1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #define _GNU_SOURCE
9 #include <sys/types.h>
10
11 /*
12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
13 * we need to use the kernel's siginfo.h file and trick glibc
14 * into accepting it.
15 */
16 #if !__GLIBC_PREREQ(2, 26)
17 # include <asm/siginfo.h>
18 # define __have_siginfo_t 1
19 # define __have_sigval_t 1
20 # define __have_sigevent_t 1
21 #endif
22
23 #include <errno.h>
24 #include <linux/filter.h>
25 #include <sys/prctl.h>
26 #include <sys/ptrace.h>
27 #include <sys/user.h>
28 #include <linux/prctl.h>
29 #include <linux/ptrace.h>
30 #include <linux/seccomp.h>
31 #include <pthread.h>
32 #include <semaphore.h>
33 #include <signal.h>
34 #include <stddef.h>
35 #include <stdbool.h>
36 #include <string.h>
37 #include <time.h>
38 #include <limits.h>
39 #include <linux/elf.h>
40 #include <sys/uio.h>
41 #include <sys/utsname.h>
42 #include <sys/fcntl.h>
43 #include <sys/mman.h>
44 #include <sys/times.h>
45 #include <sys/socket.h>
46 #include <sys/ioctl.h>
47 #include <linux/kcmp.h>
48 #include <sys/resource.h>
49
50 #include <unistd.h>
51 #include <sys/syscall.h>
52 #include <poll.h>
53
54 #include "../kselftest_harness.h"
55 #include "../clone3/clone3_selftests.h"
56
57 /* Attempt to de-conflict with the selftests tree. */
58 #ifndef SKIP
59 #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
60 #endif
61
62 #ifndef PR_SET_PTRACER
63 # define PR_SET_PTRACER 0x59616d61
64 #endif
65
66 #ifndef PR_SET_NO_NEW_PRIVS
67 #define PR_SET_NO_NEW_PRIVS 38
68 #define PR_GET_NO_NEW_PRIVS 39
69 #endif
70
71 #ifndef PR_SECCOMP_EXT
72 #define PR_SECCOMP_EXT 43
73 #endif
74
75 #ifndef SECCOMP_EXT_ACT
76 #define SECCOMP_EXT_ACT 1
77 #endif
78
79 #ifndef SECCOMP_EXT_ACT_TSYNC
80 #define SECCOMP_EXT_ACT_TSYNC 1
81 #endif
82
83 #ifndef SECCOMP_MODE_STRICT
84 #define SECCOMP_MODE_STRICT 1
85 #endif
86
87 #ifndef SECCOMP_MODE_FILTER
88 #define SECCOMP_MODE_FILTER 2
89 #endif
90
91 #ifndef SECCOMP_RET_ALLOW
92 struct seccomp_data {
93 int nr;
94 __u32 arch;
95 __u64 instruction_pointer;
96 __u64 args[6];
97 };
98 #endif
99
100 #ifndef SECCOMP_RET_KILL_PROCESS
101 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
102 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
103 #endif
104 #ifndef SECCOMP_RET_KILL
105 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
106 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
107 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
108 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
109 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
110 #endif
111 #ifndef SECCOMP_RET_LOG
112 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
113 #endif
114
115 #ifndef __NR_seccomp
116 # if defined(__i386__)
117 # define __NR_seccomp 354
118 # elif defined(__x86_64__)
119 # define __NR_seccomp 317
120 # elif defined(__arm__)
121 # define __NR_seccomp 383
122 # elif defined(__aarch64__)
123 # define __NR_seccomp 277
124 # elif defined(__riscv)
125 # define __NR_seccomp 277
126 # elif defined(__csky__)
127 # define __NR_seccomp 277
128 # elif defined(__hppa__)
129 # define __NR_seccomp 338
130 # elif defined(__powerpc__)
131 # define __NR_seccomp 358
132 # elif defined(__s390__)
133 # define __NR_seccomp 348
134 # elif defined(__xtensa__)
135 # define __NR_seccomp 337
136 # elif defined(__sh__)
137 # define __NR_seccomp 372
138 # else
139 # warning "seccomp syscall number unknown for this architecture"
140 # define __NR_seccomp 0xffff
141 # endif
142 #endif
143
144 #ifndef SECCOMP_SET_MODE_STRICT
145 #define SECCOMP_SET_MODE_STRICT 0
146 #endif
147
148 #ifndef SECCOMP_SET_MODE_FILTER
149 #define SECCOMP_SET_MODE_FILTER 1
150 #endif
151
152 #ifndef SECCOMP_GET_ACTION_AVAIL
153 #define SECCOMP_GET_ACTION_AVAIL 2
154 #endif
155
156 #ifndef SECCOMP_GET_NOTIF_SIZES
157 #define SECCOMP_GET_NOTIF_SIZES 3
158 #endif
159
160 #ifndef SECCOMP_FILTER_FLAG_TSYNC
161 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
162 #endif
163
164 #ifndef SECCOMP_FILTER_FLAG_LOG
165 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
166 #endif
167
168 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
169 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
170 #endif
171
172 #ifndef PTRACE_SECCOMP_GET_METADATA
173 #define PTRACE_SECCOMP_GET_METADATA 0x420d
174
175 struct seccomp_metadata {
176 __u64 filter_off; /* Input: which filter */
177 __u64 flags; /* Output: filter's flags */
178 };
179 #endif
180
181 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
182 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
183 #endif
184
185 #ifndef SECCOMP_RET_USER_NOTIF
186 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
187
188 #define SECCOMP_IOC_MAGIC '!'
189 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
190 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
191 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
192 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
193
194 /* Flags for seccomp notification fd ioctl. */
195 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
196 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
197 struct seccomp_notif_resp)
198 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)
199
200 struct seccomp_notif {
201 __u64 id;
202 __u32 pid;
203 __u32 flags;
204 struct seccomp_data data;
205 };
206
207 struct seccomp_notif_resp {
208 __u64 id;
209 __s64 val;
210 __s32 error;
211 __u32 flags;
212 };
213
214 struct seccomp_notif_sizes {
215 __u16 seccomp_notif;
216 __u16 seccomp_notif_resp;
217 __u16 seccomp_data;
218 };
219 #endif
220
221 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD
222 /* On success, the return value is the remote process's added fd number */
223 #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \
224 struct seccomp_notif_addfd)
225
226 /* valid flags for seccomp_notif_addfd */
227 #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */
228
229 struct seccomp_notif_addfd {
230 __u64 id;
231 __u32 flags;
232 __u32 srcfd;
233 __u32 newfd;
234 __u32 newfd_flags;
235 };
236 #endif
237
238 struct seccomp_notif_addfd_small {
239 __u64 id;
240 char weird[4];
241 };
242 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \
243 SECCOMP_IOW(3, struct seccomp_notif_addfd_small)
244
245 struct seccomp_notif_addfd_big {
246 union {
247 struct seccomp_notif_addfd addfd;
248 char buf[sizeof(struct seccomp_notif_addfd) + 8];
249 };
250 };
251 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \
252 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big)
253
254 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
255 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
256 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
257 #endif
258
259 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
260 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
261 #endif
262
263 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
264 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
265 #endif
266
267 #ifndef seccomp
seccomp(unsigned int op,unsigned int flags,void * args)268 int seccomp(unsigned int op, unsigned int flags, void *args)
269 {
270 errno = 0;
271 return syscall(__NR_seccomp, op, flags, args);
272 }
273 #endif
274
275 #if __BYTE_ORDER == __LITTLE_ENDIAN
276 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
277 #elif __BYTE_ORDER == __BIG_ENDIAN
278 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
279 #else
280 #error "wut? Unknown __BYTE_ORDER?!"
281 #endif
282
283 #define SIBLING_EXIT_UNKILLED 0xbadbeef
284 #define SIBLING_EXIT_FAILURE 0xbadface
285 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
286
__filecmp(pid_t pid1,pid_t pid2,int fd1,int fd2)287 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
288 {
289 #ifdef __NR_kcmp
290 errno = 0;
291 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
292 #else
293 errno = ENOSYS;
294 return -1;
295 #endif
296 }
297
298 /* Have TH_LOG report actual location filecmp() is used. */
299 #define filecmp(pid1, pid2, fd1, fd2) ({ \
300 int _ret; \
301 \
302 _ret = __filecmp(pid1, pid2, fd1, fd2); \
303 if (_ret != 0) { \
304 if (_ret < 0 && errno == ENOSYS) { \
305 TH_LOG("kcmp() syscall missing (test is less accurate)");\
306 _ret = 0; \
307 } \
308 } \
309 _ret; })
310
TEST(kcmp)311 TEST(kcmp)
312 {
313 int ret;
314
315 ret = __filecmp(getpid(), getpid(), 1, 1);
316 EXPECT_EQ(ret, 0);
317 if (ret != 0 && errno == ENOSYS)
318 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)");
319 }
320
TEST(mode_strict_support)321 TEST(mode_strict_support)
322 {
323 long ret;
324
325 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
326 ASSERT_EQ(0, ret) {
327 TH_LOG("Kernel does not support CONFIG_SECCOMP");
328 }
329 syscall(__NR_exit, 0);
330 }
331
TEST_SIGNAL(mode_strict_cannot_call_prctl,SIGKILL)332 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
333 {
334 long ret;
335
336 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
337 ASSERT_EQ(0, ret) {
338 TH_LOG("Kernel does not support CONFIG_SECCOMP");
339 }
340 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
341 NULL, NULL, NULL);
342 EXPECT_FALSE(true) {
343 TH_LOG("Unreachable!");
344 }
345 }
346
347 /* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)348 TEST(no_new_privs_support)
349 {
350 long ret;
351
352 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
353 EXPECT_EQ(0, ret) {
354 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
355 }
356 }
357
358 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)359 TEST(mode_filter_support)
360 {
361 long ret;
362
363 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
364 ASSERT_EQ(0, ret) {
365 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
366 }
367 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
368 EXPECT_EQ(-1, ret);
369 EXPECT_EQ(EFAULT, errno) {
370 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
371 }
372 }
373
TEST(mode_filter_without_nnp)374 TEST(mode_filter_without_nnp)
375 {
376 struct sock_filter filter[] = {
377 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
378 };
379 struct sock_fprog prog = {
380 .len = (unsigned short)ARRAY_SIZE(filter),
381 .filter = filter,
382 };
383 long ret;
384
385 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
386 ASSERT_LE(0, ret) {
387 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
388 }
389 errno = 0;
390 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
391 /* Succeeds with CAP_SYS_ADMIN, fails without */
392 /* TODO(wad) check caps not euid */
393 if (geteuid()) {
394 EXPECT_EQ(-1, ret);
395 EXPECT_EQ(EACCES, errno);
396 } else {
397 EXPECT_EQ(0, ret);
398 }
399 }
400
401 #define MAX_INSNS_PER_PATH 32768
402
TEST(filter_size_limits)403 TEST(filter_size_limits)
404 {
405 int i;
406 int count = BPF_MAXINSNS + 1;
407 struct sock_filter allow[] = {
408 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
409 };
410 struct sock_filter *filter;
411 struct sock_fprog prog = { };
412 long ret;
413
414 filter = calloc(count, sizeof(*filter));
415 ASSERT_NE(NULL, filter);
416
417 for (i = 0; i < count; i++)
418 filter[i] = allow[0];
419
420 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
421 ASSERT_EQ(0, ret);
422
423 prog.filter = filter;
424 prog.len = count;
425
426 /* Too many filter instructions in a single filter. */
427 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
428 ASSERT_NE(0, ret) {
429 TH_LOG("Installing %d insn filter was allowed", prog.len);
430 }
431
432 /* One less is okay, though. */
433 prog.len -= 1;
434 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
435 ASSERT_EQ(0, ret) {
436 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
437 }
438 }
439
TEST(filter_chain_limits)440 TEST(filter_chain_limits)
441 {
442 int i;
443 int count = BPF_MAXINSNS;
444 struct sock_filter allow[] = {
445 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
446 };
447 struct sock_filter *filter;
448 struct sock_fprog prog = { };
449 long ret;
450
451 filter = calloc(count, sizeof(*filter));
452 ASSERT_NE(NULL, filter);
453
454 for (i = 0; i < count; i++)
455 filter[i] = allow[0];
456
457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
458 ASSERT_EQ(0, ret);
459
460 prog.filter = filter;
461 prog.len = 1;
462
463 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
464 ASSERT_EQ(0, ret);
465
466 prog.len = count;
467
468 /* Too many total filter instructions. */
469 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
470 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
471 if (ret != 0)
472 break;
473 }
474 ASSERT_NE(0, ret) {
475 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
476 i, count, i * (count + 4));
477 }
478 }
479
TEST(mode_filter_cannot_move_to_strict)480 TEST(mode_filter_cannot_move_to_strict)
481 {
482 struct sock_filter filter[] = {
483 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
484 };
485 struct sock_fprog prog = {
486 .len = (unsigned short)ARRAY_SIZE(filter),
487 .filter = filter,
488 };
489 long ret;
490
491 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
492 ASSERT_EQ(0, ret);
493
494 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
495 ASSERT_EQ(0, ret);
496
497 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
498 EXPECT_EQ(-1, ret);
499 EXPECT_EQ(EINVAL, errno);
500 }
501
502
TEST(mode_filter_get_seccomp)503 TEST(mode_filter_get_seccomp)
504 {
505 struct sock_filter filter[] = {
506 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
507 };
508 struct sock_fprog prog = {
509 .len = (unsigned short)ARRAY_SIZE(filter),
510 .filter = filter,
511 };
512 long ret;
513
514 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
515 ASSERT_EQ(0, ret);
516
517 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
518 EXPECT_EQ(0, ret);
519
520 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
521 ASSERT_EQ(0, ret);
522
523 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
524 EXPECT_EQ(2, ret);
525 }
526
527
TEST(ALLOW_all)528 TEST(ALLOW_all)
529 {
530 struct sock_filter filter[] = {
531 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
532 };
533 struct sock_fprog prog = {
534 .len = (unsigned short)ARRAY_SIZE(filter),
535 .filter = filter,
536 };
537 long ret;
538
539 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
540 ASSERT_EQ(0, ret);
541
542 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
543 ASSERT_EQ(0, ret);
544 }
545
TEST(empty_prog)546 TEST(empty_prog)
547 {
548 struct sock_filter filter[] = {
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 EXPECT_EQ(-1, ret);
561 EXPECT_EQ(EINVAL, errno);
562 }
563
TEST(log_all)564 TEST(log_all)
565 {
566 struct sock_filter filter[] = {
567 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
568 };
569 struct sock_fprog prog = {
570 .len = (unsigned short)ARRAY_SIZE(filter),
571 .filter = filter,
572 };
573 long ret;
574 pid_t parent = getppid();
575
576 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
577 ASSERT_EQ(0, ret);
578
579 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
580 ASSERT_EQ(0, ret);
581
582 /* getppid() should succeed and be logged (no check for logging) */
583 EXPECT_EQ(parent, syscall(__NR_getppid));
584 }
585
TEST_SIGNAL(unknown_ret_is_kill_inside,SIGSYS)586 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
587 {
588 struct sock_filter filter[] = {
589 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
590 };
591 struct sock_fprog prog = {
592 .len = (unsigned short)ARRAY_SIZE(filter),
593 .filter = filter,
594 };
595 long ret;
596
597 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
598 ASSERT_EQ(0, ret);
599
600 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
601 ASSERT_EQ(0, ret);
602 EXPECT_EQ(0, syscall(__NR_getpid)) {
603 TH_LOG("getpid() shouldn't ever return");
604 }
605 }
606
607 /* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow,SIGSYS)608 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
609 {
610 struct sock_filter filter[] = {
611 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
612 };
613 struct sock_fprog prog = {
614 .len = (unsigned short)ARRAY_SIZE(filter),
615 .filter = filter,
616 };
617 long ret;
618
619 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
620 ASSERT_EQ(0, ret);
621
622 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
623 ASSERT_EQ(0, ret);
624 EXPECT_EQ(0, syscall(__NR_getpid)) {
625 TH_LOG("getpid() shouldn't ever return");
626 }
627 }
628
TEST_SIGNAL(KILL_all,SIGSYS)629 TEST_SIGNAL(KILL_all, SIGSYS)
630 {
631 struct sock_filter filter[] = {
632 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
633 };
634 struct sock_fprog prog = {
635 .len = (unsigned short)ARRAY_SIZE(filter),
636 .filter = filter,
637 };
638 long ret;
639
640 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
641 ASSERT_EQ(0, ret);
642
643 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
644 ASSERT_EQ(0, ret);
645 }
646
TEST_SIGNAL(KILL_one,SIGSYS)647 TEST_SIGNAL(KILL_one, SIGSYS)
648 {
649 struct sock_filter filter[] = {
650 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
651 offsetof(struct seccomp_data, nr)),
652 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
653 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
654 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
655 };
656 struct sock_fprog prog = {
657 .len = (unsigned short)ARRAY_SIZE(filter),
658 .filter = filter,
659 };
660 long ret;
661 pid_t parent = getppid();
662
663 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
664 ASSERT_EQ(0, ret);
665
666 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
667 ASSERT_EQ(0, ret);
668
669 EXPECT_EQ(parent, syscall(__NR_getppid));
670 /* getpid() should never return. */
671 EXPECT_EQ(0, syscall(__NR_getpid));
672 }
673
TEST_SIGNAL(KILL_one_arg_one,SIGSYS)674 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
675 {
676 void *fatal_address;
677 struct sock_filter filter[] = {
678 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
679 offsetof(struct seccomp_data, nr)),
680 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
681 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
682 /* Only both with lower 32-bit for now. */
683 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
684 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
685 (unsigned long)&fatal_address, 0, 1),
686 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
687 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
688 };
689 struct sock_fprog prog = {
690 .len = (unsigned short)ARRAY_SIZE(filter),
691 .filter = filter,
692 };
693 long ret;
694 pid_t parent = getppid();
695 struct tms timebuf;
696 clock_t clock = times(&timebuf);
697
698 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
699 ASSERT_EQ(0, ret);
700
701 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
702 ASSERT_EQ(0, ret);
703
704 EXPECT_EQ(parent, syscall(__NR_getppid));
705 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
706 /* times() should never return. */
707 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
708 }
709
TEST_SIGNAL(KILL_one_arg_six,SIGSYS)710 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
711 {
712 #ifndef __NR_mmap2
713 int sysno = __NR_mmap;
714 #else
715 int sysno = __NR_mmap2;
716 #endif
717 struct sock_filter filter[] = {
718 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
719 offsetof(struct seccomp_data, nr)),
720 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
721 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
722 /* Only both with lower 32-bit for now. */
723 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
724 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
725 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
726 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
727 };
728 struct sock_fprog prog = {
729 .len = (unsigned short)ARRAY_SIZE(filter),
730 .filter = filter,
731 };
732 long ret;
733 pid_t parent = getppid();
734 int fd;
735 void *map1, *map2;
736 int page_size = sysconf(_SC_PAGESIZE);
737
738 ASSERT_LT(0, page_size);
739
740 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
741 ASSERT_EQ(0, ret);
742
743 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
744 ASSERT_EQ(0, ret);
745
746 fd = open("/dev/zero", O_RDONLY);
747 ASSERT_NE(-1, fd);
748
749 EXPECT_EQ(parent, syscall(__NR_getppid));
750 map1 = (void *)syscall(sysno,
751 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
752 EXPECT_NE(MAP_FAILED, map1);
753 /* mmap2() should never return. */
754 map2 = (void *)syscall(sysno,
755 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
756 EXPECT_EQ(MAP_FAILED, map2);
757
758 /* The test failed, so clean up the resources. */
759 munmap(map1, page_size);
760 munmap(map2, page_size);
761 close(fd);
762 }
763
764 /* This is a thread task to die via seccomp filter violation. */
kill_thread(void * data)765 void *kill_thread(void *data)
766 {
767 bool die = (bool)data;
768
769 if (die) {
770 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
771 return (void *)SIBLING_EXIT_FAILURE;
772 }
773
774 return (void *)SIBLING_EXIT_UNKILLED;
775 }
776
777 enum kill_t {
778 KILL_THREAD,
779 KILL_PROCESS,
780 RET_UNKNOWN
781 };
782
783 /* Prepare a thread that will kill itself or both of us. */
kill_thread_or_group(struct __test_metadata * _metadata,enum kill_t kill_how)784 void kill_thread_or_group(struct __test_metadata *_metadata,
785 enum kill_t kill_how)
786 {
787 pthread_t thread;
788 void *status;
789 /* Kill only when calling __NR_prctl. */
790 struct sock_filter filter_thread[] = {
791 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
792 offsetof(struct seccomp_data, nr)),
793 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
794 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
795 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
796 };
797 struct sock_fprog prog_thread = {
798 .len = (unsigned short)ARRAY_SIZE(filter_thread),
799 .filter = filter_thread,
800 };
801 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAAA;
802 struct sock_filter filter_process[] = {
803 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
804 offsetof(struct seccomp_data, nr)),
805 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
806 BPF_STMT(BPF_RET|BPF_K, kill),
807 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
808 };
809 struct sock_fprog prog_process = {
810 .len = (unsigned short)ARRAY_SIZE(filter_process),
811 .filter = filter_process,
812 };
813
814 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
815 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
816 }
817
818 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
819 kill_how == KILL_THREAD ? &prog_thread
820 : &prog_process));
821
822 /*
823 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
824 * flag cannot be downgraded by a new filter.
825 */
826 if (kill_how == KILL_PROCESS)
827 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
828
829 /* Start a thread that will exit immediately. */
830 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
831 ASSERT_EQ(0, pthread_join(thread, &status));
832 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
833
834 /* Start a thread that will die immediately. */
835 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
836 ASSERT_EQ(0, pthread_join(thread, &status));
837 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
838
839 /*
840 * If we get here, only the spawned thread died. Let the parent know
841 * the whole process didn't die (i.e. this thread, the spawner,
842 * stayed running).
843 */
844 exit(42);
845 }
846
TEST(KILL_thread)847 TEST(KILL_thread)
848 {
849 int status;
850 pid_t child_pid;
851
852 child_pid = fork();
853 ASSERT_LE(0, child_pid);
854 if (child_pid == 0) {
855 kill_thread_or_group(_metadata, KILL_THREAD);
856 _exit(38);
857 }
858
859 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
860
861 /* If only the thread was killed, we'll see exit 42. */
862 ASSERT_TRUE(WIFEXITED(status));
863 ASSERT_EQ(42, WEXITSTATUS(status));
864 }
865
TEST(KILL_process)866 TEST(KILL_process)
867 {
868 int status;
869 pid_t child_pid;
870
871 child_pid = fork();
872 ASSERT_LE(0, child_pid);
873 if (child_pid == 0) {
874 kill_thread_or_group(_metadata, KILL_PROCESS);
875 _exit(38);
876 }
877
878 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
879
880 /* If the entire process was killed, we'll see SIGSYS. */
881 ASSERT_TRUE(WIFSIGNALED(status));
882 ASSERT_EQ(SIGSYS, WTERMSIG(status));
883 }
884
TEST(KILL_unknown)885 TEST(KILL_unknown)
886 {
887 int status;
888 pid_t child_pid;
889
890 child_pid = fork();
891 ASSERT_LE(0, child_pid);
892 if (child_pid == 0) {
893 kill_thread_or_group(_metadata, RET_UNKNOWN);
894 _exit(38);
895 }
896
897 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
898
899 /* If the entire process was killed, we'll see SIGSYS. */
900 EXPECT_TRUE(WIFSIGNALED(status)) {
901 TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
902 }
903 ASSERT_EQ(SIGSYS, WTERMSIG(status));
904 }
905
906 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)907 TEST(arg_out_of_range)
908 {
909 struct sock_filter filter[] = {
910 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
911 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
912 };
913 struct sock_fprog prog = {
914 .len = (unsigned short)ARRAY_SIZE(filter),
915 .filter = filter,
916 };
917 long ret;
918
919 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
920 ASSERT_EQ(0, ret);
921
922 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
923 EXPECT_EQ(-1, ret);
924 EXPECT_EQ(EINVAL, errno);
925 }
926
927 #define ERRNO_FILTER(name, errno) \
928 struct sock_filter _read_filter_##name[] = { \
929 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
930 offsetof(struct seccomp_data, nr)), \
931 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
932 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
933 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
934 }; \
935 struct sock_fprog prog_##name = { \
936 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
937 .filter = _read_filter_##name, \
938 }
939
940 /* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)941 TEST(ERRNO_valid)
942 {
943 ERRNO_FILTER(valid, E2BIG);
944 long ret;
945 pid_t parent = getppid();
946
947 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
948 ASSERT_EQ(0, ret);
949
950 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
951 ASSERT_EQ(0, ret);
952
953 EXPECT_EQ(parent, syscall(__NR_getppid));
954 EXPECT_EQ(-1, read(0, NULL, 0));
955 EXPECT_EQ(E2BIG, errno);
956 }
957
958 /* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)959 TEST(ERRNO_zero)
960 {
961 ERRNO_FILTER(zero, 0);
962 long ret;
963 pid_t parent = getppid();
964
965 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
966 ASSERT_EQ(0, ret);
967
968 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
969 ASSERT_EQ(0, ret);
970
971 EXPECT_EQ(parent, syscall(__NR_getppid));
972 /* "errno" of 0 is ok. */
973 EXPECT_EQ(0, read(0, NULL, 0));
974 }
975
976 /*
977 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
978 * This tests that the errno value gets capped correctly, fixed by
979 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
980 */
TEST(ERRNO_capped)981 TEST(ERRNO_capped)
982 {
983 ERRNO_FILTER(capped, 4096);
984 long ret;
985 pid_t parent = getppid();
986
987 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
988 ASSERT_EQ(0, ret);
989
990 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
991 ASSERT_EQ(0, ret);
992
993 EXPECT_EQ(parent, syscall(__NR_getppid));
994 EXPECT_EQ(-1, read(0, NULL, 0));
995 EXPECT_EQ(4095, errno);
996 }
997
998 /*
999 * Filters are processed in reverse order: last applied is executed first.
1000 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
1001 * SECCOMP_RET_DATA mask results will follow the most recently applied
1002 * matching filter return (and not the lowest or highest value).
1003 */
TEST(ERRNO_order)1004 TEST(ERRNO_order)
1005 {
1006 ERRNO_FILTER(first, 11);
1007 ERRNO_FILTER(second, 13);
1008 ERRNO_FILTER(third, 12);
1009 long ret;
1010 pid_t parent = getppid();
1011
1012 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1013 ASSERT_EQ(0, ret);
1014
1015 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
1016 ASSERT_EQ(0, ret);
1017
1018 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
1019 ASSERT_EQ(0, ret);
1020
1021 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
1022 ASSERT_EQ(0, ret);
1023
1024 EXPECT_EQ(parent, syscall(__NR_getppid));
1025 EXPECT_EQ(-1, read(0, NULL, 0));
1026 EXPECT_EQ(12, errno);
1027 }
1028
FIXTURE(TRAP)1029 FIXTURE(TRAP) {
1030 struct sock_fprog prog;
1031 };
1032
FIXTURE_SETUP(TRAP)1033 FIXTURE_SETUP(TRAP)
1034 {
1035 struct sock_filter filter[] = {
1036 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1037 offsetof(struct seccomp_data, nr)),
1038 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1039 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1040 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1041 };
1042
1043 memset(&self->prog, 0, sizeof(self->prog));
1044 self->prog.filter = malloc(sizeof(filter));
1045 ASSERT_NE(NULL, self->prog.filter);
1046 memcpy(self->prog.filter, filter, sizeof(filter));
1047 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1048 }
1049
FIXTURE_TEARDOWN(TRAP)1050 FIXTURE_TEARDOWN(TRAP)
1051 {
1052 if (self->prog.filter)
1053 free(self->prog.filter);
1054 }
1055
TEST_F_SIGNAL(TRAP,dfl,SIGSYS)1056 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
1057 {
1058 long ret;
1059
1060 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1061 ASSERT_EQ(0, ret);
1062
1063 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1064 ASSERT_EQ(0, ret);
1065 syscall(__NR_getpid);
1066 }
1067
1068 /* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP,ign,SIGSYS)1069 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
1070 {
1071 long ret;
1072
1073 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1074 ASSERT_EQ(0, ret);
1075
1076 signal(SIGSYS, SIG_IGN);
1077
1078 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1079 ASSERT_EQ(0, ret);
1080 syscall(__NR_getpid);
1081 }
1082
1083 static siginfo_t TRAP_info;
1084 static volatile int TRAP_nr;
TRAP_action(int nr,siginfo_t * info,void * void_context)1085 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
1086 {
1087 memcpy(&TRAP_info, info, sizeof(TRAP_info));
1088 TRAP_nr = nr;
1089 }
1090
TEST_F(TRAP,handler)1091 TEST_F(TRAP, handler)
1092 {
1093 int ret, test;
1094 struct sigaction act;
1095 sigset_t mask;
1096
1097 memset(&act, 0, sizeof(act));
1098 sigemptyset(&mask);
1099 sigaddset(&mask, SIGSYS);
1100
1101 act.sa_sigaction = &TRAP_action;
1102 act.sa_flags = SA_SIGINFO;
1103 ret = sigaction(SIGSYS, &act, NULL);
1104 ASSERT_EQ(0, ret) {
1105 TH_LOG("sigaction failed");
1106 }
1107 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
1108 ASSERT_EQ(0, ret) {
1109 TH_LOG("sigprocmask failed");
1110 }
1111
1112 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1113 ASSERT_EQ(0, ret);
1114 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1115 ASSERT_EQ(0, ret);
1116 TRAP_nr = 0;
1117 memset(&TRAP_info, 0, sizeof(TRAP_info));
1118 /* Expect the registers to be rolled back. (nr = error) may vary
1119 * based on arch. */
1120 ret = syscall(__NR_getpid);
1121 /* Silence gcc warning about volatile. */
1122 test = TRAP_nr;
1123 EXPECT_EQ(SIGSYS, test);
1124 struct local_sigsys {
1125 void *_call_addr; /* calling user insn */
1126 int _syscall; /* triggering system call number */
1127 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1128 } *sigsys = (struct local_sigsys *)
1129 #ifdef si_syscall
1130 &(TRAP_info.si_call_addr);
1131 #else
1132 &TRAP_info.si_pid;
1133 #endif
1134 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1135 /* Make sure arch is non-zero. */
1136 EXPECT_NE(0, sigsys->_arch);
1137 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1138 }
1139
FIXTURE(precedence)1140 FIXTURE(precedence) {
1141 struct sock_fprog allow;
1142 struct sock_fprog log;
1143 struct sock_fprog trace;
1144 struct sock_fprog error;
1145 struct sock_fprog trap;
1146 struct sock_fprog kill;
1147 };
1148
FIXTURE_SETUP(precedence)1149 FIXTURE_SETUP(precedence)
1150 {
1151 struct sock_filter allow_insns[] = {
1152 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1153 };
1154 struct sock_filter log_insns[] = {
1155 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1156 offsetof(struct seccomp_data, nr)),
1157 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1158 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1159 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1160 };
1161 struct sock_filter trace_insns[] = {
1162 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1163 offsetof(struct seccomp_data, nr)),
1164 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1165 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1166 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1167 };
1168 struct sock_filter error_insns[] = {
1169 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1170 offsetof(struct seccomp_data, nr)),
1171 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1172 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1173 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1174 };
1175 struct sock_filter trap_insns[] = {
1176 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1177 offsetof(struct seccomp_data, nr)),
1178 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1179 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1180 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1181 };
1182 struct sock_filter kill_insns[] = {
1183 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1184 offsetof(struct seccomp_data, nr)),
1185 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1186 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1187 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1188 };
1189
1190 memset(self, 0, sizeof(*self));
1191 #define FILTER_ALLOC(_x) \
1192 self->_x.filter = malloc(sizeof(_x##_insns)); \
1193 ASSERT_NE(NULL, self->_x.filter); \
1194 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1195 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1196 FILTER_ALLOC(allow);
1197 FILTER_ALLOC(log);
1198 FILTER_ALLOC(trace);
1199 FILTER_ALLOC(error);
1200 FILTER_ALLOC(trap);
1201 FILTER_ALLOC(kill);
1202 }
1203
FIXTURE_TEARDOWN(precedence)1204 FIXTURE_TEARDOWN(precedence)
1205 {
1206 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1207 FILTER_FREE(allow);
1208 FILTER_FREE(log);
1209 FILTER_FREE(trace);
1210 FILTER_FREE(error);
1211 FILTER_FREE(trap);
1212 FILTER_FREE(kill);
1213 }
1214
TEST_F(precedence,allow_ok)1215 TEST_F(precedence, allow_ok)
1216 {
1217 pid_t parent, res = 0;
1218 long ret;
1219
1220 parent = getppid();
1221 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1222 ASSERT_EQ(0, ret);
1223
1224 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1225 ASSERT_EQ(0, ret);
1226 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1227 ASSERT_EQ(0, ret);
1228 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1229 ASSERT_EQ(0, ret);
1230 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1231 ASSERT_EQ(0, ret);
1232 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1233 ASSERT_EQ(0, ret);
1234 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1235 ASSERT_EQ(0, ret);
1236 /* Should work just fine. */
1237 res = syscall(__NR_getppid);
1238 EXPECT_EQ(parent, res);
1239 }
1240
TEST_F_SIGNAL(precedence,kill_is_highest,SIGSYS)1241 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1242 {
1243 pid_t parent, res = 0;
1244 long ret;
1245
1246 parent = getppid();
1247 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1248 ASSERT_EQ(0, ret);
1249
1250 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1251 ASSERT_EQ(0, ret);
1252 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1253 ASSERT_EQ(0, ret);
1254 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1255 ASSERT_EQ(0, ret);
1256 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1257 ASSERT_EQ(0, ret);
1258 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1259 ASSERT_EQ(0, ret);
1260 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1261 ASSERT_EQ(0, ret);
1262 /* Should work just fine. */
1263 res = syscall(__NR_getppid);
1264 EXPECT_EQ(parent, res);
1265 /* getpid() should never return. */
1266 res = syscall(__NR_getpid);
1267 EXPECT_EQ(0, res);
1268 }
1269
TEST_F_SIGNAL(precedence,kill_is_highest_in_any_order,SIGSYS)1270 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1271 {
1272 pid_t parent;
1273 long ret;
1274
1275 parent = getppid();
1276 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1277 ASSERT_EQ(0, ret);
1278
1279 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1280 ASSERT_EQ(0, ret);
1281 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1282 ASSERT_EQ(0, ret);
1283 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1284 ASSERT_EQ(0, ret);
1285 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1286 ASSERT_EQ(0, ret);
1287 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1288 ASSERT_EQ(0, ret);
1289 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1290 ASSERT_EQ(0, ret);
1291 /* Should work just fine. */
1292 EXPECT_EQ(parent, syscall(__NR_getppid));
1293 /* getpid() should never return. */
1294 EXPECT_EQ(0, syscall(__NR_getpid));
1295 }
1296
TEST_F_SIGNAL(precedence,trap_is_second,SIGSYS)1297 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1298 {
1299 pid_t parent;
1300 long ret;
1301
1302 parent = getppid();
1303 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1304 ASSERT_EQ(0, ret);
1305
1306 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1307 ASSERT_EQ(0, ret);
1308 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1309 ASSERT_EQ(0, ret);
1310 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1311 ASSERT_EQ(0, ret);
1312 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1313 ASSERT_EQ(0, ret);
1314 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1315 ASSERT_EQ(0, ret);
1316 /* Should work just fine. */
1317 EXPECT_EQ(parent, syscall(__NR_getppid));
1318 /* getpid() should never return. */
1319 EXPECT_EQ(0, syscall(__NR_getpid));
1320 }
1321
TEST_F_SIGNAL(precedence,trap_is_second_in_any_order,SIGSYS)1322 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1323 {
1324 pid_t parent;
1325 long ret;
1326
1327 parent = getppid();
1328 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1329 ASSERT_EQ(0, ret);
1330
1331 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1332 ASSERT_EQ(0, ret);
1333 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1334 ASSERT_EQ(0, ret);
1335 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1336 ASSERT_EQ(0, ret);
1337 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1338 ASSERT_EQ(0, ret);
1339 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1340 ASSERT_EQ(0, ret);
1341 /* Should work just fine. */
1342 EXPECT_EQ(parent, syscall(__NR_getppid));
1343 /* getpid() should never return. */
1344 EXPECT_EQ(0, syscall(__NR_getpid));
1345 }
1346
TEST_F(precedence,errno_is_third)1347 TEST_F(precedence, errno_is_third)
1348 {
1349 pid_t parent;
1350 long ret;
1351
1352 parent = getppid();
1353 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1354 ASSERT_EQ(0, ret);
1355
1356 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1357 ASSERT_EQ(0, ret);
1358 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1359 ASSERT_EQ(0, ret);
1360 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1361 ASSERT_EQ(0, ret);
1362 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1363 ASSERT_EQ(0, ret);
1364 /* Should work just fine. */
1365 EXPECT_EQ(parent, syscall(__NR_getppid));
1366 EXPECT_EQ(0, syscall(__NR_getpid));
1367 }
1368
TEST_F(precedence,errno_is_third_in_any_order)1369 TEST_F(precedence, errno_is_third_in_any_order)
1370 {
1371 pid_t parent;
1372 long ret;
1373
1374 parent = getppid();
1375 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1376 ASSERT_EQ(0, ret);
1377
1378 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1379 ASSERT_EQ(0, ret);
1380 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1381 ASSERT_EQ(0, ret);
1382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1383 ASSERT_EQ(0, ret);
1384 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1385 ASSERT_EQ(0, ret);
1386 /* Should work just fine. */
1387 EXPECT_EQ(parent, syscall(__NR_getppid));
1388 EXPECT_EQ(0, syscall(__NR_getpid));
1389 }
1390
TEST_F(precedence,trace_is_fourth)1391 TEST_F(precedence, trace_is_fourth)
1392 {
1393 pid_t parent;
1394 long ret;
1395
1396 parent = getppid();
1397 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1398 ASSERT_EQ(0, ret);
1399
1400 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1401 ASSERT_EQ(0, ret);
1402 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1403 ASSERT_EQ(0, ret);
1404 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1405 ASSERT_EQ(0, ret);
1406 /* Should work just fine. */
1407 EXPECT_EQ(parent, syscall(__NR_getppid));
1408 /* No ptracer */
1409 EXPECT_EQ(-1, syscall(__NR_getpid));
1410 }
1411
TEST_F(precedence,trace_is_fourth_in_any_order)1412 TEST_F(precedence, trace_is_fourth_in_any_order)
1413 {
1414 pid_t parent;
1415 long ret;
1416
1417 parent = getppid();
1418 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1419 ASSERT_EQ(0, ret);
1420
1421 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1422 ASSERT_EQ(0, ret);
1423 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1424 ASSERT_EQ(0, ret);
1425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1426 ASSERT_EQ(0, ret);
1427 /* Should work just fine. */
1428 EXPECT_EQ(parent, syscall(__NR_getppid));
1429 /* No ptracer */
1430 EXPECT_EQ(-1, syscall(__NR_getpid));
1431 }
1432
TEST_F(precedence,log_is_fifth)1433 TEST_F(precedence, log_is_fifth)
1434 {
1435 pid_t mypid, parent;
1436 long ret;
1437
1438 mypid = getpid();
1439 parent = getppid();
1440 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1441 ASSERT_EQ(0, ret);
1442
1443 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1444 ASSERT_EQ(0, ret);
1445 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1446 ASSERT_EQ(0, ret);
1447 /* Should work just fine. */
1448 EXPECT_EQ(parent, syscall(__NR_getppid));
1449 /* Should also work just fine */
1450 EXPECT_EQ(mypid, syscall(__NR_getpid));
1451 }
1452
TEST_F(precedence,log_is_fifth_in_any_order)1453 TEST_F(precedence, log_is_fifth_in_any_order)
1454 {
1455 pid_t mypid, parent;
1456 long ret;
1457
1458 mypid = getpid();
1459 parent = getppid();
1460 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1461 ASSERT_EQ(0, ret);
1462
1463 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1464 ASSERT_EQ(0, ret);
1465 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1466 ASSERT_EQ(0, ret);
1467 /* Should work just fine. */
1468 EXPECT_EQ(parent, syscall(__NR_getppid));
1469 /* Should also work just fine */
1470 EXPECT_EQ(mypid, syscall(__NR_getpid));
1471 }
1472
1473 #ifndef PTRACE_O_TRACESECCOMP
1474 #define PTRACE_O_TRACESECCOMP 0x00000080
1475 #endif
1476
1477 /* Catch the Ubuntu 12.04 value error. */
1478 #if PTRACE_EVENT_SECCOMP != 7
1479 #undef PTRACE_EVENT_SECCOMP
1480 #endif
1481
1482 #ifndef PTRACE_EVENT_SECCOMP
1483 #define PTRACE_EVENT_SECCOMP 7
1484 #endif
1485
1486 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1487 bool tracer_running;
tracer_stop(int sig)1488 void tracer_stop(int sig)
1489 {
1490 tracer_running = false;
1491 }
1492
1493 typedef void tracer_func_t(struct __test_metadata *_metadata,
1494 pid_t tracee, int status, void *args);
1495
start_tracer(struct __test_metadata * _metadata,int fd,pid_t tracee,tracer_func_t tracer_func,void * args,bool ptrace_syscall)1496 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1497 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1498 {
1499 int ret = -1;
1500 struct sigaction action = {
1501 .sa_handler = tracer_stop,
1502 };
1503
1504 /* Allow external shutdown. */
1505 tracer_running = true;
1506 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1507
1508 errno = 0;
1509 while (ret == -1 && errno != EINVAL)
1510 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1511 ASSERT_EQ(0, ret) {
1512 kill(tracee, SIGKILL);
1513 }
1514 /* Wait for attach stop */
1515 wait(NULL);
1516
1517 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1518 PTRACE_O_TRACESYSGOOD :
1519 PTRACE_O_TRACESECCOMP);
1520 ASSERT_EQ(0, ret) {
1521 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1522 kill(tracee, SIGKILL);
1523 }
1524 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1525 tracee, NULL, 0);
1526 ASSERT_EQ(0, ret);
1527
1528 /* Unblock the tracee */
1529 ASSERT_EQ(1, write(fd, "A", 1));
1530 ASSERT_EQ(0, close(fd));
1531
1532 /* Run until we're shut down. Must assert to stop execution. */
1533 while (tracer_running) {
1534 int status;
1535
1536 if (wait(&status) != tracee)
1537 continue;
1538 if (WIFSIGNALED(status) || WIFEXITED(status))
1539 /* Child is dead. Time to go. */
1540 return;
1541
1542 /* Check if this is a seccomp event. */
1543 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1544
1545 tracer_func(_metadata, tracee, status, args);
1546
1547 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1548 tracee, NULL, 0);
1549 ASSERT_EQ(0, ret);
1550 }
1551 /* Directly report the status of our test harness results. */
1552 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1553 }
1554
1555 /* Common tracer setup/teardown functions. */
cont_handler(int num)1556 void cont_handler(int num)
1557 { }
setup_trace_fixture(struct __test_metadata * _metadata,tracer_func_t func,void * args,bool ptrace_syscall)1558 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1559 tracer_func_t func, void *args, bool ptrace_syscall)
1560 {
1561 char sync;
1562 int pipefd[2];
1563 pid_t tracer_pid;
1564 pid_t tracee = getpid();
1565
1566 /* Setup a pipe for clean synchronization. */
1567 ASSERT_EQ(0, pipe(pipefd));
1568
1569 /* Fork a child which we'll promote to tracer */
1570 tracer_pid = fork();
1571 ASSERT_LE(0, tracer_pid);
1572 signal(SIGALRM, cont_handler);
1573 if (tracer_pid == 0) {
1574 close(pipefd[0]);
1575 start_tracer(_metadata, pipefd[1], tracee, func, args,
1576 ptrace_syscall);
1577 syscall(__NR_exit, 0);
1578 }
1579 close(pipefd[1]);
1580 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1581 read(pipefd[0], &sync, 1);
1582 close(pipefd[0]);
1583
1584 return tracer_pid;
1585 }
1586
teardown_trace_fixture(struct __test_metadata * _metadata,pid_t tracer)1587 void teardown_trace_fixture(struct __test_metadata *_metadata,
1588 pid_t tracer)
1589 {
1590 if (tracer) {
1591 int status;
1592 /*
1593 * Extract the exit code from the other process and
1594 * adopt it for ourselves in case its asserts failed.
1595 */
1596 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1597 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1598 if (WEXITSTATUS(status))
1599 _metadata->passed = 0;
1600 }
1601 }
1602
1603 /* "poke" tracer arguments and function. */
1604 struct tracer_args_poke_t {
1605 unsigned long poke_addr;
1606 };
1607
tracer_poke(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1608 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1609 void *args)
1610 {
1611 int ret;
1612 unsigned long msg;
1613 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1614
1615 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1616 EXPECT_EQ(0, ret);
1617 /* If this fails, don't try to recover. */
1618 ASSERT_EQ(0x1001, msg) {
1619 kill(tracee, SIGKILL);
1620 }
1621 /*
1622 * Poke in the message.
1623 * Registers are not touched to try to keep this relatively arch
1624 * agnostic.
1625 */
1626 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1627 EXPECT_EQ(0, ret);
1628 }
1629
FIXTURE(TRACE_poke)1630 FIXTURE(TRACE_poke) {
1631 struct sock_fprog prog;
1632 pid_t tracer;
1633 long poked;
1634 struct tracer_args_poke_t tracer_args;
1635 };
1636
FIXTURE_SETUP(TRACE_poke)1637 FIXTURE_SETUP(TRACE_poke)
1638 {
1639 struct sock_filter filter[] = {
1640 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1641 offsetof(struct seccomp_data, nr)),
1642 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1643 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1644 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1645 };
1646
1647 self->poked = 0;
1648 memset(&self->prog, 0, sizeof(self->prog));
1649 self->prog.filter = malloc(sizeof(filter));
1650 ASSERT_NE(NULL, self->prog.filter);
1651 memcpy(self->prog.filter, filter, sizeof(filter));
1652 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1653
1654 /* Set up tracer args. */
1655 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1656
1657 /* Launch tracer. */
1658 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1659 &self->tracer_args, false);
1660 }
1661
FIXTURE_TEARDOWN(TRACE_poke)1662 FIXTURE_TEARDOWN(TRACE_poke)
1663 {
1664 teardown_trace_fixture(_metadata, self->tracer);
1665 if (self->prog.filter)
1666 free(self->prog.filter);
1667 }
1668
TEST_F(TRACE_poke,read_has_side_effects)1669 TEST_F(TRACE_poke, read_has_side_effects)
1670 {
1671 ssize_t ret;
1672
1673 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1674 ASSERT_EQ(0, ret);
1675
1676 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1677 ASSERT_EQ(0, ret);
1678
1679 EXPECT_EQ(0, self->poked);
1680 ret = read(-1, NULL, 0);
1681 EXPECT_EQ(-1, ret);
1682 EXPECT_EQ(0x1001, self->poked);
1683 }
1684
TEST_F(TRACE_poke,getpid_runs_normally)1685 TEST_F(TRACE_poke, getpid_runs_normally)
1686 {
1687 long ret;
1688
1689 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1690 ASSERT_EQ(0, ret);
1691
1692 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1693 ASSERT_EQ(0, ret);
1694
1695 EXPECT_EQ(0, self->poked);
1696 EXPECT_NE(0, syscall(__NR_getpid));
1697 EXPECT_EQ(0, self->poked);
1698 }
1699
1700 #if defined(__x86_64__)
1701 # define ARCH_REGS struct user_regs_struct
1702 # define SYSCALL_NUM(_regs) (_regs).orig_rax
1703 # define SYSCALL_RET(_regs) (_regs).rax
1704 #elif defined(__i386__)
1705 # define ARCH_REGS struct user_regs_struct
1706 # define SYSCALL_NUM(_regs) (_regs).orig_eax
1707 # define SYSCALL_RET(_regs) (_regs).eax
1708 #elif defined(__arm__)
1709 # define ARCH_REGS struct pt_regs
1710 # define SYSCALL_NUM(_regs) (_regs).ARM_r7
1711 # ifndef PTRACE_SET_SYSCALL
1712 # define PTRACE_SET_SYSCALL 23
1713 # endif
1714 # define SYSCALL_NUM_SET(_regs, _nr) \
1715 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
1716 # define SYSCALL_RET(_regs) (_regs).ARM_r0
1717 #elif defined(__aarch64__)
1718 # define ARCH_REGS struct user_pt_regs
1719 # define SYSCALL_NUM(_regs) (_regs).regs[8]
1720 # ifndef NT_ARM_SYSTEM_CALL
1721 # define NT_ARM_SYSTEM_CALL 0x404
1722 # endif
1723 # define SYSCALL_NUM_SET(_regs, _nr) \
1724 do { \
1725 struct iovec __v; \
1726 typeof(_nr) __nr = (_nr); \
1727 __v.iov_base = &__nr; \
1728 __v.iov_len = sizeof(__nr); \
1729 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \
1730 NT_ARM_SYSTEM_CALL, &__v)); \
1731 } while (0)
1732 # define SYSCALL_RET(_regs) (_regs).regs[0]
1733 #elif defined(__riscv) && __riscv_xlen == 64
1734 # define ARCH_REGS struct user_regs_struct
1735 # define SYSCALL_NUM(_regs) (_regs).a7
1736 # define SYSCALL_RET(_regs) (_regs).a0
1737 #elif defined(__csky__)
1738 # define ARCH_REGS struct pt_regs
1739 # if defined(__CSKYABIV2__)
1740 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1741 # else
1742 # define SYSCALL_NUM(_regs) (_regs).regs[9]
1743 # endif
1744 # define SYSCALL_RET(_regs) (_regs).a0
1745 #elif defined(__hppa__)
1746 # define ARCH_REGS struct user_regs_struct
1747 # define SYSCALL_NUM(_regs) (_regs).gr[20]
1748 # define SYSCALL_RET(_regs) (_regs).gr[28]
1749 #elif defined(__powerpc__)
1750 # define ARCH_REGS struct pt_regs
1751 # define SYSCALL_NUM(_regs) (_regs).gpr[0]
1752 # define SYSCALL_RET(_regs) (_regs).gpr[3]
1753 # define SYSCALL_RET_SET(_regs, _val) \
1754 do { \
1755 typeof(_val) _result = (_val); \
1756 /* \
1757 * A syscall error is signaled by CR0 SO bit \
1758 * and the code is stored as a positive value. \
1759 */ \
1760 if (_result < 0) { \
1761 SYSCALL_RET(_regs) = -_result; \
1762 (_regs).ccr |= 0x10000000; \
1763 } else { \
1764 SYSCALL_RET(_regs) = _result; \
1765 (_regs).ccr &= ~0x10000000; \
1766 } \
1767 } while (0)
1768 # define SYSCALL_RET_SET_ON_PTRACE_EXIT
1769 #elif defined(__s390__)
1770 # define ARCH_REGS s390_regs
1771 # define SYSCALL_NUM(_regs) (_regs).gprs[2]
1772 # define SYSCALL_RET_SET(_regs, _val) \
1773 TH_LOG("Can't modify syscall return on this architecture")
1774 #elif defined(__mips__)
1775 # include <asm/unistd_nr_n32.h>
1776 # include <asm/unistd_nr_n64.h>
1777 # include <asm/unistd_nr_o32.h>
1778 # define ARCH_REGS struct pt_regs
1779 # define SYSCALL_NUM(_regs) \
1780 ({ \
1781 typeof((_regs).regs[2]) _nr; \
1782 if ((_regs).regs[2] == __NR_O32_Linux) \
1783 _nr = (_regs).regs[4]; \
1784 else \
1785 _nr = (_regs).regs[2]; \
1786 _nr; \
1787 })
1788 # define SYSCALL_NUM_SET(_regs, _nr) \
1789 do { \
1790 if ((_regs).regs[2] == __NR_O32_Linux) \
1791 (_regs).regs[4] = _nr; \
1792 else \
1793 (_regs).regs[2] = _nr; \
1794 } while (0)
1795 # define SYSCALL_RET_SET(_regs, _val) \
1796 TH_LOG("Can't modify syscall return on this architecture")
1797 #elif defined(__xtensa__)
1798 # define ARCH_REGS struct user_pt_regs
1799 # define SYSCALL_NUM(_regs) (_regs).syscall
1800 /*
1801 * On xtensa syscall return value is in the register
1802 * a2 of the current window which is not fixed.
1803 */
1804 #define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2]
1805 #elif defined(__sh__)
1806 # define ARCH_REGS struct pt_regs
1807 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1808 # define SYSCALL_RET(_regs) (_regs).regs[0]
1809 #else
1810 # error "Do not know how to find your architecture's registers and syscalls"
1811 #endif
1812
1813 /*
1814 * Most architectures can change the syscall by just updating the
1815 * associated register. This is the default if not defined above.
1816 */
1817 #ifndef SYSCALL_NUM_SET
1818 # define SYSCALL_NUM_SET(_regs, _nr) \
1819 do { \
1820 SYSCALL_NUM(_regs) = (_nr); \
1821 } while (0)
1822 #endif
1823 /*
1824 * Most architectures can change the syscall return value by just
1825 * writing to the SYSCALL_RET register. This is the default if not
1826 * defined above. If an architecture cannot set the return value
1827 * (for example when the syscall and return value register is
1828 * shared), report it with TH_LOG() in an arch-specific definition
1829 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
1830 */
1831 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
1832 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
1833 #endif
1834 #ifndef SYSCALL_RET_SET
1835 # define SYSCALL_RET_SET(_regs, _val) \
1836 do { \
1837 SYSCALL_RET(_regs) = (_val); \
1838 } while (0)
1839 #endif
1840
1841 /* When the syscall return can't be changed, stub out the tests for it. */
1842 #ifndef SYSCALL_RET
1843 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1844 #else
1845 # define EXPECT_SYSCALL_RETURN(val, action) \
1846 do { \
1847 errno = 0; \
1848 if (val < 0) { \
1849 EXPECT_EQ(-1, action); \
1850 EXPECT_EQ(-(val), errno); \
1851 } else { \
1852 EXPECT_EQ(val, action); \
1853 } \
1854 } while (0)
1855 #endif
1856
1857 /*
1858 * Some architectures (e.g. powerpc) can only set syscall
1859 * return values on syscall exit during ptrace.
1860 */
1861 const bool ptrace_entry_set_syscall_nr = true;
1862 const bool ptrace_entry_set_syscall_ret =
1863 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
1864 true;
1865 #else
1866 false;
1867 #endif
1868
1869 /*
1870 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1871 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1872 */
1873 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1874 # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
1875 # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
1876 #else
1877 # define ARCH_GETREGS(_regs) ({ \
1878 struct iovec __v; \
1879 __v.iov_base = &(_regs); \
1880 __v.iov_len = sizeof(_regs); \
1881 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \
1882 })
1883 # define ARCH_SETREGS(_regs) ({ \
1884 struct iovec __v; \
1885 __v.iov_base = &(_regs); \
1886 __v.iov_len = sizeof(_regs); \
1887 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \
1888 })
1889 #endif
1890
1891 /* Architecture-specific syscall fetching routine. */
get_syscall(struct __test_metadata * _metadata,pid_t tracee)1892 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1893 {
1894 ARCH_REGS regs;
1895
1896 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1897 return -1;
1898 }
1899
1900 return SYSCALL_NUM(regs);
1901 }
1902
1903 /* Architecture-specific syscall changing routine. */
__change_syscall(struct __test_metadata * _metadata,pid_t tracee,long * syscall,long * ret)1904 void __change_syscall(struct __test_metadata *_metadata,
1905 pid_t tracee, long *syscall, long *ret)
1906 {
1907 ARCH_REGS orig, regs;
1908
1909 /* Do not get/set registers if we have nothing to do. */
1910 if (!syscall && !ret)
1911 return;
1912
1913 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1914 return;
1915 }
1916 orig = regs;
1917
1918 if (syscall)
1919 SYSCALL_NUM_SET(regs, *syscall);
1920
1921 if (ret)
1922 SYSCALL_RET_SET(regs, *ret);
1923
1924 /* Flush any register changes made. */
1925 if (memcmp(&orig, ®s, sizeof(orig)) != 0)
1926 EXPECT_EQ(0, ARCH_SETREGS(regs));
1927 }
1928
1929 /* Change only syscall number. */
change_syscall_nr(struct __test_metadata * _metadata,pid_t tracee,long syscall)1930 void change_syscall_nr(struct __test_metadata *_metadata,
1931 pid_t tracee, long syscall)
1932 {
1933 __change_syscall(_metadata, tracee, &syscall, NULL);
1934 }
1935
1936 /* Change syscall return value (and set syscall number to -1). */
change_syscall_ret(struct __test_metadata * _metadata,pid_t tracee,long ret)1937 void change_syscall_ret(struct __test_metadata *_metadata,
1938 pid_t tracee, long ret)
1939 {
1940 long syscall = -1;
1941
1942 __change_syscall(_metadata, tracee, &syscall, &ret);
1943 }
1944
tracer_seccomp(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1945 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
1946 int status, void *args)
1947 {
1948 int ret;
1949 unsigned long msg;
1950
1951 /* Make sure we got the right message. */
1952 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1953 EXPECT_EQ(0, ret);
1954
1955 /* Validate and take action on expected syscalls. */
1956 switch (msg) {
1957 case 0x1002:
1958 /* change getpid to getppid. */
1959 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1960 change_syscall_nr(_metadata, tracee, __NR_getppid);
1961 break;
1962 case 0x1003:
1963 /* skip gettid with valid return code. */
1964 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1965 change_syscall_ret(_metadata, tracee, 45000);
1966 break;
1967 case 0x1004:
1968 /* skip openat with error. */
1969 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
1970 change_syscall_ret(_metadata, tracee, -ESRCH);
1971 break;
1972 case 0x1005:
1973 /* do nothing (allow getppid) */
1974 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1975 break;
1976 default:
1977 EXPECT_EQ(0, msg) {
1978 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1979 kill(tracee, SIGKILL);
1980 }
1981 }
1982
1983 }
1984
FIXTURE(TRACE_syscall)1985 FIXTURE(TRACE_syscall) {
1986 struct sock_fprog prog;
1987 pid_t tracer, mytid, mypid, parent;
1988 long syscall_nr;
1989 };
1990
tracer_ptrace(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1991 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1992 int status, void *args)
1993 {
1994 int ret;
1995 unsigned long msg;
1996 static bool entry;
1997 long syscall_nr_val, syscall_ret_val;
1998 long *syscall_nr = NULL, *syscall_ret = NULL;
1999 FIXTURE_DATA(TRACE_syscall) *self = args;
2000
2001 /*
2002 * The traditional way to tell PTRACE_SYSCALL entry/exit
2003 * is by counting.
2004 */
2005 entry = !entry;
2006
2007 /* Make sure we got an appropriate message. */
2008 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
2009 EXPECT_EQ(0, ret);
2010 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
2011 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
2012
2013 /*
2014 * Some architectures only support setting return values during
2015 * syscall exit under ptrace, and on exit the syscall number may
2016 * no longer be available. Therefore, save the initial sycall
2017 * number here, so it can be examined during both entry and exit
2018 * phases.
2019 */
2020 if (entry)
2021 self->syscall_nr = get_syscall(_metadata, tracee);
2022
2023 /*
2024 * Depending on the architecture's syscall setting abilities, we
2025 * pick which things to set during this phase (entry or exit).
2026 */
2027 if (entry == ptrace_entry_set_syscall_nr)
2028 syscall_nr = &syscall_nr_val;
2029 if (entry == ptrace_entry_set_syscall_ret)
2030 syscall_ret = &syscall_ret_val;
2031
2032 /* Now handle the actual rewriting cases. */
2033 switch (self->syscall_nr) {
2034 case __NR_getpid:
2035 syscall_nr_val = __NR_getppid;
2036 /* Never change syscall return for this case. */
2037 syscall_ret = NULL;
2038 break;
2039 case __NR_gettid:
2040 syscall_nr_val = -1;
2041 syscall_ret_val = 45000;
2042 break;
2043 case __NR_openat:
2044 syscall_nr_val = -1;
2045 syscall_ret_val = -ESRCH;
2046 break;
2047 default:
2048 /* Unhandled, do nothing. */
2049 return;
2050 }
2051
2052 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
2053 }
2054
FIXTURE_VARIANT(TRACE_syscall)2055 FIXTURE_VARIANT(TRACE_syscall) {
2056 /*
2057 * All of the SECCOMP_RET_TRACE behaviors can be tested with either
2058 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL.
2059 * This indicates if we should use SECCOMP_RET_TRACE (false), or
2060 * ptrace (true).
2061 */
2062 bool use_ptrace;
2063 };
2064
FIXTURE_VARIANT_ADD(TRACE_syscall,ptrace)2065 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) {
2066 .use_ptrace = true,
2067 };
2068
FIXTURE_VARIANT_ADD(TRACE_syscall,seccomp)2069 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) {
2070 .use_ptrace = false,
2071 };
2072
FIXTURE_SETUP(TRACE_syscall)2073 FIXTURE_SETUP(TRACE_syscall)
2074 {
2075 struct sock_filter filter[] = {
2076 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2077 offsetof(struct seccomp_data, nr)),
2078 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2079 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
2080 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
2081 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
2082 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
2083 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
2084 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2085 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
2086 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2087 };
2088 struct sock_fprog prog = {
2089 .len = (unsigned short)ARRAY_SIZE(filter),
2090 .filter = filter,
2091 };
2092 long ret;
2093
2094 /* Prepare some testable syscall results. */
2095 self->mytid = syscall(__NR_gettid);
2096 ASSERT_GT(self->mytid, 0);
2097 ASSERT_NE(self->mytid, 1) {
2098 TH_LOG("Running this test as init is not supported. :)");
2099 }
2100
2101 self->mypid = getpid();
2102 ASSERT_GT(self->mypid, 0);
2103 ASSERT_EQ(self->mytid, self->mypid);
2104
2105 self->parent = getppid();
2106 ASSERT_GT(self->parent, 0);
2107 ASSERT_NE(self->parent, self->mypid);
2108
2109 /* Launch tracer. */
2110 self->tracer = setup_trace_fixture(_metadata,
2111 variant->use_ptrace ? tracer_ptrace
2112 : tracer_seccomp,
2113 self, variant->use_ptrace);
2114
2115 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2116 ASSERT_EQ(0, ret);
2117
2118 if (variant->use_ptrace)
2119 return;
2120
2121 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2122 ASSERT_EQ(0, ret);
2123 }
2124
FIXTURE_TEARDOWN(TRACE_syscall)2125 FIXTURE_TEARDOWN(TRACE_syscall)
2126 {
2127 teardown_trace_fixture(_metadata, self->tracer);
2128 }
2129
TEST(negative_ENOSYS)2130 TEST(negative_ENOSYS)
2131 {
2132 /*
2133 * There should be no difference between an "internal" skip
2134 * and userspace asking for syscall "-1".
2135 */
2136 errno = 0;
2137 EXPECT_EQ(-1, syscall(-1));
2138 EXPECT_EQ(errno, ENOSYS);
2139 /* And no difference for "still not valid but not -1". */
2140 errno = 0;
2141 EXPECT_EQ(-1, syscall(-101));
2142 EXPECT_EQ(errno, ENOSYS);
2143 }
2144
TEST_F(TRACE_syscall,negative_ENOSYS)2145 TEST_F(TRACE_syscall, negative_ENOSYS)
2146 {
2147 negative_ENOSYS(_metadata);
2148 }
2149
TEST_F(TRACE_syscall,syscall_allowed)2150 TEST_F(TRACE_syscall, syscall_allowed)
2151 {
2152 /* getppid works as expected (no changes). */
2153 EXPECT_EQ(self->parent, syscall(__NR_getppid));
2154 EXPECT_NE(self->mypid, syscall(__NR_getppid));
2155 }
2156
TEST_F(TRACE_syscall,syscall_redirected)2157 TEST_F(TRACE_syscall, syscall_redirected)
2158 {
2159 /* getpid has been redirected to getppid as expected. */
2160 EXPECT_EQ(self->parent, syscall(__NR_getpid));
2161 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2162 }
2163
TEST_F(TRACE_syscall,syscall_errno)2164 TEST_F(TRACE_syscall, syscall_errno)
2165 {
2166 /* Tracer should skip the open syscall, resulting in ESRCH. */
2167 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
2168 }
2169
TEST_F(TRACE_syscall,syscall_faked)2170 TEST_F(TRACE_syscall, syscall_faked)
2171 {
2172 /* Tracer skips the gettid syscall and store altered return value. */
2173 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
2174 }
2175
TEST_F(TRACE_syscall,skip_after)2176 TEST_F(TRACE_syscall, skip_after)
2177 {
2178 struct sock_filter filter[] = {
2179 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2180 offsetof(struct seccomp_data, nr)),
2181 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2182 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2183 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2184 };
2185 struct sock_fprog prog = {
2186 .len = (unsigned short)ARRAY_SIZE(filter),
2187 .filter = filter,
2188 };
2189 long ret;
2190
2191 /* Install additional "errno on getppid" filter. */
2192 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2193 ASSERT_EQ(0, ret);
2194
2195 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2196 errno = 0;
2197 EXPECT_EQ(-1, syscall(__NR_getpid));
2198 EXPECT_EQ(EPERM, errno);
2199 }
2200
TEST_F_SIGNAL(TRACE_syscall,kill_after,SIGSYS)2201 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS)
2202 {
2203 struct sock_filter filter[] = {
2204 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2205 offsetof(struct seccomp_data, nr)),
2206 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2207 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2208 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2209 };
2210 struct sock_fprog prog = {
2211 .len = (unsigned short)ARRAY_SIZE(filter),
2212 .filter = filter,
2213 };
2214 long ret;
2215
2216 /* Install additional "death on getppid" filter. */
2217 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2218 ASSERT_EQ(0, ret);
2219
2220 /* Tracer will redirect getpid to getppid, and we should die. */
2221 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2222 }
2223
TEST(seccomp_syscall)2224 TEST(seccomp_syscall)
2225 {
2226 struct sock_filter filter[] = {
2227 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2228 };
2229 struct sock_fprog prog = {
2230 .len = (unsigned short)ARRAY_SIZE(filter),
2231 .filter = filter,
2232 };
2233 long ret;
2234
2235 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2236 ASSERT_EQ(0, ret) {
2237 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2238 }
2239
2240 /* Reject insane operation. */
2241 ret = seccomp(-1, 0, &prog);
2242 ASSERT_NE(ENOSYS, errno) {
2243 TH_LOG("Kernel does not support seccomp syscall!");
2244 }
2245 EXPECT_EQ(EINVAL, errno) {
2246 TH_LOG("Did not reject crazy op value!");
2247 }
2248
2249 /* Reject strict with flags or pointer. */
2250 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2251 EXPECT_EQ(EINVAL, errno) {
2252 TH_LOG("Did not reject mode strict with flags!");
2253 }
2254 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2255 EXPECT_EQ(EINVAL, errno) {
2256 TH_LOG("Did not reject mode strict with uargs!");
2257 }
2258
2259 /* Reject insane args for filter. */
2260 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2261 EXPECT_EQ(EINVAL, errno) {
2262 TH_LOG("Did not reject crazy filter flags!");
2263 }
2264 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2265 EXPECT_EQ(EFAULT, errno) {
2266 TH_LOG("Did not reject NULL filter!");
2267 }
2268
2269 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2270 EXPECT_EQ(0, errno) {
2271 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2272 strerror(errno));
2273 }
2274 }
2275
TEST(seccomp_syscall_mode_lock)2276 TEST(seccomp_syscall_mode_lock)
2277 {
2278 struct sock_filter filter[] = {
2279 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2280 };
2281 struct sock_fprog prog = {
2282 .len = (unsigned short)ARRAY_SIZE(filter),
2283 .filter = filter,
2284 };
2285 long ret;
2286
2287 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2288 ASSERT_EQ(0, ret) {
2289 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2290 }
2291
2292 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2293 ASSERT_NE(ENOSYS, errno) {
2294 TH_LOG("Kernel does not support seccomp syscall!");
2295 }
2296 EXPECT_EQ(0, ret) {
2297 TH_LOG("Could not install filter!");
2298 }
2299
2300 /* Make sure neither entry point will switch to strict. */
2301 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2302 EXPECT_EQ(EINVAL, errno) {
2303 TH_LOG("Switched to mode strict!");
2304 }
2305
2306 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2307 EXPECT_EQ(EINVAL, errno) {
2308 TH_LOG("Switched to mode strict!");
2309 }
2310 }
2311
2312 /*
2313 * Test detection of known and unknown filter flags. Userspace needs to be able
2314 * to check if a filter flag is supported by the current kernel and a good way
2315 * of doing that is by attempting to enter filter mode, with the flag bit in
2316 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2317 * that the flag is valid and EINVAL indicates that the flag is invalid.
2318 */
TEST(detect_seccomp_filter_flags)2319 TEST(detect_seccomp_filter_flags)
2320 {
2321 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2322 SECCOMP_FILTER_FLAG_LOG,
2323 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2324 SECCOMP_FILTER_FLAG_NEW_LISTENER,
2325 SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
2326 unsigned int exclusive[] = {
2327 SECCOMP_FILTER_FLAG_TSYNC,
2328 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2329 unsigned int flag, all_flags, exclusive_mask;
2330 int i;
2331 long ret;
2332
2333 /* Test detection of individual known-good filter flags */
2334 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2335 int bits = 0;
2336
2337 flag = flags[i];
2338 /* Make sure the flag is a single bit! */
2339 while (flag) {
2340 if (flag & 0x1)
2341 bits ++;
2342 flag >>= 1;
2343 }
2344 ASSERT_EQ(1, bits);
2345 flag = flags[i];
2346
2347 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2348 ASSERT_NE(ENOSYS, errno) {
2349 TH_LOG("Kernel does not support seccomp syscall!");
2350 }
2351 EXPECT_EQ(-1, ret);
2352 EXPECT_EQ(EFAULT, errno) {
2353 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2354 flag);
2355 }
2356
2357 all_flags |= flag;
2358 }
2359
2360 /*
2361 * Test detection of all known-good filter flags combined. But
2362 * for the exclusive flags we need to mask them out and try them
2363 * individually for the "all flags" testing.
2364 */
2365 exclusive_mask = 0;
2366 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2367 exclusive_mask |= exclusive[i];
2368 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2369 flag = all_flags & ~exclusive_mask;
2370 flag |= exclusive[i];
2371
2372 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2373 EXPECT_EQ(-1, ret);
2374 EXPECT_EQ(EFAULT, errno) {
2375 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2376 flag);
2377 }
2378 }
2379
2380 /* Test detection of an unknown filter flags, without exclusives. */
2381 flag = -1;
2382 flag &= ~exclusive_mask;
2383 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2384 EXPECT_EQ(-1, ret);
2385 EXPECT_EQ(EINVAL, errno) {
2386 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2387 flag);
2388 }
2389
2390 /*
2391 * Test detection of an unknown filter flag that may simply need to be
2392 * added to this test
2393 */
2394 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2395 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2396 EXPECT_EQ(-1, ret);
2397 EXPECT_EQ(EINVAL, errno) {
2398 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?",
2399 flag);
2400 }
2401 }
2402
TEST(TSYNC_first)2403 TEST(TSYNC_first)
2404 {
2405 struct sock_filter filter[] = {
2406 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2407 };
2408 struct sock_fprog prog = {
2409 .len = (unsigned short)ARRAY_SIZE(filter),
2410 .filter = filter,
2411 };
2412 long ret;
2413
2414 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2415 ASSERT_EQ(0, ret) {
2416 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2417 }
2418
2419 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2420 &prog);
2421 ASSERT_NE(ENOSYS, errno) {
2422 TH_LOG("Kernel does not support seccomp syscall!");
2423 }
2424 EXPECT_EQ(0, ret) {
2425 TH_LOG("Could not install initial filter with TSYNC!");
2426 }
2427 }
2428
2429 #define TSYNC_SIBLINGS 2
2430 struct tsync_sibling {
2431 pthread_t tid;
2432 pid_t system_tid;
2433 sem_t *started;
2434 pthread_cond_t *cond;
2435 pthread_mutex_t *mutex;
2436 int diverge;
2437 int num_waits;
2438 struct sock_fprog *prog;
2439 struct __test_metadata *metadata;
2440 };
2441
2442 /*
2443 * To avoid joining joined threads (which is not allowed by Bionic),
2444 * make sure we both successfully join and clear the tid to skip a
2445 * later join attempt during fixture teardown. Any remaining threads
2446 * will be directly killed during teardown.
2447 */
2448 #define PTHREAD_JOIN(tid, status) \
2449 do { \
2450 int _rc = pthread_join(tid, status); \
2451 if (_rc) { \
2452 TH_LOG("pthread_join of tid %u failed: %d\n", \
2453 (unsigned int)tid, _rc); \
2454 } else { \
2455 tid = 0; \
2456 } \
2457 } while (0)
2458
FIXTURE(TSYNC)2459 FIXTURE(TSYNC) {
2460 struct sock_fprog root_prog, apply_prog;
2461 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2462 sem_t started;
2463 pthread_cond_t cond;
2464 pthread_mutex_t mutex;
2465 int sibling_count;
2466 };
2467
FIXTURE_SETUP(TSYNC)2468 FIXTURE_SETUP(TSYNC)
2469 {
2470 struct sock_filter root_filter[] = {
2471 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2472 };
2473 struct sock_filter apply_filter[] = {
2474 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2475 offsetof(struct seccomp_data, nr)),
2476 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2477 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2478 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2479 };
2480
2481 memset(&self->root_prog, 0, sizeof(self->root_prog));
2482 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2483 memset(&self->sibling, 0, sizeof(self->sibling));
2484 self->root_prog.filter = malloc(sizeof(root_filter));
2485 ASSERT_NE(NULL, self->root_prog.filter);
2486 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2487 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2488
2489 self->apply_prog.filter = malloc(sizeof(apply_filter));
2490 ASSERT_NE(NULL, self->apply_prog.filter);
2491 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2492 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2493
2494 self->sibling_count = 0;
2495 pthread_mutex_init(&self->mutex, NULL);
2496 pthread_cond_init(&self->cond, NULL);
2497 sem_init(&self->started, 0, 0);
2498 self->sibling[0].tid = 0;
2499 self->sibling[0].cond = &self->cond;
2500 self->sibling[0].started = &self->started;
2501 self->sibling[0].mutex = &self->mutex;
2502 self->sibling[0].diverge = 0;
2503 self->sibling[0].num_waits = 1;
2504 self->sibling[0].prog = &self->root_prog;
2505 self->sibling[0].metadata = _metadata;
2506 self->sibling[1].tid = 0;
2507 self->sibling[1].cond = &self->cond;
2508 self->sibling[1].started = &self->started;
2509 self->sibling[1].mutex = &self->mutex;
2510 self->sibling[1].diverge = 0;
2511 self->sibling[1].prog = &self->root_prog;
2512 self->sibling[1].num_waits = 1;
2513 self->sibling[1].metadata = _metadata;
2514 }
2515
FIXTURE_TEARDOWN(TSYNC)2516 FIXTURE_TEARDOWN(TSYNC)
2517 {
2518 int sib = 0;
2519
2520 if (self->root_prog.filter)
2521 free(self->root_prog.filter);
2522 if (self->apply_prog.filter)
2523 free(self->apply_prog.filter);
2524
2525 for ( ; sib < self->sibling_count; ++sib) {
2526 struct tsync_sibling *s = &self->sibling[sib];
2527
2528 if (!s->tid)
2529 continue;
2530 /*
2531 * If a thread is still running, it may be stuck, so hit
2532 * it over the head really hard.
2533 */
2534 pthread_kill(s->tid, 9);
2535 }
2536 pthread_mutex_destroy(&self->mutex);
2537 pthread_cond_destroy(&self->cond);
2538 sem_destroy(&self->started);
2539 }
2540
tsync_sibling(void * data)2541 void *tsync_sibling(void *data)
2542 {
2543 long ret = 0;
2544 struct tsync_sibling *me = data;
2545
2546 me->system_tid = syscall(__NR_gettid);
2547
2548 pthread_mutex_lock(me->mutex);
2549 if (me->diverge) {
2550 /* Just re-apply the root prog to fork the tree */
2551 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2552 me->prog, 0, 0);
2553 }
2554 sem_post(me->started);
2555 /* Return outside of started so parent notices failures. */
2556 if (ret) {
2557 pthread_mutex_unlock(me->mutex);
2558 return (void *)SIBLING_EXIT_FAILURE;
2559 }
2560 do {
2561 pthread_cond_wait(me->cond, me->mutex);
2562 me->num_waits = me->num_waits - 1;
2563 } while (me->num_waits);
2564 pthread_mutex_unlock(me->mutex);
2565
2566 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2567 if (!ret)
2568 return (void *)SIBLING_EXIT_NEWPRIVS;
2569 read(0, NULL, 0);
2570 return (void *)SIBLING_EXIT_UNKILLED;
2571 }
2572
tsync_start_sibling(struct tsync_sibling * sibling)2573 void tsync_start_sibling(struct tsync_sibling *sibling)
2574 {
2575 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2576 }
2577
TEST_F(TSYNC,siblings_fail_prctl)2578 TEST_F(TSYNC, siblings_fail_prctl)
2579 {
2580 long ret;
2581 void *status;
2582 struct sock_filter filter[] = {
2583 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2584 offsetof(struct seccomp_data, nr)),
2585 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2586 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2587 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2588 };
2589 struct sock_fprog prog = {
2590 .len = (unsigned short)ARRAY_SIZE(filter),
2591 .filter = filter,
2592 };
2593
2594 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2595 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2596 }
2597
2598 /* Check prctl failure detection by requesting sib 0 diverge. */
2599 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2600 ASSERT_NE(ENOSYS, errno) {
2601 TH_LOG("Kernel does not support seccomp syscall!");
2602 }
2603 ASSERT_EQ(0, ret) {
2604 TH_LOG("setting filter failed");
2605 }
2606
2607 self->sibling[0].diverge = 1;
2608 tsync_start_sibling(&self->sibling[0]);
2609 tsync_start_sibling(&self->sibling[1]);
2610
2611 while (self->sibling_count < TSYNC_SIBLINGS) {
2612 sem_wait(&self->started);
2613 self->sibling_count++;
2614 }
2615
2616 /* Signal the threads to clean up*/
2617 pthread_mutex_lock(&self->mutex);
2618 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2619 TH_LOG("cond broadcast non-zero");
2620 }
2621 pthread_mutex_unlock(&self->mutex);
2622
2623 /* Ensure diverging sibling failed to call prctl. */
2624 PTHREAD_JOIN(self->sibling[0].tid, &status);
2625 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2626 PTHREAD_JOIN(self->sibling[1].tid, &status);
2627 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2628 }
2629
TEST_F(TSYNC,two_siblings_with_ancestor)2630 TEST_F(TSYNC, two_siblings_with_ancestor)
2631 {
2632 long ret;
2633 void *status;
2634
2635 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2636 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2637 }
2638
2639 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2640 ASSERT_NE(ENOSYS, errno) {
2641 TH_LOG("Kernel does not support seccomp syscall!");
2642 }
2643 ASSERT_EQ(0, ret) {
2644 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2645 }
2646 tsync_start_sibling(&self->sibling[0]);
2647 tsync_start_sibling(&self->sibling[1]);
2648
2649 while (self->sibling_count < TSYNC_SIBLINGS) {
2650 sem_wait(&self->started);
2651 self->sibling_count++;
2652 }
2653
2654 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2655 &self->apply_prog);
2656 ASSERT_EQ(0, ret) {
2657 TH_LOG("Could install filter on all threads!");
2658 }
2659 /* Tell the siblings to test the policy */
2660 pthread_mutex_lock(&self->mutex);
2661 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2662 TH_LOG("cond broadcast non-zero");
2663 }
2664 pthread_mutex_unlock(&self->mutex);
2665 /* Ensure they are both killed and don't exit cleanly. */
2666 PTHREAD_JOIN(self->sibling[0].tid, &status);
2667 EXPECT_EQ(0x0, (long)status);
2668 PTHREAD_JOIN(self->sibling[1].tid, &status);
2669 EXPECT_EQ(0x0, (long)status);
2670 }
2671
TEST_F(TSYNC,two_sibling_want_nnp)2672 TEST_F(TSYNC, two_sibling_want_nnp)
2673 {
2674 void *status;
2675
2676 /* start siblings before any prctl() operations */
2677 tsync_start_sibling(&self->sibling[0]);
2678 tsync_start_sibling(&self->sibling[1]);
2679 while (self->sibling_count < TSYNC_SIBLINGS) {
2680 sem_wait(&self->started);
2681 self->sibling_count++;
2682 }
2683
2684 /* Tell the siblings to test no policy */
2685 pthread_mutex_lock(&self->mutex);
2686 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2687 TH_LOG("cond broadcast non-zero");
2688 }
2689 pthread_mutex_unlock(&self->mutex);
2690
2691 /* Ensure they are both upset about lacking nnp. */
2692 PTHREAD_JOIN(self->sibling[0].tid, &status);
2693 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2694 PTHREAD_JOIN(self->sibling[1].tid, &status);
2695 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2696 }
2697
TEST_F(TSYNC,two_siblings_with_no_filter)2698 TEST_F(TSYNC, two_siblings_with_no_filter)
2699 {
2700 long ret;
2701 void *status;
2702
2703 /* start siblings before any prctl() operations */
2704 tsync_start_sibling(&self->sibling[0]);
2705 tsync_start_sibling(&self->sibling[1]);
2706 while (self->sibling_count < TSYNC_SIBLINGS) {
2707 sem_wait(&self->started);
2708 self->sibling_count++;
2709 }
2710
2711 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2712 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2713 }
2714
2715 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2716 &self->apply_prog);
2717 ASSERT_NE(ENOSYS, errno) {
2718 TH_LOG("Kernel does not support seccomp syscall!");
2719 }
2720 ASSERT_EQ(0, ret) {
2721 TH_LOG("Could install filter on all threads!");
2722 }
2723
2724 /* Tell the siblings to test the policy */
2725 pthread_mutex_lock(&self->mutex);
2726 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2727 TH_LOG("cond broadcast non-zero");
2728 }
2729 pthread_mutex_unlock(&self->mutex);
2730
2731 /* Ensure they are both killed and don't exit cleanly. */
2732 PTHREAD_JOIN(self->sibling[0].tid, &status);
2733 EXPECT_EQ(0x0, (long)status);
2734 PTHREAD_JOIN(self->sibling[1].tid, &status);
2735 EXPECT_EQ(0x0, (long)status);
2736 }
2737
TEST_F(TSYNC,two_siblings_with_one_divergence)2738 TEST_F(TSYNC, two_siblings_with_one_divergence)
2739 {
2740 long ret;
2741 void *status;
2742
2743 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2744 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2745 }
2746
2747 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2748 ASSERT_NE(ENOSYS, errno) {
2749 TH_LOG("Kernel does not support seccomp syscall!");
2750 }
2751 ASSERT_EQ(0, ret) {
2752 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2753 }
2754 self->sibling[0].diverge = 1;
2755 tsync_start_sibling(&self->sibling[0]);
2756 tsync_start_sibling(&self->sibling[1]);
2757
2758 while (self->sibling_count < TSYNC_SIBLINGS) {
2759 sem_wait(&self->started);
2760 self->sibling_count++;
2761 }
2762
2763 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2764 &self->apply_prog);
2765 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2766 TH_LOG("Did not fail on diverged sibling.");
2767 }
2768
2769 /* Wake the threads */
2770 pthread_mutex_lock(&self->mutex);
2771 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2772 TH_LOG("cond broadcast non-zero");
2773 }
2774 pthread_mutex_unlock(&self->mutex);
2775
2776 /* Ensure they are both unkilled. */
2777 PTHREAD_JOIN(self->sibling[0].tid, &status);
2778 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2779 PTHREAD_JOIN(self->sibling[1].tid, &status);
2780 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2781 }
2782
TEST_F(TSYNC,two_siblings_with_one_divergence_no_tid_in_err)2783 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
2784 {
2785 long ret, flags;
2786 void *status;
2787
2788 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2789 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2790 }
2791
2792 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2793 ASSERT_NE(ENOSYS, errno) {
2794 TH_LOG("Kernel does not support seccomp syscall!");
2795 }
2796 ASSERT_EQ(0, ret) {
2797 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2798 }
2799 self->sibling[0].diverge = 1;
2800 tsync_start_sibling(&self->sibling[0]);
2801 tsync_start_sibling(&self->sibling[1]);
2802
2803 while (self->sibling_count < TSYNC_SIBLINGS) {
2804 sem_wait(&self->started);
2805 self->sibling_count++;
2806 }
2807
2808 flags = SECCOMP_FILTER_FLAG_TSYNC | \
2809 SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
2810 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
2811 ASSERT_EQ(ESRCH, errno) {
2812 TH_LOG("Did not return ESRCH for diverged sibling.");
2813 }
2814 ASSERT_EQ(-1, ret) {
2815 TH_LOG("Did not fail on diverged sibling.");
2816 }
2817
2818 /* Wake the threads */
2819 pthread_mutex_lock(&self->mutex);
2820 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2821 TH_LOG("cond broadcast non-zero");
2822 }
2823 pthread_mutex_unlock(&self->mutex);
2824
2825 /* Ensure they are both unkilled. */
2826 PTHREAD_JOIN(self->sibling[0].tid, &status);
2827 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2828 PTHREAD_JOIN(self->sibling[1].tid, &status);
2829 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2830 }
2831
TEST_F(TSYNC,two_siblings_not_under_filter)2832 TEST_F(TSYNC, two_siblings_not_under_filter)
2833 {
2834 long ret, sib;
2835 void *status;
2836 struct timespec delay = { .tv_nsec = 100000000 };
2837
2838 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2839 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2840 }
2841
2842 /*
2843 * Sibling 0 will have its own seccomp policy
2844 * and Sibling 1 will not be under seccomp at
2845 * all. Sibling 1 will enter seccomp and 0
2846 * will cause failure.
2847 */
2848 self->sibling[0].diverge = 1;
2849 tsync_start_sibling(&self->sibling[0]);
2850 tsync_start_sibling(&self->sibling[1]);
2851
2852 while (self->sibling_count < TSYNC_SIBLINGS) {
2853 sem_wait(&self->started);
2854 self->sibling_count++;
2855 }
2856
2857 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2858 ASSERT_NE(ENOSYS, errno) {
2859 TH_LOG("Kernel does not support seccomp syscall!");
2860 }
2861 ASSERT_EQ(0, ret) {
2862 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2863 }
2864
2865 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2866 &self->apply_prog);
2867 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2868 TH_LOG("Did not fail on diverged sibling.");
2869 }
2870 sib = 1;
2871 if (ret == self->sibling[0].system_tid)
2872 sib = 0;
2873
2874 pthread_mutex_lock(&self->mutex);
2875
2876 /* Increment the other siblings num_waits so we can clean up
2877 * the one we just saw.
2878 */
2879 self->sibling[!sib].num_waits += 1;
2880
2881 /* Signal the thread to clean up*/
2882 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2883 TH_LOG("cond broadcast non-zero");
2884 }
2885 pthread_mutex_unlock(&self->mutex);
2886 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2887 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2888 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2889 while (!kill(self->sibling[sib].system_tid, 0))
2890 nanosleep(&delay, NULL);
2891 /* Switch to the remaining sibling */
2892 sib = !sib;
2893
2894 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2895 &self->apply_prog);
2896 ASSERT_EQ(0, ret) {
2897 TH_LOG("Expected the remaining sibling to sync");
2898 };
2899
2900 pthread_mutex_lock(&self->mutex);
2901
2902 /* If remaining sibling didn't have a chance to wake up during
2903 * the first broadcast, manually reduce the num_waits now.
2904 */
2905 if (self->sibling[sib].num_waits > 1)
2906 self->sibling[sib].num_waits = 1;
2907 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2908 TH_LOG("cond broadcast non-zero");
2909 }
2910 pthread_mutex_unlock(&self->mutex);
2911 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2912 EXPECT_EQ(0, (long)status);
2913 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2914 while (!kill(self->sibling[sib].system_tid, 0))
2915 nanosleep(&delay, NULL);
2916
2917 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2918 &self->apply_prog);
2919 ASSERT_EQ(0, ret); /* just us chickens */
2920 }
2921
2922 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)2923 TEST(syscall_restart)
2924 {
2925 long ret;
2926 unsigned long msg;
2927 pid_t child_pid;
2928 int pipefd[2];
2929 int status;
2930 siginfo_t info = { };
2931 struct sock_filter filter[] = {
2932 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2933 offsetof(struct seccomp_data, nr)),
2934
2935 #ifdef __NR_sigreturn
2936 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0),
2937 #endif
2938 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0),
2939 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0),
2940 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0),
2941 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0),
2942 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0),
2943 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2944
2945 /* Allow __NR_write for easy logging. */
2946 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2947 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2948 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2949 /* The nanosleep jump target. */
2950 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2951 /* The restart_syscall jump target. */
2952 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2953 };
2954 struct sock_fprog prog = {
2955 .len = (unsigned short)ARRAY_SIZE(filter),
2956 .filter = filter,
2957 };
2958 #if defined(__arm__)
2959 struct utsname utsbuf;
2960 #endif
2961
2962 ASSERT_EQ(0, pipe(pipefd));
2963
2964 child_pid = fork();
2965 ASSERT_LE(0, child_pid);
2966 if (child_pid == 0) {
2967 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2968 char buf = ' ';
2969 struct timespec timeout = { };
2970
2971 /* Attach parent as tracer and stop. */
2972 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2973 EXPECT_EQ(0, raise(SIGSTOP));
2974
2975 EXPECT_EQ(0, close(pipefd[1]));
2976
2977 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2978 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2979 }
2980
2981 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2982 EXPECT_EQ(0, ret) {
2983 TH_LOG("Failed to install filter!");
2984 }
2985
2986 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2987 TH_LOG("Failed to read() sync from parent");
2988 }
2989 EXPECT_EQ('.', buf) {
2990 TH_LOG("Failed to get sync data from read()");
2991 }
2992
2993 /* Start nanosleep to be interrupted. */
2994 timeout.tv_sec = 1;
2995 errno = 0;
2996 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2997 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2998 }
2999
3000 /* Read final sync from parent. */
3001 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3002 TH_LOG("Failed final read() from parent");
3003 }
3004 EXPECT_EQ('!', buf) {
3005 TH_LOG("Failed to get final data from read()");
3006 }
3007
3008 /* Directly report the status of our test harness results. */
3009 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
3010 : EXIT_FAILURE);
3011 }
3012 EXPECT_EQ(0, close(pipefd[0]));
3013
3014 /* Attach to child, setup options, and release. */
3015 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3016 ASSERT_EQ(true, WIFSTOPPED(status));
3017 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
3018 PTRACE_O_TRACESECCOMP));
3019 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3020 ASSERT_EQ(1, write(pipefd[1], ".", 1));
3021
3022 /* Wait for nanosleep() to start. */
3023 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3024 ASSERT_EQ(true, WIFSTOPPED(status));
3025 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3026 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3027 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3028 ASSERT_EQ(0x100, msg);
3029 ret = get_syscall(_metadata, child_pid);
3030 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep);
3031
3032 /* Might as well check siginfo for sanity while we're here. */
3033 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3034 ASSERT_EQ(SIGTRAP, info.si_signo);
3035 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
3036 EXPECT_EQ(0, info.si_errno);
3037 EXPECT_EQ(getuid(), info.si_uid);
3038 /* Verify signal delivery came from child (seccomp-triggered). */
3039 EXPECT_EQ(child_pid, info.si_pid);
3040
3041 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
3042 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
3043 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3044 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3045 ASSERT_EQ(true, WIFSTOPPED(status));
3046 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
3047 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3048 /*
3049 * There is no siginfo on SIGSTOP any more, so we can't verify
3050 * signal delivery came from parent now (getpid() == info.si_pid).
3051 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
3052 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
3053 */
3054 EXPECT_EQ(SIGSTOP, info.si_signo);
3055
3056 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
3057 ASSERT_EQ(0, kill(child_pid, SIGCONT));
3058 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3059 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3060 ASSERT_EQ(true, WIFSTOPPED(status));
3061 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
3062 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3063
3064 /* Wait for restart_syscall() to start. */
3065 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3066 ASSERT_EQ(true, WIFSTOPPED(status));
3067 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3068 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3069 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3070
3071 ASSERT_EQ(0x200, msg);
3072 ret = get_syscall(_metadata, child_pid);
3073 #if defined(__arm__)
3074 /*
3075 * FIXME:
3076 * - native ARM registers do NOT expose true syscall.
3077 * - compat ARM registers on ARM64 DO expose true syscall.
3078 */
3079 ASSERT_EQ(0, uname(&utsbuf));
3080 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
3081 EXPECT_EQ(__NR_nanosleep, ret);
3082 } else
3083 #endif
3084 {
3085 EXPECT_EQ(__NR_restart_syscall, ret);
3086 }
3087
3088 /* Write again to end test. */
3089 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3090 ASSERT_EQ(1, write(pipefd[1], "!", 1));
3091 EXPECT_EQ(0, close(pipefd[1]));
3092
3093 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3094 if (WIFSIGNALED(status) || WEXITSTATUS(status))
3095 _metadata->passed = 0;
3096 }
3097
TEST_SIGNAL(filter_flag_log,SIGSYS)3098 TEST_SIGNAL(filter_flag_log, SIGSYS)
3099 {
3100 struct sock_filter allow_filter[] = {
3101 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3102 };
3103 struct sock_filter kill_filter[] = {
3104 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3105 offsetof(struct seccomp_data, nr)),
3106 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
3107 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
3108 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3109 };
3110 struct sock_fprog allow_prog = {
3111 .len = (unsigned short)ARRAY_SIZE(allow_filter),
3112 .filter = allow_filter,
3113 };
3114 struct sock_fprog kill_prog = {
3115 .len = (unsigned short)ARRAY_SIZE(kill_filter),
3116 .filter = kill_filter,
3117 };
3118 long ret;
3119 pid_t parent = getppid();
3120
3121 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3122 ASSERT_EQ(0, ret);
3123
3124 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
3125 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
3126 &allow_prog);
3127 ASSERT_NE(ENOSYS, errno) {
3128 TH_LOG("Kernel does not support seccomp syscall!");
3129 }
3130 EXPECT_NE(0, ret) {
3131 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
3132 }
3133 EXPECT_EQ(EINVAL, errno) {
3134 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
3135 }
3136
3137 /* Verify that a simple, permissive filter can be added with no flags */
3138 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
3139 EXPECT_EQ(0, ret);
3140
3141 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
3142 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3143 &allow_prog);
3144 ASSERT_NE(EINVAL, errno) {
3145 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
3146 }
3147 EXPECT_EQ(0, ret);
3148
3149 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
3150 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3151 &kill_prog);
3152 EXPECT_EQ(0, ret);
3153
3154 EXPECT_EQ(parent, syscall(__NR_getppid));
3155 /* getpid() should never return. */
3156 EXPECT_EQ(0, syscall(__NR_getpid));
3157 }
3158
TEST(get_action_avail)3159 TEST(get_action_avail)
3160 {
3161 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
3162 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
3163 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
3164 __u32 unknown_action = 0x10000000U;
3165 int i;
3166 long ret;
3167
3168 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
3169 ASSERT_NE(ENOSYS, errno) {
3170 TH_LOG("Kernel does not support seccomp syscall!");
3171 }
3172 ASSERT_NE(EINVAL, errno) {
3173 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
3174 }
3175 EXPECT_EQ(ret, 0);
3176
3177 for (i = 0; i < ARRAY_SIZE(actions); i++) {
3178 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
3179 EXPECT_EQ(ret, 0) {
3180 TH_LOG("Expected action (0x%X) not available!",
3181 actions[i]);
3182 }
3183 }
3184
3185 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
3186 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
3187 EXPECT_EQ(ret, -1);
3188 EXPECT_EQ(errno, EOPNOTSUPP);
3189 }
3190
TEST(get_metadata)3191 TEST(get_metadata)
3192 {
3193 pid_t pid;
3194 int pipefd[2];
3195 char buf;
3196 struct seccomp_metadata md;
3197 long ret;
3198
3199 /* Only real root can get metadata. */
3200 if (geteuid()) {
3201 SKIP(return, "get_metadata requires real root");
3202 return;
3203 }
3204
3205 ASSERT_EQ(0, pipe(pipefd));
3206
3207 pid = fork();
3208 ASSERT_GE(pid, 0);
3209 if (pid == 0) {
3210 struct sock_filter filter[] = {
3211 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3212 };
3213 struct sock_fprog prog = {
3214 .len = (unsigned short)ARRAY_SIZE(filter),
3215 .filter = filter,
3216 };
3217
3218 /* one with log, one without */
3219 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3220 SECCOMP_FILTER_FLAG_LOG, &prog));
3221 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3222
3223 EXPECT_EQ(0, close(pipefd[0]));
3224 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3225 ASSERT_EQ(0, close(pipefd[1]));
3226
3227 while (1)
3228 sleep(100);
3229 }
3230
3231 ASSERT_EQ(0, close(pipefd[1]));
3232 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3233
3234 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3235 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3236
3237 /* Past here must not use ASSERT or child process is never killed. */
3238
3239 md.filter_off = 0;
3240 errno = 0;
3241 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3242 EXPECT_EQ(sizeof(md), ret) {
3243 if (errno == EINVAL)
3244 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3245 }
3246
3247 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3248 EXPECT_EQ(md.filter_off, 0);
3249
3250 md.filter_off = 1;
3251 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3252 EXPECT_EQ(sizeof(md), ret);
3253 EXPECT_EQ(md.flags, 0);
3254 EXPECT_EQ(md.filter_off, 1);
3255
3256 skip:
3257 ASSERT_EQ(0, kill(pid, SIGKILL));
3258 }
3259
user_notif_syscall(int nr,unsigned int flags)3260 static int user_notif_syscall(int nr, unsigned int flags)
3261 {
3262 struct sock_filter filter[] = {
3263 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3264 offsetof(struct seccomp_data, nr)),
3265 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
3266 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
3267 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3268 };
3269
3270 struct sock_fprog prog = {
3271 .len = (unsigned short)ARRAY_SIZE(filter),
3272 .filter = filter,
3273 };
3274
3275 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3276 }
3277
3278 #define USER_NOTIF_MAGIC INT_MAX
TEST(user_notification_basic)3279 TEST(user_notification_basic)
3280 {
3281 pid_t pid;
3282 long ret;
3283 int status, listener;
3284 struct seccomp_notif req = {};
3285 struct seccomp_notif_resp resp = {};
3286 struct pollfd pollfd;
3287
3288 struct sock_filter filter[] = {
3289 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3290 };
3291 struct sock_fprog prog = {
3292 .len = (unsigned short)ARRAY_SIZE(filter),
3293 .filter = filter,
3294 };
3295
3296 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3297 ASSERT_EQ(0, ret) {
3298 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3299 }
3300
3301 pid = fork();
3302 ASSERT_GE(pid, 0);
3303
3304 /* Check that we get -ENOSYS with no listener attached */
3305 if (pid == 0) {
3306 if (user_notif_syscall(__NR_getppid, 0) < 0)
3307 exit(1);
3308 ret = syscall(__NR_getppid);
3309 exit(ret >= 0 || errno != ENOSYS);
3310 }
3311
3312 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3313 EXPECT_EQ(true, WIFEXITED(status));
3314 EXPECT_EQ(0, WEXITSTATUS(status));
3315
3316 /* Add some no-op filters for grins. */
3317 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3318 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3319 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3320 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3321
3322 /* Check that the basic notification machinery works */
3323 listener = user_notif_syscall(__NR_getppid,
3324 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3325 ASSERT_GE(listener, 0);
3326
3327 /* Installing a second listener in the chain should EBUSY */
3328 EXPECT_EQ(user_notif_syscall(__NR_getppid,
3329 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3330 -1);
3331 EXPECT_EQ(errno, EBUSY);
3332
3333 pid = fork();
3334 ASSERT_GE(pid, 0);
3335
3336 if (pid == 0) {
3337 ret = syscall(__NR_getppid);
3338 exit(ret != USER_NOTIF_MAGIC);
3339 }
3340
3341 pollfd.fd = listener;
3342 pollfd.events = POLLIN | POLLOUT;
3343
3344 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3345 EXPECT_EQ(pollfd.revents, POLLIN);
3346
3347 /* Test that we can't pass garbage to the kernel. */
3348 memset(&req, 0, sizeof(req));
3349 req.pid = -1;
3350 errno = 0;
3351 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
3352 EXPECT_EQ(-1, ret);
3353 EXPECT_EQ(EINVAL, errno);
3354
3355 if (ret) {
3356 req.pid = 0;
3357 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3358 }
3359
3360 pollfd.fd = listener;
3361 pollfd.events = POLLIN | POLLOUT;
3362
3363 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3364 EXPECT_EQ(pollfd.revents, POLLOUT);
3365
3366 EXPECT_EQ(req.data.nr, __NR_getppid);
3367
3368 resp.id = req.id;
3369 resp.error = 0;
3370 resp.val = USER_NOTIF_MAGIC;
3371
3372 /* check that we make sure flags == 0 */
3373 resp.flags = 1;
3374 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3375 EXPECT_EQ(errno, EINVAL);
3376
3377 resp.flags = 0;
3378 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3379
3380 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3381 EXPECT_EQ(true, WIFEXITED(status));
3382 EXPECT_EQ(0, WEXITSTATUS(status));
3383 }
3384
TEST(user_notification_with_tsync)3385 TEST(user_notification_with_tsync)
3386 {
3387 int ret;
3388 unsigned int flags;
3389
3390 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3391 ASSERT_EQ(0, ret) {
3392 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3393 }
3394
3395 /* these were exclusive */
3396 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
3397 SECCOMP_FILTER_FLAG_TSYNC;
3398 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags));
3399 ASSERT_EQ(EINVAL, errno);
3400
3401 /* but now they're not */
3402 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
3403 ret = user_notif_syscall(__NR_getppid, flags);
3404 close(ret);
3405 ASSERT_LE(0, ret);
3406 }
3407
TEST(user_notification_kill_in_middle)3408 TEST(user_notification_kill_in_middle)
3409 {
3410 pid_t pid;
3411 long ret;
3412 int listener;
3413 struct seccomp_notif req = {};
3414 struct seccomp_notif_resp resp = {};
3415
3416 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3417 ASSERT_EQ(0, ret) {
3418 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3419 }
3420
3421 listener = user_notif_syscall(__NR_getppid,
3422 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3423 ASSERT_GE(listener, 0);
3424
3425 /*
3426 * Check that nothing bad happens when we kill the task in the middle
3427 * of a syscall.
3428 */
3429 pid = fork();
3430 ASSERT_GE(pid, 0);
3431
3432 if (pid == 0) {
3433 ret = syscall(__NR_getppid);
3434 exit(ret != USER_NOTIF_MAGIC);
3435 }
3436
3437 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3438 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3439
3440 EXPECT_EQ(kill(pid, SIGKILL), 0);
3441 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3442
3443 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3444
3445 resp.id = req.id;
3446 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3447 EXPECT_EQ(ret, -1);
3448 EXPECT_EQ(errno, ENOENT);
3449 }
3450
3451 static int handled = -1;
3452
signal_handler(int signal)3453 static void signal_handler(int signal)
3454 {
3455 if (write(handled, "c", 1) != 1)
3456 perror("write from signal");
3457 }
3458
TEST(user_notification_signal)3459 TEST(user_notification_signal)
3460 {
3461 pid_t pid;
3462 long ret;
3463 int status, listener, sk_pair[2];
3464 struct seccomp_notif req = {};
3465 struct seccomp_notif_resp resp = {};
3466 char c;
3467
3468 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3469 ASSERT_EQ(0, ret) {
3470 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3471 }
3472
3473 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3474
3475 listener = user_notif_syscall(__NR_gettid,
3476 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3477 ASSERT_GE(listener, 0);
3478
3479 pid = fork();
3480 ASSERT_GE(pid, 0);
3481
3482 if (pid == 0) {
3483 close(sk_pair[0]);
3484 handled = sk_pair[1];
3485 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3486 perror("signal");
3487 exit(1);
3488 }
3489 /*
3490 * ERESTARTSYS behavior is a bit hard to test, because we need
3491 * to rely on a signal that has not yet been handled. Let's at
3492 * least check that the error code gets propagated through, and
3493 * hope that it doesn't break when there is actually a signal :)
3494 */
3495 ret = syscall(__NR_gettid);
3496 exit(!(ret == -1 && errno == 512));
3497 }
3498
3499 close(sk_pair[1]);
3500
3501 memset(&req, 0, sizeof(req));
3502 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3503
3504 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3505
3506 /*
3507 * Make sure the signal really is delivered, which means we're not
3508 * stuck in the user notification code any more and the notification
3509 * should be dead.
3510 */
3511 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3512
3513 resp.id = req.id;
3514 resp.error = -EPERM;
3515 resp.val = 0;
3516
3517 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3518 EXPECT_EQ(errno, ENOENT);
3519
3520 memset(&req, 0, sizeof(req));
3521 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3522
3523 resp.id = req.id;
3524 resp.error = -512; /* -ERESTARTSYS */
3525 resp.val = 0;
3526
3527 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3528
3529 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3530 EXPECT_EQ(true, WIFEXITED(status));
3531 EXPECT_EQ(0, WEXITSTATUS(status));
3532 }
3533
TEST(user_notification_closed_listener)3534 TEST(user_notification_closed_listener)
3535 {
3536 pid_t pid;
3537 long ret;
3538 int status, listener;
3539
3540 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3541 ASSERT_EQ(0, ret) {
3542 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3543 }
3544
3545 listener = user_notif_syscall(__NR_getppid,
3546 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3547 ASSERT_GE(listener, 0);
3548
3549 /*
3550 * Check that we get an ENOSYS when the listener is closed.
3551 */
3552 pid = fork();
3553 ASSERT_GE(pid, 0);
3554 if (pid == 0) {
3555 close(listener);
3556 ret = syscall(__NR_getppid);
3557 exit(ret != -1 && errno != ENOSYS);
3558 }
3559
3560 close(listener);
3561
3562 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3563 EXPECT_EQ(true, WIFEXITED(status));
3564 EXPECT_EQ(0, WEXITSTATUS(status));
3565 }
3566
3567 /*
3568 * Check that a pid in a child namespace still shows up as valid in ours.
3569 */
TEST(user_notification_child_pid_ns)3570 TEST(user_notification_child_pid_ns)
3571 {
3572 pid_t pid;
3573 int status, listener;
3574 struct seccomp_notif req = {};
3575 struct seccomp_notif_resp resp = {};
3576
3577 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
3578 if (errno == EINVAL)
3579 SKIP(return, "kernel missing CLONE_NEWUSER support");
3580 };
3581
3582 listener = user_notif_syscall(__NR_getppid,
3583 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3584 ASSERT_GE(listener, 0);
3585
3586 pid = fork();
3587 ASSERT_GE(pid, 0);
3588
3589 if (pid == 0)
3590 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3591
3592 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3593 EXPECT_EQ(req.pid, pid);
3594
3595 resp.id = req.id;
3596 resp.error = 0;
3597 resp.val = USER_NOTIF_MAGIC;
3598
3599 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3600
3601 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3602 EXPECT_EQ(true, WIFEXITED(status));
3603 EXPECT_EQ(0, WEXITSTATUS(status));
3604 close(listener);
3605 }
3606
3607 /*
3608 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3609 * invalid.
3610 */
TEST(user_notification_sibling_pid_ns)3611 TEST(user_notification_sibling_pid_ns)
3612 {
3613 pid_t pid, pid2;
3614 int status, listener;
3615 struct seccomp_notif req = {};
3616 struct seccomp_notif_resp resp = {};
3617
3618 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3619 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3620 }
3621
3622 listener = user_notif_syscall(__NR_getppid,
3623 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3624 ASSERT_GE(listener, 0);
3625
3626 pid = fork();
3627 ASSERT_GE(pid, 0);
3628
3629 if (pid == 0) {
3630 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3631
3632 pid2 = fork();
3633 ASSERT_GE(pid2, 0);
3634
3635 if (pid2 == 0)
3636 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3637
3638 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3639 EXPECT_EQ(true, WIFEXITED(status));
3640 EXPECT_EQ(0, WEXITSTATUS(status));
3641 exit(WEXITSTATUS(status));
3642 }
3643
3644 /* Create the sibling ns, and sibling in it. */
3645 ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
3646 if (errno == EPERM)
3647 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
3648 }
3649 ASSERT_EQ(errno, 0);
3650
3651 pid2 = fork();
3652 ASSERT_GE(pid2, 0);
3653
3654 if (pid2 == 0) {
3655 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3656 /*
3657 * The pid should be 0, i.e. the task is in some namespace that
3658 * we can't "see".
3659 */
3660 EXPECT_EQ(req.pid, 0);
3661
3662 resp.id = req.id;
3663 resp.error = 0;
3664 resp.val = USER_NOTIF_MAGIC;
3665
3666 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3667 exit(0);
3668 }
3669
3670 close(listener);
3671
3672 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3673 EXPECT_EQ(true, WIFEXITED(status));
3674 EXPECT_EQ(0, WEXITSTATUS(status));
3675
3676 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3677 EXPECT_EQ(true, WIFEXITED(status));
3678 EXPECT_EQ(0, WEXITSTATUS(status));
3679 }
3680
TEST(user_notification_fault_recv)3681 TEST(user_notification_fault_recv)
3682 {
3683 pid_t pid;
3684 int status, listener;
3685 struct seccomp_notif req = {};
3686 struct seccomp_notif_resp resp = {};
3687
3688 ASSERT_EQ(unshare(CLONE_NEWUSER), 0);
3689
3690 listener = user_notif_syscall(__NR_getppid,
3691 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3692 ASSERT_GE(listener, 0);
3693
3694 pid = fork();
3695 ASSERT_GE(pid, 0);
3696
3697 if (pid == 0)
3698 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3699
3700 /* Do a bad recv() */
3701 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3702 EXPECT_EQ(errno, EFAULT);
3703
3704 /* We should still be able to receive this notification, though. */
3705 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3706 EXPECT_EQ(req.pid, pid);
3707
3708 resp.id = req.id;
3709 resp.error = 0;
3710 resp.val = USER_NOTIF_MAGIC;
3711
3712 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3713
3714 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3715 EXPECT_EQ(true, WIFEXITED(status));
3716 EXPECT_EQ(0, WEXITSTATUS(status));
3717 }
3718
TEST(seccomp_get_notif_sizes)3719 TEST(seccomp_get_notif_sizes)
3720 {
3721 struct seccomp_notif_sizes sizes;
3722
3723 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3724 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3725 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3726 }
3727
TEST(user_notification_continue)3728 TEST(user_notification_continue)
3729 {
3730 pid_t pid;
3731 long ret;
3732 int status, listener;
3733 struct seccomp_notif req = {};
3734 struct seccomp_notif_resp resp = {};
3735 struct pollfd pollfd;
3736
3737 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3738 ASSERT_EQ(0, ret) {
3739 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3740 }
3741
3742 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3743 ASSERT_GE(listener, 0);
3744
3745 pid = fork();
3746 ASSERT_GE(pid, 0);
3747
3748 if (pid == 0) {
3749 int dup_fd, pipe_fds[2];
3750 pid_t self;
3751
3752 ASSERT_GE(pipe(pipe_fds), 0);
3753
3754 dup_fd = dup(pipe_fds[0]);
3755 ASSERT_GE(dup_fd, 0);
3756 EXPECT_NE(pipe_fds[0], dup_fd);
3757
3758 self = getpid();
3759 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
3760 exit(0);
3761 }
3762
3763 pollfd.fd = listener;
3764 pollfd.events = POLLIN | POLLOUT;
3765
3766 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3767 EXPECT_EQ(pollfd.revents, POLLIN);
3768
3769 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3770
3771 pollfd.fd = listener;
3772 pollfd.events = POLLIN | POLLOUT;
3773
3774 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3775 EXPECT_EQ(pollfd.revents, POLLOUT);
3776
3777 EXPECT_EQ(req.data.nr, __NR_dup);
3778
3779 resp.id = req.id;
3780 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
3781
3782 /*
3783 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
3784 * args be set to 0.
3785 */
3786 resp.error = 0;
3787 resp.val = USER_NOTIF_MAGIC;
3788 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3789 EXPECT_EQ(errno, EINVAL);
3790
3791 resp.error = USER_NOTIF_MAGIC;
3792 resp.val = 0;
3793 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3794 EXPECT_EQ(errno, EINVAL);
3795
3796 resp.error = 0;
3797 resp.val = 0;
3798 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
3799 if (errno == EINVAL)
3800 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
3801 }
3802
3803 skip:
3804 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3805 EXPECT_EQ(true, WIFEXITED(status));
3806 EXPECT_EQ(0, WEXITSTATUS(status)) {
3807 if (WEXITSTATUS(status) == 2) {
3808 SKIP(return, "Kernel does not support kcmp() syscall");
3809 return;
3810 }
3811 }
3812 }
3813
TEST(user_notification_filter_empty)3814 TEST(user_notification_filter_empty)
3815 {
3816 pid_t pid;
3817 long ret;
3818 int status;
3819 struct pollfd pollfd;
3820 struct __clone_args args = {
3821 .flags = CLONE_FILES,
3822 .exit_signal = SIGCHLD,
3823 };
3824
3825 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3826 ASSERT_EQ(0, ret) {
3827 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3828 }
3829
3830 pid = sys_clone3(&args, sizeof(args));
3831 ASSERT_GE(pid, 0);
3832
3833 if (pid == 0) {
3834 int listener;
3835
3836 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3837 if (listener < 0)
3838 _exit(EXIT_FAILURE);
3839
3840 if (dup2(listener, 200) != 200)
3841 _exit(EXIT_FAILURE);
3842
3843 close(listener);
3844
3845 _exit(EXIT_SUCCESS);
3846 }
3847
3848 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3849 EXPECT_EQ(true, WIFEXITED(status));
3850 EXPECT_EQ(0, WEXITSTATUS(status));
3851
3852 /*
3853 * The seccomp filter has become unused so we should be notified once
3854 * the kernel gets around to cleaning up task struct.
3855 */
3856 pollfd.fd = 200;
3857 pollfd.events = POLLHUP;
3858
3859 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
3860 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
3861 }
3862
do_thread(void * data)3863 static void *do_thread(void *data)
3864 {
3865 return NULL;
3866 }
3867
TEST(user_notification_filter_empty_threaded)3868 TEST(user_notification_filter_empty_threaded)
3869 {
3870 pid_t pid;
3871 long ret;
3872 int status;
3873 struct pollfd pollfd;
3874 struct __clone_args args = {
3875 .flags = CLONE_FILES,
3876 .exit_signal = SIGCHLD,
3877 };
3878
3879 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3880 ASSERT_EQ(0, ret) {
3881 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3882 }
3883
3884 pid = sys_clone3(&args, sizeof(args));
3885 ASSERT_GE(pid, 0);
3886
3887 if (pid == 0) {
3888 pid_t pid1, pid2;
3889 int listener, status;
3890 pthread_t thread;
3891
3892 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3893 if (listener < 0)
3894 _exit(EXIT_FAILURE);
3895
3896 if (dup2(listener, 200) != 200)
3897 _exit(EXIT_FAILURE);
3898
3899 close(listener);
3900
3901 pid1 = fork();
3902 if (pid1 < 0)
3903 _exit(EXIT_FAILURE);
3904
3905 if (pid1 == 0)
3906 _exit(EXIT_SUCCESS);
3907
3908 pid2 = fork();
3909 if (pid2 < 0)
3910 _exit(EXIT_FAILURE);
3911
3912 if (pid2 == 0)
3913 _exit(EXIT_SUCCESS);
3914
3915 if (pthread_create(&thread, NULL, do_thread, NULL) ||
3916 pthread_join(thread, NULL))
3917 _exit(EXIT_FAILURE);
3918
3919 if (pthread_create(&thread, NULL, do_thread, NULL) ||
3920 pthread_join(thread, NULL))
3921 _exit(EXIT_FAILURE);
3922
3923 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) ||
3924 WEXITSTATUS(status))
3925 _exit(EXIT_FAILURE);
3926
3927 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) ||
3928 WEXITSTATUS(status))
3929 _exit(EXIT_FAILURE);
3930
3931 exit(EXIT_SUCCESS);
3932 }
3933
3934 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3935 EXPECT_EQ(true, WIFEXITED(status));
3936 EXPECT_EQ(0, WEXITSTATUS(status));
3937
3938 /*
3939 * The seccomp filter has become unused so we should be notified once
3940 * the kernel gets around to cleaning up task struct.
3941 */
3942 pollfd.fd = 200;
3943 pollfd.events = POLLHUP;
3944
3945 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
3946 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
3947 }
3948
TEST(user_notification_addfd)3949 TEST(user_notification_addfd)
3950 {
3951 pid_t pid;
3952 long ret;
3953 int status, listener, memfd, fd;
3954 struct seccomp_notif_addfd addfd = {};
3955 struct seccomp_notif_addfd_small small = {};
3956 struct seccomp_notif_addfd_big big = {};
3957 struct seccomp_notif req = {};
3958 struct seccomp_notif_resp resp = {};
3959 /* 100 ms */
3960 struct timespec delay = { .tv_nsec = 100000000 };
3961
3962 memfd = memfd_create("test", 0);
3963 ASSERT_GE(memfd, 0);
3964
3965 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3966 ASSERT_EQ(0, ret) {
3967 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3968 }
3969
3970 /* Check that the basic notification machinery works */
3971 listener = user_notif_syscall(__NR_getppid,
3972 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3973 ASSERT_GE(listener, 0);
3974
3975 pid = fork();
3976 ASSERT_GE(pid, 0);
3977
3978 if (pid == 0) {
3979 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC)
3980 exit(1);
3981 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3982 }
3983
3984 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3985
3986 addfd.srcfd = memfd;
3987 addfd.newfd = 0;
3988 addfd.id = req.id;
3989 addfd.flags = 0x0;
3990
3991 /* Verify bad newfd_flags cannot be set */
3992 addfd.newfd_flags = ~O_CLOEXEC;
3993 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
3994 EXPECT_EQ(errno, EINVAL);
3995 addfd.newfd_flags = O_CLOEXEC;
3996
3997 /* Verify bad flags cannot be set */
3998 addfd.flags = 0xff;
3999 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4000 EXPECT_EQ(errno, EINVAL);
4001 addfd.flags = 0;
4002
4003 /* Verify that remote_fd cannot be set without setting flags */
4004 addfd.newfd = 1;
4005 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4006 EXPECT_EQ(errno, EINVAL);
4007 addfd.newfd = 0;
4008
4009 /* Verify small size cannot be set */
4010 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1);
4011 EXPECT_EQ(errno, EINVAL);
4012
4013 /* Verify we can't send bits filled in unknown buffer area */
4014 memset(&big, 0xAA, sizeof(big));
4015 big.addfd = addfd;
4016 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1);
4017 EXPECT_EQ(errno, E2BIG);
4018
4019
4020 /* Verify we can set an arbitrary remote fd */
4021 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4022 EXPECT_GE(fd, 0);
4023 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4024
4025 /* Verify we can set an arbitrary remote fd with large size */
4026 memset(&big, 0x0, sizeof(big));
4027 big.addfd = addfd;
4028 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
4029 EXPECT_GE(fd, 0);
4030
4031 /* Verify we can set a specific remote fd */
4032 addfd.newfd = 42;
4033 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4034 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4035 EXPECT_EQ(fd, 42);
4036 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4037
4038 /* Resume syscall */
4039 resp.id = req.id;
4040 resp.error = 0;
4041 resp.val = USER_NOTIF_MAGIC;
4042 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4043
4044 /*
4045 * This sets the ID of the ADD FD to the last request plus 1. The
4046 * notification ID increments 1 per notification.
4047 */
4048 addfd.id = req.id + 1;
4049
4050 /* This spins until the underlying notification is generated */
4051 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4052 errno != -EINPROGRESS)
4053 nanosleep(&delay, NULL);
4054
4055 memset(&req, 0, sizeof(req));
4056 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4057 ASSERT_EQ(addfd.id, req.id);
4058
4059 resp.id = req.id;
4060 resp.error = 0;
4061 resp.val = USER_NOTIF_MAGIC;
4062 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4063
4064 /* Wait for child to finish. */
4065 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4066 EXPECT_EQ(true, WIFEXITED(status));
4067 EXPECT_EQ(0, WEXITSTATUS(status));
4068
4069 close(memfd);
4070 }
4071
TEST(user_notification_addfd_rlimit)4072 TEST(user_notification_addfd_rlimit)
4073 {
4074 pid_t pid;
4075 long ret;
4076 int status, listener, memfd;
4077 struct seccomp_notif_addfd addfd = {};
4078 struct seccomp_notif req = {};
4079 struct seccomp_notif_resp resp = {};
4080 const struct rlimit lim = {
4081 .rlim_cur = 0,
4082 .rlim_max = 0,
4083 };
4084
4085 memfd = memfd_create("test", 0);
4086 ASSERT_GE(memfd, 0);
4087
4088 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4089 ASSERT_EQ(0, ret) {
4090 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4091 }
4092
4093 /* Check that the basic notification machinery works */
4094 listener = user_notif_syscall(__NR_getppid,
4095 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4096 ASSERT_GE(listener, 0);
4097
4098 pid = fork();
4099 ASSERT_GE(pid, 0);
4100
4101 if (pid == 0)
4102 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4103
4104
4105 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4106
4107 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0);
4108
4109 addfd.srcfd = memfd;
4110 addfd.newfd_flags = O_CLOEXEC;
4111 addfd.newfd = 0;
4112 addfd.id = req.id;
4113 addfd.flags = 0;
4114
4115 /* Should probably spot check /proc/sys/fs/file-nr */
4116 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4117 EXPECT_EQ(errno, EMFILE);
4118
4119 addfd.newfd = 100;
4120 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4121 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4122 EXPECT_EQ(errno, EBADF);
4123
4124 resp.id = req.id;
4125 resp.error = 0;
4126 resp.val = USER_NOTIF_MAGIC;
4127
4128 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4129
4130 /* Wait for child to finish. */
4131 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4132 EXPECT_EQ(true, WIFEXITED(status));
4133 EXPECT_EQ(0, WEXITSTATUS(status));
4134
4135 close(memfd);
4136 }
4137
4138 /*
4139 * TODO:
4140 * - expand NNP testing
4141 * - better arch-specific TRACE and TRAP handlers.
4142 * - endianness checking when appropriate
4143 * - 64-bit arg prodding
4144 * - arch value testing (x86 modes especially)
4145 * - verify that FILTER_FLAG_LOG filters generate log messages
4146 * - verify that RET_LOG generates log messages
4147 */
4148
4149 TEST_HARNESS_MAIN
4150