ 376 long ret; 377 378 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 379 ASSERT_EQ(0, ret) { 380 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 381 } 382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); 383 EXPECT_EQ(-1, ret); 384 EXPECT_EQ(EFAULT, errno) { 385 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); 386 } 387} 388 389TEST(mode_filter_without_nnp) 390{ 391 struct sock_filter filter[] = { 392 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 393 }; 394 struct sock_fprog prog = { 395 .len = (unsigned short)ARRAY_SIZE(filter), 396 .filter = filter, 397 }; 398 long ret; 399 cap_t cap = cap_get_proc(); 400 cap_flag_value_t is_cap_sys_admin = 0; 401 402 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); 403 ASSERT_LE(0, ret) { 404 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); 405 } 406 errno = 0; 407 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 408 /* Succeeds with CAP_SYS_ADMIN, fails without */ 409 cap_get_flag(cap, CAP_SYS_ADMIN, CAP_EFFECTIVE, &is_cap_sys_admin); 410 if (!is_cap_sys_admin) { 411 EXPECT_EQ(-1, ret); 412 EXPECT_EQ(EACCES, errno); 413 } else { 414 EXPECT_EQ(0, ret); 415 } 416} 417 418#define MAX_INSNS_PER_PATH 32768 419 420TEST(filter_size_limits) 421{ 422 int i; 423 int count = BPF_MAXINSNS + 1; 424 struct sock_filter allow[] = { 425 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 426 }; 427 struct sock_filter *filter; 428 struct sock_fprog prog = { }; 429 long ret; 430 431 filter = calloc(count, sizeof(*filter)); 432 ASSERT_NE(NULL, filter); 433 434 for (i = 0; i < count; i++) 435 filter[i] = allow[0]; 436 437 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 438 ASSERT_EQ(0, ret); 439 440 prog.filter = filter; 441 prog.len = count; 442 443 /* Too many filter instructions in a single filter. */ 444 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 445 ASSERT_NE(0, ret) { 446 TH_LOG("Installing %d insn filter was allowed", prog.len); 447 } 448 449 /* One less is okay, though. */ 450 prog.len -= 1; 451 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 452 ASSERT_EQ(0, ret) { 453 TH_LOG("Installing %d insn filter wasn't allowed", prog.len); 454 } 455} 456 457TEST(filter_chain_limits) 458{ 459 int i; 460 int count = BPF_MAXINSNS; 461 struct sock_filter allow[] = { 462 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 463 }; 464 struct sock_filter *filter; 465 struct sock_fprog prog = { }; 466 long ret; 467 468 filter = calloc(count, sizeof(*filter)); 469 ASSERT_NE(NULL, filter); 470 471 for (i = 0; i < count; i++) 472 filter[i] = allow[0]; 473 474 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 475 ASSERT_EQ(0, ret); 476 477 prog.filter = filter; 478 prog.len = 1; 479 480 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 481 ASSERT_EQ(0, ret); 482 483 prog.len = count; 484 485 /* Too many total filter instructions. */ 486 for (i = 0; i < MAX_INSNS_PER_PATH; i++) { 487 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 488 if (ret != 0) 489 break; 490 } 491 ASSERT_NE(0, ret) { 492 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", 493 i, count, i * (count + 4)); 494 } 495} 496 497TEST(mode_filter_cannot_move_to_strict) 498{ 499 struct sock_filter filter[] = { 500 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 501 }; 502 struct sock_fprog prog = { 503 .len = (unsigned short)ARRAY_SIZE(filter), 504 .filter = filter, 505 }; 506 long ret; 507 508 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 509 ASSERT_EQ(0, ret); 510 511 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 512 ASSERT_EQ(0, ret); 513 514 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); 515 EXPECT_EQ(-1, ret); 516 EXPECT_EQ(EINVAL, errno); 517} 518 519 520TEST(mode_filter_get_seccomp) 521{ 522 struct sock_filter filter[] = { 523 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 524 }; 525 struct sock_fprog prog = { 526 .len = (unsigned short)ARRAY_SIZE(filter), 527 .filter = filter, 528 }; 529 long ret; 530 531 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 532 ASSERT_EQ(0, ret); 533 534 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 535 EXPECT_EQ(0, ret); 536 537 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 538 ASSERT_EQ(0, ret); 539 540 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); 541 EXPECT_EQ(2, ret); 542} 543 544 545TEST(ALLOW_all) 546{ 547 struct sock_filter filter[] = { 548 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 549 }; 550 struct sock_fprog prog = { 551 .len = (unsigned short)ARRAY_SIZE(filter), 552 .filter = filter, 553 }; 554 long ret; 555 556 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 557 ASSERT_EQ(0, ret); 558 559 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 560 ASSERT_EQ(0, ret); 561} 562 563TEST(empty_prog) 564{ 565 struct sock_filter filter[] = { 566 }; 567 struct sock_fprog prog = { 568 .len = (unsigned short)ARRAY_SIZE(filter), 569 .filter = filter, 570 }; 571 long ret; 572 573 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 574 ASSERT_EQ(0, ret); 575 576 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 577 EXPECT_EQ(-1, ret); 578 EXPECT_EQ(EINVAL, errno); 579} 580 581TEST(log_all) 582{ 583 struct sock_filter filter[] = { 584 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 585 }; 586 struct sock_fprog prog = { 587 .len = (unsigned short)ARRAY_SIZE(filter), 588 .filter = filter, 589 }; 590 long ret; 591 pid_t parent = getppid(); 592 593 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 594 ASSERT_EQ(0, ret); 595 596 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 597 ASSERT_EQ(0, ret); 598 599 /* getppid() should succeed and be logged (no check for logging) */ 600 EXPECT_EQ(parent, syscall(__NR_getppid)); 601} 602 603TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) 604{ 605 struct sock_filter filter[] = { 606 BPF_STMT(BPF_RET|BPF_K, 0x10000000U), 607 }; 608 struct sock_fprog prog = { 609 .len = (unsigned short)ARRAY_SIZE(filter), 610 .filter = filter, 611 }; 612 long ret; 613 614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 615 ASSERT_EQ(0, ret); 616 617 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 618 ASSERT_EQ(0, ret); 619 EXPECT_EQ(0, syscall(__NR_getpid)) { 620 TH_LOG("getpid() shouldn't ever return"); 621 } 622} 623 624/* return code >= 0x80000000 is unused. */ 625TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) 626{ 627 struct sock_filter filter[] = { 628 BPF_STMT(BPF_RET|BPF_K, 0x90000000U), 629 }; 630 struct sock_fprog prog = { 631 .len = (unsigned short)ARRAY_SIZE(filter), 632 .filter = filter, 633 }; 634 long ret; 635 636 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 637 ASSERT_EQ(0, ret); 638 639 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 640 ASSERT_EQ(0, ret); 641 EXPECT_EQ(0, syscall(__NR_getpid)) { 642 TH_LOG("getpid() shouldn't ever return"); 643 } 644} 645 646TEST_SIGNAL(KILL_all, SIGSYS) 647{ 648 struct sock_filter filter[] = { 649 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 650 }; 651 struct sock_fprog prog = { 652 .len = (unsigned short)ARRAY_SIZE(filter), 653 .filter = filter, 654 }; 655 long ret; 656 657 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 658 ASSERT_EQ(0, ret); 659 660 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 661 ASSERT_EQ(0, ret); 662} 663 664TEST_SIGNAL(KILL_one, SIGSYS) 665{ 666 struct sock_filter filter[] = { 667 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 668 offsetof(struct seccomp_data, nr)), 669 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 670 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 671 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 672 }; 673 struct sock_fprog prog = { 674 .len = (unsigned short)ARRAY_SIZE(filter), 675 .filter = filter, 676 }; 677 long ret; 678 pid_t parent = getppid(); 679 680 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 681 ASSERT_EQ(0, ret); 682 683 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 684 ASSERT_EQ(0, ret); 685 686 EXPECT_EQ(parent, syscall(__NR_getppid)); 687 /* getpid() should never return. */ 688 EXPECT_EQ(0, syscall(__NR_getpid)); 689} 690 691TEST_SIGNAL(KILL_one_arg_one, SIGSYS) 692{ 693 void *fatal_address; 694 struct sock_filter filter[] = { 695 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 696 offsetof(struct seccomp_data, nr)), 697 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0), 698 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 699 /* Only both with lower 32-bit for now. */ 700 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), 701 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 702 (unsigned long)&fatal_address, 0, 1), 703 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 704 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 705 }; 706 struct sock_fprog prog = { 707 .len = (unsigned short)ARRAY_SIZE(filter), 708 .filter = filter, 709 }; 710 long ret; 711 pid_t parent = getppid(); 712 struct tms timebuf; 713 clock_t clock = times(&timebuf); 714 715 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 716 ASSERT_EQ(0, ret); 717 718 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 719 ASSERT_EQ(0, ret); 720 721 EXPECT_EQ(parent, syscall(__NR_getppid)); 722 EXPECT_LE(clock, syscall(__NR_times, &timebuf)); 723 /* times() should never return. */ 724 EXPECT_EQ(0, syscall(__NR_times, &fatal_address)); 725} 726 727TEST_SIGNAL(KILL_one_arg_six, SIGSYS) 728{ 729#ifndef __NR_mmap2 730 int sysno = __NR_mmap; 731#else 732 int sysno = __NR_mmap2; 733#endif 734 struct sock_filter filter[] = { 735 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 736 offsetof(struct seccomp_data, nr)), 737 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0), 738 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 739 /* Only both with lower 32-bit for now. */ 740 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), 741 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), 742 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 743 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 744 }; 745 struct sock_fprog prog = { 746 .len = (unsigned short)ARRAY_SIZE(filter), 747 .filter = filter, 748 }; 749 long ret; 750 pid_t parent = getppid(); 751 int fd; 752 void *map1, *map2; 753 int page_size = sysconf(_SC_PAGESIZE); 754 755 ASSERT_LT(0, page_size); 756 757 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 758 ASSERT_EQ(0, ret); 759 760 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 761 ASSERT_EQ(0, ret); 762 763 fd = open("/dev/zero", O_RDONLY); 764 ASSERT_NE(-1, fd); 765 766 EXPECT_EQ(parent, syscall(__NR_getppid)); 767 map1 = (void *)syscall(sysno, 768 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size); 769 EXPECT_NE(MAP_FAILED, map1); 770 /* mmap2() should never return. */ 771 map2 = (void *)syscall(sysno, 772 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE); 773 EXPECT_EQ(MAP_FAILED, map2); 774 775 /* The test failed, so clean up the resources. */ 776 munmap(map1, page_size); 777 munmap(map2, page_size); 778 close(fd); 779} 780 781/* This is a thread task to die via seccomp filter violation. */ 782void *kill_thread(void *data) 783{ 784 bool die = (bool)data; 785 786 if (die) { 787 syscall(__NR_getpid); 788 return (void *)SIBLING_EXIT_FAILURE; 789 } 790 791 return (void *)SIBLING_EXIT_UNKILLED; 792} 793 794enum kill_t { 795 KILL_THREAD, 796 KILL_PROCESS, 797 RET_UNKNOWN 798}; 799 800/* Prepare a thread that will kill itself or both of us. */ 801void kill_thread_or_group(struct __test_metadata *_metadata, 802 enum kill_t kill_how) 803{ 804 pthread_t thread; 805 void *status; 806 /* Kill only when calling __NR_getpid. */ 807 struct sock_filter filter_thread[] = { 808 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 809 offsetof(struct seccomp_data, nr)), 810 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 811 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), 812 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 813 }; 814 struct sock_fprog prog_thread = { 815 .len = (unsigned short)ARRAY_SIZE(filter_thread), 816 .filter = filter_thread, 817 }; 818 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAA; 819 struct sock_filter filter_process[] = { 820 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 821 offsetof(struct seccomp_data, nr)), 822 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 823 BPF_STMT(BPF_RET|BPF_K, kill), 824 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 825 }; 826 struct sock_fprog prog_process = { 827 .len = (unsigned short)ARRAY_SIZE(filter_process), 828 .filter = filter_process, 829 }; 830 831 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 832 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 833 } 834 835 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, 836 kill_how == KILL_THREAD ? &prog_thread 837 : &prog_process)); 838 839 /* 840 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS 841 * flag cannot be downgraded by a new filter. 842 */ 843 if (kill_how == KILL_PROCESS) 844 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread)); 845 846 /* Start a thread that will exit immediately. */ 847 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false)); 848 ASSERT_EQ(0, pthread_join(thread, &status)); 849 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status); 850 851 /* Start a thread that will die immediately. */ 852 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true)); 853 ASSERT_EQ(0, pthread_join(thread, &status)); 854 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status); 855 856 /* 857 * If we get here, only the spawned thread died. Let the parent know 858 * the whole process didn't die (i.e. this thread, the spawner, 859 * stayed running). 860 */ 861 exit(42); 862} 863 864TEST(KILL_thread) 865{ 866 int status; 867 pid_t child_pid; 868 869 child_pid = fork(); 870 ASSERT_LE(0, child_pid); 871 if (child_pid == 0) { 872 kill_thread_or_group(_metadata, KILL_THREAD); 873 _exit(38); 874 } 875 876 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 877 878 /* If only the thread was killed, we'll see exit 42. */ 879 ASSERT_TRUE(WIFEXITED(status)); 880 ASSERT_EQ(42, WEXITSTATUS(status)); 881} 882 883TEST(KILL_process) 884{ 885 int status; 886 pid_t child_pid; 887 888 child_pid = fork(); 889 ASSERT_LE(0, child_pid); 890 if (child_pid == 0) { 891 kill_thread_or_group(_metadata, KILL_PROCESS); 892 _exit(38); 893 } 894 895 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 896 897 /* If the entire process was killed, we'll see SIGSYS. */ 898 ASSERT_TRUE(WIFSIGNALED(status)); 899 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 900} 901 902TEST(KILL_unknown) 903{ 904 int status; 905 pid_t child_pid; 906 907 child_pid = fork(); 908 ASSERT_LE(0, child_pid); 909 if (child_pid == 0) { 910 kill_thread_or_group(_metadata, RET_UNKNOWN); 911 _exit(38); 912 } 913 914 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 915 916 /* If the entire process was killed, we'll see SIGSYS. */ 917 EXPECT_TRUE(WIFSIGNALED(status)) { 918 TH_LOG("Unknown SECCOMP_RET is only killing the thread?"); 919 } 920 ASSERT_EQ(SIGSYS, WTERMSIG(status)); 921} 922 923/* TODO(wad) add 64-bit versus 32-bit arg tests. */ 924TEST(arg_out_of_range) 925{ 926 struct sock_filter filter[] = { 927 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), 928 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 929 }; 930 struct sock_fprog prog = { 931 .len = (unsigned short)ARRAY_SIZE(filter), 932 .filter = filter, 933 }; 934 long ret; 935 936 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 937 ASSERT_EQ(0, ret); 938 939 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); 940 EXPECT_EQ(-1, ret); 941 EXPECT_EQ(EINVAL, errno); 942} 943 944#define ERRNO_FILTER(name, errno) \ 945 struct sock_filter _read_filter_##name[] = { \ 946 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \ 947 offsetof(struct seccomp_data, nr)), \ 948 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \ 949 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \ 950 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \ 951 }; \ 952 struct sock_fprog prog_##name = { \ 953 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \ 954 .filter = _read_filter_##name, \ 955 } 956 957/* Make sure basic errno values are correctly passed through a filter. */ 958TEST(ERRNO_valid) 959{ 960 ERRNO_FILTER(valid, E2BIG); 961 long ret; 962 pid_t parent = getppid(); 963 964 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 965 ASSERT_EQ(0, ret); 966 967 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid); 968 ASSERT_EQ(0, ret); 969 970 EXPECT_EQ(parent, syscall(__NR_getppid)); 971 EXPECT_EQ(-1, read(-1, NULL, 0)); 972 EXPECT_EQ(E2BIG, errno); 973} 974 975/* Make sure an errno of zero is correctly handled by the arch code. */ 976TEST(ERRNO_zero) 977{ 978 ERRNO_FILTER(zero, 0); 979 long ret; 980 pid_t parent = getppid(); 981 982 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 983 ASSERT_EQ(0, ret); 984 985 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero); 986 ASSERT_EQ(0, ret); 987 988 EXPECT_EQ(parent, syscall(__NR_getppid)); 989 /* "errno" of 0 is ok. */ 990 EXPECT_EQ(0, read(-1, NULL, 0)); 991} 992 993/* 994 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller. 995 * This tests that the errno value gets capped correctly, fixed by 996 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO"). 997 */ 998TEST(ERRNO_capped) 999{ 1000 ERRNO_FILTER(capped, 4096); 1001 long ret; 1002 pid_t parent = getppid(); 1003 1004 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1005 ASSERT_EQ(0, ret); 1006 1007 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped); 1008 ASSERT_EQ(0, ret); 1009 1010 EXPECT_EQ(parent, syscall(__NR_getppid)); 1011 EXPECT_EQ(-1, read(-1, NULL, 0)); 1012 EXPECT_EQ(4095, errno); 1013} 1014 1015/* 1016 * Filters are processed in reverse order: last applied is executed first. 1017 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the 1018 * SECCOMP_RET_DATA mask results will follow the most recently applied 1019 * matching filter return (and not the lowest or highest value). 1020 */ 1021TEST(ERRNO_order) 1022{ 1023 ERRNO_FILTER(first, 11); 1024 ERRNO_FILTER(second, 13); 1025 ERRNO_FILTER(third, 12); 1026 long ret; 1027 pid_t parent = getppid(); 1028 1029 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1030 ASSERT_EQ(0, ret); 1031 1032 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first); 1033 ASSERT_EQ(0, ret); 1034 1035 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second); 1036 ASSERT_EQ(0, ret); 1037 1038 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third); 1039 ASSERT_EQ(0, ret); 1040 1041 EXPECT_EQ(parent, syscall(__NR_getppid)); 1042 EXPECT_EQ(-1, read(-1, NULL, 0)); 1043 EXPECT_EQ(12, errno); 1044} 1045 1046FIXTURE(TRAP) { 1047 struct sock_fprog prog; 1048}; 1049 1050FIXTURE_SETUP(TRAP) 1051{ 1052 struct sock_filter filter[] = { 1053 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1054 offsetof(struct seccomp_data, nr)), 1055 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 1056 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 1057 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1058 }; 1059 1060 memset(&self->prog, 0, sizeof(self->prog)); 1061 self->prog.filter = malloc(sizeof(filter)); 1062 ASSERT_NE(NULL, self->prog.filter); 1063 memcpy(self->prog.filter, filter, sizeof(filter)); 1064 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1065} 1066 1067FIXTURE_TEARDOWN(TRAP) 1068{ 1069 if (self->prog.filter) 1070 free(self->prog.filter); 1071} 1072 1073TEST_F_SIGNAL(TRAP, dfl, 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 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1081 ASSERT_EQ(0, ret); 1082 syscall(__NR_getpid); 1083} 1084 1085/* Ensure that SIGSYS overrides SIG_IGN */ 1086TEST_F_SIGNAL(TRAP, ign, SIGSYS) 1087{ 1088 long ret; 1089 1090 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1091 ASSERT_EQ(0, ret); 1092 1093 signal(SIGSYS, SIG_IGN); 1094 1095 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1096 ASSERT_EQ(0, ret); 1097 syscall(__NR_getpid); 1098} 1099 1100static siginfo_t TRAP_info; 1101static volatile int TRAP_nr; 1102static void TRAP_action(int nr, siginfo_t *info, void *void_context) 1103{ 1104 memcpy(&TRAP_info, info, sizeof(TRAP_info)); 1105 TRAP_nr = nr; 1106} 1107 1108TEST_F(TRAP, handler) 1109{ 1110 int ret, test; 1111 struct sigaction act; 1112 sigset_t mask; 1113 1114 memset(&act, 0, sizeof(act)); 1115 sigemptyset(&mask); 1116 sigaddset(&mask, SIGSYS); 1117 1118 act.sa_sigaction = &TRAP_action; 1119 act.sa_flags = SA_SIGINFO; 1120 ret = sigaction(SIGSYS, &act, NULL); 1121 ASSERT_EQ(0, ret) { 1122 TH_LOG("sigaction failed"); 1123 } 1124 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); 1125 ASSERT_EQ(0, ret) { 1126 TH_LOG("sigprocmask failed"); 1127 } 1128 1129 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1130 ASSERT_EQ(0, ret); 1131 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); 1132 ASSERT_EQ(0, ret); 1133 TRAP_nr = 0; 1134 memset(&TRAP_info, 0, sizeof(TRAP_info)); 1135 /* Expect the registers to be rolled back. (nr = error) may vary 1136 * based on arch. */ 1137 ret = syscall(__NR_getpid); 1138 /* Silence gcc warning about volatile. */ 1139 test = TRAP_nr; 1140 EXPECT_EQ(SIGSYS, test); 1141 struct local_sigsys { 1142 void *_call_addr; /* calling user insn */ 1143 int _syscall; /* triggering system call number */ 1144 unsigned int _arch; /* AUDIT_ARCH_* of syscall */ 1145 } *sigsys = (struct local_sigsys *) 1146#ifdef si_syscall 1147 &(TRAP_info.si_call_addr); 1148#else 1149 &TRAP_info.si_pid; 1150#endif 1151 EXPECT_EQ(__NR_getpid, sigsys->_syscall); 1152 /* Make sure arch is non-zero. */ 1153 EXPECT_NE(0, sigsys->_arch); 1154 EXPECT_NE(0, (unsigned long)sigsys->_call_addr); 1155} 1156 1157FIXTURE(precedence) { 1158 struct sock_fprog allow; 1159 struct sock_fprog log; 1160 struct sock_fprog trace; 1161 struct sock_fprog error; 1162 struct sock_fprog trap; 1163 struct sock_fprog kill; 1164}; 1165 1166FIXTURE_SETUP(precedence) 1167{ 1168 struct sock_filter allow_insns[] = { 1169 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1170 }; 1171 struct sock_filter log_insns[] = { 1172 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1173 offsetof(struct seccomp_data, nr)), 1174 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1175 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1176 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), 1177 }; 1178 struct sock_filter trace_insns[] = { 1179 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1180 offsetof(struct seccomp_data, nr)), 1181 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1182 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1183 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), 1184 }; 1185 struct sock_filter error_insns[] = { 1186 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1187 offsetof(struct seccomp_data, nr)), 1188 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1189 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1190 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), 1191 }; 1192 struct sock_filter trap_insns[] = { 1193 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1194 offsetof(struct seccomp_data, nr)), 1195 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1196 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1197 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), 1198 }; 1199 struct sock_filter kill_insns[] = { 1200 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1201 offsetof(struct seccomp_data, nr)), 1202 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), 1203 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1204 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 1205 }; 1206 1207 memset(self, 0, sizeof(*self)); 1208#define FILTER_ALLOC(_x) \ 1209 self->_x.filter = malloc(sizeof(_x##_insns)); \ 1210 ASSERT_NE(NULL, self->_x.filter); \ 1211 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ 1212 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) 1213 FILTER_ALLOC(allow); 1214 FILTER_ALLOC(log); 1215 FILTER_ALLOC(trace); 1216 FILTER_ALLOC(error); 1217 FILTER_ALLOC(trap); 1218 FILTER_ALLOC(kill); 1219} 1220 1221FIXTURE_TEARDOWN(precedence) 1222{ 1223#define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) 1224 FILTER_FREE(allow); 1225 FILTER_FREE(log); 1226 FILTER_FREE(trace); 1227 FILTER_FREE(error); 1228 FILTER_FREE(trap); 1229 FILTER_FREE(kill); 1230} 1231 1232TEST_F(precedence, allow_ok) 1233{ 1234 pid_t parent, res = 0; 1235 long ret; 1236 1237 parent = getppid(); 1238 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1239 ASSERT_EQ(0, ret); 1240 1241 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1242 ASSERT_EQ(0, ret); 1243 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1244 ASSERT_EQ(0, ret); 1245 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1246 ASSERT_EQ(0, ret); 1247 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1248 ASSERT_EQ(0, ret); 1249 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1250 ASSERT_EQ(0, ret); 1251 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1252 ASSERT_EQ(0, ret); 1253 /* Should work just fine. */ 1254 res = syscall(__NR_getppid); 1255 EXPECT_EQ(parent, res); 1256} 1257 1258TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) 1259{ 1260 pid_t parent, res = 0; 1261 long ret; 1262 1263 parent = getppid(); 1264 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1265 ASSERT_EQ(0, ret); 1266 1267 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1268 ASSERT_EQ(0, ret); 1269 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1270 ASSERT_EQ(0, ret); 1271 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1272 ASSERT_EQ(0, ret); 1273 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1274 ASSERT_EQ(0, ret); 1275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1276 ASSERT_EQ(0, ret); 1277 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1278 ASSERT_EQ(0, ret); 1279 /* Should work just fine. */ 1280 res = syscall(__NR_getppid); 1281 EXPECT_EQ(parent, res); 1282 /* getpid() should never return. */ 1283 res = syscall(__NR_getpid); 1284 EXPECT_EQ(0, res); 1285} 1286 1287TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) 1288{ 1289 pid_t parent; 1290 long ret; 1291 1292 parent = getppid(); 1293 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1294 ASSERT_EQ(0, ret); 1295 1296 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1297 ASSERT_EQ(0, ret); 1298 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); 1299 ASSERT_EQ(0, ret); 1300 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1301 ASSERT_EQ(0, ret); 1302 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1303 ASSERT_EQ(0, ret); 1304 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1305 ASSERT_EQ(0, ret); 1306 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1307 ASSERT_EQ(0, ret); 1308 /* Should work just fine. */ 1309 EXPECT_EQ(parent, syscall(__NR_getppid)); 1310 /* getpid() should never return. */ 1311 EXPECT_EQ(0, syscall(__NR_getpid)); 1312} 1313 1314TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) 1315{ 1316 pid_t parent; 1317 long ret; 1318 1319 parent = getppid(); 1320 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1321 ASSERT_EQ(0, ret); 1322 1323 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1324 ASSERT_EQ(0, ret); 1325 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1326 ASSERT_EQ(0, ret); 1327 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1328 ASSERT_EQ(0, ret); 1329 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1330 ASSERT_EQ(0, ret); 1331 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1332 ASSERT_EQ(0, ret); 1333 /* Should work just fine. */ 1334 EXPECT_EQ(parent, syscall(__NR_getppid)); 1335 /* getpid() should never return. */ 1336 EXPECT_EQ(0, syscall(__NR_getpid)); 1337} 1338 1339TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) 1340{ 1341 pid_t parent; 1342 long ret; 1343 1344 parent = getppid(); 1345 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1346 ASSERT_EQ(0, ret); 1347 1348 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1349 ASSERT_EQ(0, ret); 1350 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); 1351 ASSERT_EQ(0, ret); 1352 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1353 ASSERT_EQ(0, ret); 1354 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1355 ASSERT_EQ(0, ret); 1356 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1357 ASSERT_EQ(0, ret); 1358 /* Should work just fine. */ 1359 EXPECT_EQ(parent, syscall(__NR_getppid)); 1360 /* getpid() should never return. */ 1361 EXPECT_EQ(0, syscall(__NR_getpid)); 1362} 1363 1364TEST_F(precedence, errno_is_third) 1365{ 1366 pid_t parent; 1367 long ret; 1368 1369 parent = getppid(); 1370 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1371 ASSERT_EQ(0, ret); 1372 1373 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1374 ASSERT_EQ(0, ret); 1375 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1376 ASSERT_EQ(0, ret); 1377 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1378 ASSERT_EQ(0, ret); 1379 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1380 ASSERT_EQ(0, ret); 1381 /* Should work just fine. */ 1382 EXPECT_EQ(parent, syscall(__NR_getppid)); 1383 EXPECT_EQ(0, syscall(__NR_getpid)); 1384} 1385 1386TEST_F(precedence, errno_is_third_in_any_order) 1387{ 1388 pid_t parent; 1389 long ret; 1390 1391 parent = getppid(); 1392 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1393 ASSERT_EQ(0, ret); 1394 1395 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1396 ASSERT_EQ(0, ret); 1397 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); 1398 ASSERT_EQ(0, ret); 1399 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1400 ASSERT_EQ(0, ret); 1401 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1402 ASSERT_EQ(0, ret); 1403 /* Should work just fine. */ 1404 EXPECT_EQ(parent, syscall(__NR_getppid)); 1405 EXPECT_EQ(0, syscall(__NR_getpid)); 1406} 1407 1408TEST_F(precedence, trace_is_fourth) 1409{ 1410 pid_t parent; 1411 long ret; 1412 1413 parent = getppid(); 1414 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1415 ASSERT_EQ(0, ret); 1416 1417 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1418 ASSERT_EQ(0, ret); 1419 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1420 ASSERT_EQ(0, ret); 1421 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1422 ASSERT_EQ(0, ret); 1423 /* Should work just fine. */ 1424 EXPECT_EQ(parent, syscall(__NR_getppid)); 1425 /* No ptracer */ 1426 EXPECT_EQ(-1, syscall(__NR_getpid)); 1427} 1428 1429TEST_F(precedence, trace_is_fourth_in_any_order) 1430{ 1431 pid_t parent; 1432 long ret; 1433 1434 parent = getppid(); 1435 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1436 ASSERT_EQ(0, ret); 1437 1438 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); 1439 ASSERT_EQ(0, ret); 1440 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1441 ASSERT_EQ(0, ret); 1442 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1443 ASSERT_EQ(0, ret); 1444 /* Should work just fine. */ 1445 EXPECT_EQ(parent, syscall(__NR_getppid)); 1446 /* No ptracer */ 1447 EXPECT_EQ(-1, syscall(__NR_getpid)); 1448} 1449 1450TEST_F(precedence, log_is_fifth) 1451{ 1452 pid_t mypid, parent; 1453 long ret; 1454 1455 mypid = getpid(); 1456 parent = getppid(); 1457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1458 ASSERT_EQ(0, ret); 1459 1460 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1461 ASSERT_EQ(0, ret); 1462 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1463 ASSERT_EQ(0, ret); 1464 /* Should work just fine. */ 1465 EXPECT_EQ(parent, syscall(__NR_getppid)); 1466 /* Should also work just fine */ 1467 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1468} 1469 1470TEST_F(precedence, log_is_fifth_in_any_order) 1471{ 1472 pid_t mypid, parent; 1473 long ret; 1474 1475 mypid = getpid(); 1476 parent = getppid(); 1477 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1478 ASSERT_EQ(0, ret); 1479 1480 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); 1481 ASSERT_EQ(0, ret); 1482 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); 1483 ASSERT_EQ(0, ret); 1484 /* Should work just fine. */ 1485 EXPECT_EQ(parent, syscall(__NR_getppid)); 1486 /* Should also work just fine */ 1487 EXPECT_EQ(mypid, syscall(__NR_getpid)); 1488} 1489 1490#ifndef PTRACE_O_TRACESECCOMP 1491#define PTRACE_O_TRACESECCOMP 0x00000080 1492#endif 1493 1494/* Catch the Ubuntu 12.04 value error. */ 1495#if PTRACE_EVENT_SECCOMP != 7 1496#undef PTRACE_EVENT_SECCOMP 1497#endif 1498 1499#ifndef PTRACE_EVENT_SECCOMP 1500#define PTRACE_EVENT_SECCOMP 7 1501#endif 1502 1503#define PTRACE_EVENT_MASK(status) ((status) >> 16) 1504bool tracer_running; 1505void tracer_stop(int sig) 1506{ 1507 tracer_running = false; 1508} 1509 1510typedef void tracer_func_t(struct __test_metadata *_metadata, 1511 pid_t tracee, int status, void *args); 1512 1513void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, 1514 tracer_func_t tracer_func, void *args, bool ptrace_syscall) 1515{ 1516 int ret = -1; 1517 struct sigaction action = { 1518 .sa_handler = tracer_stop, 1519 }; 1520 1521 /* Allow external shutdown. */ 1522 tracer_running = true; 1523 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); 1524 1525 errno = 0; 1526 while (ret == -1 && errno != EINVAL) 1527 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); 1528 ASSERT_EQ(0, ret) { 1529 kill(tracee, SIGKILL); 1530 } 1531 /* Wait for attach stop */ 1532 wait(NULL); 1533 1534 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ? 1535 PTRACE_O_TRACESYSGOOD : 1536 PTRACE_O_TRACESECCOMP); 1537 ASSERT_EQ(0, ret) { 1538 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); 1539 kill(tracee, SIGKILL); 1540 } 1541 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1542 tracee, NULL, 0); 1543 ASSERT_EQ(0, ret); 1544 1545 /* Unblock the tracee */ 1546 ASSERT_EQ(1, write(fd, "A", 1)); 1547 ASSERT_EQ(0, close(fd)); 1548 1549 /* Run until we're shut down. Must assert to stop execution. */ 1550 while (tracer_running) { 1551 int status; 1552 1553 if (wait(&status) != tracee) 1554 continue; 1555 1556 if (WIFSIGNALED(status)) { 1557 /* Child caught a fatal signal. */ 1558 return; 1559 } 1560 if (WIFEXITED(status)) { 1561 /* Child exited with code. */ 1562 return; 1563 } 1564 1565 /* Check if we got an expected event. */ 1566 ASSERT_EQ(WIFCONTINUED(status), false); 1567 ASSERT_EQ(WIFSTOPPED(status), true); 1568 ASSERT_EQ(WSTOPSIG(status) & SIGTRAP, SIGTRAP) { 1569 TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status)); 1570 } 1571 1572 tracer_func(_metadata, tracee, status, args); 1573 1574 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, 1575 tracee, NULL, 0); 1576 ASSERT_EQ(0, ret); 1577 } 1578 /* Directly report the status of our test harness results. */ 1579 syscall(__NR_exit, _metadata->exit_code); 1580} 1581 1582/* Common tracer setup/teardown functions. */ 1583void cont_handler(int num) 1584{ } 1585pid_t setup_trace_fixture(struct __test_metadata *_metadata, 1586 tracer_func_t func, void *args, bool ptrace_syscall) 1587{ 1588 char sync; 1589 int pipefd[2]; 1590 pid_t tracer_pid; 1591 pid_t tracee = getpid(); 1592 1593 /* Setup a pipe for clean synchronization. */ 1594 ASSERT_EQ(0, pipe(pipefd)); 1595 1596 /* Fork a child which we'll promote to tracer */ 1597 tracer_pid = fork(); 1598 ASSERT_LE(0, tracer_pid); 1599 signal(SIGALRM, cont_handler); 1600 if (tracer_pid == 0) { 1601 close(pipefd[0]); 1602 start_tracer(_metadata, pipefd[1], tracee, func, args, 1603 ptrace_syscall); 1604 syscall(__NR_exit, 0); 1605 } 1606 close(pipefd[1]); 1607 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); 1608 read(pipefd[0], &sync, 1); 1609 close(pipefd[0]); 1610 1611 return tracer_pid; 1612} 1613 1614void teardown_trace_fixture(struct __test_metadata *_metadata, 1615 pid_t tracer) 1616{ 1617 if (tracer) { 1618 int status; 1619 /* 1620 * Extract the exit code from the other process and 1621 * adopt it for ourselves in case its asserts failed. 1622 */ 1623 ASSERT_EQ(0, kill(tracer, SIGUSR1)); 1624 ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); 1625 if (WEXITSTATUS(status)) 1626 _metadata->exit_code = KSFT_FAIL; 1627 } 1628} 1629 1630/* "poke" tracer arguments and function. */ 1631struct tracer_args_poke_t { 1632 unsigned long poke_addr; 1633}; 1634 1635void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, 1636 void *args) 1637{ 1638 int ret; 1639 unsigned long msg; 1640 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; 1641 1642 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 1643 EXPECT_EQ(0, ret); 1644 /* If this fails, don't try to recover. */ 1645 ASSERT_EQ(0x1001, msg) { 1646 kill(tracee, SIGKILL); 1647 } 1648 /* 1649 * Poke in the message. 1650 * Registers are not touched to try to keep this relatively arch 1651 * agnostic. 1652 */ 1653 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); 1654 EXPECT_EQ(0, ret); 1655} 1656 1657FIXTURE(TRACE_poke) { 1658 struct sock_fprog prog; 1659 pid_t tracer; 1660 long poked; 1661 struct tracer_args_poke_t tracer_args; 1662}; 1663 1664FIXTURE_SETUP(TRACE_poke) 1665{ 1666 struct sock_filter filter[] = { 1667 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 1668 offsetof(struct seccomp_data, nr)), 1669 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 1670 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), 1671 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 1672 }; 1673 1674 self->poked = 0; 1675 memset(&self->prog, 0, sizeof(self->prog)); 1676 self->prog.filter = malloc(sizeof(filter)); 1677 ASSERT_NE(NULL, self->prog.filter); 1678 memcpy(self->prog.filter, filter, sizeof(filter)); 1679 self->prog.len = (unsigned short)ARRAY_SIZE(filter); 1680 1681 /* Set up tracer args. */ 1682 self->tracer_args.poke_addr = (unsigned long)&self->poked; 1683 1684 /* Launch tracer. */ 1685 self->tracer = setup_trace_fixture(_metadata, tracer_poke, 1686 &self->tracer_args, false); 1687} 1688 1689FIXTURE_TEARDOWN(TRACE_poke) 1690{ 1691 teardown_trace_fixture(_metadata, self->tracer); 1692 if (self->prog.filter) 1693 free(self->prog.filter); 1694} 1695 1696TEST_F(TRACE_poke, read_has_side_effects) 1697{ 1698 ssize_t ret; 1699 1700 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1701 ASSERT_EQ(0, ret); 1702 1703 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1704 ASSERT_EQ(0, ret); 1705 1706 EXPECT_EQ(0, self->poked); 1707 ret = read(-1, NULL, 0); 1708 EXPECT_EQ(-1, ret); 1709 EXPECT_EQ(0x1001, self->poked); 1710} 1711 1712TEST_F(TRACE_poke, getpid_runs_normally) 1713{ 1714 long ret; 1715 1716 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 1717 ASSERT_EQ(0, ret); 1718 1719 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); 1720 ASSERT_EQ(0, ret); 1721 1722 EXPECT_EQ(0, self->poked); 1723 EXPECT_NE(0, syscall(__NR_getpid)); 1724 EXPECT_EQ(0, self->poked); 1725} 1726 1727#if defined(__x86_64__) 1728# define ARCH_REGS struct user_regs_struct 1729# define SYSCALL_NUM(_regs) (_regs).orig_rax 1730# define SYSCALL_RET(_regs) (_regs).rax 1731#elif defined(__i386__) 1732# define ARCH_REGS struct user_regs_struct 1733# define SYSCALL_NUM(_regs) (_regs).orig_eax 1734# define SYSCALL_RET(_regs) (_regs).eax 1735#elif defined(__arm__) 1736# define ARCH_REGS struct pt_regs 1737# define SYSCALL_NUM(_regs) (_regs).ARM_r7 1738# ifndef PTRACE_SET_SYSCALL 1739# define PTRACE_SET_SYSCALL 23 1740# endif 1741# define SYSCALL_NUM_SET(_regs, _nr) \ 1742 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr)) 1743# define SYSCALL_RET(_regs) (_regs).ARM_r0 1744#elif defined(__aarch64__) 1745# define ARCH_REGS struct user_pt_regs 1746# define SYSCALL_NUM(_regs) (_regs).regs[8] 1747# ifndef NT_ARM_SYSTEM_CALL 1748# define NT_ARM_SYSTEM_CALL 0x404 1749# endif 1750# define SYSCALL_NUM_SET(_regs, _nr) \ 1751 do { \ 1752 struct iovec __v; \ 1753 typeof(_nr) __nr = (_nr); \ 1754 __v.iov_base = &__nr; \ 1755 __v.iov_len = sizeof(__nr); \ 1756 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \ 1757 NT_ARM_SYSTEM_CALL, &__v)); \ 1758 } while (0) 1759# define SYSCALL_RET(_regs) (_regs).regs[0] 1760#elif defined(__loongarch__) 1761# define ARCH_REGS struct user_pt_regs 1762# define SYSCALL_NUM(_regs) (_regs).regs[11] 1763# define SYSCALL_RET(_regs) (_regs).regs[4] 1764#elif defined(__riscv) && __riscv_xlen == 64 1765# define ARCH_REGS struct user_regs_struct 1766# define SYSCALL_NUM(_regs) (_regs).a7 1767# define SYSCALL_RET(_regs) (_regs).a0 1768#elif defined(__csky__) 1769# define ARCH_REGS struct pt_regs 1770# if defined(__CSKYABIV2__) 1771# define SYSCALL_NUM(_regs) (_regs).regs[3] 1772# else 1773# define SYSCALL_NUM(_regs) (_regs).regs[9] 1774# endif 1775# define SYSCALL_RET(_regs) (_regs).a0 1776#elif defined(__hppa__) 1777# define ARCH_REGS struct user_regs_struct 1778# define SYSCALL_NUM(_regs) (_regs).gr[20] 1779# define SYSCALL_RET(_regs) (_regs).gr[28] 1780#elif defined(__powerpc__) 1781# define ARCH_REGS struct pt_regs 1782# define SYSCALL_NUM(_regs) (_regs).gpr[0] 1783# define SYSCALL_RET(_regs) (_regs).gpr[3] 1784# define SYSCALL_RET_SET(_regs, _val) \ 1785 do { \ 1786 typeof(_val) _result = (_val); \ 1787 if ((_regs.trap & 0xfff0) == 0x3000) { \ 1788 /* \ 1789 * scv 0 system call uses -ve result \ 1790 * for error, so no need to adjust. \ 1791 */ \ 1792 SYSCALL_RET(_regs) = _result; \ 1793 } else { \ 1794 /* \ 1795 * A syscall error is signaled by the \ 1796 * CR0 SO bit and the code is stored as \ 1797 * a positive value. \ 1798 */ \ 1799 if (_result < 0) { \ 1800 SYSCALL_RET(_regs) = -_result; \ 1801 (_regs).ccr |= 0x10000000; \ 1802 } else { \ 1803 SYSCALL_RET(_regs) = _result; \ 1804 (_regs).ccr &= ~0x10000000; \ 1805 } \ 1806 } \ 1807 } while (0) 1808# define SYSCALL_RET_SET_ON_PTRACE_EXIT 1809#elif defined(__s390__) 1810# define ARCH_REGS s390_regs 1811# define SYSCALL_NUM(_regs) (_regs).gprs[2] 1812# define SYSCALL_RET_SET(_regs, _val) \ 1813 TH_LOG("Can't modify syscall return on this architecture") 1814#elif defined(__mips__) 1815# include <asm/unistd_nr_n32.h> 1816# include <asm/unistd_nr_n64.h> 1817# include <asm/unistd_nr_o32.h> 1818# define ARCH_REGS struct pt_regs 1819# define SYSCALL_NUM(_regs) \ 1820 ({ \ 1821 typeof((_regs).regs[2]) _nr; \ 1822 if ((_regs).regs[2] == __NR_O32_Linux) \ 1823 _nr = (_regs).regs[4]; \ 1824 else \ 1825 _nr = (_regs).regs[2]; \ 1826 _nr; \ 1827 }) 1828# define SYSCALL_NUM_SET(_regs, _nr) \ 1829 do { \ 1830 if ((_regs).regs[2] == __NR_O32_Linux) \ 1831 (_regs).regs[4] = _nr; \ 1832 else \ 1833 (_regs).regs[2] = _nr; \ 1834 } while (0) 1835# define SYSCALL_RET_SET(_regs, _val) \ 1836 TH_LOG("Can't modify syscall return on this architecture") 1837#elif defined(__xtensa__) 1838# define ARCH_REGS struct user_pt_regs 1839# define SYSCALL_NUM(_regs) (_regs).syscall 1840/* 1841 * On xtensa syscall return value is in the register 1842 * a2 of the current window which is not fixed. 1843 */ 1844#define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2] 1845#elif defined(__sh__) 1846# define ARCH_REGS struct pt_regs 1847# define SYSCALL_NUM(_regs) (_regs).regs[3] 1848# define SYSCALL_RET(_regs) (_regs).regs[0] 1849#elif defined(__mc68000__) 1850# define ARCH_REGS struct user_regs_struct 1851# define SYSCALL_NUM(_regs) (_regs).orig_d0 1852# define SYSCALL_RET(_regs) (_regs).d0 1853#else 1854# error "Do not know how to find your architecture's registers and syscalls" 1855#endif 1856 1857/* 1858 * Most architectures can change the syscall by just updating the 1859 * associated register. This is the default if not defined above. 1860 */ 1861#ifndef SYSCALL_NUM_SET 1862# define SYSCALL_NUM_SET(_regs, _nr) \ 1863 do { \ 1864 SYSCALL_NUM(_regs) = (_nr); \ 1865 } while (0) 1866#endif 1867/* 1868 * Most architectures can change the syscall return value by just 1869 * writing to the SYSCALL_RET register. This is the default if not 1870 * defined above. If an architecture cannot set the return value 1871 * (for example when the syscall and return value register is 1872 * shared), report it with TH_LOG() in an arch-specific definition 1873 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined. 1874 */ 1875#if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET) 1876# error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch" 1877#endif 1878#ifndef SYSCALL_RET_SET 1879# define SYSCALL_RET_SET(_regs, _val) \ 1880 do { \ 1881 SYSCALL_RET(_regs) = (_val); \ 1882 } while (0) 1883#endif 1884 1885/* When the syscall return can't be changed, stub out the tests for it. */ 1886#ifndef SYSCALL_RET 1887# define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action) 1888#else 1889# define EXPECT_SYSCALL_RETURN(val, action) \ 1890 do { \ 1891 errno = 0; \ 1892 if (val < 0) { \ 1893 EXPECT_EQ(-1, action); \ 1894 EXPECT_EQ(-(val), errno); \ 1895 } else { \ 1896 EXPECT_EQ(val, action); \ 1897 } \ 1898 } while (0) 1899#endif 1900 1901/* 1902 * Some architectures (e.g. powerpc) can only set syscall 1903 * return values on syscall exit during ptrace. 1904 */ 1905const bool ptrace_entry_set_syscall_nr = true; 1906const bool ptrace_entry_set_syscall_ret = 1907#ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT 1908 true; 1909#else 1910 false; 1911#endif 1912 1913/* 1914 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for 1915 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). 1916 */ 1917#if defined(__x86_64__) || defined(__i386__) || defined(__mips__) || defined(__mc68000__) 1918# define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs)) 1919# define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs)) 1920#else 1921# define ARCH_GETREGS(_regs) ({ \ 1922 struct iovec __v; \ 1923 __v.iov_base = &(_regs); \ 1924 __v.iov_len = sizeof(_regs); \ 1925 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \ 1926 }) 1927# define ARCH_SETREGS(_regs) ({ \ 1928 struct iovec __v; \ 1929 __v.iov_base = &(_regs); \ 1930 __v.iov_len = sizeof(_regs); \ 1931 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \ 1932 }) 1933#endif 1934 1935/* Architecture-specific syscall fetching routine. */ 1936int get_syscall(struct __test_metadata *_metadata, pid_t tracee) 1937{ 1938 ARCH_REGS regs; 1939 1940 EXPECT_EQ(0, ARCH_GETREGS(regs)) { 1941 return -1; 1942 } 1943 1944 return SYSCALL_NUM(regs); 1945} 1946 1947/* Architecture-specific syscall changing routine. */ 1948void __change_syscall(struct __test_metadata *_metadata, 1949 pid_t tracee, long *syscall, long *ret) 1950{ 1951 ARCH_REGS orig, regs; 1952 1953 /* Do not get/set registers if we have nothing to do. */ 1954 if (!syscall && !ret) 1955 return; 1956 1957 EXPECT_EQ(0, ARCH_GETREGS(regs)) { 1958 return; 1959 } 1960 orig = regs; 1961 1962 if (syscall) 1963 SYSCALL_NUM_SET(regs, *syscall); 1964 1965 if (ret) 1966 SYSCALL_RET_SET(regs, *ret); 1967 1968 /* Flush any register changes made. */ 1969 if (memcmp(&orig, ®s, sizeof(orig)) != 0) 1970 EXPECT_EQ(0, ARCH_SETREGS(regs)); 1971} 1972 1973/* Change only syscall number. */ 1974void change_syscall_nr(struct __test_metadata *_metadata, 1975 pid_t tracee, long syscall) 1976{ 1977 __change_syscall(_metadata, tracee, &syscall, NULL); 1978} 1979 1980/* Change syscall return value (and set syscall number to -1). */ 1981void change_syscall_ret(struct __test_metadata *_metadata, 1982 pid_t tracee, long ret) 1983{ 1984 long syscall = -1; 1985 1986 __change_syscall(_metadata, tracee, &syscall, &ret); 1987} 1988 1989void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee, 1990 int status, void *args) 1991{ 1992 int ret; 1993 unsigned long msg; 1994 1995 EXPECT_EQ(PTRACE_EVENT_MASK(status), PTRACE_EVENT_SECCOMP) { 1996 TH_LOG("Unexpected ptrace event: %d", PTRACE_EVENT_MASK(status)); 1997 return; 1998 } 1999 2000 /* Make sure we got the right message. */ 2001 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 2002 EXPECT_EQ(0, ret); 2003 2004 /* Validate and take action on expected syscalls. */ 2005 switch (msg) { 2006 case 0x1002: 2007 /* change getpid to getppid. */ 2008 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee)); 2009 change_syscall_nr(_metadata, tracee, __NR_getppid); 2010 break; 2011 case 0x1003: 2012 /* skip gettid with valid return code. */ 2013 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee)); 2014 change_syscall_ret(_metadata, tracee, 45000); 2015 break; 2016 case 0x1004: 2017 /* skip openat with error. */ 2018 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee)); 2019 change_syscall_ret(_metadata, tracee, -ESRCH); 2020 break; 2021 case 0x1005: 2022 /* do nothing (allow getppid) */ 2023 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee)); 2024 break; 2025 default: 2026 EXPECT_EQ(0, msg) { 2027 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); 2028 kill(tracee, SIGKILL); 2029 } 2030 } 2031 2032} 2033 2034FIXTURE(TRACE_syscall) { 2035 struct sock_fprog prog; 2036 pid_t tracer, mytid, mypid, parent; 2037 long syscall_nr; 2038}; 2039 2040void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee, 2041 int status, void *args) 2042{ 2043 int ret; 2044 unsigned long msg; 2045 static bool entry; 2046 long syscall_nr_val, syscall_ret_val; 2047 long *syscall_nr = NULL, *syscall_ret = NULL; 2048 FIXTURE_DATA(TRACE_syscall) *self = args; 2049 2050 EXPECT_EQ(WSTOPSIG(status) & 0x80, 0x80) { 2051 TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status)); 2052 return; 2053 } 2054 2055 /* 2056 * The traditional way to tell PTRACE_SYSCALL entry/exit 2057 * is by counting. 2058 */ 2059 entry = !entry; 2060 2061 /* Make sure we got an appropriate message. */ 2062 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); 2063 EXPECT_EQ(0, ret); 2064 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY 2065 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg); 2066 2067 /* 2068 * Some architectures only support setting return values during 2069 * syscall exit under ptrace, and on exit the syscall number may 2070 * no longer be available. Therefore, save the initial sycall 2071 * number here, so it can be examined during both entry and exit 2072 * phases. 2073 */ 2074 if (entry) 2075 self->syscall_nr = get_syscall(_metadata, tracee); 2076 2077 /* 2078 * Depending on the architecture's syscall setting abilities, we 2079 * pick which things to set during this phase (entry or exit). 2080 */ 2081 if (entry == ptrace_entry_set_syscall_nr) 2082 syscall_nr = &syscall_nr_val; 2083 if (entry == ptrace_entry_set_syscall_ret) 2084 syscall_ret = &syscall_ret_val; 2085 2086 /* Now handle the actual rewriting cases. */ 2087 switch (self->syscall_nr) { 2088 case __NR_getpid: 2089 syscall_nr_val = __NR_getppid; 2090 /* Never change syscall return for this case. */ 2091 syscall_ret = NULL; 2092 break; 2093 case __NR_gettid: 2094 syscall_nr_val = -1; 2095 syscall_ret_val = 45000; 2096 break; 2097 case __NR_openat: 2098 syscall_nr_val = -1; 2099 syscall_ret_val = -ESRCH; 2100 break; 2101 default: 2102 /* Unhandled, do nothing. */ 2103 return; 2104 } 2105 2106 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret); 2107} 2108 2109FIXTURE_VARIANT(TRACE_syscall) { 2110 /* 2111 * All of the SECCOMP_RET_TRACE behaviors can be tested with either 2112 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL. 2113 * This indicates if we should use SECCOMP_RET_TRACE (false), or 2114 * ptrace (true). 2115 */ 2116 bool use_ptrace; 2117}; 2118 2119FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) { 2120 .use_ptrace = true, 2121}; 2122 2123FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) { 2124 .use_ptrace = false, 2125}; 2126 2127FIXTURE_SETUP(TRACE_syscall) 2128{ 2129 struct sock_filter filter[] = { 2130 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2131 offsetof(struct seccomp_data, nr)), 2132 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 2133 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), 2134 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), 2135 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), 2136 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1), 2137 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), 2138 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2139 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005), 2140 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2141 }; 2142 struct sock_fprog prog = { 2143 .len = (unsigned short)ARRAY_SIZE(filter), 2144 .filter = filter, 2145 }; 2146 long ret; 2147 2148 /* Prepare some testable syscall results. */ 2149 self->mytid = syscall(__NR_gettid); 2150 ASSERT_GT(self->mytid, 0); 2151 ASSERT_NE(self->mytid, 1) { 2152 TH_LOG("Running this test as init is not supported. :)"); 2153 } 2154 2155 self->mypid = getpid(); 2156 ASSERT_GT(self->mypid, 0); 2157 ASSERT_EQ(self->mytid, self->mypid); 2158 2159 self->parent = getppid(); 2160 ASSERT_GT(self->parent, 0); 2161 ASSERT_NE(self->parent, self->mypid); 2162 2163 /* Launch tracer. */ 2164 self->tracer = setup_trace_fixture(_metadata, 2165 variant->use_ptrace ? tracer_ptrace 2166 : tracer_seccomp, 2167 self, variant->use_ptrace); 2168 2169 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2170 ASSERT_EQ(0, ret); 2171 2172 /* Do not install seccomp rewrite filters, as we'll use ptrace instead. */ 2173 if (variant->use_ptrace) 2174 return; 2175 2176 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2177 ASSERT_EQ(0, ret); 2178} 2179 2180FIXTURE_TEARDOWN(TRACE_syscall) 2181{ 2182 teardown_trace_fixture(_metadata, self->tracer); 2183} 2184 2185TEST(negative_ENOSYS) 2186{ 2187#if defined(__arm__) 2188 SKIP(return, "arm32 does not support calling syscall -1"); 2189#endif 2190 /* 2191 * There should be no difference between an "internal" skip 2192 * and userspace asking for syscall "-1". 2193 */ 2194 errno = 0; 2195 EXPECT_EQ(-1, syscall(-1)); 2196 EXPECT_EQ(errno, ENOSYS); 2197 /* And no difference for "still not valid but not -1". */ 2198 errno = 0; 2199 EXPECT_EQ(-1, syscall(-101)); 2200 EXPECT_EQ(errno, ENOSYS); 2201} 2202 2203TEST_F(TRACE_syscall, negative_ENOSYS) 2204{ 2205 negative_ENOSYS(_metadata); 2206} 2207 2208TEST_F(TRACE_syscall, syscall_allowed) 2209{ 2210 /* getppid works as expected (no changes). */ 2211 EXPECT_EQ(self->parent, syscall(__NR_getppid)); 2212 EXPECT_NE(self->mypid, syscall(__NR_getppid)); 2213} 2214 2215TEST_F(TRACE_syscall, syscall_redirected) 2216{ 2217 /* getpid has been redirected to getppid as expected. */ 2218 EXPECT_EQ(self->parent, syscall(__NR_getpid)); 2219 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 2220} 2221 2222TEST_F(TRACE_syscall, syscall_errno) 2223{ 2224 /* Tracer should skip the open syscall, resulting in ESRCH. */ 2225 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat)); 2226} 2227 2228TEST_F(TRACE_syscall, syscall_faked) 2229{ 2230 /* Tracer skips the gettid syscall and store altered return value. */ 2231 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid)); 2232} 2233 2234TEST_F_SIGNAL(TRACE_syscall, kill_immediate, SIGSYS) 2235{ 2236 struct sock_filter filter[] = { 2237 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2238 offsetof(struct seccomp_data, nr)), 2239 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_mknodat, 0, 1), 2240 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), 2241 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2242 }; 2243 struct sock_fprog prog = { 2244 .len = (unsigned short)ARRAY_SIZE(filter), 2245 .filter = filter, 2246 }; 2247 long ret; 2248 2249 /* Install "kill on mknodat" filter. */ 2250 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2251 ASSERT_EQ(0, ret); 2252 2253 /* This should immediately die with SIGSYS, regardless of tracer. */ 2254 EXPECT_EQ(-1, syscall(__NR_mknodat, -1, NULL, 0, 0)); 2255} 2256 2257TEST_F(TRACE_syscall, skip_after) 2258{ 2259 struct sock_filter filter[] = { 2260 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2261 offsetof(struct seccomp_data, nr)), 2262 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2263 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), 2264 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2265 }; 2266 struct sock_fprog prog = { 2267 .len = (unsigned short)ARRAY_SIZE(filter), 2268 .filter = filter, 2269 }; 2270 long ret; 2271 2272 /* Install additional "errno on getppid" filter. */ 2273 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2274 ASSERT_EQ(0, ret); 2275 2276 /* Tracer will redirect getpid to getppid, and we should see EPERM. */ 2277 errno = 0; 2278 EXPECT_EQ(-1, syscall(__NR_getpid)); 2279 EXPECT_EQ(EPERM, errno); 2280} 2281 2282TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS) 2283{ 2284 struct sock_filter filter[] = { 2285 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2286 offsetof(struct seccomp_data, nr)), 2287 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), 2288 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2289 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2290 }; 2291 struct sock_fprog prog = { 2292 .len = (unsigned short)ARRAY_SIZE(filter), 2293 .filter = filter, 2294 }; 2295 long ret; 2296 2297 /* Install additional "death on getppid" filter. */ 2298 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 2299 ASSERT_EQ(0, ret); 2300 2301 /* Tracer will redirect getpid to getppid, and we should die. */ 2302 EXPECT_NE(self->mypid, syscall(__NR_getpid)); 2303} 2304 2305TEST(seccomp_syscall) 2306{ 2307 struct sock_filter filter[] = { 2308 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2309 }; 2310 struct sock_fprog prog = { 2311 .len = (unsigned short)ARRAY_SIZE(filter), 2312 .filter = filter, 2313 }; 2314 long ret; 2315 2316 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 2317 ASSERT_EQ(0, ret) { 2318 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2319 } 2320 2321 /* Reject insane operation. */ 2322 ret = seccomp(-1, 0, &prog); 2323 ASSERT_NE(ENOSYS, errno) { 2324 TH_LOG("Kernel does not support seccomp syscall!"); 2325 } 2326 EXPECT_EQ(EINVAL, errno) { 2327 TH_LOG("Did not reject crazy op value!"); 2328 } 2329 2330 /* Reject strict with flags or pointer. */ 2331 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); 2332 EXPECT_EQ(EINVAL, errno) { 2333 TH_LOG("Did not reject mode strict with flags!"); 2334 } 2335 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); 2336 EXPECT_EQ(EINVAL, errno) { 2337 TH_LOG("Did not reject mode strict with uargs!"); 2338 } 2339 2340 /* Reject insane args for filter. */ 2341 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); 2342 EXPECT_EQ(EINVAL, errno) { 2343 TH_LOG("Did not reject crazy filter flags!"); 2344 } 2345 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); 2346 EXPECT_EQ(EFAULT, errno) { 2347 TH_LOG("Did not reject NULL filter!"); 2348 } 2349 2350 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2351 EXPECT_EQ(0, errno) { 2352 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", 2353 strerror(errno)); 2354 } 2355} 2356 2357TEST(seccomp_syscall_mode_lock) 2358{ 2359 struct sock_filter filter[] = { 2360 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2361 }; 2362 struct sock_fprog prog = { 2363 .len = (unsigned short)ARRAY_SIZE(filter), 2364 .filter = filter, 2365 }; 2366 long ret; 2367 2368 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2369 ASSERT_EQ(0, ret) { 2370 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2371 } 2372 2373 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2374 ASSERT_NE(ENOSYS, errno) { 2375 TH_LOG("Kernel does not support seccomp syscall!"); 2376 } 2377 EXPECT_EQ(0, ret) { 2378 TH_LOG("Could not install filter!"); 2379 } 2380 2381 /* Make sure neither entry point will switch to strict. */ 2382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); 2383 EXPECT_EQ(EINVAL, errno) { 2384 TH_LOG("Switched to mode strict!"); 2385 } 2386 2387 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); 2388 EXPECT_EQ(EINVAL, errno) { 2389 TH_LOG("Switched to mode strict!"); 2390 } 2391} 2392 2393/* 2394 * Test detection of known and unknown filter flags. Userspace needs to be able 2395 * to check if a filter flag is supported by the current kernel and a good way 2396 * of doing that is by attempting to enter filter mode, with the flag bit in 2397 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates 2398 * that the flag is valid and EINVAL indicates that the flag is invalid. 2399 */ 2400TEST(detect_seccomp_filter_flags) 2401{ 2402 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC, 2403 SECCOMP_FILTER_FLAG_LOG, 2404 SECCOMP_FILTER_FLAG_SPEC_ALLOW, 2405 SECCOMP_FILTER_FLAG_NEW_LISTENER, 2406 SECCOMP_FILTER_FLAG_TSYNC_ESRCH }; 2407 unsigned int exclusive[] = { 2408 SECCOMP_FILTER_FLAG_TSYNC, 2409 SECCOMP_FILTER_FLAG_NEW_LISTENER }; 2410 unsigned int flag, all_flags, exclusive_mask; 2411 int i; 2412 long ret; 2413 2414 /* Test detection of individual known-good filter flags */ 2415 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) { 2416 int bits = 0; 2417 2418 flag = flags[i]; 2419 /* Make sure the flag is a single bit! */ 2420 while (flag) { 2421 if (flag & 0x1) 2422 bits ++; 2423 flag >>= 1; 2424 } 2425 ASSERT_EQ(1, bits); 2426 flag = flags[i]; 2427 2428 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2429 ASSERT_NE(ENOSYS, errno) { 2430 TH_LOG("Kernel does not support seccomp syscall!"); 2431 } 2432 EXPECT_EQ(-1, ret); 2433 EXPECT_EQ(EFAULT, errno) { 2434 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!", 2435 flag); 2436 } 2437 2438 all_flags |= flag; 2439 } 2440 2441 /* 2442 * Test detection of all known-good filter flags combined. But 2443 * for the exclusive flags we need to mask them out and try them 2444 * individually for the "all flags" testing. 2445 */ 2446 exclusive_mask = 0; 2447 for (i = 0; i < ARRAY_SIZE(exclusive); i++) 2448 exclusive_mask |= exclusive[i]; 2449 for (i = 0; i < ARRAY_SIZE(exclusive); i++) { 2450 flag = all_flags & ~exclusive_mask; 2451 flag |= exclusive[i]; 2452 2453 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2454 EXPECT_EQ(-1, ret); 2455 EXPECT_EQ(EFAULT, errno) { 2456 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!", 2457 flag); 2458 } 2459 } 2460 2461 /* Test detection of an unknown filter flags, without exclusives. */ 2462 flag = -1; 2463 flag &= ~exclusive_mask; 2464 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2465 EXPECT_EQ(-1, ret); 2466 EXPECT_EQ(EINVAL, errno) { 2467 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!", 2468 flag); 2469 } 2470 2471 /* 2472 * Test detection of an unknown filter flag that may simply need to be 2473 * added to this test 2474 */ 2475 flag = flags[ARRAY_SIZE(flags) - 1] << 1; 2476 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); 2477 EXPECT_EQ(-1, ret); 2478 EXPECT_EQ(EINVAL, errno) { 2479 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?", 2480 flag); 2481 } 2482} 2483 2484TEST(TSYNC_first) 2485{ 2486 struct sock_filter filter[] = { 2487 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2488 }; 2489 struct sock_fprog prog = { 2490 .len = (unsigned short)ARRAY_SIZE(filter), 2491 .filter = filter, 2492 }; 2493 long ret; 2494 2495 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); 2496 ASSERT_EQ(0, ret) { 2497 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2498 } 2499 2500 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2501 &prog); 2502 ASSERT_NE(ENOSYS, errno) { 2503 TH_LOG("Kernel does not support seccomp syscall!"); 2504 } 2505 EXPECT_EQ(0, ret) { 2506 TH_LOG("Could not install initial filter with TSYNC!"); 2507 } 2508} 2509 2510#define TSYNC_SIBLINGS 2 2511struct tsync_sibling { 2512 pthread_t tid; 2513 pid_t system_tid; 2514 sem_t *started; 2515 pthread_cond_t *cond; 2516 pthread_mutex_t *mutex; 2517 int diverge; 2518 int num_waits; 2519 struct sock_fprog *prog; 2520 struct __test_metadata *metadata; 2521}; 2522 2523/* 2524 * To avoid joining joined threads (which is not allowed by Bionic), 2525 * make sure we both successfully join and clear the tid to skip a 2526 * later join attempt during fixture teardown. Any remaining threads 2527 * will be directly killed during teardown. 2528 */ 2529#define PTHREAD_JOIN(tid, status) \ 2530 do { \ 2531 int _rc = pthread_join(tid, status); \ 2532 if (_rc) { \ 2533 TH_LOG("pthread_join of tid %u failed: %d\n", \ 2534 (unsigned int)tid, _rc); \ 2535 } else { \ 2536 tid = 0; \ 2537 } \ 2538 } while (0) 2539 2540FIXTURE(TSYNC) { 2541 struct sock_fprog root_prog, apply_prog; 2542 struct tsync_sibling sibling[TSYNC_SIBLINGS]; 2543 sem_t started; 2544 pthread_cond_t cond; 2545 pthread_mutex_t mutex; 2546 int sibling_count; 2547}; 2548 2549FIXTURE_SETUP(TSYNC) 2550{ 2551 struct sock_filter root_filter[] = { 2552 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2553 }; 2554 struct sock_filter apply_filter[] = { 2555 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2556 offsetof(struct seccomp_data, nr)), 2557 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), 2558 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 2559 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2560 }; 2561 2562 memset(&self->root_prog, 0, sizeof(self->root_prog)); 2563 memset(&self->apply_prog, 0, sizeof(self->apply_prog)); 2564 memset(&self->sibling, 0, sizeof(self->sibling)); 2565 self->root_prog.filter = malloc(sizeof(root_filter)); 2566 ASSERT_NE(NULL, self->root_prog.filter); 2567 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); 2568 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); 2569 2570 self->apply_prog.filter = malloc(sizeof(apply_filter)); 2571 ASSERT_NE(NULL, self->apply_prog.filter); 2572 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); 2573 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); 2574 2575 self->sibling_count = 0; 2576 pthread_mutex_init(&self->mutex, NULL); 2577 pthread_cond_init(&self->cond, NULL); 2578 sem_init(&self->started, 0, 0); 2579 self->sibling[0].tid = 0; 2580 self->sibling[0].cond = &self->cond; 2581 self->sibling[0].started = &self->started; 2582 self->sibling[0].mutex = &self->mutex; 2583 self->sibling[0].diverge = 0; 2584 self->sibling[0].num_waits = 1; 2585 self->sibling[0].prog = &self->root_prog; 2586 self->sibling[0].metadata = _metadata; 2587 self->sibling[1].tid = 0; 2588 self->sibling[1].cond = &self->cond; 2589 self->sibling[1].started = &self->started; 2590 self->sibling[1].mutex = &self->mutex; 2591 self->sibling[1].diverge = 0; 2592 self->sibling[1].prog = &self->root_prog; 2593 self->sibling[1].num_waits = 1; 2594 self->sibling[1].metadata = _metadata; 2595} 2596 2597FIXTURE_TEARDOWN(TSYNC) 2598{ 2599 int sib = 0; 2600 2601 if (self->root_prog.filter) 2602 free(self->root_prog.filter); 2603 if (self->apply_prog.filter) 2604 free(self->apply_prog.filter); 2605 2606 for ( ; sib < self->sibling_count; ++sib) { 2607 struct tsync_sibling *s = &self->sibling[sib]; 2608 2609 if (!s->tid) 2610 continue; 2611 /* 2612 * If a thread is still running, it may be stuck, so hit 2613 * it over the head really hard. 2614 */ 2615 pthread_kill(s->tid, 9); 2616 } 2617 pthread_mutex_destroy(&self->mutex); 2618 pthread_cond_destroy(&self->cond); 2619 sem_destroy(&self->started); 2620} 2621 2622void *tsync_sibling(void *data) 2623{ 2624 long ret = 0; 2625 struct tsync_sibling *me = data; 2626 2627 me->system_tid = syscall(__NR_gettid); 2628 2629 pthread_mutex_lock(me->mutex); 2630 if (me->diverge) { 2631 /* Just re-apply the root prog to fork the tree */ 2632 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 2633 me->prog, 0, 0); 2634 } 2635 sem_post(me->started); 2636 /* Return outside of started so parent notices failures. */ 2637 if (ret) { 2638 pthread_mutex_unlock(me->mutex); 2639 return (void *)SIBLING_EXIT_FAILURE; 2640 } 2641 do { 2642 pthread_cond_wait(me->cond, me->mutex); 2643 me->num_waits = me->num_waits - 1; 2644 } while (me->num_waits); 2645 pthread_mutex_unlock(me->mutex); 2646 2647 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); 2648 if (!ret) 2649 return (void *)SIBLING_EXIT_NEWPRIVS; 2650 read(-1, NULL, 0); 2651 return (void *)SIBLING_EXIT_UNKILLED; 2652} 2653 2654void tsync_start_sibling(struct tsync_sibling *sibling) 2655{ 2656 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); 2657} 2658 2659TEST_F(TSYNC, siblings_fail_prctl) 2660{ 2661 long ret; 2662 void *status; 2663 struct sock_filter filter[] = { 2664 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2665 offsetof(struct seccomp_data, nr)), 2666 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), 2667 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), 2668 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 2669 }; 2670 struct sock_fprog prog = { 2671 .len = (unsigned short)ARRAY_SIZE(filter), 2672 .filter = filter, 2673 }; 2674 2675 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2676 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2677 } 2678 2679 /* Check prctl failure detection by requesting sib 0 diverge. */ 2680 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); 2681 ASSERT_NE(ENOSYS, errno) { 2682 TH_LOG("Kernel does not support seccomp syscall!"); 2683 } 2684 ASSERT_EQ(0, ret) { 2685 TH_LOG("setting filter failed"); 2686 } 2687 2688 self->sibling[0].diverge = 1; 2689 tsync_start_sibling(&self->sibling[0]); 2690 tsync_start_sibling(&self->sibling[1]); 2691 2692 while (self->sibling_count < TSYNC_SIBLINGS) { 2693 sem_wait(&self->started); 2694 self->sibling_count++; 2695 } 2696 2697 /* Signal the threads to clean up*/ 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 diverging sibling failed to call prctl. */ 2705 PTHREAD_JOIN(self->sibling[0].tid, &status); 2706 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); 2707 PTHREAD_JOIN(self->sibling[1].tid, &status); 2708 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2709} 2710 2711TEST_F(TSYNC, two_siblings_with_ancestor) 2712{ 2713 long ret; 2714 void *status; 2715 2716 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2717 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2718 } 2719 2720 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2721 ASSERT_NE(ENOSYS, errno) { 2722 TH_LOG("Kernel does not support seccomp syscall!"); 2723 } 2724 ASSERT_EQ(0, ret) { 2725 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2726 } 2727 tsync_start_sibling(&self->sibling[0]); 2728 tsync_start_sibling(&self->sibling[1]); 2729 2730 while (self->sibling_count < TSYNC_SIBLINGS) { 2731 sem_wait(&self->started); 2732 self->sibling_count++; 2733 } 2734 2735 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2736 &self->apply_prog); 2737 ASSERT_EQ(0, ret) { 2738 TH_LOG("Could install filter on all threads!"); 2739 } 2740 /* Tell the siblings to test the policy */ 2741 pthread_mutex_lock(&self->mutex); 2742 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2743 TH_LOG("cond broadcast non-zero"); 2744 } 2745 pthread_mutex_unlock(&self->mutex); 2746 /* Ensure they are both killed and don't exit cleanly. */ 2747 PTHREAD_JOIN(self->sibling[0].tid, &status); 2748 EXPECT_EQ(0x0, (long)status); 2749 PTHREAD_JOIN(self->sibling[1].tid, &status); 2750 EXPECT_EQ(0x0, (long)status); 2751} 2752 2753TEST_F(TSYNC, two_sibling_want_nnp) 2754{ 2755 void *status; 2756 2757 /* start siblings before any prctl() operations */ 2758 tsync_start_sibling(&self->sibling[0]); 2759 tsync_start_sibling(&self->sibling[1]); 2760 while (self->sibling_count < TSYNC_SIBLINGS) { 2761 sem_wait(&self->started); 2762 self->sibling_count++; 2763 } 2764 2765 /* Tell the siblings to test no policy */ 2766 pthread_mutex_lock(&self->mutex); 2767 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2768 TH_LOG("cond broadcast non-zero"); 2769 } 2770 pthread_mutex_unlock(&self->mutex); 2771 2772 /* Ensure they are both upset about lacking nnp. */ 2773 PTHREAD_JOIN(self->sibling[0].tid, &status); 2774 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2775 PTHREAD_JOIN(self->sibling[1].tid, &status); 2776 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); 2777} 2778 2779TEST_F(TSYNC, two_siblings_with_no_filter) 2780{ 2781 long ret; 2782 void *status; 2783 2784 /* start siblings before any prctl() operations */ 2785 tsync_start_sibling(&self->sibling[0]); 2786 tsync_start_sibling(&self->sibling[1]); 2787 while (self->sibling_count < TSYNC_SIBLINGS) { 2788 sem_wait(&self->started); 2789 self->sibling_count++; 2790 } 2791 2792 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2793 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2794 } 2795 2796 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2797 &self->apply_prog); 2798 ASSERT_NE(ENOSYS, errno) { 2799 TH_LOG("Kernel does not support seccomp syscall!"); 2800 } 2801 ASSERT_EQ(0, ret) { 2802 TH_LOG("Could install filter on all threads!"); 2803 } 2804 2805 /* Tell the siblings to test the policy */ 2806 pthread_mutex_lock(&self->mutex); 2807 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2808 TH_LOG("cond broadcast non-zero"); 2809 } 2810 pthread_mutex_unlock(&self->mutex); 2811 2812 /* Ensure they are both killed and don't exit cleanly. */ 2813 PTHREAD_JOIN(self->sibling[0].tid, &status); 2814 EXPECT_EQ(0x0, (long)status); 2815 PTHREAD_JOIN(self->sibling[1].tid, &status); 2816 EXPECT_EQ(0x0, (long)status); 2817} 2818 2819TEST_F(TSYNC, two_siblings_with_one_divergence) 2820{ 2821 long ret; 2822 void *status; 2823 2824 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2825 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2826 } 2827 2828 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2829 ASSERT_NE(ENOSYS, errno) { 2830 TH_LOG("Kernel does not support seccomp syscall!"); 2831 } 2832 ASSERT_EQ(0, ret) { 2833 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2834 } 2835 self->sibling[0].diverge = 1; 2836 tsync_start_sibling(&self->sibling[0]); 2837 tsync_start_sibling(&self->sibling[1]); 2838 2839 while (self->sibling_count < TSYNC_SIBLINGS) { 2840 sem_wait(&self->started); 2841 self->sibling_count++; 2842 } 2843 2844 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2845 &self->apply_prog); 2846 ASSERT_EQ(self->sibling[0].system_tid, ret) { 2847 TH_LOG("Did not fail on diverged sibling."); 2848 } 2849 2850 /* Wake the threads */ 2851 pthread_mutex_lock(&self->mutex); 2852 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2853 TH_LOG("cond broadcast non-zero"); 2854 } 2855 pthread_mutex_unlock(&self->mutex); 2856 2857 /* Ensure they are both unkilled. */ 2858 PTHREAD_JOIN(self->sibling[0].tid, &status); 2859 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2860 PTHREAD_JOIN(self->sibling[1].tid, &status); 2861 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2862} 2863 2864TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err) 2865{ 2866 long ret, flags; 2867 void *status; 2868 2869 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2870 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2871 } 2872 2873 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2874 ASSERT_NE(ENOSYS, errno) { 2875 TH_LOG("Kernel does not support seccomp syscall!"); 2876 } 2877 ASSERT_EQ(0, ret) { 2878 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2879 } 2880 self->sibling[0].diverge = 1; 2881 tsync_start_sibling(&self->sibling[0]); 2882 tsync_start_sibling(&self->sibling[1]); 2883 2884 while (self->sibling_count < TSYNC_SIBLINGS) { 2885 sem_wait(&self->started); 2886 self->sibling_count++; 2887 } 2888 2889 flags = SECCOMP_FILTER_FLAG_TSYNC | \ 2890 SECCOMP_FILTER_FLAG_TSYNC_ESRCH; 2891 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog); 2892 ASSERT_EQ(ESRCH, errno) { 2893 TH_LOG("Did not return ESRCH for diverged sibling."); 2894 } 2895 ASSERT_EQ(-1, ret) { 2896 TH_LOG("Did not fail on diverged sibling."); 2897 } 2898 2899 /* Wake the threads */ 2900 pthread_mutex_lock(&self->mutex); 2901 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2902 TH_LOG("cond broadcast non-zero"); 2903 } 2904 pthread_mutex_unlock(&self->mutex); 2905 2906 /* Ensure they are both unkilled. */ 2907 PTHREAD_JOIN(self->sibling[0].tid, &status); 2908 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2909 PTHREAD_JOIN(self->sibling[1].tid, &status); 2910 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2911} 2912 2913TEST_F(TSYNC, two_siblings_not_under_filter) 2914{ 2915 long ret, sib; 2916 void *status; 2917 struct timespec delay = { .tv_nsec = 100000000 }; 2918 2919 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 2920 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 2921 } 2922 2923 /* 2924 * Sibling 0 will have its own seccomp policy 2925 * and Sibling 1 will not be under seccomp at 2926 * all. Sibling 1 will enter seccomp and 0 2927 * will cause failure. 2928 */ 2929 self->sibling[0].diverge = 1; 2930 tsync_start_sibling(&self->sibling[0]); 2931 tsync_start_sibling(&self->sibling[1]); 2932 2933 while (self->sibling_count < TSYNC_SIBLINGS) { 2934 sem_wait(&self->started); 2935 self->sibling_count++; 2936 } 2937 2938 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); 2939 ASSERT_NE(ENOSYS, errno) { 2940 TH_LOG("Kernel does not support seccomp syscall!"); 2941 } 2942 ASSERT_EQ(0, ret) { 2943 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); 2944 } 2945 2946 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2947 &self->apply_prog); 2948 ASSERT_EQ(ret, self->sibling[0].system_tid) { 2949 TH_LOG("Did not fail on diverged sibling."); 2950 } 2951 sib = 1; 2952 if (ret == self->sibling[0].system_tid) 2953 sib = 0; 2954 2955 pthread_mutex_lock(&self->mutex); 2956 2957 /* Increment the other siblings num_waits so we can clean up 2958 * the one we just saw. 2959 */ 2960 self->sibling[!sib].num_waits += 1; 2961 2962 /* Signal the thread to clean up*/ 2963 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2964 TH_LOG("cond broadcast non-zero"); 2965 } 2966 pthread_mutex_unlock(&self->mutex); 2967 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2968 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); 2969 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2970 while (!kill(self->sibling[sib].system_tid, 0)) 2971 nanosleep(&delay, NULL); 2972 /* Switch to the remaining sibling */ 2973 sib = !sib; 2974 2975 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2976 &self->apply_prog); 2977 ASSERT_EQ(0, ret) { 2978 TH_LOG("Expected the remaining sibling to sync"); 2979 }; 2980 2981 pthread_mutex_lock(&self->mutex); 2982 2983 /* If remaining sibling didn't have a chance to wake up during 2984 * the first broadcast, manually reduce the num_waits now. 2985 */ 2986 if (self->sibling[sib].num_waits > 1) 2987 self->sibling[sib].num_waits = 1; 2988 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { 2989 TH_LOG("cond broadcast non-zero"); 2990 } 2991 pthread_mutex_unlock(&self->mutex); 2992 PTHREAD_JOIN(self->sibling[sib].tid, &status); 2993 EXPECT_EQ(0, (long)status); 2994 /* Poll for actual task death. pthread_join doesn't guarantee it. */ 2995 while (!kill(self->sibling[sib].system_tid, 0)) 2996 nanosleep(&delay, NULL); 2997 2998 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, 2999 &self->apply_prog); 3000 ASSERT_EQ(0, ret); /* just us chickens */ 3001} 3002 3003/* Make sure restarted syscalls are seen directly as "restart_syscall". */ 3004TEST(syscall_restart) 3005{ 3006 long ret; 3007 unsigned long msg; 3008 pid_t child_pid; 3009 int pipefd[2]; 3010 int status; 3011 siginfo_t info = { }; 3012 struct sock_filter filter[] = { 3013 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3014 offsetof(struct seccomp_data, nr)), 3015 3016#ifdef __NR_sigreturn 3017 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0), 3018#endif 3019 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0), 3020 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0), 3021 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0), 3022 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0), 3023 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0), 3024 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), 3025 3026 /* Allow __NR_write for easy logging. */ 3027 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), 3028 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3029 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 3030 /* The nanosleep jump target. */ 3031 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), 3032 /* The restart_syscall jump target. */ 3033 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), 3034 }; 3035 struct sock_fprog prog = { 3036 .len = (unsigned short)ARRAY_SIZE(filter), 3037 .filter = filter, 3038 }; 3039#if defined(__arm__) 3040 struct utsname utsbuf; 3041#endif 3042 3043 ASSERT_EQ(0, pipe(pipefd)); 3044 3045 child_pid = fork(); 3046 ASSERT_LE(0, child_pid); 3047 if (child_pid == 0) { 3048 /* Child uses EXPECT not ASSERT to deliver status correctly. */ 3049 char buf = ' '; 3050 struct timespec timeout = { }; 3051 3052 /* Attach parent as tracer and stop. */ 3053 EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); 3054 EXPECT_EQ(0, raise(SIGSTOP)); 3055 3056 EXPECT_EQ(0, close(pipefd[1])); 3057 3058 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { 3059 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3060 } 3061 3062 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 3063 EXPECT_EQ(0, ret) { 3064 TH_LOG("Failed to install filter!"); 3065 } 3066 3067 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 3068 TH_LOG("Failed to read() sync from parent"); 3069 } 3070 EXPECT_EQ('.', buf) { 3071 TH_LOG("Failed to get sync data from read()"); 3072 } 3073 3074 /* Start nanosleep to be interrupted. */ 3075 timeout.tv_sec = 1; 3076 errno = 0; 3077 EXPECT_EQ(0, nanosleep(&timeout, NULL)) { 3078 TH_LOG("Call to nanosleep() failed (errno %d: %s)", 3079 errno, strerror(errno)); 3080 } 3081 3082 /* Read final sync from parent. */ 3083 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { 3084 TH_LOG("Failed final read() from parent"); 3085 } 3086 EXPECT_EQ('!', buf) { 3087 TH_LOG("Failed to get final data from read()"); 3088 } 3089 3090 /* Directly report the status of our test harness results. */ 3091 syscall(__NR_exit, _metadata->exit_code); 3092 } 3093 EXPECT_EQ(0, close(pipefd[0])); 3094 3095 /* Attach to child, setup options, and release. */ 3096 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3097 ASSERT_EQ(true, WIFSTOPPED(status)); 3098 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, 3099 PTRACE_O_TRACESECCOMP)); 3100 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3101 ASSERT_EQ(1, write(pipefd[1], ".", 1)); 3102 3103 /* Wait for nanosleep() to start. */ 3104 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3105 ASSERT_EQ(true, WIFSTOPPED(status)); 3106 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 3107 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 3108 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 3109 ASSERT_EQ(0x100, msg); 3110 ret = get_syscall(_metadata, child_pid); 3111 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep); 3112 3113 /* Might as well check siginfo for sanity while we're here. */ 3114 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 3115 ASSERT_EQ(SIGTRAP, info.si_signo); 3116 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); 3117 EXPECT_EQ(0, info.si_errno); 3118 EXPECT_EQ(getuid(), info.si_uid); 3119 /* Verify signal delivery came from child (seccomp-triggered). */ 3120 EXPECT_EQ(child_pid, info.si_pid); 3121 3122 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */ 3123 ASSERT_EQ(0, kill(child_pid, SIGSTOP)); 3124 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3125 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3126 ASSERT_EQ(true, WIFSTOPPED(status)); 3127 ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); 3128 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); 3129 /* 3130 * There is no siginfo on SIGSTOP any more, so we can't verify 3131 * signal delivery came from parent now (getpid() == info.si_pid). 3132 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com 3133 * At least verify the SIGSTOP via PTRACE_GETSIGINFO. 3134 */ 3135 EXPECT_EQ(SIGSTOP, info.si_signo); 3136 3137 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ 3138 ASSERT_EQ(0, kill(child_pid, SIGCONT)); 3139 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3140 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3141 ASSERT_EQ(true, WIFSTOPPED(status)); 3142 ASSERT_EQ(SIGCONT, WSTOPSIG(status)); 3143 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3144 3145 /* Wait for restart_syscall() to start. */ 3146 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3147 ASSERT_EQ(true, WIFSTOPPED(status)); 3148 ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); 3149 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); 3150 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); 3151 3152 ASSERT_EQ(0x200, msg); 3153 ret = get_syscall(_metadata, child_pid); 3154#if defined(__arm__) 3155 /* 3156 * FIXME: 3157 * - native ARM registers do NOT expose true syscall. 3158 * - compat ARM registers on ARM64 DO expose true syscall. 3159 */ 3160 ASSERT_EQ(0, uname(&utsbuf)); 3161 if (strncmp(utsbuf.machine, "arm", 3) == 0) { 3162 EXPECT_EQ(__NR_nanosleep, ret); 3163 } else 3164#endif 3165 { 3166 EXPECT_EQ(__NR_restart_syscall, ret); 3167 } 3168 3169 /* Write again to end test. */ 3170 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); 3171 ASSERT_EQ(1, write(pipefd[1], "!", 1)); 3172 EXPECT_EQ(0, close(pipefd[1])); 3173 3174 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); 3175 if (WIFSIGNALED(status) || WEXITSTATUS(status)) 3176 _metadata->exit_code = KSFT_FAIL; 3177} 3178 3179TEST_SIGNAL(filter_flag_log, SIGSYS) 3180{ 3181 struct sock_filter allow_filter[] = { 3182 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3183 }; 3184 struct sock_filter kill_filter[] = { 3185 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3186 offsetof(struct seccomp_data, nr)), 3187 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), 3188 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), 3189 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3190 }; 3191 struct sock_fprog allow_prog = { 3192 .len = (unsigned short)ARRAY_SIZE(allow_filter), 3193 .filter = allow_filter, 3194 }; 3195 struct sock_fprog kill_prog = { 3196 .len = (unsigned short)ARRAY_SIZE(kill_filter), 3197 .filter = kill_filter, 3198 }; 3199 long ret; 3200 pid_t parent = getppid(); 3201 3202 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3203 ASSERT_EQ(0, ret); 3204 3205 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */ 3206 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG, 3207 &allow_prog); 3208 ASSERT_NE(ENOSYS, errno) { 3209 TH_LOG("Kernel does not support seccomp syscall!"); 3210 } 3211 EXPECT_NE(0, ret) { 3212 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!"); 3213 } 3214 EXPECT_EQ(EINVAL, errno) { 3215 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!"); 3216 } 3217 3218 /* Verify that a simple, permissive filter can be added with no flags */ 3219 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog); 3220 EXPECT_EQ(0, ret); 3221 3222 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */ 3223 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 3224 &allow_prog); 3225 ASSERT_NE(EINVAL, errno) { 3226 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!"); 3227 } 3228 EXPECT_EQ(0, ret); 3229 3230 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */ 3231 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, 3232 &kill_prog); 3233 EXPECT_EQ(0, ret); 3234 3235 EXPECT_EQ(parent, syscall(__NR_getppid)); 3236 /* getpid() should never return. */ 3237 EXPECT_EQ(0, syscall(__NR_getpid)); 3238} 3239 3240TEST(get_action_avail) 3241{ 3242 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP, 3243 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE, 3244 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW }; 3245 __u32 unknown_action = 0x10000000U; 3246 int i; 3247 long ret; 3248 3249 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]); 3250 ASSERT_NE(ENOSYS, errno) { 3251 TH_LOG("Kernel does not support seccomp syscall!"); 3252 } 3253 ASSERT_NE(EINVAL, errno) { 3254 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!"); 3255 } 3256 EXPECT_EQ(ret, 0); 3257 3258 for (i = 0; i < ARRAY_SIZE(actions); i++) { 3259 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]); 3260 EXPECT_EQ(ret, 0) { 3261 TH_LOG("Expected action (0x%X) not available!", 3262 actions[i]); 3263 } 3264 } 3265 3266 /* Check that an unknown action is handled properly (EOPNOTSUPP) */ 3267 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action); 3268 EXPECT_EQ(ret, -1); 3269 EXPECT_EQ(errno, EOPNOTSUPP); 3270} 3271 3272TEST(get_metadata) 3273{ 3274 pid_t pid; 3275 int pipefd[2]; 3276 char buf; 3277 struct seccomp_metadata md; 3278 long ret; 3279 3280 /* Only real root can get metadata. */ 3281 if (geteuid()) { 3282 SKIP(return, "get_metadata requires real root"); 3283 return; 3284 } 3285 3286 ASSERT_EQ(0, pipe(pipefd)); 3287 3288 pid = fork(); 3289 ASSERT_GE(pid, 0); 3290 if (pid == 0) { 3291 struct sock_filter filter[] = { 3292 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3293 }; 3294 struct sock_fprog prog = { 3295 .len = (unsigned short)ARRAY_SIZE(filter), 3296 .filter = filter, 3297 }; 3298 3299 /* one with log, one without */ 3300 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 3301 SECCOMP_FILTER_FLAG_LOG, &prog)); 3302 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog)); 3303 3304 EXPECT_EQ(0, close(pipefd[0])); 3305 ASSERT_EQ(1, write(pipefd[1], "1", 1)); 3306 ASSERT_EQ(0, close(pipefd[1])); 3307 3308 while (1) 3309 sleep(100); 3310 } 3311 3312 ASSERT_EQ(0, close(pipefd[1])); 3313 ASSERT_EQ(1, read(pipefd[0], &buf, 1)); 3314 3315 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid)); 3316 ASSERT_EQ(pid, waitpid(pid, NULL, 0)); 3317 3318 /* Past here must not use ASSERT or child process is never killed. */ 3319 3320 md.filter_off = 0; 3321 errno = 0; 3322 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); 3323 EXPECT_EQ(sizeof(md), ret) { 3324 if (errno == EINVAL) 3325 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)"); 3326 } 3327 3328 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG); 3329 EXPECT_EQ(md.filter_off, 0); 3330 3331 md.filter_off = 1; 3332 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); 3333 EXPECT_EQ(sizeof(md), ret); 3334 EXPECT_EQ(md.flags, 0); 3335 EXPECT_EQ(md.filter_off, 1); 3336 3337skip: 3338 ASSERT_EQ(0, kill(pid, SIGKILL)); 3339} 3340 3341static int user_notif_syscall(int nr, unsigned int flags) 3342{ 3343 struct sock_filter filter[] = { 3344 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 3345 offsetof(struct seccomp_data, nr)), 3346 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1), 3347 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF), 3348 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3349 }; 3350 3351 struct sock_fprog prog = { 3352 .len = (unsigned short)ARRAY_SIZE(filter), 3353 .filter = filter, 3354 }; 3355 3356 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog); 3357} 3358 3359#define USER_NOTIF_MAGIC INT_MAX 3360TEST(user_notification_basic) 3361{ 3362 pid_t pid; 3363 long ret; 3364 int status, listener; 3365 struct seccomp_notif req = {}; 3366 struct seccomp_notif_resp resp = {}; 3367 struct pollfd pollfd; 3368 3369 struct sock_filter filter[] = { 3370 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), 3371 }; 3372 struct sock_fprog prog = { 3373 .len = (unsigned short)ARRAY_SIZE(filter), 3374 .filter = filter, 3375 }; 3376 3377 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3378 ASSERT_EQ(0, ret) { 3379 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3380 } 3381 3382 pid = fork(); 3383 ASSERT_GE(pid, 0); 3384 3385 /* Check that we get -ENOSYS with no listener attached */ 3386 if (pid == 0) { 3387 if (user_notif_syscall(__NR_getppid, 0) < 0) 3388 exit(1); 3389 ret = syscall(__NR_getppid); 3390 exit(ret >= 0 || errno != ENOSYS); 3391 } 3392 3393 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3394 EXPECT_EQ(true, WIFEXITED(status)); 3395 EXPECT_EQ(0, WEXITSTATUS(status)); 3396 3397 /* Add some no-op filters for grins. */ 3398 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3399 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3400 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3401 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); 3402 3403 /* Check that the basic notification machinery works */ 3404 listener = user_notif_syscall(__NR_getppid, 3405 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3406 ASSERT_GE(listener, 0); 3407 3408 /* Installing a second listener in the chain should EBUSY */ 3409 EXPECT_EQ(user_notif_syscall(__NR_getppid, 3410 SECCOMP_FILTER_FLAG_NEW_LISTENER), 3411 -1); 3412 EXPECT_EQ(errno, EBUSY); 3413 3414 pid = fork(); 3415 ASSERT_GE(pid, 0); 3416 3417 if (pid == 0) { 3418 ret = syscall(__NR_getppid); 3419 exit(ret != USER_NOTIF_MAGIC); 3420 } 3421 3422 pollfd.fd = listener; 3423 pollfd.events = POLLIN | POLLOUT; 3424 3425 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3426 EXPECT_EQ(pollfd.revents, POLLIN); 3427 3428 /* Test that we can't pass garbage to the kernel. */ 3429 memset(&req, 0, sizeof(req)); 3430 req.pid = -1; 3431 errno = 0; 3432 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req); 3433 EXPECT_EQ(-1, ret); 3434 EXPECT_EQ(EINVAL, errno); 3435 3436 if (ret) { 3437 req.pid = 0; 3438 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3439 } 3440 3441 pollfd.fd = listener; 3442 pollfd.events = POLLIN | POLLOUT; 3443 3444 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3445 EXPECT_EQ(pollfd.revents, POLLOUT); 3446 3447 EXPECT_EQ(req.data.nr, __NR_getppid); 3448 3449 resp.id = req.id; 3450 resp.error = 0; 3451 resp.val = USER_NOTIF_MAGIC; 3452 3453 /* check that we make sure flags == 0 */ 3454 resp.flags = 1; 3455 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3456 EXPECT_EQ(errno, EINVAL); 3457 3458 resp.flags = 0; 3459 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3460 3461 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3462 EXPECT_EQ(true, WIFEXITED(status)); 3463 EXPECT_EQ(0, WEXITSTATUS(status)); 3464} 3465 3466TEST(user_notification_with_tsync) 3467{ 3468 int ret; 3469 unsigned int flags; 3470 3471 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3472 ASSERT_EQ(0, ret) { 3473 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3474 } 3475 3476 /* these were exclusive */ 3477 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER | 3478 SECCOMP_FILTER_FLAG_TSYNC; 3479 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags)); 3480 ASSERT_EQ(EINVAL, errno); 3481 3482 /* but now they're not */ 3483 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH; 3484 ret = user_notif_syscall(__NR_getppid, flags); 3485 close(ret); 3486 ASSERT_LE(0, ret); 3487} 3488 3489TEST(user_notification_kill_in_middle) 3490{ 3491 pid_t pid; 3492 long ret; 3493 int listener; 3494 struct seccomp_notif req = {}; 3495 struct seccomp_notif_resp resp = {}; 3496 3497 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3498 ASSERT_EQ(0, ret) { 3499 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3500 } 3501 3502 listener = user_notif_syscall(__NR_getppid, 3503 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3504 ASSERT_GE(listener, 0); 3505 3506 /* 3507 * Check that nothing bad happens when we kill the task in the middle 3508 * of a syscall. 3509 */ 3510 pid = fork(); 3511 ASSERT_GE(pid, 0); 3512 3513 if (pid == 0) { 3514 ret = syscall(__NR_getppid); 3515 exit(ret != USER_NOTIF_MAGIC); 3516 } 3517 3518 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3519 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0); 3520 3521 EXPECT_EQ(kill(pid, SIGKILL), 0); 3522 EXPECT_EQ(waitpid(pid, NULL, 0), pid); 3523 3524 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1); 3525 3526 resp.id = req.id; 3527 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp); 3528 EXPECT_EQ(ret, -1); 3529 EXPECT_EQ(errno, ENOENT); 3530} 3531 3532static int handled = -1; 3533 3534static void signal_handler(int signal) 3535{ 3536 if (write(handled, "c", 1) != 1) 3537 perror("write from signal"); 3538} 3539 3540TEST(user_notification_signal) 3541{ 3542 pid_t pid; 3543 long ret; 3544 int status, listener, sk_pair[2]; 3545 struct seccomp_notif req = {}; 3546 struct seccomp_notif_resp resp = {}; 3547 char c; 3548 3549 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3550 ASSERT_EQ(0, ret) { 3551 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3552 } 3553 3554 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); 3555 3556 listener = user_notif_syscall(__NR_gettid, 3557 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3558 ASSERT_GE(listener, 0); 3559 3560 pid = fork(); 3561 ASSERT_GE(pid, 0); 3562 3563 if (pid == 0) { 3564 close(sk_pair[0]); 3565 handled = sk_pair[1]; 3566 if (signal(SIGUSR1, signal_handler) == SIG_ERR) { 3567 perror("signal"); 3568 exit(1); 3569 } 3570 /* 3571 * ERESTARTSYS behavior is a bit hard to test, because we need 3572 * to rely on a signal that has not yet been handled. Let's at 3573 * least check that the error code gets propagated through, and 3574 * hope that it doesn't break when there is actually a signal :) 3575 */ 3576 ret = syscall(__NR_gettid); 3577 exit(!(ret == -1 && errno == 512)); 3578 } 3579 3580 close(sk_pair[1]); 3581 3582 memset(&req, 0, sizeof(req)); 3583 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3584 3585 EXPECT_EQ(kill(pid, SIGUSR1), 0); 3586 3587 /* 3588 * Make sure the signal really is delivered, which means we're not 3589 * stuck in the user notification code any more and the notification 3590 * should be dead. 3591 */ 3592 EXPECT_EQ(read(sk_pair[0], &c, 1), 1); 3593 3594 resp.id = req.id; 3595 resp.error = -EPERM; 3596 resp.val = 0; 3597 3598 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3599 EXPECT_EQ(errno, ENOENT); 3600 3601 memset(&req, 0, sizeof(req)); 3602 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3603 3604 resp.id = req.id; 3605 resp.error = -512; /* -ERESTARTSYS */ 3606 resp.val = 0; 3607 3608 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3609 3610 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3611 EXPECT_EQ(true, WIFEXITED(status)); 3612 EXPECT_EQ(0, WEXITSTATUS(status)); 3613} 3614 3615TEST(user_notification_closed_listener) 3616{ 3617 pid_t pid; 3618 long ret; 3619 int status, listener; 3620 3621 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3622 ASSERT_EQ(0, ret) { 3623 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3624 } 3625 3626 listener = user_notif_syscall(__NR_getppid, 3627 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3628 ASSERT_GE(listener, 0); 3629 3630 /* 3631 * Check that we get an ENOSYS when the listener is closed. 3632 */ 3633 pid = fork(); 3634 ASSERT_GE(pid, 0); 3635 if (pid == 0) { 3636 close(listener); 3637 ret = syscall(__NR_getppid); 3638 exit(ret != -1 && errno != ENOSYS); 3639 } 3640 3641 close(listener); 3642 3643 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3644 EXPECT_EQ(true, WIFEXITED(status)); 3645 EXPECT_EQ(0, WEXITSTATUS(status)); 3646} 3647 3648/* 3649 * Check that a pid in a child namespace still shows up as valid in ours. 3650 */ 3651TEST(user_notification_child_pid_ns) 3652{ 3653 pid_t pid; 3654 int status, listener; 3655 struct seccomp_notif req = {}; 3656 struct seccomp_notif_resp resp = {}; 3657 3658 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) { 3659 if (errno == EINVAL) 3660 SKIP(return, "kernel missing CLONE_NEWUSER support"); 3661 }; 3662 3663 listener = user_notif_syscall(__NR_getppid, 3664 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3665 ASSERT_GE(listener, 0); 3666 3667 pid = fork(); 3668 ASSERT_GE(pid, 0); 3669 3670 if (pid == 0) 3671 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3672 3673 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3674 EXPECT_EQ(req.pid, pid); 3675 3676 resp.id = req.id; 3677 resp.error = 0; 3678 resp.val = USER_NOTIF_MAGIC; 3679 3680 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3681 3682 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3683 EXPECT_EQ(true, WIFEXITED(status)); 3684 EXPECT_EQ(0, WEXITSTATUS(status)); 3685 close(listener); 3686} 3687 3688/* 3689 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e. 3690 * invalid. 3691 */ 3692TEST(user_notification_sibling_pid_ns) 3693{ 3694 pid_t pid, pid2; 3695 int status, listener; 3696 struct seccomp_notif req = {}; 3697 struct seccomp_notif_resp resp = {}; 3698 3699 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) { 3700 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3701 } 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 ASSERT_EQ(unshare(CLONE_NEWPID), 0) { 3712 if (errno == EPERM) 3713 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); 3714 else if (errno == EINVAL) 3715 SKIP(return, "CLONE_NEWPID is invalid (missing CONFIG_PID_NS?)"); 3716 } 3717 3718 pid2 = fork(); 3719 ASSERT_GE(pid2, 0); 3720 3721 if (pid2 == 0) 3722 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3723 3724 EXPECT_EQ(waitpid(pid2, &status, 0), pid2); 3725 EXPECT_EQ(true, WIFEXITED(status)); 3726 EXPECT_EQ(0, WEXITSTATUS(status)); 3727 exit(WEXITSTATUS(status)); 3728 } 3729 3730 /* Create the sibling ns, and sibling in it. */ 3731 ASSERT_EQ(unshare(CLONE_NEWPID), 0) { 3732 if (errno == EPERM) 3733 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); 3734 else if (errno == EINVAL) 3735 SKIP(return, "CLONE_NEWPID is invalid (missing CONFIG_PID_NS?)"); 3736 } 3737 ASSERT_EQ(errno, 0); 3738 3739 pid2 = fork(); 3740 ASSERT_GE(pid2, 0); 3741 3742 if (pid2 == 0) { 3743 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3744 /* 3745 * The pid should be 0, i.e. the task is in some namespace that 3746 * we can't "see". 3747 */ 3748 EXPECT_EQ(req.pid, 0); 3749 3750 resp.id = req.id; 3751 resp.error = 0; 3752 resp.val = USER_NOTIF_MAGIC; 3753 3754 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3755 exit(0); 3756 } 3757 3758 close(listener); 3759 3760 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3761 EXPECT_EQ(true, WIFEXITED(status)); 3762 EXPECT_EQ(0, WEXITSTATUS(status)); 3763 3764 EXPECT_EQ(waitpid(pid2, &status, 0), pid2); 3765 EXPECT_EQ(true, WIFEXITED(status)); 3766 EXPECT_EQ(0, WEXITSTATUS(status)); 3767} 3768 3769TEST(user_notification_fault_recv) 3770{ 3771 pid_t pid; 3772 int status, listener; 3773 struct seccomp_notif req = {}; 3774 struct seccomp_notif_resp resp = {}; 3775 3776 ASSERT_EQ(unshare(CLONE_NEWUSER), 0) { 3777 if (errno == EINVAL) 3778 SKIP(return, "kernel missing CLONE_NEWUSER support"); 3779 } 3780 3781 listener = user_notif_syscall(__NR_getppid, 3782 SECCOMP_FILTER_FLAG_NEW_LISTENER); 3783 ASSERT_GE(listener, 0); 3784 3785 pid = fork(); 3786 ASSERT_GE(pid, 0); 3787 3788 if (pid == 0) 3789 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 3790 3791 /* Do a bad recv() */ 3792 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1); 3793 EXPECT_EQ(errno, EFAULT); 3794 3795 /* We should still be able to receive this notification, though. */ 3796 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3797 EXPECT_EQ(req.pid, pid); 3798 3799 resp.id = req.id; 3800 resp.error = 0; 3801 resp.val = USER_NOTIF_MAGIC; 3802 3803 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 3804 3805 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3806 EXPECT_EQ(true, WIFEXITED(status)); 3807 EXPECT_EQ(0, WEXITSTATUS(status)); 3808} 3809 3810TEST(seccomp_get_notif_sizes) 3811{ 3812 struct seccomp_notif_sizes sizes; 3813 3814 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0); 3815 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif)); 3816 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp)); 3817} 3818 3819TEST(user_notification_continue) 3820{ 3821 pid_t pid; 3822 long ret; 3823 int status, listener; 3824 struct seccomp_notif req = {}; 3825 struct seccomp_notif_resp resp = {}; 3826 struct pollfd pollfd; 3827 3828 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3829 ASSERT_EQ(0, ret) { 3830 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3831 } 3832 3833 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3834 ASSERT_GE(listener, 0); 3835 3836 pid = fork(); 3837 ASSERT_GE(pid, 0); 3838 3839 if (pid == 0) { 3840 int dup_fd, pipe_fds[2]; 3841 pid_t self; 3842 3843 ASSERT_GE(pipe(pipe_fds), 0); 3844 3845 dup_fd = dup(pipe_fds[0]); 3846 ASSERT_GE(dup_fd, 0); 3847 EXPECT_NE(pipe_fds[0], dup_fd); 3848 3849 self = getpid(); 3850 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0); 3851 exit(0); 3852 } 3853 3854 pollfd.fd = listener; 3855 pollfd.events = POLLIN | POLLOUT; 3856 3857 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3858 EXPECT_EQ(pollfd.revents, POLLIN); 3859 3860 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 3861 3862 pollfd.fd = listener; 3863 pollfd.events = POLLIN | POLLOUT; 3864 3865 EXPECT_GT(poll(&pollfd, 1, -1), 0); 3866 EXPECT_EQ(pollfd.revents, POLLOUT); 3867 3868 EXPECT_EQ(req.data.nr, __NR_dup); 3869 3870 resp.id = req.id; 3871 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE; 3872 3873 /* 3874 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other 3875 * args be set to 0. 3876 */ 3877 resp.error = 0; 3878 resp.val = USER_NOTIF_MAGIC; 3879 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3880 EXPECT_EQ(errno, EINVAL); 3881 3882 resp.error = USER_NOTIF_MAGIC; 3883 resp.val = 0; 3884 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); 3885 EXPECT_EQ(errno, EINVAL); 3886 3887 resp.error = 0; 3888 resp.val = 0; 3889 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) { 3890 if (errno == EINVAL) 3891 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE"); 3892 } 3893 3894skip: 3895 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3896 EXPECT_EQ(true, WIFEXITED(status)); 3897 EXPECT_EQ(0, WEXITSTATUS(status)) { 3898 if (WEXITSTATUS(status) == 2) { 3899 SKIP(return, "Kernel does not support kcmp() syscall"); 3900 return; 3901 } 3902 } 3903} 3904 3905TEST(user_notification_filter_empty) 3906{ 3907 pid_t pid; 3908 long ret; 3909 int status; 3910 struct pollfd pollfd; 3911 struct __clone_args args = { 3912 .flags = CLONE_FILES, 3913 .exit_signal = SIGCHLD, 3914 }; 3915 3916 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3917 ASSERT_EQ(0, ret) { 3918 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3919 } 3920 3921 if (__NR_clone3 < 0) 3922 SKIP(return, "Test not built with clone3 support"); 3923 3924 pid = sys_clone3(&args, sizeof(args)); 3925 ASSERT_GE(pid, 0); 3926 3927 if (pid == 0) { 3928 int listener; 3929 3930 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3931 if (listener < 0) 3932 _exit(EXIT_FAILURE); 3933 3934 if (dup2(listener, 200) != 200) 3935 _exit(EXIT_FAILURE); 3936 3937 close(listener); 3938 3939 _exit(EXIT_SUCCESS); 3940 } 3941 3942 EXPECT_EQ(waitpid(pid, &status, 0), pid); 3943 EXPECT_EQ(true, WIFEXITED(status)); 3944 EXPECT_EQ(0, WEXITSTATUS(status)); 3945 3946 /* 3947 * The seccomp filter has become unused so we should be notified once 3948 * the kernel gets around to cleaning up task struct. 3949 */ 3950 pollfd.fd = 200; 3951 pollfd.events = POLLHUP; 3952 3953 EXPECT_GT(poll(&pollfd, 1, 2000), 0); 3954 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); 3955} 3956 3957static void *do_thread(void *data) 3958{ 3959 return NULL; 3960} 3961 3962TEST(user_notification_filter_empty_threaded) 3963{ 3964 pid_t pid; 3965 long ret; 3966 int status; 3967 struct pollfd pollfd; 3968 struct __clone_args args = { 3969 .flags = CLONE_FILES, 3970 .exit_signal = SIGCHLD, 3971 }; 3972 3973 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 3974 ASSERT_EQ(0, ret) { 3975 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 3976 } 3977 3978 if (__NR_clone3 < 0) 3979 SKIP(return, "Test not built with clone3 support"); 3980 3981 pid = sys_clone3(&args, sizeof(args)); 3982 ASSERT_GE(pid, 0); 3983 3984 if (pid == 0) { 3985 pid_t pid1, pid2; 3986 int listener, status; 3987 pthread_t thread; 3988 3989 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); 3990 if (listener < 0) 3991 _exit(EXIT_FAILURE); 3992 3993 if (dup2(listener, 200) != 200) 3994 _exit(EXIT_FAILURE); 3995 3996 close(listener); 3997 3998 pid1 = fork(); 3999 if (pid1 < 0) 4000 _exit(EXIT_FAILURE); 4001 4002 if (pid1 == 0) 4003 _exit(EXIT_SUCCESS); 4004 4005 pid2 = fork(); 4006 if (pid2 < 0) 4007 _exit(EXIT_FAILURE); 4008 4009 if (pid2 == 0) 4010 _exit(EXIT_SUCCESS); 4011 4012 if (pthread_create(&thread, NULL, do_thread, NULL) || 4013 pthread_join(thread, NULL)) 4014 _exit(EXIT_FAILURE); 4015 4016 if (pthread_create(&thread, NULL, do_thread, NULL) || 4017 pthread_join(thread, NULL)) 4018 _exit(EXIT_FAILURE); 4019 4020 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) || 4021 WEXITSTATUS(status)) 4022 _exit(EXIT_FAILURE); 4023 4024 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) || 4025 WEXITSTATUS(status)) 4026 _exit(EXIT_FAILURE); 4027 4028 exit(EXIT_SUCCESS); 4029 } 4030 4031 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4032 EXPECT_EQ(true, WIFEXITED(status)); 4033 EXPECT_EQ(0, WEXITSTATUS(status)); 4034 4035 /* 4036 * The seccomp filter has become unused so we should be notified once 4037 * the kernel gets around to cleaning up task struct. 4038 */ 4039 pollfd.fd = 200; 4040 pollfd.events = POLLHUP; 4041 4042 EXPECT_GT(poll(&pollfd, 1, 2000), 0); 4043 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); 4044} 4045 4046 4047int get_next_fd(int prev_fd) 4048{ 4049 for (int i = prev_fd + 1; i < FD_SETSIZE; ++i) { 4050 if (fcntl(i, F_GETFD) == -1) 4051 return i; 4052 } 4053 _exit(EXIT_FAILURE); 4054} 4055 4056TEST(user_notification_addfd) 4057{ 4058 pid_t pid; 4059 long ret; 4060 int status, listener, memfd, fd, nextfd; 4061 struct seccomp_notif_addfd addfd = {}; 4062 struct seccomp_notif_addfd_small small = {}; 4063 struct seccomp_notif_addfd_big big = {}; 4064 struct seccomp_notif req = {}; 4065 struct seccomp_notif_resp resp = {}; 4066 /* 100 ms */ 4067 struct timespec delay = { .tv_nsec = 100000000 }; 4068 4069 /* There may be arbitrary already-open fds at test start. */ 4070 memfd = memfd_create("test", 0); 4071 ASSERT_GE(memfd, 0); 4072 nextfd = get_next_fd(memfd); 4073 4074 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4075 ASSERT_EQ(0, ret) { 4076 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4077 } 4078 4079 /* fd: 4 */ 4080 /* Check that the basic notification machinery works */ 4081 listener = user_notif_syscall(__NR_getppid, 4082 SECCOMP_FILTER_FLAG_NEW_LISTENER); 4083 ASSERT_EQ(listener, nextfd); 4084 nextfd = get_next_fd(nextfd); 4085 4086 pid = fork(); 4087 ASSERT_GE(pid, 0); 4088 4089 if (pid == 0) { 4090 /* fds will be added and this value is expected */ 4091 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) 4092 exit(1); 4093 4094 /* Atomic addfd+send is received here. Check it is a valid fd */ 4095 if (fcntl(syscall(__NR_getppid), F_GETFD) == -1) 4096 exit(1); 4097 4098 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 4099 } 4100 4101 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4102 4103 addfd.srcfd = memfd; 4104 addfd.newfd = 0; 4105 addfd.id = req.id; 4106 addfd.flags = 0x0; 4107 4108 /* Verify bad newfd_flags cannot be set */ 4109 addfd.newfd_flags = ~O_CLOEXEC; 4110 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4111 EXPECT_EQ(errno, EINVAL); 4112 addfd.newfd_flags = O_CLOEXEC; 4113 4114 /* Verify bad flags cannot be set */ 4115 addfd.flags = 0xff; 4116 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4117 EXPECT_EQ(errno, EINVAL); 4118 addfd.flags = 0; 4119 4120 /* Verify that remote_fd cannot be set without setting flags */ 4121 addfd.newfd = 1; 4122 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4123 EXPECT_EQ(errno, EINVAL); 4124 addfd.newfd = 0; 4125 4126 /* Verify small size cannot be set */ 4127 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1); 4128 EXPECT_EQ(errno, EINVAL); 4129 4130 /* Verify we can't send bits filled in unknown buffer area */ 4131 memset(&big, 0xAA, sizeof(big)); 4132 big.addfd = addfd; 4133 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1); 4134 EXPECT_EQ(errno, E2BIG); 4135 4136 4137 /* Verify we can set an arbitrary remote fd */ 4138 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4139 EXPECT_EQ(fd, nextfd); 4140 nextfd = get_next_fd(nextfd); 4141 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4142 4143 /* Verify we can set an arbitrary remote fd with large size */ 4144 memset(&big, 0x0, sizeof(big)); 4145 big.addfd = addfd; 4146 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); 4147 EXPECT_EQ(fd, nextfd); 4148 nextfd = get_next_fd(nextfd); 4149 4150 /* Verify we can set a specific remote fd */ 4151 addfd.newfd = 42; 4152 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; 4153 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4154 EXPECT_EQ(fd, 42); 4155 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4156 4157 /* Resume syscall */ 4158 resp.id = req.id; 4159 resp.error = 0; 4160 resp.val = USER_NOTIF_MAGIC; 4161 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4162 4163 /* 4164 * This sets the ID of the ADD FD to the last request plus 1. The 4165 * notification ID increments 1 per notification. 4166 */ 4167 addfd.id = req.id + 1; 4168 4169 /* This spins until the underlying notification is generated */ 4170 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && 4171 errno != -EINPROGRESS) 4172 nanosleep(&delay, NULL); 4173 4174 memset(&req, 0, sizeof(req)); 4175 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4176 ASSERT_EQ(addfd.id, req.id); 4177 4178 /* Verify we can do an atomic addfd and send */ 4179 addfd.newfd = 0; 4180 addfd.flags = SECCOMP_ADDFD_FLAG_SEND; 4181 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); 4182 /* 4183 * Child has earlier "low" fds and now 42, so we expect the next 4184 * lowest available fd to be assigned here. 4185 */ 4186 EXPECT_EQ(fd, nextfd); 4187 nextfd = get_next_fd(nextfd); 4188 ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0); 4189 4190 /* 4191 * This sets the ID of the ADD FD to the last request plus 1. The 4192 * notification ID increments 1 per notification. 4193 */ 4194 addfd.id = req.id + 1; 4195 4196 /* This spins until the underlying notification is generated */ 4197 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && 4198 errno != -EINPROGRESS) 4199 nanosleep(&delay, NULL); 4200 4201 memset(&req, 0, sizeof(req)); 4202 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4203 ASSERT_EQ(addfd.id, req.id); 4204 4205 resp.id = req.id; 4206 resp.error = 0; 4207 resp.val = USER_NOTIF_MAGIC; 4208 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4209 4210 /* Wait for child to finish. */ 4211 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4212 EXPECT_EQ(true, WIFEXITED(status)); 4213 EXPECT_EQ(0, WEXITSTATUS(status)); 4214 4215 close(memfd); 4216} 4217 4218TEST(user_notification_addfd_rlimit) 4219{ 4220 pid_t pid; 4221 long ret; 4222 int status, listener, memfd; 4223 struct seccomp_notif_addfd addfd = {}; 4224 struct seccomp_notif req = {}; 4225 struct seccomp_notif_resp resp = {}; 4226 const struct rlimit lim = { 4227 .rlim_cur = 0, 4228 .rlim_max = 0, 4229 }; 4230 4231 memfd = memfd_create("test", 0); 4232 ASSERT_GE(memfd, 0); 4233 4234 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4235 ASSERT_EQ(0, ret) { 4236 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4237 } 4238 4239 /* Check that the basic notification machinery works */ 4240 listener = user_notif_syscall(__NR_getppid, 4241 SECCOMP_FILTER_FLAG_NEW_LISTENER); 4242 ASSERT_GE(listener, 0); 4243 4244 pid = fork(); 4245 ASSERT_GE(pid, 0); 4246 4247 if (pid == 0) 4248 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); 4249 4250 4251 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4252 4253 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0); 4254 4255 addfd.srcfd = memfd; 4256 addfd.newfd_flags = O_CLOEXEC; 4257 addfd.newfd = 0; 4258 addfd.id = req.id; 4259 addfd.flags = 0; 4260 4261 /* Should probably spot check /proc/sys/fs/file-nr */ 4262 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4263 EXPECT_EQ(errno, EMFILE); 4264 4265 addfd.flags = SECCOMP_ADDFD_FLAG_SEND; 4266 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4267 EXPECT_EQ(errno, EMFILE); 4268 4269 addfd.newfd = 100; 4270 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; 4271 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); 4272 EXPECT_EQ(errno, EBADF); 4273 4274 resp.id = req.id; 4275 resp.error = 0; 4276 resp.val = USER_NOTIF_MAGIC; 4277 4278 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4279 4280 /* Wait for child to finish. */ 4281 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4282 EXPECT_EQ(true, WIFEXITED(status)); 4283 EXPECT_EQ(0, WEXITSTATUS(status)); 4284 4285 close(memfd); 4286} 4287 4288#ifndef SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP 4289#define SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP (1UL << 0) 4290#define SECCOMP_IOCTL_NOTIF_SET_FLAGS SECCOMP_IOW(4, __u64) 4291#endif 4292 4293TEST(user_notification_sync) 4294{ 4295 struct seccomp_notif req = {}; 4296 struct seccomp_notif_resp resp = {}; 4297 int status, listener; 4298 pid_t pid; 4299 long ret; 4300 4301 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4302 ASSERT_EQ(0, ret) { 4303 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4304 } 4305 4306 listener = user_notif_syscall(__NR_getppid, 4307 SECCOMP_FILTER_FLAG_NEW_LISTENER); 4308 ASSERT_GE(listener, 0); 4309 4310 /* Try to set invalid flags. */ 4311 EXPECT_SYSCALL_RETURN(-EINVAL, 4312 ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_FLAGS, 0xffffffff, 0)); 4313 4314 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_FLAGS, 4315 SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP, 0), 0); 4316 4317 pid = fork(); 4318 ASSERT_GE(pid, 0); 4319 if (pid == 0) { 4320 ret = syscall(__NR_getppid); 4321 ASSERT_EQ(ret, USER_NOTIF_MAGIC) { 4322 _exit(1); 4323 } 4324 _exit(0); 4325 } 4326 4327 req.pid = 0; 4328 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4329 4330 ASSERT_EQ(req.data.nr, __NR_getppid); 4331 4332 resp.id = req.id; 4333 resp.error = 0; 4334 resp.val = USER_NOTIF_MAGIC; 4335 resp.flags = 0; 4336 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4337 4338 ASSERT_EQ(waitpid(pid, &status, 0), pid); 4339 ASSERT_EQ(status, 0); 4340} 4341 4342 4343/* Make sure PTRACE_O_SUSPEND_SECCOMP requires CAP_SYS_ADMIN. */ 4344FIXTURE(O_SUSPEND_SECCOMP) { 4345 pid_t pid; 4346}; 4347 4348FIXTURE_SETUP(O_SUSPEND_SECCOMP) 4349{ 4350 ERRNO_FILTER(block_read, E2BIG); 4351 cap_value_t cap_list[] = { CAP_SYS_ADMIN }; 4352 cap_t caps; 4353 4354 self->pid = 0; 4355 4356 /* make sure we don't have CAP_SYS_ADMIN */ 4357 caps = cap_get_proc(); 4358 ASSERT_NE(NULL, caps); 4359 ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, cap_list, CAP_CLEAR)); 4360 ASSERT_EQ(0, cap_set_proc(caps)); 4361 cap_free(caps); 4362 4363 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 4364 ASSERT_EQ(0, prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_block_read)); 4365 4366 self->pid = fork(); 4367 ASSERT_GE(self->pid, 0); 4368 4369 if (self->pid == 0) { 4370 while (1) 4371 pause(); 4372 _exit(127); 4373 } 4374} 4375 4376FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP) 4377{ 4378 if (self->pid) 4379 kill(self->pid, SIGKILL); 4380} 4381 4382TEST_F(O_SUSPEND_SECCOMP, setoptions) 4383{ 4384 int wstatus; 4385 4386 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, self->pid, NULL, 0)); 4387 ASSERT_EQ(self->pid, wait(&wstatus)); 4388 ASSERT_EQ(-1, ptrace(PTRACE_SETOPTIONS, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP)); 4389 if (errno == EINVAL) 4390 SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)"); 4391 ASSERT_EQ(EPERM, errno); 4392} 4393 4394TEST_F(O_SUSPEND_SECCOMP, seize) 4395{ 4396 int ret; 4397 4398 ret = ptrace(PTRACE_SEIZE, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP); 4399 ASSERT_EQ(-1, ret); 4400 if (errno == EINVAL) 4401 SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)"); 4402 ASSERT_EQ(EPERM, errno); 4403} 4404 4405/* 4406 * get_nth - Get the nth, space separated entry in a file. 4407 * 4408 * Returns the length of the read field. 4409 * Throws error if field is zero-lengthed. 4410 */ 4411static ssize_t get_nth(struct __test_metadata *_metadata, const char *path, 4412 const unsigned int position, char **entry) 4413{ 4414 char *line = NULL; 4415 unsigned int i; 4416 ssize_t nread; 4417 size_t len = 0; 4418 FILE *f; 4419 4420 f = fopen(path, "r"); 4421 ASSERT_NE(f, NULL) { 4422 TH_LOG("Could not open %s: %s", path, strerror(errno)); 4423 } 4424 4425 for (i = 0; i < position; i++) { 4426 nread = getdelim(&line, &len, ' ', f); 4427 ASSERT_GE(nread, 0) { 4428 TH_LOG("Failed to read %d entry in file %s", i, path); 4429 } 4430 } 4431 fclose(f); 4432 4433 ASSERT_GT(nread, 0) { 4434 TH_LOG("Entry in file %s had zero length", path); 4435 } 4436 4437 *entry = line; 4438 return nread - 1; 4439} 4440 4441/* For a given PID, get the task state (D, R, etc...) */ 4442static char get_proc_stat(struct __test_metadata *_metadata, pid_t pid) 4443{ 4444 char proc_path[100] = {0}; 4445 char status; 4446 char *line; 4447 4448 snprintf(proc_path, sizeof(proc_path), "/proc/%d/stat", pid); 4449 ASSERT_EQ(get_nth(_metadata, proc_path, 3, &line), 1); 4450 4451 status = *line; 4452 free(line); 4453 4454 return status; 4455} 4456 4457TEST(user_notification_fifo) 4458{ 4459 struct seccomp_notif_resp resp = {}; 4460 struct seccomp_notif req = {}; 4461 int i, status, listener; 4462 pid_t pid, pids[3]; 4463 __u64 baseid; 4464 long ret; 4465 /* 100 ms */ 4466 struct timespec delay = { .tv_nsec = 100000000 }; 4467 4468 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4469 ASSERT_EQ(0, ret) { 4470 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4471 } 4472 4473 /* Setup a listener */ 4474 listener = user_notif_syscall(__NR_getppid, 4475 SECCOMP_FILTER_FLAG_NEW_LISTENER); 4476 ASSERT_GE(listener, 0); 4477 4478 pid = fork(); 4479 ASSERT_GE(pid, 0); 4480 4481 if (pid == 0) { 4482 ret = syscall(__NR_getppid); 4483 exit(ret != USER_NOTIF_MAGIC); 4484 } 4485 4486 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4487 baseid = req.id + 1; 4488 4489 resp.id = req.id; 4490 resp.error = 0; 4491 resp.val = USER_NOTIF_MAGIC; 4492 4493 /* check that we make sure flags == 0 */ 4494 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4495 4496 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4497 EXPECT_EQ(true, WIFEXITED(status)); 4498 EXPECT_EQ(0, WEXITSTATUS(status)); 4499 4500 /* Start children, and generate notifications */ 4501 for (i = 0; i < ARRAY_SIZE(pids); i++) { 4502 pid = fork(); 4503 if (pid == 0) { 4504 ret = syscall(__NR_getppid); 4505 exit(ret != USER_NOTIF_MAGIC); 4506 } 4507 pids[i] = pid; 4508 } 4509 4510 /* This spins until all of the children are sleeping */ 4511restart_wait: 4512 for (i = 0; i < ARRAY_SIZE(pids); i++) { 4513 if (get_proc_stat(_metadata, pids[i]) != 'S') { 4514 nanosleep(&delay, NULL); 4515 goto restart_wait; 4516 } 4517 } 4518 4519 /* Read the notifications in order (and respond) */ 4520 for (i = 0; i < ARRAY_SIZE(pids); i++) { 4521 memset(&req, 0, sizeof(req)); 4522 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4523 EXPECT_EQ(req.id, baseid + i); 4524 resp.id = req.id; 4525 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4526 } 4527 4528 /* Make sure notifications were received */ 4529 for (i = 0; i < ARRAY_SIZE(pids); i++) { 4530 EXPECT_EQ(waitpid(pids[i], &status, 0), pids[i]); 4531 EXPECT_EQ(true, WIFEXITED(status)); 4532 EXPECT_EQ(0, WEXITSTATUS(status)); 4533 } 4534} 4535 4536/* get_proc_syscall - Get the syscall in progress for a given pid 4537 * 4538 * Returns the current syscall number for a given process 4539 * Returns -1 if not in syscall (running or blocked) 4540 */ 4541static long get_proc_syscall(struct __test_metadata *_metadata, int pid) 4542{ 4543 char proc_path[100] = {0}; 4544 long ret = -1; 4545 ssize_t nread; 4546 char *line; 4547 4548 snprintf(proc_path, sizeof(proc_path), "/proc/%d/syscall", pid); 4549 nread = get_nth(_metadata, proc_path, 1, &line); 4550 ASSERT_GT(nread, 0); 4551 4552 if (!strncmp("running", line, MIN(7, nread))) 4553 ret = strtol(line, NULL, 16); 4554 4555 free(line); 4556 return ret; 4557} 4558 4559/* Ensure non-fatal signals prior to receive are unmodified */ 4560TEST(user_notification_wait_killable_pre_notification) 4561{ 4562 struct sigaction new_action = { 4563 .sa_handler = signal_handler, 4564 }; 4565 int listener, status, sk_pair[2]; 4566 pid_t pid; 4567 long ret; 4568 char c; 4569 /* 100 ms */ 4570 struct timespec delay = { .tv_nsec = 100000000 }; 4571 4572 ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0); 4573 4574 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4575 ASSERT_EQ(0, ret) 4576 { 4577 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4578 } 4579 4580 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); 4581 4582 listener = user_notif_syscall( 4583 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER | 4584 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV); 4585 ASSERT_GE(listener, 0); 4586 4587 /* 4588 * Check that we can kill the process with SIGUSR1 prior to receiving 4589 * the notification. SIGUSR1 is wired up to a custom signal handler, 4590 * and make sure it gets called. 4591 */ 4592 pid = fork(); 4593 ASSERT_GE(pid, 0); 4594 4595 if (pid == 0) { 4596 close(sk_pair[0]); 4597 handled = sk_pair[1]; 4598 4599 /* Setup the non-fatal sigaction without SA_RESTART */ 4600 if (sigaction(SIGUSR1, &new_action, NULL)) { 4601 perror("sigaction"); 4602 exit(1); 4603 } 4604 4605 ret = syscall(__NR_getppid); 4606 /* Make sure we got a return from a signal interruption */ 4607 exit(ret != -1 || errno != EINTR); 4608 } 4609 4610 /* 4611 * Make sure we've gotten to the seccomp user notification wait 4612 * from getppid prior to sending any signals 4613 */ 4614 while (get_proc_syscall(_metadata, pid) != __NR_getppid && 4615 get_proc_stat(_metadata, pid) != 'S') 4616 nanosleep(&delay, NULL); 4617 4618 /* Send non-fatal kill signal */ 4619 EXPECT_EQ(kill(pid, SIGUSR1), 0); 4620 4621 /* wait for process to exit (exit checks for EINTR) */ 4622 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4623 EXPECT_EQ(true, WIFEXITED(status)); 4624 EXPECT_EQ(0, WEXITSTATUS(status)); 4625 4626 EXPECT_EQ(read(sk_pair[0], &c, 1), 1); 4627} 4628 4629/* Ensure non-fatal signals after receive are blocked */ 4630TEST(user_notification_wait_killable) 4631{ 4632 struct sigaction new_action = { 4633 .sa_handler = signal_handler, 4634 }; 4635 struct seccomp_notif_resp resp = {}; 4636 struct seccomp_notif req = {}; 4637 int listener, status, sk_pair[2]; 4638 pid_t pid; 4639 long ret; 4640 char c; 4641 /* 100 ms */ 4642 struct timespec delay = { .tv_nsec = 100000000 }; 4643 4644 ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0); 4645 4646 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4647 ASSERT_EQ(0, ret) 4648 { 4649 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4650 } 4651 4652 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); 4653 4654 listener = user_notif_syscall( 4655 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER | 4656 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV); 4657 ASSERT_GE(listener, 0); 4658 4659 pid = fork(); 4660 ASSERT_GE(pid, 0); 4661 4662 if (pid == 0) { 4663 close(sk_pair[0]); 4664 handled = sk_pair[1]; 4665 4666 /* Setup the sigaction without SA_RESTART */ 4667 if (sigaction(SIGUSR1, &new_action, NULL)) { 4668 perror("sigaction"); 4669 exit(1); 4670 } 4671 4672 /* Make sure that the syscall is completed (no EINTR) */ 4673 ret = syscall(__NR_getppid); 4674 exit(ret != USER_NOTIF_MAGIC); 4675 } 4676 4677 /* 4678 * Get the notification, to make move the notifying process into a 4679 * non-preemptible (TASK_KILLABLE) state. 4680 */ 4681 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4682 /* Send non-fatal kill signal */ 4683 EXPECT_EQ(kill(pid, SIGUSR1), 0); 4684 4685 /* 4686 * Make sure the task enters moves to TASK_KILLABLE by waiting for 4687 * D (Disk Sleep) state after receiving non-fatal signal. 4688 */ 4689 while (get_proc_stat(_metadata, pid) != 'D') 4690 nanosleep(&delay, NULL); 4691 4692 resp.id = req.id; 4693 resp.val = USER_NOTIF_MAGIC; 4694 /* Make sure the notification is found and able to be replied to */ 4695 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); 4696 4697 /* 4698 * Make sure that the signal handler does get called once we're back in 4699 * userspace. 4700 */ 4701 EXPECT_EQ(read(sk_pair[0], &c, 1), 1); 4702 /* wait for process to exit (exit checks for USER_NOTIF_MAGIC) */ 4703 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4704 EXPECT_EQ(true, WIFEXITED(status)); 4705 EXPECT_EQ(0, WEXITSTATUS(status)); 4706} 4707 4708/* Ensure fatal signals after receive are not blocked */ 4709TEST(user_notification_wait_killable_fatal) 4710{ 4711 struct seccomp_notif req = {}; 4712 int listener, status; 4713 pid_t pid; 4714 long ret; 4715 /* 100 ms */ 4716 struct timespec delay = { .tv_nsec = 100000000 }; 4717 4718 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 4719 ASSERT_EQ(0, ret) 4720 { 4721 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); 4722 } 4723 4724 listener = user_notif_syscall( 4725 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER | 4726 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV); 4727 ASSERT_GE(listener, 0); 4728 4729 pid = fork(); 4730 ASSERT_GE(pid, 0); 4731 4732 if (pid == 0) { 4733 /* This should never complete as it should get a SIGTERM */ 4734 syscall(__NR_getppid); 4735 exit(1); 4736 } 4737 4738 while (get_proc_stat(_metadata, pid) != 'S') 4739 nanosleep(&delay, NULL); 4740 4741 /* 4742 * Get the notification, to make move the notifying process into a 4743 * non-preemptible (TASK_KILLABLE) state. 4744 */ 4745 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); 4746 /* Kill the process with a fatal signal */ 4747 EXPECT_EQ(kill(pid, SIGTERM), 0); 4748 4749 /* 4750 * Wait for the process to exit, and make sure the process terminated 4751 * due to the SIGTERM signal. 4752 */ 4753 EXPECT_EQ(waitpid(pid, &status, 0), pid); 4754 EXPECT_EQ(true, WIFSIGNALED(status)); 4755 EXPECT_EQ(SIGTERM, WTERMSIG(status)); 4756} 4757 4758/* 4759 * TODO: 4760 * - expand NNP testing 4761 * - better arch-specific TRACE and TRAP handlers. 4762 * - endianness checking when appropriate 4763 * - 64-bit arg prodding 4764 * - arch value testing (x86 modes especially) 4765 * - verify that FILTER_FLAG_LOG filters generate log messages 4766 * - verify that RET_LOG generates log messages 4767 */ 4768 4769TEST_HARNESS_MAIN 4770