1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #define _GNU_SOURCE
9 #include <sys/types.h>
10
11 /*
12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
13 * we need to use the kernel's siginfo.h file and trick glibc
14 * into accepting it.
15 */
16 #if !__GLIBC_PREREQ(2, 26)
17 # include <asm/siginfo.h>
18 # define __have_siginfo_t 1
19 # define __have_sigval_t 1
20 # define __have_sigevent_t 1
21 #endif
22
23 #include <errno.h>
24 #include <linux/filter.h>
25 #include <sys/prctl.h>
26 #include <sys/ptrace.h>
27 #include <sys/user.h>
28 #include <linux/prctl.h>
29 #include <linux/ptrace.h>
30 #include <linux/seccomp.h>
31 #include <pthread.h>
32 #include <semaphore.h>
33 #include <signal.h>
34 #include <stddef.h>
35 #include <stdbool.h>
36 #include <string.h>
37 #include <time.h>
38 #include <limits.h>
39 #include <linux/elf.h>
40 #include <sys/uio.h>
41 #include <sys/utsname.h>
42 #include <sys/fcntl.h>
43 #include <sys/mman.h>
44 #include <sys/times.h>
45 #include <sys/socket.h>
46 #include <sys/ioctl.h>
47 #include <linux/kcmp.h>
48 #include <sys/resource.h>
49
50 #include <unistd.h>
51 #include <sys/syscall.h>
52 #include <poll.h>
53
54 #include "../kselftest_harness.h"
55 #include "../clone3/clone3_selftests.h"
56
57 /* Attempt to de-conflict with the selftests tree. */
58 #ifndef SKIP
59 #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
60 #endif
61
62 #ifndef PR_SET_PTRACER
63 # define PR_SET_PTRACER 0x59616d61
64 #endif
65
66 #ifndef PR_SET_NO_NEW_PRIVS
67 #define PR_SET_NO_NEW_PRIVS 38
68 #define PR_GET_NO_NEW_PRIVS 39
69 #endif
70
71 #ifndef PR_SECCOMP_EXT
72 #define PR_SECCOMP_EXT 43
73 #endif
74
75 #ifndef SECCOMP_EXT_ACT
76 #define SECCOMP_EXT_ACT 1
77 #endif
78
79 #ifndef SECCOMP_EXT_ACT_TSYNC
80 #define SECCOMP_EXT_ACT_TSYNC 1
81 #endif
82
83 #ifndef SECCOMP_MODE_STRICT
84 #define SECCOMP_MODE_STRICT 1
85 #endif
86
87 #ifndef SECCOMP_MODE_FILTER
88 #define SECCOMP_MODE_FILTER 2
89 #endif
90
91 #ifndef SECCOMP_RET_ALLOW
92 struct seccomp_data {
93 int nr;
94 __u32 arch;
95 __u64 instruction_pointer;
96 __u64 args[6];
97 };
98 #endif
99
100 #ifndef SECCOMP_RET_KILL_PROCESS
101 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
102 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
103 #endif
104 #ifndef SECCOMP_RET_KILL
105 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
106 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
107 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
108 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
109 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
110 #endif
111 #ifndef SECCOMP_RET_LOG
112 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
113 #endif
114
115 #ifndef __NR_seccomp
116 # if defined(__i386__)
117 # define __NR_seccomp 354
118 # elif defined(__x86_64__)
119 # define __NR_seccomp 317
120 # elif defined(__arm__)
121 # define __NR_seccomp 383
122 # elif defined(__aarch64__)
123 # define __NR_seccomp 277
124 # elif defined(__riscv)
125 # define __NR_seccomp 277
126 # elif defined(__csky__)
127 # define __NR_seccomp 277
128 # elif defined(__hppa__)
129 # define __NR_seccomp 338
130 # elif defined(__powerpc__)
131 # define __NR_seccomp 358
132 # elif defined(__s390__)
133 # define __NR_seccomp 348
134 # elif defined(__xtensa__)
135 # define __NR_seccomp 337
136 # elif defined(__sh__)
137 # define __NR_seccomp 372
138 # else
139 # warning "seccomp syscall number unknown for this architecture"
140 # define __NR_seccomp 0xffff
141 # endif
142 #endif
143
144 #ifndef SECCOMP_SET_MODE_STRICT
145 #define SECCOMP_SET_MODE_STRICT 0
146 #endif
147
148 #ifndef SECCOMP_SET_MODE_FILTER
149 #define SECCOMP_SET_MODE_FILTER 1
150 #endif
151
152 #ifndef SECCOMP_GET_ACTION_AVAIL
153 #define SECCOMP_GET_ACTION_AVAIL 2
154 #endif
155
156 #ifndef SECCOMP_GET_NOTIF_SIZES
157 #define SECCOMP_GET_NOTIF_SIZES 3
158 #endif
159
160 #ifndef SECCOMP_FILTER_FLAG_TSYNC
161 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
162 #endif
163
164 #ifndef SECCOMP_FILTER_FLAG_LOG
165 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
166 #endif
167
168 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
169 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
170 #endif
171
172 #ifndef PTRACE_SECCOMP_GET_METADATA
173 #define PTRACE_SECCOMP_GET_METADATA 0x420d
174
175 struct seccomp_metadata {
176 __u64 filter_off; /* Input: which filter */
177 __u64 flags; /* Output: filter's flags */
178 };
179 #endif
180
181 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
182 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
183 #endif
184
185 #ifndef SECCOMP_RET_USER_NOTIF
186 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
187
188 #define SECCOMP_IOC_MAGIC '!'
189 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
190 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
191 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
192 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
193
194 /* Flags for seccomp notification fd ioctl. */
195 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
196 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
197 struct seccomp_notif_resp)
198 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)
199
200 struct seccomp_notif {
201 __u64 id;
202 __u32 pid;
203 __u32 flags;
204 struct seccomp_data data;
205 };
206
207 struct seccomp_notif_resp {
208 __u64 id;
209 __s64 val;
210 __s32 error;
211 __u32 flags;
212 };
213
214 struct seccomp_notif_sizes {
215 __u16 seccomp_notif;
216 __u16 seccomp_notif_resp;
217 __u16 seccomp_data;
218 };
219 #endif
220
221 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD
222 /* On success, the return value is the remote process's added fd number */
223 #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \
224 struct seccomp_notif_addfd)
225
226 /* valid flags for seccomp_notif_addfd */
227 #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */
228
229 struct seccomp_notif_addfd {
230 __u64 id;
231 __u32 flags;
232 __u32 srcfd;
233 __u32 newfd;
234 __u32 newfd_flags;
235 };
236 #endif
237
238 #ifndef SECCOMP_ADDFD_FLAG_SEND
239 #define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */
240 #endif
241
242 struct seccomp_notif_addfd_small {
243 __u64 id;
244 char weird[4];
245 };
246 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \
247 SECCOMP_IOW(3, struct seccomp_notif_addfd_small)
248
249 struct seccomp_notif_addfd_big {
250 union {
251 struct seccomp_notif_addfd addfd;
252 char buf[sizeof(struct seccomp_notif_addfd) + 8];
253 };
254 };
255 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \
256 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big)
257
258 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
259 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
260 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
261 #endif
262
263 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
264 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
265 #endif
266
267 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
268 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
269 #endif
270
271 #ifndef seccomp
seccomp(unsigned int op,unsigned int flags,void * args)272 int seccomp(unsigned int op, unsigned int flags, void *args)
273 {
274 errno = 0;
275 return syscall(__NR_seccomp, op, flags, args);
276 }
277 #endif
278
279 #if __BYTE_ORDER == __LITTLE_ENDIAN
280 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
281 #elif __BYTE_ORDER == __BIG_ENDIAN
282 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
283 #else
284 #error "wut? Unknown __BYTE_ORDER?!"
285 #endif
286
287 #define SIBLING_EXIT_UNKILLED 0xbadbeef
288 #define SIBLING_EXIT_FAILURE 0xbadface
289 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
290
__filecmp(pid_t pid1,pid_t pid2,int fd1,int fd2)291 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
292 {
293 #ifdef __NR_kcmp
294 errno = 0;
295 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
296 #else
297 errno = ENOSYS;
298 return -1;
299 #endif
300 }
301
302 /* Have TH_LOG report actual location filecmp() is used. */
303 #define filecmp(pid1, pid2, fd1, fd2) ({ \
304 int _ret; \
305 \
306 _ret = __filecmp(pid1, pid2, fd1, fd2); \
307 if (_ret != 0) { \
308 if (_ret < 0 && errno == ENOSYS) { \
309 TH_LOG("kcmp() syscall missing (test is less accurate)");\
310 _ret = 0; \
311 } \
312 } \
313 _ret; })
314
TEST(kcmp)315 TEST(kcmp)
316 {
317 int ret;
318
319 ret = __filecmp(getpid(), getpid(), 1, 1);
320 EXPECT_EQ(ret, 0);
321 if (ret != 0 && errno == ENOSYS)
322 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)");
323 }
324
TEST(mode_strict_support)325 TEST(mode_strict_support)
326 {
327 long ret;
328
329 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
330 ASSERT_EQ(0, ret) {
331 TH_LOG("Kernel does not support CONFIG_SECCOMP");
332 }
333 syscall(__NR_exit, 0);
334 }
335
TEST_SIGNAL(mode_strict_cannot_call_prctl,SIGKILL)336 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
337 {
338 long ret;
339
340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
341 ASSERT_EQ(0, ret) {
342 TH_LOG("Kernel does not support CONFIG_SECCOMP");
343 }
344 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
345 NULL, NULL, NULL);
346 EXPECT_FALSE(true) {
347 TH_LOG("Unreachable!");
348 }
349 }
350
351 /* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)352 TEST(no_new_privs_support)
353 {
354 long ret;
355
356 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
357 EXPECT_EQ(0, ret) {
358 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
359 }
360 }
361
362 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)363 TEST(mode_filter_support)
364 {
365 long ret;
366
367 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
368 ASSERT_EQ(0, ret) {
369 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
370 }
371 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
372 EXPECT_EQ(-1, ret);
373 EXPECT_EQ(EFAULT, errno) {
374 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
375 }
376 }
377
TEST(mode_filter_without_nnp)378 TEST(mode_filter_without_nnp)
379 {
380 struct sock_filter filter[] = {
381 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
382 };
383 struct sock_fprog prog = {
384 .len = (unsigned short)ARRAY_SIZE(filter),
385 .filter = filter,
386 };
387 long ret;
388
389 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
390 ASSERT_LE(0, ret) {
391 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
392 }
393 errno = 0;
394 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
395 /* Succeeds with CAP_SYS_ADMIN, fails without */
396 /* TODO(wad) check caps not euid */
397 if (geteuid()) {
398 EXPECT_EQ(-1, ret);
399 EXPECT_EQ(EACCES, errno);
400 } else {
401 EXPECT_EQ(0, ret);
402 }
403 }
404
405 #define MAX_INSNS_PER_PATH 32768
406
TEST(filter_size_limits)407 TEST(filter_size_limits)
408 {
409 int i;
410 int count = BPF_MAXINSNS + 1;
411 struct sock_filter allow[] = {
412 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
413 };
414 struct sock_filter *filter;
415 struct sock_fprog prog = { };
416 long ret;
417
418 filter = calloc(count, sizeof(*filter));
419 ASSERT_NE(NULL, filter);
420
421 for (i = 0; i < count; i++)
422 filter[i] = allow[0];
423
424 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
425 ASSERT_EQ(0, ret);
426
427 prog.filter = filter;
428 prog.len = count;
429
430 /* Too many filter instructions in a single filter. */
431 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
432 ASSERT_NE(0, ret) {
433 TH_LOG("Installing %d insn filter was allowed", prog.len);
434 }
435
436 /* One less is okay, though. */
437 prog.len -= 1;
438 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
439 ASSERT_EQ(0, ret) {
440 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
441 }
442 }
443
TEST(filter_chain_limits)444 TEST(filter_chain_limits)
445 {
446 int i;
447 int count = BPF_MAXINSNS;
448 struct sock_filter allow[] = {
449 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
450 };
451 struct sock_filter *filter;
452 struct sock_fprog prog = { };
453 long ret;
454
455 filter = calloc(count, sizeof(*filter));
456 ASSERT_NE(NULL, filter);
457
458 for (i = 0; i < count; i++)
459 filter[i] = allow[0];
460
461 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
462 ASSERT_EQ(0, ret);
463
464 prog.filter = filter;
465 prog.len = 1;
466
467 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
468 ASSERT_EQ(0, ret);
469
470 prog.len = count;
471
472 /* Too many total filter instructions. */
473 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
474 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
475 if (ret != 0)
476 break;
477 }
478 ASSERT_NE(0, ret) {
479 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
480 i, count, i * (count + 4));
481 }
482 }
483
TEST(mode_filter_cannot_move_to_strict)484 TEST(mode_filter_cannot_move_to_strict)
485 {
486 struct sock_filter filter[] = {
487 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
488 };
489 struct sock_fprog prog = {
490 .len = (unsigned short)ARRAY_SIZE(filter),
491 .filter = filter,
492 };
493 long ret;
494
495 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
496 ASSERT_EQ(0, ret);
497
498 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
499 ASSERT_EQ(0, ret);
500
501 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
502 EXPECT_EQ(-1, ret);
503 EXPECT_EQ(EINVAL, errno);
504 }
505
506
TEST(mode_filter_get_seccomp)507 TEST(mode_filter_get_seccomp)
508 {
509 struct sock_filter filter[] = {
510 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
511 };
512 struct sock_fprog prog = {
513 .len = (unsigned short)ARRAY_SIZE(filter),
514 .filter = filter,
515 };
516 long ret;
517
518 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
519 ASSERT_EQ(0, ret);
520
521 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
522 EXPECT_EQ(0, ret);
523
524 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
525 ASSERT_EQ(0, ret);
526
527 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
528 EXPECT_EQ(2, ret);
529 }
530
531
TEST(ALLOW_all)532 TEST(ALLOW_all)
533 {
534 struct sock_filter filter[] = {
535 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
536 };
537 struct sock_fprog prog = {
538 .len = (unsigned short)ARRAY_SIZE(filter),
539 .filter = filter,
540 };
541 long ret;
542
543 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
544 ASSERT_EQ(0, ret);
545
546 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
547 ASSERT_EQ(0, ret);
548 }
549
TEST(empty_prog)550 TEST(empty_prog)
551 {
552 struct sock_filter filter[] = {
553 };
554 struct sock_fprog prog = {
555 .len = (unsigned short)ARRAY_SIZE(filter),
556 .filter = filter,
557 };
558 long ret;
559
560 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
561 ASSERT_EQ(0, ret);
562
563 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
564 EXPECT_EQ(-1, ret);
565 EXPECT_EQ(EINVAL, errno);
566 }
567
TEST(log_all)568 TEST(log_all)
569 {
570 struct sock_filter filter[] = {
571 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
572 };
573 struct sock_fprog prog = {
574 .len = (unsigned short)ARRAY_SIZE(filter),
575 .filter = filter,
576 };
577 long ret;
578 pid_t parent = getppid();
579
580 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
581 ASSERT_EQ(0, ret);
582
583 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
584 ASSERT_EQ(0, ret);
585
586 /* getppid() should succeed and be logged (no check for logging) */
587 EXPECT_EQ(parent, syscall(__NR_getppid));
588 }
589
TEST_SIGNAL(unknown_ret_is_kill_inside,SIGSYS)590 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
591 {
592 struct sock_filter filter[] = {
593 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
594 };
595 struct sock_fprog prog = {
596 .len = (unsigned short)ARRAY_SIZE(filter),
597 .filter = filter,
598 };
599 long ret;
600
601 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
602 ASSERT_EQ(0, ret);
603
604 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
605 ASSERT_EQ(0, ret);
606 EXPECT_EQ(0, syscall(__NR_getpid)) {
607 TH_LOG("getpid() shouldn't ever return");
608 }
609 }
610
611 /* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow,SIGSYS)612 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
613 {
614 struct sock_filter filter[] = {
615 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
616 };
617 struct sock_fprog prog = {
618 .len = (unsigned short)ARRAY_SIZE(filter),
619 .filter = filter,
620 };
621 long ret;
622
623 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
624 ASSERT_EQ(0, ret);
625
626 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
627 ASSERT_EQ(0, ret);
628 EXPECT_EQ(0, syscall(__NR_getpid)) {
629 TH_LOG("getpid() shouldn't ever return");
630 }
631 }
632
TEST_SIGNAL(KILL_all,SIGSYS)633 TEST_SIGNAL(KILL_all, SIGSYS)
634 {
635 struct sock_filter filter[] = {
636 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
637 };
638 struct sock_fprog prog = {
639 .len = (unsigned short)ARRAY_SIZE(filter),
640 .filter = filter,
641 };
642 long ret;
643
644 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
645 ASSERT_EQ(0, ret);
646
647 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
648 ASSERT_EQ(0, ret);
649 }
650
TEST_SIGNAL(KILL_one,SIGSYS)651 TEST_SIGNAL(KILL_one, SIGSYS)
652 {
653 struct sock_filter filter[] = {
654 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
655 offsetof(struct seccomp_data, nr)),
656 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
657 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
658 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
659 };
660 struct sock_fprog prog = {
661 .len = (unsigned short)ARRAY_SIZE(filter),
662 .filter = filter,
663 };
664 long ret;
665 pid_t parent = getppid();
666
667 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
668 ASSERT_EQ(0, ret);
669
670 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
671 ASSERT_EQ(0, ret);
672
673 EXPECT_EQ(parent, syscall(__NR_getppid));
674 /* getpid() should never return. */
675 EXPECT_EQ(0, syscall(__NR_getpid));
676 }
677
TEST_SIGNAL(KILL_one_arg_one,SIGSYS)678 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
679 {
680 void *fatal_address;
681 struct sock_filter filter[] = {
682 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
683 offsetof(struct seccomp_data, nr)),
684 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
685 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
686 /* Only both with lower 32-bit for now. */
687 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
688 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
689 (unsigned long)&fatal_address, 0, 1),
690 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
691 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
692 };
693 struct sock_fprog prog = {
694 .len = (unsigned short)ARRAY_SIZE(filter),
695 .filter = filter,
696 };
697 long ret;
698 pid_t parent = getppid();
699 struct tms timebuf;
700 clock_t clock = times(&timebuf);
701
702 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
703 ASSERT_EQ(0, ret);
704
705 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
706 ASSERT_EQ(0, ret);
707
708 EXPECT_EQ(parent, syscall(__NR_getppid));
709 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
710 /* times() should never return. */
711 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
712 }
713
TEST_SIGNAL(KILL_one_arg_six,SIGSYS)714 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
715 {
716 #ifndef __NR_mmap2
717 int sysno = __NR_mmap;
718 #else
719 int sysno = __NR_mmap2;
720 #endif
721 struct sock_filter filter[] = {
722 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
723 offsetof(struct seccomp_data, nr)),
724 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
725 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
726 /* Only both with lower 32-bit for now. */
727 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
728 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
729 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
730 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
731 };
732 struct sock_fprog prog = {
733 .len = (unsigned short)ARRAY_SIZE(filter),
734 .filter = filter,
735 };
736 long ret;
737 pid_t parent = getppid();
738 int fd;
739 void *map1, *map2;
740 int page_size = sysconf(_SC_PAGESIZE);
741
742 ASSERT_LT(0, page_size);
743
744 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
745 ASSERT_EQ(0, ret);
746
747 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
748 ASSERT_EQ(0, ret);
749
750 fd = open("/dev/zero", O_RDONLY);
751 ASSERT_NE(-1, fd);
752
753 EXPECT_EQ(parent, syscall(__NR_getppid));
754 map1 = (void *)syscall(sysno,
755 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
756 EXPECT_NE(MAP_FAILED, map1);
757 /* mmap2() should never return. */
758 map2 = (void *)syscall(sysno,
759 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
760 EXPECT_EQ(MAP_FAILED, map2);
761
762 /* The test failed, so clean up the resources. */
763 munmap(map1, page_size);
764 munmap(map2, page_size);
765 close(fd);
766 }
767
768 /* This is a thread task to die via seccomp filter violation. */
kill_thread(void * data)769 void *kill_thread(void *data)
770 {
771 bool die = (bool)data;
772
773 if (die) {
774 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
775 return (void *)SIBLING_EXIT_FAILURE;
776 }
777
778 return (void *)SIBLING_EXIT_UNKILLED;
779 }
780
781 enum kill_t {
782 KILL_THREAD,
783 KILL_PROCESS,
784 RET_UNKNOWN
785 };
786
787 /* Prepare a thread that will kill itself or both of us. */
kill_thread_or_group(struct __test_metadata * _metadata,enum kill_t kill_how)788 void kill_thread_or_group(struct __test_metadata *_metadata,
789 enum kill_t kill_how)
790 {
791 pthread_t thread;
792 void *status;
793 /* Kill only when calling __NR_prctl. */
794 struct sock_filter filter_thread[] = {
795 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
796 offsetof(struct seccomp_data, nr)),
797 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
798 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
799 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
800 };
801 struct sock_fprog prog_thread = {
802 .len = (unsigned short)ARRAY_SIZE(filter_thread),
803 .filter = filter_thread,
804 };
805 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAAA;
806 struct sock_filter filter_process[] = {
807 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
808 offsetof(struct seccomp_data, nr)),
809 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
810 BPF_STMT(BPF_RET|BPF_K, kill),
811 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
812 };
813 struct sock_fprog prog_process = {
814 .len = (unsigned short)ARRAY_SIZE(filter_process),
815 .filter = filter_process,
816 };
817
818 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
819 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
820 }
821
822 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
823 kill_how == KILL_THREAD ? &prog_thread
824 : &prog_process));
825
826 /*
827 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
828 * flag cannot be downgraded by a new filter.
829 */
830 if (kill_how == KILL_PROCESS)
831 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
832
833 /* Start a thread that will exit immediately. */
834 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
835 ASSERT_EQ(0, pthread_join(thread, &status));
836 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
837
838 /* Start a thread that will die immediately. */
839 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
840 ASSERT_EQ(0, pthread_join(thread, &status));
841 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
842
843 /*
844 * If we get here, only the spawned thread died. Let the parent know
845 * the whole process didn't die (i.e. this thread, the spawner,
846 * stayed running).
847 */
848 exit(42);
849 }
850
TEST(KILL_thread)851 TEST(KILL_thread)
852 {
853 int status;
854 pid_t child_pid;
855
856 child_pid = fork();
857 ASSERT_LE(0, child_pid);
858 if (child_pid == 0) {
859 kill_thread_or_group(_metadata, KILL_THREAD);
860 _exit(38);
861 }
862
863 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
864
865 /* If only the thread was killed, we'll see exit 42. */
866 ASSERT_TRUE(WIFEXITED(status));
867 ASSERT_EQ(42, WEXITSTATUS(status));
868 }
869
TEST(KILL_process)870 TEST(KILL_process)
871 {
872 int status;
873 pid_t child_pid;
874
875 child_pid = fork();
876 ASSERT_LE(0, child_pid);
877 if (child_pid == 0) {
878 kill_thread_or_group(_metadata, KILL_PROCESS);
879 _exit(38);
880 }
881
882 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
883
884 /* If the entire process was killed, we'll see SIGSYS. */
885 ASSERT_TRUE(WIFSIGNALED(status));
886 ASSERT_EQ(SIGSYS, WTERMSIG(status));
887 }
888
TEST(KILL_unknown)889 TEST(KILL_unknown)
890 {
891 int status;
892 pid_t child_pid;
893
894 child_pid = fork();
895 ASSERT_LE(0, child_pid);
896 if (child_pid == 0) {
897 kill_thread_or_group(_metadata, RET_UNKNOWN);
898 _exit(38);
899 }
900
901 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
902
903 /* If the entire process was killed, we'll see SIGSYS. */
904 EXPECT_TRUE(WIFSIGNALED(status)) {
905 TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
906 }
907 ASSERT_EQ(SIGSYS, WTERMSIG(status));
908 }
909
910 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)911 TEST(arg_out_of_range)
912 {
913 struct sock_filter filter[] = {
914 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
915 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
916 };
917 struct sock_fprog prog = {
918 .len = (unsigned short)ARRAY_SIZE(filter),
919 .filter = filter,
920 };
921 long ret;
922
923 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
924 ASSERT_EQ(0, ret);
925
926 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
927 EXPECT_EQ(-1, ret);
928 EXPECT_EQ(EINVAL, errno);
929 }
930
931 #define ERRNO_FILTER(name, errno) \
932 struct sock_filter _read_filter_##name[] = { \
933 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
934 offsetof(struct seccomp_data, nr)), \
935 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
936 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
937 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
938 }; \
939 struct sock_fprog prog_##name = { \
940 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
941 .filter = _read_filter_##name, \
942 }
943
944 /* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)945 TEST(ERRNO_valid)
946 {
947 ERRNO_FILTER(valid, E2BIG);
948 long ret;
949 pid_t parent = getppid();
950
951 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
952 ASSERT_EQ(0, ret);
953
954 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
955 ASSERT_EQ(0, ret);
956
957 EXPECT_EQ(parent, syscall(__NR_getppid));
958 EXPECT_EQ(-1, read(0, NULL, 0));
959 EXPECT_EQ(E2BIG, errno);
960 }
961
962 /* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)963 TEST(ERRNO_zero)
964 {
965 ERRNO_FILTER(zero, 0);
966 long ret;
967 pid_t parent = getppid();
968
969 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
970 ASSERT_EQ(0, ret);
971
972 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
973 ASSERT_EQ(0, ret);
974
975 EXPECT_EQ(parent, syscall(__NR_getppid));
976 /* "errno" of 0 is ok. */
977 EXPECT_EQ(0, read(0, NULL, 0));
978 }
979
980 /*
981 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
982 * This tests that the errno value gets capped correctly, fixed by
983 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
984 */
TEST(ERRNO_capped)985 TEST(ERRNO_capped)
986 {
987 ERRNO_FILTER(capped, 4096);
988 long ret;
989 pid_t parent = getppid();
990
991 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
992 ASSERT_EQ(0, ret);
993
994 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
995 ASSERT_EQ(0, ret);
996
997 EXPECT_EQ(parent, syscall(__NR_getppid));
998 EXPECT_EQ(-1, read(0, NULL, 0));
999 EXPECT_EQ(4095, errno);
1000 }
1001
1002 /*
1003 * Filters are processed in reverse order: last applied is executed first.
1004 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
1005 * SECCOMP_RET_DATA mask results will follow the most recently applied
1006 * matching filter return (and not the lowest or highest value).
1007 */
TEST(ERRNO_order)1008 TEST(ERRNO_order)
1009 {
1010 ERRNO_FILTER(first, 11);
1011 ERRNO_FILTER(second, 13);
1012 ERRNO_FILTER(third, 12);
1013 long ret;
1014 pid_t parent = getppid();
1015
1016 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1017 ASSERT_EQ(0, ret);
1018
1019 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
1020 ASSERT_EQ(0, ret);
1021
1022 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
1023 ASSERT_EQ(0, ret);
1024
1025 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
1026 ASSERT_EQ(0, ret);
1027
1028 EXPECT_EQ(parent, syscall(__NR_getppid));
1029 EXPECT_EQ(-1, read(0, NULL, 0));
1030 EXPECT_EQ(12, errno);
1031 }
1032
FIXTURE(TRAP)1033 FIXTURE(TRAP) {
1034 struct sock_fprog prog;
1035 };
1036
FIXTURE_SETUP(TRAP)1037 FIXTURE_SETUP(TRAP)
1038 {
1039 struct sock_filter filter[] = {
1040 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1041 offsetof(struct seccomp_data, nr)),
1042 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1043 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1044 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1045 };
1046
1047 memset(&self->prog, 0, sizeof(self->prog));
1048 self->prog.filter = malloc(sizeof(filter));
1049 ASSERT_NE(NULL, self->prog.filter);
1050 memcpy(self->prog.filter, filter, sizeof(filter));
1051 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1052 }
1053
FIXTURE_TEARDOWN(TRAP)1054 FIXTURE_TEARDOWN(TRAP)
1055 {
1056 if (self->prog.filter)
1057 free(self->prog.filter);
1058 }
1059
TEST_F_SIGNAL(TRAP,dfl,SIGSYS)1060 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
1061 {
1062 long ret;
1063
1064 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1065 ASSERT_EQ(0, ret);
1066
1067 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1068 ASSERT_EQ(0, ret);
1069 syscall(__NR_getpid);
1070 }
1071
1072 /* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP,ign,SIGSYS)1073 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
1074 {
1075 long ret;
1076
1077 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1078 ASSERT_EQ(0, ret);
1079
1080 signal(SIGSYS, SIG_IGN);
1081
1082 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1083 ASSERT_EQ(0, ret);
1084 syscall(__NR_getpid);
1085 }
1086
1087 static siginfo_t TRAP_info;
1088 static volatile int TRAP_nr;
TRAP_action(int nr,siginfo_t * info,void * void_context)1089 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
1090 {
1091 memcpy(&TRAP_info, info, sizeof(TRAP_info));
1092 TRAP_nr = nr;
1093 }
1094
TEST_F(TRAP,handler)1095 TEST_F(TRAP, handler)
1096 {
1097 int ret, test;
1098 struct sigaction act;
1099 sigset_t mask;
1100
1101 memset(&act, 0, sizeof(act));
1102 sigemptyset(&mask);
1103 sigaddset(&mask, SIGSYS);
1104
1105 act.sa_sigaction = &TRAP_action;
1106 act.sa_flags = SA_SIGINFO;
1107 ret = sigaction(SIGSYS, &act, NULL);
1108 ASSERT_EQ(0, ret) {
1109 TH_LOG("sigaction failed");
1110 }
1111 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
1112 ASSERT_EQ(0, ret) {
1113 TH_LOG("sigprocmask failed");
1114 }
1115
1116 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1117 ASSERT_EQ(0, ret);
1118 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1119 ASSERT_EQ(0, ret);
1120 TRAP_nr = 0;
1121 memset(&TRAP_info, 0, sizeof(TRAP_info));
1122 /* Expect the registers to be rolled back. (nr = error) may vary
1123 * based on arch. */
1124 ret = syscall(__NR_getpid);
1125 /* Silence gcc warning about volatile. */
1126 test = TRAP_nr;
1127 EXPECT_EQ(SIGSYS, test);
1128 struct local_sigsys {
1129 void *_call_addr; /* calling user insn */
1130 int _syscall; /* triggering system call number */
1131 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1132 } *sigsys = (struct local_sigsys *)
1133 #ifdef si_syscall
1134 &(TRAP_info.si_call_addr);
1135 #else
1136 &TRAP_info.si_pid;
1137 #endif
1138 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1139 /* Make sure arch is non-zero. */
1140 EXPECT_NE(0, sigsys->_arch);
1141 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1142 }
1143
FIXTURE(precedence)1144 FIXTURE(precedence) {
1145 struct sock_fprog allow;
1146 struct sock_fprog log;
1147 struct sock_fprog trace;
1148 struct sock_fprog error;
1149 struct sock_fprog trap;
1150 struct sock_fprog kill;
1151 };
1152
FIXTURE_SETUP(precedence)1153 FIXTURE_SETUP(precedence)
1154 {
1155 struct sock_filter allow_insns[] = {
1156 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1157 };
1158 struct sock_filter log_insns[] = {
1159 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1160 offsetof(struct seccomp_data, nr)),
1161 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1162 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1163 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1164 };
1165 struct sock_filter trace_insns[] = {
1166 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1167 offsetof(struct seccomp_data, nr)),
1168 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1169 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1170 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1171 };
1172 struct sock_filter error_insns[] = {
1173 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1174 offsetof(struct seccomp_data, nr)),
1175 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1176 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1177 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1178 };
1179 struct sock_filter trap_insns[] = {
1180 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1181 offsetof(struct seccomp_data, nr)),
1182 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1183 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1184 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1185 };
1186 struct sock_filter kill_insns[] = {
1187 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1188 offsetof(struct seccomp_data, nr)),
1189 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1190 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1191 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1192 };
1193
1194 memset(self, 0, sizeof(*self));
1195 #define FILTER_ALLOC(_x) \
1196 self->_x.filter = malloc(sizeof(_x##_insns)); \
1197 ASSERT_NE(NULL, self->_x.filter); \
1198 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1199 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1200 FILTER_ALLOC(allow);
1201 FILTER_ALLOC(log);
1202 FILTER_ALLOC(trace);
1203 FILTER_ALLOC(error);
1204 FILTER_ALLOC(trap);
1205 FILTER_ALLOC(kill);
1206 }
1207
FIXTURE_TEARDOWN(precedence)1208 FIXTURE_TEARDOWN(precedence)
1209 {
1210 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1211 FILTER_FREE(allow);
1212 FILTER_FREE(log);
1213 FILTER_FREE(trace);
1214 FILTER_FREE(error);
1215 FILTER_FREE(trap);
1216 FILTER_FREE(kill);
1217 }
1218
TEST_F(precedence,allow_ok)1219 TEST_F(precedence, allow_ok)
1220 {
1221 pid_t parent, res = 0;
1222 long ret;
1223
1224 parent = getppid();
1225 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1226 ASSERT_EQ(0, ret);
1227
1228 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1229 ASSERT_EQ(0, ret);
1230 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1231 ASSERT_EQ(0, ret);
1232 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1233 ASSERT_EQ(0, ret);
1234 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1235 ASSERT_EQ(0, ret);
1236 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1237 ASSERT_EQ(0, ret);
1238 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1239 ASSERT_EQ(0, ret);
1240 /* Should work just fine. */
1241 res = syscall(__NR_getppid);
1242 EXPECT_EQ(parent, res);
1243 }
1244
TEST_F_SIGNAL(precedence,kill_is_highest,SIGSYS)1245 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1246 {
1247 pid_t parent, res = 0;
1248 long ret;
1249
1250 parent = getppid();
1251 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1252 ASSERT_EQ(0, ret);
1253
1254 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1255 ASSERT_EQ(0, ret);
1256 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1257 ASSERT_EQ(0, ret);
1258 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1259 ASSERT_EQ(0, ret);
1260 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1261 ASSERT_EQ(0, ret);
1262 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1263 ASSERT_EQ(0, ret);
1264 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1265 ASSERT_EQ(0, ret);
1266 /* Should work just fine. */
1267 res = syscall(__NR_getppid);
1268 EXPECT_EQ(parent, res);
1269 /* getpid() should never return. */
1270 res = syscall(__NR_getpid);
1271 EXPECT_EQ(0, res);
1272 }
1273
TEST_F_SIGNAL(precedence,kill_is_highest_in_any_order,SIGSYS)1274 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1275 {
1276 pid_t parent;
1277 long ret;
1278
1279 parent = getppid();
1280 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1281 ASSERT_EQ(0, ret);
1282
1283 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1284 ASSERT_EQ(0, ret);
1285 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1286 ASSERT_EQ(0, ret);
1287 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1288 ASSERT_EQ(0, ret);
1289 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1290 ASSERT_EQ(0, ret);
1291 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1292 ASSERT_EQ(0, ret);
1293 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1294 ASSERT_EQ(0, ret);
1295 /* Should work just fine. */
1296 EXPECT_EQ(parent, syscall(__NR_getppid));
1297 /* getpid() should never return. */
1298 EXPECT_EQ(0, syscall(__NR_getpid));
1299 }
1300
TEST_F_SIGNAL(precedence,trap_is_second,SIGSYS)1301 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1302 {
1303 pid_t parent;
1304 long ret;
1305
1306 parent = getppid();
1307 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1308 ASSERT_EQ(0, ret);
1309
1310 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1311 ASSERT_EQ(0, ret);
1312 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1313 ASSERT_EQ(0, ret);
1314 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1315 ASSERT_EQ(0, ret);
1316 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1317 ASSERT_EQ(0, ret);
1318 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1319 ASSERT_EQ(0, ret);
1320 /* Should work just fine. */
1321 EXPECT_EQ(parent, syscall(__NR_getppid));
1322 /* getpid() should never return. */
1323 EXPECT_EQ(0, syscall(__NR_getpid));
1324 }
1325
TEST_F_SIGNAL(precedence,trap_is_second_in_any_order,SIGSYS)1326 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1327 {
1328 pid_t parent;
1329 long ret;
1330
1331 parent = getppid();
1332 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1333 ASSERT_EQ(0, ret);
1334
1335 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1336 ASSERT_EQ(0, ret);
1337 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1338 ASSERT_EQ(0, ret);
1339 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1340 ASSERT_EQ(0, ret);
1341 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1342 ASSERT_EQ(0, ret);
1343 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1344 ASSERT_EQ(0, ret);
1345 /* Should work just fine. */
1346 EXPECT_EQ(parent, syscall(__NR_getppid));
1347 /* getpid() should never return. */
1348 EXPECT_EQ(0, syscall(__NR_getpid));
1349 }
1350
TEST_F(precedence,errno_is_third)1351 TEST_F(precedence, errno_is_third)
1352 {
1353 pid_t parent;
1354 long ret;
1355
1356 parent = getppid();
1357 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1358 ASSERT_EQ(0, ret);
1359
1360 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1361 ASSERT_EQ(0, ret);
1362 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1363 ASSERT_EQ(0, ret);
1364 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1365 ASSERT_EQ(0, ret);
1366 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1367 ASSERT_EQ(0, ret);
1368 /* Should work just fine. */
1369 EXPECT_EQ(parent, syscall(__NR_getppid));
1370 EXPECT_EQ(0, syscall(__NR_getpid));
1371 }
1372
TEST_F(precedence,errno_is_third_in_any_order)1373 TEST_F(precedence, errno_is_third_in_any_order)
1374 {
1375 pid_t parent;
1376 long ret;
1377
1378 parent = getppid();
1379 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1380 ASSERT_EQ(0, ret);
1381
1382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1383 ASSERT_EQ(0, ret);
1384 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1385 ASSERT_EQ(0, ret);
1386 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1387 ASSERT_EQ(0, ret);
1388 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1389 ASSERT_EQ(0, ret);
1390 /* Should work just fine. */
1391 EXPECT_EQ(parent, syscall(__NR_getppid));
1392 EXPECT_EQ(0, syscall(__NR_getpid));
1393 }
1394
TEST_F(precedence,trace_is_fourth)1395 TEST_F(precedence, trace_is_fourth)
1396 {
1397 pid_t parent;
1398 long ret;
1399
1400 parent = getppid();
1401 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1402 ASSERT_EQ(0, ret);
1403
1404 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1405 ASSERT_EQ(0, ret);
1406 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1407 ASSERT_EQ(0, ret);
1408 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1409 ASSERT_EQ(0, ret);
1410 /* Should work just fine. */
1411 EXPECT_EQ(parent, syscall(__NR_getppid));
1412 /* No ptracer */
1413 EXPECT_EQ(-1, syscall(__NR_getpid));
1414 }
1415
TEST_F(precedence,trace_is_fourth_in_any_order)1416 TEST_F(precedence, trace_is_fourth_in_any_order)
1417 {
1418 pid_t parent;
1419 long ret;
1420
1421 parent = getppid();
1422 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1423 ASSERT_EQ(0, ret);
1424
1425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1426 ASSERT_EQ(0, ret);
1427 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1428 ASSERT_EQ(0, ret);
1429 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1430 ASSERT_EQ(0, ret);
1431 /* Should work just fine. */
1432 EXPECT_EQ(parent, syscall(__NR_getppid));
1433 /* No ptracer */
1434 EXPECT_EQ(-1, syscall(__NR_getpid));
1435 }
1436
TEST_F(precedence,log_is_fifth)1437 TEST_F(precedence, log_is_fifth)
1438 {
1439 pid_t mypid, parent;
1440 long ret;
1441
1442 mypid = getpid();
1443 parent = getppid();
1444 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1445 ASSERT_EQ(0, ret);
1446
1447 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1448 ASSERT_EQ(0, ret);
1449 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1450 ASSERT_EQ(0, ret);
1451 /* Should work just fine. */
1452 EXPECT_EQ(parent, syscall(__NR_getppid));
1453 /* Should also work just fine */
1454 EXPECT_EQ(mypid, syscall(__NR_getpid));
1455 }
1456
TEST_F(precedence,log_is_fifth_in_any_order)1457 TEST_F(precedence, log_is_fifth_in_any_order)
1458 {
1459 pid_t mypid, parent;
1460 long ret;
1461
1462 mypid = getpid();
1463 parent = getppid();
1464 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1465 ASSERT_EQ(0, ret);
1466
1467 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1468 ASSERT_EQ(0, ret);
1469 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1470 ASSERT_EQ(0, ret);
1471 /* Should work just fine. */
1472 EXPECT_EQ(parent, syscall(__NR_getppid));
1473 /* Should also work just fine */
1474 EXPECT_EQ(mypid, syscall(__NR_getpid));
1475 }
1476
1477 #ifndef PTRACE_O_TRACESECCOMP
1478 #define PTRACE_O_TRACESECCOMP 0x00000080
1479 #endif
1480
1481 /* Catch the Ubuntu 12.04 value error. */
1482 #if PTRACE_EVENT_SECCOMP != 7
1483 #undef PTRACE_EVENT_SECCOMP
1484 #endif
1485
1486 #ifndef PTRACE_EVENT_SECCOMP
1487 #define PTRACE_EVENT_SECCOMP 7
1488 #endif
1489
1490 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1491 bool tracer_running;
tracer_stop(int sig)1492 void tracer_stop(int sig)
1493 {
1494 tracer_running = false;
1495 }
1496
1497 typedef void tracer_func_t(struct __test_metadata *_metadata,
1498 pid_t tracee, int status, void *args);
1499
start_tracer(struct __test_metadata * _metadata,int fd,pid_t tracee,tracer_func_t tracer_func,void * args,bool ptrace_syscall)1500 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1501 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1502 {
1503 int ret = -1;
1504 struct sigaction action = {
1505 .sa_handler = tracer_stop,
1506 };
1507
1508 /* Allow external shutdown. */
1509 tracer_running = true;
1510 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1511
1512 errno = 0;
1513 while (ret == -1 && errno != EINVAL)
1514 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1515 ASSERT_EQ(0, ret) {
1516 kill(tracee, SIGKILL);
1517 }
1518 /* Wait for attach stop */
1519 wait(NULL);
1520
1521 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1522 PTRACE_O_TRACESYSGOOD :
1523 PTRACE_O_TRACESECCOMP);
1524 ASSERT_EQ(0, ret) {
1525 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1526 kill(tracee, SIGKILL);
1527 }
1528 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1529 tracee, NULL, 0);
1530 ASSERT_EQ(0, ret);
1531
1532 /* Unblock the tracee */
1533 ASSERT_EQ(1, write(fd, "A", 1));
1534 ASSERT_EQ(0, close(fd));
1535
1536 /* Run until we're shut down. Must assert to stop execution. */
1537 while (tracer_running) {
1538 int status;
1539
1540 if (wait(&status) != tracee)
1541 continue;
1542 if (WIFSIGNALED(status) || WIFEXITED(status))
1543 /* Child is dead. Time to go. */
1544 return;
1545
1546 /* Check if this is a seccomp event. */
1547 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1548
1549 tracer_func(_metadata, tracee, status, args);
1550
1551 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1552 tracee, NULL, 0);
1553 ASSERT_EQ(0, ret);
1554 }
1555 /* Directly report the status of our test harness results. */
1556 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1557 }
1558
1559 /* Common tracer setup/teardown functions. */
cont_handler(int num)1560 void cont_handler(int num)
1561 { }
setup_trace_fixture(struct __test_metadata * _metadata,tracer_func_t func,void * args,bool ptrace_syscall)1562 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1563 tracer_func_t func, void *args, bool ptrace_syscall)
1564 {
1565 char sync;
1566 int pipefd[2];
1567 pid_t tracer_pid;
1568 pid_t tracee = getpid();
1569
1570 /* Setup a pipe for clean synchronization. */
1571 ASSERT_EQ(0, pipe(pipefd));
1572
1573 /* Fork a child which we'll promote to tracer */
1574 tracer_pid = fork();
1575 ASSERT_LE(0, tracer_pid);
1576 signal(SIGALRM, cont_handler);
1577 if (tracer_pid == 0) {
1578 close(pipefd[0]);
1579 start_tracer(_metadata, pipefd[1], tracee, func, args,
1580 ptrace_syscall);
1581 syscall(__NR_exit, 0);
1582 }
1583 close(pipefd[1]);
1584 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1585 read(pipefd[0], &sync, 1);
1586 close(pipefd[0]);
1587
1588 return tracer_pid;
1589 }
1590
teardown_trace_fixture(struct __test_metadata * _metadata,pid_t tracer)1591 void teardown_trace_fixture(struct __test_metadata *_metadata,
1592 pid_t tracer)
1593 {
1594 if (tracer) {
1595 int status;
1596 /*
1597 * Extract the exit code from the other process and
1598 * adopt it for ourselves in case its asserts failed.
1599 */
1600 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1601 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1602 if (WEXITSTATUS(status))
1603 _metadata->passed = 0;
1604 }
1605 }
1606
1607 /* "poke" tracer arguments and function. */
1608 struct tracer_args_poke_t {
1609 unsigned long poke_addr;
1610 };
1611
tracer_poke(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1612 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1613 void *args)
1614 {
1615 int ret;
1616 unsigned long msg;
1617 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1618
1619 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1620 EXPECT_EQ(0, ret);
1621 /* If this fails, don't try to recover. */
1622 ASSERT_EQ(0x1001, msg) {
1623 kill(tracee, SIGKILL);
1624 }
1625 /*
1626 * Poke in the message.
1627 * Registers are not touched to try to keep this relatively arch
1628 * agnostic.
1629 */
1630 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1631 EXPECT_EQ(0, ret);
1632 }
1633
FIXTURE(TRACE_poke)1634 FIXTURE(TRACE_poke) {
1635 struct sock_fprog prog;
1636 pid_t tracer;
1637 long poked;
1638 struct tracer_args_poke_t tracer_args;
1639 };
1640
FIXTURE_SETUP(TRACE_poke)1641 FIXTURE_SETUP(TRACE_poke)
1642 {
1643 struct sock_filter filter[] = {
1644 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1645 offsetof(struct seccomp_data, nr)),
1646 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1647 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1648 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1649 };
1650
1651 self->poked = 0;
1652 memset(&self->prog, 0, sizeof(self->prog));
1653 self->prog.filter = malloc(sizeof(filter));
1654 ASSERT_NE(NULL, self->prog.filter);
1655 memcpy(self->prog.filter, filter, sizeof(filter));
1656 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1657
1658 /* Set up tracer args. */
1659 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1660
1661 /* Launch tracer. */
1662 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1663 &self->tracer_args, false);
1664 }
1665
FIXTURE_TEARDOWN(TRACE_poke)1666 FIXTURE_TEARDOWN(TRACE_poke)
1667 {
1668 teardown_trace_fixture(_metadata, self->tracer);
1669 if (self->prog.filter)
1670 free(self->prog.filter);
1671 }
1672
TEST_F(TRACE_poke,read_has_side_effects)1673 TEST_F(TRACE_poke, read_has_side_effects)
1674 {
1675 ssize_t ret;
1676
1677 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1678 ASSERT_EQ(0, ret);
1679
1680 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1681 ASSERT_EQ(0, ret);
1682
1683 EXPECT_EQ(0, self->poked);
1684 ret = read(-1, NULL, 0);
1685 EXPECT_EQ(-1, ret);
1686 EXPECT_EQ(0x1001, self->poked);
1687 }
1688
TEST_F(TRACE_poke,getpid_runs_normally)1689 TEST_F(TRACE_poke, getpid_runs_normally)
1690 {
1691 long ret;
1692
1693 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1694 ASSERT_EQ(0, ret);
1695
1696 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1697 ASSERT_EQ(0, ret);
1698
1699 EXPECT_EQ(0, self->poked);
1700 EXPECT_NE(0, syscall(__NR_getpid));
1701 EXPECT_EQ(0, self->poked);
1702 }
1703
1704 #if defined(__x86_64__)
1705 # define ARCH_REGS struct user_regs_struct
1706 # define SYSCALL_NUM(_regs) (_regs).orig_rax
1707 # define SYSCALL_RET(_regs) (_regs).rax
1708 #elif defined(__i386__)
1709 # define ARCH_REGS struct user_regs_struct
1710 # define SYSCALL_NUM(_regs) (_regs).orig_eax
1711 # define SYSCALL_RET(_regs) (_regs).eax
1712 #elif defined(__arm__)
1713 # define ARCH_REGS struct pt_regs
1714 # define SYSCALL_NUM(_regs) (_regs).ARM_r7
1715 # ifndef PTRACE_SET_SYSCALL
1716 # define PTRACE_SET_SYSCALL 23
1717 # endif
1718 # define SYSCALL_NUM_SET(_regs, _nr) \
1719 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
1720 # define SYSCALL_RET(_regs) (_regs).ARM_r0
1721 #elif defined(__aarch64__)
1722 # define ARCH_REGS struct user_pt_regs
1723 # define SYSCALL_NUM(_regs) (_regs).regs[8]
1724 # ifndef NT_ARM_SYSTEM_CALL
1725 # define NT_ARM_SYSTEM_CALL 0x404
1726 # endif
1727 # define SYSCALL_NUM_SET(_regs, _nr) \
1728 do { \
1729 struct iovec __v; \
1730 typeof(_nr) __nr = (_nr); \
1731 __v.iov_base = &__nr; \
1732 __v.iov_len = sizeof(__nr); \
1733 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \
1734 NT_ARM_SYSTEM_CALL, &__v)); \
1735 } while (0)
1736 # define SYSCALL_RET(_regs) (_regs).regs[0]
1737 #elif defined(__riscv) && __riscv_xlen == 64
1738 # define ARCH_REGS struct user_regs_struct
1739 # define SYSCALL_NUM(_regs) (_regs).a7
1740 # define SYSCALL_RET(_regs) (_regs).a0
1741 #elif defined(__csky__)
1742 # define ARCH_REGS struct pt_regs
1743 # if defined(__CSKYABIV2__)
1744 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1745 # else
1746 # define SYSCALL_NUM(_regs) (_regs).regs[9]
1747 # endif
1748 # define SYSCALL_RET(_regs) (_regs).a0
1749 #elif defined(__hppa__)
1750 # define ARCH_REGS struct user_regs_struct
1751 # define SYSCALL_NUM(_regs) (_regs).gr[20]
1752 # define SYSCALL_RET(_regs) (_regs).gr[28]
1753 #elif defined(__powerpc__)
1754 # define ARCH_REGS struct pt_regs
1755 # define SYSCALL_NUM(_regs) (_regs).gpr[0]
1756 # define SYSCALL_RET(_regs) (_regs).gpr[3]
1757 # define SYSCALL_RET_SET(_regs, _val) \
1758 do { \
1759 typeof(_val) _result = (_val); \
1760 if ((_regs.trap & 0xfff0) == 0x3000) { \
1761 /* \
1762 * scv 0 system call uses -ve result \
1763 * for error, so no need to adjust. \
1764 */ \
1765 SYSCALL_RET(_regs) = _result; \
1766 } else { \
1767 /* \
1768 * A syscall error is signaled by the \
1769 * CR0 SO bit and the code is stored as \
1770 * a positive value. \
1771 */ \
1772 if (_result < 0) { \
1773 SYSCALL_RET(_regs) = -_result; \
1774 (_regs).ccr |= 0x10000000; \
1775 } else { \
1776 SYSCALL_RET(_regs) = _result; \
1777 (_regs).ccr &= ~0x10000000; \
1778 } \
1779 } \
1780 } while (0)
1781 # define SYSCALL_RET_SET_ON_PTRACE_EXIT
1782 #elif defined(__s390__)
1783 # define ARCH_REGS s390_regs
1784 # define SYSCALL_NUM(_regs) (_regs).gprs[2]
1785 # define SYSCALL_RET_SET(_regs, _val) \
1786 TH_LOG("Can't modify syscall return on this architecture")
1787 #elif defined(__mips__)
1788 # include <asm/unistd_nr_n32.h>
1789 # include <asm/unistd_nr_n64.h>
1790 # include <asm/unistd_nr_o32.h>
1791 # define ARCH_REGS struct pt_regs
1792 # define SYSCALL_NUM(_regs) \
1793 ({ \
1794 typeof((_regs).regs[2]) _nr; \
1795 if ((_regs).regs[2] == __NR_O32_Linux) \
1796 _nr = (_regs).regs[4]; \
1797 else \
1798 _nr = (_regs).regs[2]; \
1799 _nr; \
1800 })
1801 # define SYSCALL_NUM_SET(_regs, _nr) \
1802 do { \
1803 if ((_regs).regs[2] == __NR_O32_Linux) \
1804 (_regs).regs[4] = _nr; \
1805 else \
1806 (_regs).regs[2] = _nr; \
1807 } while (0)
1808 # define SYSCALL_RET_SET(_regs, _val) \
1809 TH_LOG("Can't modify syscall return on this architecture")
1810 #elif defined(__xtensa__)
1811 # define ARCH_REGS struct user_pt_regs
1812 # define SYSCALL_NUM(_regs) (_regs).syscall
1813 /*
1814 * On xtensa syscall return value is in the register
1815 * a2 of the current window which is not fixed.
1816 */
1817 #define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2]
1818 #elif defined(__sh__)
1819 # define ARCH_REGS struct pt_regs
1820 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1821 # define SYSCALL_RET(_regs) (_regs).regs[0]
1822 #else
1823 # error "Do not know how to find your architecture's registers and syscalls"
1824 #endif
1825
1826 /*
1827 * Most architectures can change the syscall by just updating the
1828 * associated register. This is the default if not defined above.
1829 */
1830 #ifndef SYSCALL_NUM_SET
1831 # define SYSCALL_NUM_SET(_regs, _nr) \
1832 do { \
1833 SYSCALL_NUM(_regs) = (_nr); \
1834 } while (0)
1835 #endif
1836 /*
1837 * Most architectures can change the syscall return value by just
1838 * writing to the SYSCALL_RET register. This is the default if not
1839 * defined above. If an architecture cannot set the return value
1840 * (for example when the syscall and return value register is
1841 * shared), report it with TH_LOG() in an arch-specific definition
1842 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
1843 */
1844 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
1845 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
1846 #endif
1847 #ifndef SYSCALL_RET_SET
1848 # define SYSCALL_RET_SET(_regs, _val) \
1849 do { \
1850 SYSCALL_RET(_regs) = (_val); \
1851 } while (0)
1852 #endif
1853
1854 /* When the syscall return can't be changed, stub out the tests for it. */
1855 #ifndef SYSCALL_RET
1856 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1857 #else
1858 # define EXPECT_SYSCALL_RETURN(val, action) \
1859 do { \
1860 errno = 0; \
1861 if (val < 0) { \
1862 EXPECT_EQ(-1, action); \
1863 EXPECT_EQ(-(val), errno); \
1864 } else { \
1865 EXPECT_EQ(val, action); \
1866 } \
1867 } while (0)
1868 #endif
1869
1870 /*
1871 * Some architectures (e.g. powerpc) can only set syscall
1872 * return values on syscall exit during ptrace.
1873 */
1874 const bool ptrace_entry_set_syscall_nr = true;
1875 const bool ptrace_entry_set_syscall_ret =
1876 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
1877 true;
1878 #else
1879 false;
1880 #endif
1881
1882 /*
1883 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1884 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1885 */
1886 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1887 # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
1888 # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
1889 #else
1890 # define ARCH_GETREGS(_regs) ({ \
1891 struct iovec __v; \
1892 __v.iov_base = &(_regs); \
1893 __v.iov_len = sizeof(_regs); \
1894 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \
1895 })
1896 # define ARCH_SETREGS(_regs) ({ \
1897 struct iovec __v; \
1898 __v.iov_base = &(_regs); \
1899 __v.iov_len = sizeof(_regs); \
1900 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \
1901 })
1902 #endif
1903
1904 /* Architecture-specific syscall fetching routine. */
get_syscall(struct __test_metadata * _metadata,pid_t tracee)1905 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1906 {
1907 ARCH_REGS regs;
1908
1909 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1910 return -1;
1911 }
1912
1913 return SYSCALL_NUM(regs);
1914 }
1915
1916 /* Architecture-specific syscall changing routine. */
__change_syscall(struct __test_metadata * _metadata,pid_t tracee,long * syscall,long * ret)1917 void __change_syscall(struct __test_metadata *_metadata,
1918 pid_t tracee, long *syscall, long *ret)
1919 {
1920 ARCH_REGS orig, regs;
1921
1922 /* Do not get/set registers if we have nothing to do. */
1923 if (!syscall && !ret)
1924 return;
1925
1926 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1927 return;
1928 }
1929 orig = regs;
1930
1931 if (syscall)
1932 SYSCALL_NUM_SET(regs, *syscall);
1933
1934 if (ret)
1935 SYSCALL_RET_SET(regs, *ret);
1936
1937 /* Flush any register changes made. */
1938 if (memcmp(&orig, ®s, sizeof(orig)) != 0)
1939 EXPECT_EQ(0, ARCH_SETREGS(regs));
1940 }
1941
1942 /* Change only syscall number. */
change_syscall_nr(struct __test_metadata * _metadata,pid_t tracee,long syscall)1943 void change_syscall_nr(struct __test_metadata *_metadata,
1944 pid_t tracee, long syscall)
1945 {
1946 __change_syscall(_metadata, tracee, &syscall, NULL);
1947 }
1948
1949 /* Change syscall return value (and set syscall number to -1). */
change_syscall_ret(struct __test_metadata * _metadata,pid_t tracee,long ret)1950 void change_syscall_ret(struct __test_metadata *_metadata,
1951 pid_t tracee, long ret)
1952 {
1953 long syscall = -1;
1954
1955 __change_syscall(_metadata, tracee, &syscall, &ret);
1956 }
1957
tracer_seccomp(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1958 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
1959 int status, void *args)
1960 {
1961 int ret;
1962 unsigned long msg;
1963
1964 /* Make sure we got the right message. */
1965 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1966 EXPECT_EQ(0, ret);
1967
1968 /* Validate and take action on expected syscalls. */
1969 switch (msg) {
1970 case 0x1002:
1971 /* change getpid to getppid. */
1972 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1973 change_syscall_nr(_metadata, tracee, __NR_getppid);
1974 break;
1975 case 0x1003:
1976 /* skip gettid with valid return code. */
1977 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1978 change_syscall_ret(_metadata, tracee, 45000);
1979 break;
1980 case 0x1004:
1981 /* skip openat with error. */
1982 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
1983 change_syscall_ret(_metadata, tracee, -ESRCH);
1984 break;
1985 case 0x1005:
1986 /* do nothing (allow getppid) */
1987 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1988 break;
1989 default:
1990 EXPECT_EQ(0, msg) {
1991 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1992 kill(tracee, SIGKILL);
1993 }
1994 }
1995
1996 }
1997
FIXTURE(TRACE_syscall)1998 FIXTURE(TRACE_syscall) {
1999 struct sock_fprog prog;
2000 pid_t tracer, mytid, mypid, parent;
2001 long syscall_nr;
2002 };
2003
tracer_ptrace(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)2004 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
2005 int status, void *args)
2006 {
2007 int ret;
2008 unsigned long msg;
2009 static bool entry;
2010 long syscall_nr_val, syscall_ret_val;
2011 long *syscall_nr = NULL, *syscall_ret = NULL;
2012 FIXTURE_DATA(TRACE_syscall) *self = args;
2013
2014 /*
2015 * The traditional way to tell PTRACE_SYSCALL entry/exit
2016 * is by counting.
2017 */
2018 entry = !entry;
2019
2020 /* Make sure we got an appropriate message. */
2021 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
2022 EXPECT_EQ(0, ret);
2023 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
2024 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
2025
2026 /*
2027 * Some architectures only support setting return values during
2028 * syscall exit under ptrace, and on exit the syscall number may
2029 * no longer be available. Therefore, save the initial sycall
2030 * number here, so it can be examined during both entry and exit
2031 * phases.
2032 */
2033 if (entry)
2034 self->syscall_nr = get_syscall(_metadata, tracee);
2035
2036 /*
2037 * Depending on the architecture's syscall setting abilities, we
2038 * pick which things to set during this phase (entry or exit).
2039 */
2040 if (entry == ptrace_entry_set_syscall_nr)
2041 syscall_nr = &syscall_nr_val;
2042 if (entry == ptrace_entry_set_syscall_ret)
2043 syscall_ret = &syscall_ret_val;
2044
2045 /* Now handle the actual rewriting cases. */
2046 switch (self->syscall_nr) {
2047 case __NR_getpid:
2048 syscall_nr_val = __NR_getppid;
2049 /* Never change syscall return for this case. */
2050 syscall_ret = NULL;
2051 break;
2052 case __NR_gettid:
2053 syscall_nr_val = -1;
2054 syscall_ret_val = 45000;
2055 break;
2056 case __NR_openat:
2057 syscall_nr_val = -1;
2058 syscall_ret_val = -ESRCH;
2059 break;
2060 default:
2061 /* Unhandled, do nothing. */
2062 return;
2063 }
2064
2065 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
2066 }
2067
FIXTURE_VARIANT(TRACE_syscall)2068 FIXTURE_VARIANT(TRACE_syscall) {
2069 /*
2070 * All of the SECCOMP_RET_TRACE behaviors can be tested with either
2071 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL.
2072 * This indicates if we should use SECCOMP_RET_TRACE (false), or
2073 * ptrace (true).
2074 */
2075 bool use_ptrace;
2076 };
2077
FIXTURE_VARIANT_ADD(TRACE_syscall,ptrace)2078 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) {
2079 .use_ptrace = true,
2080 };
2081
FIXTURE_VARIANT_ADD(TRACE_syscall,seccomp)2082 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) {
2083 .use_ptrace = false,
2084 };
2085
FIXTURE_SETUP(TRACE_syscall)2086 FIXTURE_SETUP(TRACE_syscall)
2087 {
2088 struct sock_filter filter[] = {
2089 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2090 offsetof(struct seccomp_data, nr)),
2091 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2092 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
2093 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
2094 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
2095 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
2096 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
2097 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2098 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
2099 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2100 };
2101 struct sock_fprog prog = {
2102 .len = (unsigned short)ARRAY_SIZE(filter),
2103 .filter = filter,
2104 };
2105 long ret;
2106
2107 /* Prepare some testable syscall results. */
2108 self->mytid = syscall(__NR_gettid);
2109 ASSERT_GT(self->mytid, 0);
2110 ASSERT_NE(self->mytid, 1) {
2111 TH_LOG("Running this test as init is not supported. :)");
2112 }
2113
2114 self->mypid = getpid();
2115 ASSERT_GT(self->mypid, 0);
2116 ASSERT_EQ(self->mytid, self->mypid);
2117
2118 self->parent = getppid();
2119 ASSERT_GT(self->parent, 0);
2120 ASSERT_NE(self->parent, self->mypid);
2121
2122 /* Launch tracer. */
2123 self->tracer = setup_trace_fixture(_metadata,
2124 variant->use_ptrace ? tracer_ptrace
2125 : tracer_seccomp,
2126 self, variant->use_ptrace);
2127
2128 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2129 ASSERT_EQ(0, ret);
2130
2131 if (variant->use_ptrace)
2132 return;
2133
2134 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2135 ASSERT_EQ(0, ret);
2136 }
2137
FIXTURE_TEARDOWN(TRACE_syscall)2138 FIXTURE_TEARDOWN(TRACE_syscall)
2139 {
2140 teardown_trace_fixture(_metadata, self->tracer);
2141 }
2142
TEST(negative_ENOSYS)2143 TEST(negative_ENOSYS)
2144 {
2145 /*
2146 * There should be no difference between an "internal" skip
2147 * and userspace asking for syscall "-1".
2148 */
2149 errno = 0;
2150 EXPECT_EQ(-1, syscall(-1));
2151 EXPECT_EQ(errno, ENOSYS);
2152 /* And no difference for "still not valid but not -1". */
2153 errno = 0;
2154 EXPECT_EQ(-1, syscall(-101));
2155 EXPECT_EQ(errno, ENOSYS);
2156 }
2157
TEST_F(TRACE_syscall,negative_ENOSYS)2158 TEST_F(TRACE_syscall, negative_ENOSYS)
2159 {
2160 negative_ENOSYS(_metadata);
2161 }
2162
TEST_F(TRACE_syscall,syscall_allowed)2163 TEST_F(TRACE_syscall, syscall_allowed)
2164 {
2165 /* getppid works as expected (no changes). */
2166 EXPECT_EQ(self->parent, syscall(__NR_getppid));
2167 EXPECT_NE(self->mypid, syscall(__NR_getppid));
2168 }
2169
TEST_F(TRACE_syscall,syscall_redirected)2170 TEST_F(TRACE_syscall, syscall_redirected)
2171 {
2172 /* getpid has been redirected to getppid as expected. */
2173 EXPECT_EQ(self->parent, syscall(__NR_getpid));
2174 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2175 }
2176
TEST_F(TRACE_syscall,syscall_errno)2177 TEST_F(TRACE_syscall, syscall_errno)
2178 {
2179 /* Tracer should skip the open syscall, resulting in ESRCH. */
2180 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
2181 }
2182
TEST_F(TRACE_syscall,syscall_faked)2183 TEST_F(TRACE_syscall, syscall_faked)
2184 {
2185 /* Tracer skips the gettid syscall and store altered return value. */
2186 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
2187 }
2188
TEST_F(TRACE_syscall,skip_after)2189 TEST_F(TRACE_syscall, skip_after)
2190 {
2191 struct sock_filter filter[] = {
2192 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2193 offsetof(struct seccomp_data, nr)),
2194 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2195 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2196 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2197 };
2198 struct sock_fprog prog = {
2199 .len = (unsigned short)ARRAY_SIZE(filter),
2200 .filter = filter,
2201 };
2202 long ret;
2203
2204 /* Install additional "errno on getppid" filter. */
2205 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2206 ASSERT_EQ(0, ret);
2207
2208 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2209 errno = 0;
2210 EXPECT_EQ(-1, syscall(__NR_getpid));
2211 EXPECT_EQ(EPERM, errno);
2212 }
2213
TEST_F_SIGNAL(TRACE_syscall,kill_after,SIGSYS)2214 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS)
2215 {
2216 struct sock_filter filter[] = {
2217 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2218 offsetof(struct seccomp_data, nr)),
2219 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2220 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2221 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2222 };
2223 struct sock_fprog prog = {
2224 .len = (unsigned short)ARRAY_SIZE(filter),
2225 .filter = filter,
2226 };
2227 long ret;
2228
2229 /* Install additional "death on getppid" filter. */
2230 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2231 ASSERT_EQ(0, ret);
2232
2233 /* Tracer will redirect getpid to getppid, and we should die. */
2234 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2235 }
2236
TEST(seccomp_syscall)2237 TEST(seccomp_syscall)
2238 {
2239 struct sock_filter filter[] = {
2240 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2241 };
2242 struct sock_fprog prog = {
2243 .len = (unsigned short)ARRAY_SIZE(filter),
2244 .filter = filter,
2245 };
2246 long ret;
2247
2248 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2249 ASSERT_EQ(0, ret) {
2250 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2251 }
2252
2253 /* Reject insane operation. */
2254 ret = seccomp(-1, 0, &prog);
2255 ASSERT_NE(ENOSYS, errno) {
2256 TH_LOG("Kernel does not support seccomp syscall!");
2257 }
2258 EXPECT_EQ(EINVAL, errno) {
2259 TH_LOG("Did not reject crazy op value!");
2260 }
2261
2262 /* Reject strict with flags or pointer. */
2263 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2264 EXPECT_EQ(EINVAL, errno) {
2265 TH_LOG("Did not reject mode strict with flags!");
2266 }
2267 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2268 EXPECT_EQ(EINVAL, errno) {
2269 TH_LOG("Did not reject mode strict with uargs!");
2270 }
2271
2272 /* Reject insane args for filter. */
2273 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2274 EXPECT_EQ(EINVAL, errno) {
2275 TH_LOG("Did not reject crazy filter flags!");
2276 }
2277 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2278 EXPECT_EQ(EFAULT, errno) {
2279 TH_LOG("Did not reject NULL filter!");
2280 }
2281
2282 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2283 EXPECT_EQ(0, errno) {
2284 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2285 strerror(errno));
2286 }
2287 }
2288
TEST(seccomp_syscall_mode_lock)2289 TEST(seccomp_syscall_mode_lock)
2290 {
2291 struct sock_filter filter[] = {
2292 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2293 };
2294 struct sock_fprog prog = {
2295 .len = (unsigned short)ARRAY_SIZE(filter),
2296 .filter = filter,
2297 };
2298 long ret;
2299
2300 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2301 ASSERT_EQ(0, ret) {
2302 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2303 }
2304
2305 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2306 ASSERT_NE(ENOSYS, errno) {
2307 TH_LOG("Kernel does not support seccomp syscall!");
2308 }
2309 EXPECT_EQ(0, ret) {
2310 TH_LOG("Could not install filter!");
2311 }
2312
2313 /* Make sure neither entry point will switch to strict. */
2314 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2315 EXPECT_EQ(EINVAL, errno) {
2316 TH_LOG("Switched to mode strict!");
2317 }
2318
2319 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2320 EXPECT_EQ(EINVAL, errno) {
2321 TH_LOG("Switched to mode strict!");
2322 }
2323 }
2324
2325 /*
2326 * Test detection of known and unknown filter flags. Userspace needs to be able
2327 * to check if a filter flag is supported by the current kernel and a good way
2328 * of doing that is by attempting to enter filter mode, with the flag bit in
2329 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2330 * that the flag is valid and EINVAL indicates that the flag is invalid.
2331 */
TEST(detect_seccomp_filter_flags)2332 TEST(detect_seccomp_filter_flags)
2333 {
2334 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2335 SECCOMP_FILTER_FLAG_LOG,
2336 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2337 SECCOMP_FILTER_FLAG_NEW_LISTENER,
2338 SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
2339 unsigned int exclusive[] = {
2340 SECCOMP_FILTER_FLAG_TSYNC,
2341 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2342 unsigned int flag, all_flags, exclusive_mask;
2343 int i;
2344 long ret;
2345
2346 /* Test detection of individual known-good filter flags */
2347 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2348 int bits = 0;
2349
2350 flag = flags[i];
2351 /* Make sure the flag is a single bit! */
2352 while (flag) {
2353 if (flag & 0x1)
2354 bits ++;
2355 flag >>= 1;
2356 }
2357 ASSERT_EQ(1, bits);
2358 flag = flags[i];
2359
2360 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2361 ASSERT_NE(ENOSYS, errno) {
2362 TH_LOG("Kernel does not support seccomp syscall!");
2363 }
2364 EXPECT_EQ(-1, ret);
2365 EXPECT_EQ(EFAULT, errno) {
2366 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2367 flag);
2368 }
2369
2370 all_flags |= flag;
2371 }
2372
2373 /*
2374 * Test detection of all known-good filter flags combined. But
2375 * for the exclusive flags we need to mask them out and try them
2376 * individually for the "all flags" testing.
2377 */
2378 exclusive_mask = 0;
2379 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2380 exclusive_mask |= exclusive[i];
2381 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2382 flag = all_flags & ~exclusive_mask;
2383 flag |= exclusive[i];
2384
2385 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2386 EXPECT_EQ(-1, ret);
2387 EXPECT_EQ(EFAULT, errno) {
2388 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2389 flag);
2390 }
2391 }
2392
2393 /* Test detection of an unknown filter flags, without exclusives. */
2394 flag = -1;
2395 flag &= ~exclusive_mask;
2396 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2397 EXPECT_EQ(-1, ret);
2398 EXPECT_EQ(EINVAL, errno) {
2399 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2400 flag);
2401 }
2402
2403 /*
2404 * Test detection of an unknown filter flag that may simply need to be
2405 * added to this test
2406 */
2407 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2408 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2409 EXPECT_EQ(-1, ret);
2410 EXPECT_EQ(EINVAL, errno) {
2411 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
2412 flag);
2413 }
2414 }
2415
TEST(TSYNC_first)2416 TEST(TSYNC_first)
2417 {
2418 struct sock_filter filter[] = {
2419 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2420 };
2421 struct sock_fprog prog = {
2422 .len = (unsigned short)ARRAY_SIZE(filter),
2423 .filter = filter,
2424 };
2425 long ret;
2426
2427 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2428 ASSERT_EQ(0, ret) {
2429 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2430 }
2431
2432 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2433 &prog);
2434 ASSERT_NE(ENOSYS, errno) {
2435 TH_LOG("Kernel does not support seccomp syscall!");
2436 }
2437 EXPECT_EQ(0, ret) {
2438 TH_LOG("Could not install initial filter with TSYNC!");
2439 }
2440 }
2441
2442 #define TSYNC_SIBLINGS 2
2443 struct tsync_sibling {
2444 pthread_t tid;
2445 pid_t system_tid;
2446 sem_t *started;
2447 pthread_cond_t *cond;
2448 pthread_mutex_t *mutex;
2449 int diverge;
2450 int num_waits;
2451 struct sock_fprog *prog;
2452 struct __test_metadata *metadata;
2453 };
2454
2455 /*
2456 * To avoid joining joined threads (which is not allowed by Bionic),
2457 * make sure we both successfully join and clear the tid to skip a
2458 * later join attempt during fixture teardown. Any remaining threads
2459 * will be directly killed during teardown.
2460 */
2461 #define PTHREAD_JOIN(tid, status) \
2462 do { \
2463 int _rc = pthread_join(tid, status); \
2464 if (_rc) { \
2465 TH_LOG("pthread_join of tid %u failed: %d\n", \
2466 (unsigned int)tid, _rc); \
2467 } else { \
2468 tid = 0; \
2469 } \
2470 } while (0)
2471
FIXTURE(TSYNC)2472 FIXTURE(TSYNC) {
2473 struct sock_fprog root_prog, apply_prog;
2474 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2475 sem_t started;
2476 pthread_cond_t cond;
2477 pthread_mutex_t mutex;
2478 int sibling_count;
2479 };
2480
FIXTURE_SETUP(TSYNC)2481 FIXTURE_SETUP(TSYNC)
2482 {
2483 struct sock_filter root_filter[] = {
2484 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2485 };
2486 struct sock_filter apply_filter[] = {
2487 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2488 offsetof(struct seccomp_data, nr)),
2489 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2490 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2491 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2492 };
2493
2494 memset(&self->root_prog, 0, sizeof(self->root_prog));
2495 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2496 memset(&self->sibling, 0, sizeof(self->sibling));
2497 self->root_prog.filter = malloc(sizeof(root_filter));
2498 ASSERT_NE(NULL, self->root_prog.filter);
2499 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2500 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2501
2502 self->apply_prog.filter = malloc(sizeof(apply_filter));
2503 ASSERT_NE(NULL, self->apply_prog.filter);
2504 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2505 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2506
2507 self->sibling_count = 0;
2508 pthread_mutex_init(&self->mutex, NULL);
2509 pthread_cond_init(&self->cond, NULL);
2510 sem_init(&self->started, 0, 0);
2511 self->sibling[0].tid = 0;
2512 self->sibling[0].cond = &self->cond;
2513 self->sibling[0].started = &self->started;
2514 self->sibling[0].mutex = &self->mutex;
2515 self->sibling[0].diverge = 0;
2516 self->sibling[0].num_waits = 1;
2517 self->sibling[0].prog = &self->root_prog;
2518 self->sibling[0].metadata = _metadata;
2519 self->sibling[1].tid = 0;
2520 self->sibling[1].cond = &self->cond;
2521 self->sibling[1].started = &self->started;
2522 self->sibling[1].mutex = &self->mutex;
2523 self->sibling[1].diverge = 0;
2524 self->sibling[1].prog = &self->root_prog;
2525 self->sibling[1].num_waits = 1;
2526 self->sibling[1].metadata = _metadata;
2527 }
2528
FIXTURE_TEARDOWN(TSYNC)2529 FIXTURE_TEARDOWN(TSYNC)
2530 {
2531 int sib = 0;
2532
2533 if (self->root_prog.filter)
2534 free(self->root_prog.filter);
2535 if (self->apply_prog.filter)
2536 free(self->apply_prog.filter);
2537
2538 for ( ; sib < self->sibling_count; ++sib) {
2539 struct tsync_sibling *s = &self->sibling[sib];
2540
2541 if (!s->tid)
2542 continue;
2543 /*
2544 * If a thread is still running, it may be stuck, so hit
2545 * it over the head really hard.
2546 */
2547 pthread_kill(s->tid, 9);
2548 }
2549 pthread_mutex_destroy(&self->mutex);
2550 pthread_cond_destroy(&self->cond);
2551 sem_destroy(&self->started);
2552 }
2553
tsync_sibling(void * data)2554 void *tsync_sibling(void *data)
2555 {
2556 long ret = 0;
2557 struct tsync_sibling *me = data;
2558
2559 me->system_tid = syscall(__NR_gettid);
2560
2561 pthread_mutex_lock(me->mutex);
2562 if (me->diverge) {
2563 /* Just re-apply the root prog to fork the tree */
2564 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2565 me->prog, 0, 0);
2566 }
2567 sem_post(me->started);
2568 /* Return outside of started so parent notices failures. */
2569 if (ret) {
2570 pthread_mutex_unlock(me->mutex);
2571 return (void *)SIBLING_EXIT_FAILURE;
2572 }
2573 do {
2574 pthread_cond_wait(me->cond, me->mutex);
2575 me->num_waits = me->num_waits - 1;
2576 } while (me->num_waits);
2577 pthread_mutex_unlock(me->mutex);
2578
2579 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2580 if (!ret)
2581 return (void *)SIBLING_EXIT_NEWPRIVS;
2582 read(0, NULL, 0);
2583 return (void *)SIBLING_EXIT_UNKILLED;
2584 }
2585
tsync_start_sibling(struct tsync_sibling * sibling)2586 void tsync_start_sibling(struct tsync_sibling *sibling)
2587 {
2588 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2589 }
2590
TEST_F(TSYNC,siblings_fail_prctl)2591 TEST_F(TSYNC, siblings_fail_prctl)
2592 {
2593 long ret;
2594 void *status;
2595 struct sock_filter filter[] = {
2596 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2597 offsetof(struct seccomp_data, nr)),
2598 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2599 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2600 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2601 };
2602 struct sock_fprog prog = {
2603 .len = (unsigned short)ARRAY_SIZE(filter),
2604 .filter = filter,
2605 };
2606
2607 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2608 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2609 }
2610
2611 /* Check prctl failure detection by requesting sib 0 diverge. */
2612 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2613 ASSERT_NE(ENOSYS, errno) {
2614 TH_LOG("Kernel does not support seccomp syscall!");
2615 }
2616 ASSERT_EQ(0, ret) {
2617 TH_LOG("setting filter failed");
2618 }
2619
2620 self->sibling[0].diverge = 1;
2621 tsync_start_sibling(&self->sibling[0]);
2622 tsync_start_sibling(&self->sibling[1]);
2623
2624 while (self->sibling_count < TSYNC_SIBLINGS) {
2625 sem_wait(&self->started);
2626 self->sibling_count++;
2627 }
2628
2629 /* Signal the threads to clean up*/
2630 pthread_mutex_lock(&self->mutex);
2631 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2632 TH_LOG("cond broadcast non-zero");
2633 }
2634 pthread_mutex_unlock(&self->mutex);
2635
2636 /* Ensure diverging sibling failed to call prctl. */
2637 PTHREAD_JOIN(self->sibling[0].tid, &status);
2638 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2639 PTHREAD_JOIN(self->sibling[1].tid, &status);
2640 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2641 }
2642
TEST_F(TSYNC,two_siblings_with_ancestor)2643 TEST_F(TSYNC, two_siblings_with_ancestor)
2644 {
2645 long ret;
2646 void *status;
2647
2648 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2649 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2650 }
2651
2652 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2653 ASSERT_NE(ENOSYS, errno) {
2654 TH_LOG("Kernel does not support seccomp syscall!");
2655 }
2656 ASSERT_EQ(0, ret) {
2657 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2658 }
2659 tsync_start_sibling(&self->sibling[0]);
2660 tsync_start_sibling(&self->sibling[1]);
2661
2662 while (self->sibling_count < TSYNC_SIBLINGS) {
2663 sem_wait(&self->started);
2664 self->sibling_count++;
2665 }
2666
2667 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2668 &self->apply_prog);
2669 ASSERT_EQ(0, ret) {
2670 TH_LOG("Could install filter on all threads!");
2671 }
2672 /* Tell the siblings to test the policy */
2673 pthread_mutex_lock(&self->mutex);
2674 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2675 TH_LOG("cond broadcast non-zero");
2676 }
2677 pthread_mutex_unlock(&self->mutex);
2678 /* Ensure they are both killed and don't exit cleanly. */
2679 PTHREAD_JOIN(self->sibling[0].tid, &status);
2680 EXPECT_EQ(0x0, (long)status);
2681 PTHREAD_JOIN(self->sibling[1].tid, &status);
2682 EXPECT_EQ(0x0, (long)status);
2683 }
2684
TEST_F(TSYNC,two_sibling_want_nnp)2685 TEST_F(TSYNC, two_sibling_want_nnp)
2686 {
2687 void *status;
2688
2689 /* start siblings before any prctl() operations */
2690 tsync_start_sibling(&self->sibling[0]);
2691 tsync_start_sibling(&self->sibling[1]);
2692 while (self->sibling_count < TSYNC_SIBLINGS) {
2693 sem_wait(&self->started);
2694 self->sibling_count++;
2695 }
2696
2697 /* Tell the siblings to test no policy */
2698 pthread_mutex_lock(&self->mutex);
2699 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2700 TH_LOG("cond broadcast non-zero");
2701 }
2702 pthread_mutex_unlock(&self->mutex);
2703
2704 /* Ensure they are both upset about lacking nnp. */
2705 PTHREAD_JOIN(self->sibling[0].tid, &status);
2706 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2707 PTHREAD_JOIN(self->sibling[1].tid, &status);
2708 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2709 }
2710
TEST_F(TSYNC,two_siblings_with_no_filter)2711 TEST_F(TSYNC, two_siblings_with_no_filter)
2712 {
2713 long ret;
2714 void *status;
2715
2716 /* start siblings before any prctl() operations */
2717 tsync_start_sibling(&self->sibling[0]);
2718 tsync_start_sibling(&self->sibling[1]);
2719 while (self->sibling_count < TSYNC_SIBLINGS) {
2720 sem_wait(&self->started);
2721 self->sibling_count++;
2722 }
2723
2724 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2725 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2726 }
2727
2728 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2729 &self->apply_prog);
2730 ASSERT_NE(ENOSYS, errno) {
2731 TH_LOG("Kernel does not support seccomp syscall!");
2732 }
2733 ASSERT_EQ(0, ret) {
2734 TH_LOG("Could install filter on all threads!");
2735 }
2736
2737 /* Tell the siblings to test the policy */
2738 pthread_mutex_lock(&self->mutex);
2739 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2740 TH_LOG("cond broadcast non-zero");
2741 }
2742 pthread_mutex_unlock(&self->mutex);
2743
2744 /* Ensure they are both killed and don't exit cleanly. */
2745 PTHREAD_JOIN(self->sibling[0].tid, &status);
2746 EXPECT_EQ(0x0, (long)status);
2747 PTHREAD_JOIN(self->sibling[1].tid, &status);
2748 EXPECT_EQ(0x0, (long)status);
2749 }
2750
TEST_F(TSYNC,two_siblings_with_one_divergence)2751 TEST_F(TSYNC, two_siblings_with_one_divergence)
2752 {
2753 long ret;
2754 void *status;
2755
2756 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2757 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2758 }
2759
2760 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2761 ASSERT_NE(ENOSYS, errno) {
2762 TH_LOG("Kernel does not support seccomp syscall!");
2763 }
2764 ASSERT_EQ(0, ret) {
2765 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2766 }
2767 self->sibling[0].diverge = 1;
2768 tsync_start_sibling(&self->sibling[0]);
2769 tsync_start_sibling(&self->sibling[1]);
2770
2771 while (self->sibling_count < TSYNC_SIBLINGS) {
2772 sem_wait(&self->started);
2773 self->sibling_count++;
2774 }
2775
2776 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2777 &self->apply_prog);
2778 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2779 TH_LOG("Did not fail on diverged sibling.");
2780 }
2781
2782 /* Wake the threads */
2783 pthread_mutex_lock(&self->mutex);
2784 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2785 TH_LOG("cond broadcast non-zero");
2786 }
2787 pthread_mutex_unlock(&self->mutex);
2788
2789 /* Ensure they are both unkilled. */
2790 PTHREAD_JOIN(self->sibling[0].tid, &status);
2791 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2792 PTHREAD_JOIN(self->sibling[1].tid, &status);
2793 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2794 }
2795
TEST_F(TSYNC,two_siblings_with_one_divergence_no_tid_in_err)2796 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
2797 {
2798 long ret, flags;
2799 void *status;
2800
2801 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2802 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2803 }
2804
2805 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2806 ASSERT_NE(ENOSYS, errno) {
2807 TH_LOG("Kernel does not support seccomp syscall!");
2808 }
2809 ASSERT_EQ(0, ret) {
2810 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2811 }
2812 self->sibling[0].diverge = 1;
2813 tsync_start_sibling(&self->sibling[0]);
2814 tsync_start_sibling(&self->sibling[1]);
2815
2816 while (self->sibling_count < TSYNC_SIBLINGS) {
2817 sem_wait(&self->started);
2818 self->sibling_count++;
2819 }
2820
2821 flags = SECCOMP_FILTER_FLAG_TSYNC | \
2822 SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
2823 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
2824 ASSERT_EQ(ESRCH, errno) {
2825 TH_LOG("Did not return ESRCH for diverged sibling.");
2826 }
2827 ASSERT_EQ(-1, ret) {
2828 TH_LOG("Did not fail on diverged sibling.");
2829 }
2830
2831 /* Wake the threads */
2832 pthread_mutex_lock(&self->mutex);
2833 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2834 TH_LOG("cond broadcast non-zero");
2835 }
2836 pthread_mutex_unlock(&self->mutex);
2837
2838 /* Ensure they are both unkilled. */
2839 PTHREAD_JOIN(self->sibling[0].tid, &status);
2840 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2841 PTHREAD_JOIN(self->sibling[1].tid, &status);
2842 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2843 }
2844
TEST_F(TSYNC,two_siblings_not_under_filter)2845 TEST_F(TSYNC, two_siblings_not_under_filter)
2846 {
2847 long ret, sib;
2848 void *status;
2849 struct timespec delay = { .tv_nsec = 100000000 };
2850
2851 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2852 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2853 }
2854
2855 /*
2856 * Sibling 0 will have its own seccomp policy
2857 * and Sibling 1 will not be under seccomp at
2858 * all. Sibling 1 will enter seccomp and 0
2859 * will cause failure.
2860 */
2861 self->sibling[0].diverge = 1;
2862 tsync_start_sibling(&self->sibling[0]);
2863 tsync_start_sibling(&self->sibling[1]);
2864
2865 while (self->sibling_count < TSYNC_SIBLINGS) {
2866 sem_wait(&self->started);
2867 self->sibling_count++;
2868 }
2869
2870 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2871 ASSERT_NE(ENOSYS, errno) {
2872 TH_LOG("Kernel does not support seccomp syscall!");
2873 }
2874 ASSERT_EQ(0, ret) {
2875 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2876 }
2877
2878 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2879 &self->apply_prog);
2880 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2881 TH_LOG("Did not fail on diverged sibling.");
2882 }
2883 sib = 1;
2884 if (ret == self->sibling[0].system_tid)
2885 sib = 0;
2886
2887 pthread_mutex_lock(&self->mutex);
2888
2889 /* Increment the other siblings num_waits so we can clean up
2890 * the one we just saw.
2891 */
2892 self->sibling[!sib].num_waits += 1;
2893
2894 /* Signal the thread to clean up*/
2895 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2896 TH_LOG("cond broadcast non-zero");
2897 }
2898 pthread_mutex_unlock(&self->mutex);
2899 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2900 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2901 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2902 while (!kill(self->sibling[sib].system_tid, 0))
2903 nanosleep(&delay, NULL);
2904 /* Switch to the remaining sibling */
2905 sib = !sib;
2906
2907 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2908 &self->apply_prog);
2909 ASSERT_EQ(0, ret) {
2910 TH_LOG("Expected the remaining sibling to sync");
2911 };
2912
2913 pthread_mutex_lock(&self->mutex);
2914
2915 /* If remaining sibling didn't have a chance to wake up during
2916 * the first broadcast, manually reduce the num_waits now.
2917 */
2918 if (self->sibling[sib].num_waits > 1)
2919 self->sibling[sib].num_waits = 1;
2920 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2921 TH_LOG("cond broadcast non-zero");
2922 }
2923 pthread_mutex_unlock(&self->mutex);
2924 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2925 EXPECT_EQ(0, (long)status);
2926 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2927 while (!kill(self->sibling[sib].system_tid, 0))
2928 nanosleep(&delay, NULL);
2929
2930 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2931 &self->apply_prog);
2932 ASSERT_EQ(0, ret); /* just us chickens */
2933 }
2934
2935 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)2936 TEST(syscall_restart)
2937 {
2938 long ret;
2939 unsigned long msg;
2940 pid_t child_pid;
2941 int pipefd[2];
2942 int status;
2943 siginfo_t info = { };
2944 struct sock_filter filter[] = {
2945 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2946 offsetof(struct seccomp_data, nr)),
2947
2948 #ifdef __NR_sigreturn
2949 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0),
2950 #endif
2951 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0),
2952 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0),
2953 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0),
2954 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0),
2955 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0),
2956 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2957
2958 /* Allow __NR_write for easy logging. */
2959 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2960 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2961 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2962 /* The nanosleep jump target. */
2963 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2964 /* The restart_syscall jump target. */
2965 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2966 };
2967 struct sock_fprog prog = {
2968 .len = (unsigned short)ARRAY_SIZE(filter),
2969 .filter = filter,
2970 };
2971 #if defined(__arm__)
2972 struct utsname utsbuf;
2973 #endif
2974
2975 ASSERT_EQ(0, pipe(pipefd));
2976
2977 child_pid = fork();
2978 ASSERT_LE(0, child_pid);
2979 if (child_pid == 0) {
2980 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2981 char buf = ' ';
2982 struct timespec timeout = { };
2983
2984 /* Attach parent as tracer and stop. */
2985 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2986 EXPECT_EQ(0, raise(SIGSTOP));
2987
2988 EXPECT_EQ(0, close(pipefd[1]));
2989
2990 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2991 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2992 }
2993
2994 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2995 EXPECT_EQ(0, ret) {
2996 TH_LOG("Failed to install filter!");
2997 }
2998
2999 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3000 TH_LOG("Failed to read() sync from parent");
3001 }
3002 EXPECT_EQ('.', buf) {
3003 TH_LOG("Failed to get sync data from read()");
3004 }
3005
3006 /* Start nanosleep to be interrupted. */
3007 timeout.tv_sec = 1;
3008 errno = 0;
3009 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
3010 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
3011 }
3012
3013 /* Read final sync from parent. */
3014 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3015 TH_LOG("Failed final read() from parent");
3016 }
3017 EXPECT_EQ('!', buf) {
3018 TH_LOG("Failed to get final data from read()");
3019 }
3020
3021 /* Directly report the status of our test harness results. */
3022 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
3023 : EXIT_FAILURE);
3024 }
3025 EXPECT_EQ(0, close(pipefd[0]));
3026
3027 /* Attach to child, setup options, and release. */
3028 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3029 ASSERT_EQ(true, WIFSTOPPED(status));
3030 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
3031 PTRACE_O_TRACESECCOMP));
3032 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3033 ASSERT_EQ(1, write(pipefd[1], ".", 1));
3034
3035 /* Wait for nanosleep() to start. */
3036 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3037 ASSERT_EQ(true, WIFSTOPPED(status));
3038 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3039 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3040 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3041 ASSERT_EQ(0x100, msg);
3042 ret = get_syscall(_metadata, child_pid);
3043 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep);
3044
3045 /* Might as well check siginfo for sanity while we're here. */
3046 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3047 ASSERT_EQ(SIGTRAP, info.si_signo);
3048 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
3049 EXPECT_EQ(0, info.si_errno);
3050 EXPECT_EQ(getuid(), info.si_uid);
3051 /* Verify signal delivery came from child (seccomp-triggered). */
3052 EXPECT_EQ(child_pid, info.si_pid);
3053
3054 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
3055 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
3056 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3057 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3058 ASSERT_EQ(true, WIFSTOPPED(status));
3059 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
3060 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3061 /*
3062 * There is no siginfo on SIGSTOP any more, so we can't verify
3063 * signal delivery came from parent now (getpid() == info.si_pid).
3064 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
3065 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
3066 */
3067 EXPECT_EQ(SIGSTOP, info.si_signo);
3068
3069 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
3070 ASSERT_EQ(0, kill(child_pid, SIGCONT));
3071 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3072 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3073 ASSERT_EQ(true, WIFSTOPPED(status));
3074 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
3075 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3076
3077 /* Wait for restart_syscall() to start. */
3078 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3079 ASSERT_EQ(true, WIFSTOPPED(status));
3080 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3081 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3082 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3083
3084 ASSERT_EQ(0x200, msg);
3085 ret = get_syscall(_metadata, child_pid);
3086 #if defined(__arm__)
3087 /*
3088 * FIXME:
3089 * - native ARM registers do NOT expose true syscall.
3090 * - compat ARM registers on ARM64 DO expose true syscall.
3091 */
3092 ASSERT_EQ(0, uname(&utsbuf));
3093 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
3094 EXPECT_EQ(__NR_nanosleep, ret);
3095 } else
3096 #endif
3097 {
3098 EXPECT_EQ(__NR_restart_syscall, ret);
3099 }
3100
3101 /* Write again to end test. */
3102 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3103 ASSERT_EQ(1, write(pipefd[1], "!", 1));
3104 EXPECT_EQ(0, close(pipefd[1]));
3105
3106 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3107 if (WIFSIGNALED(status) || WEXITSTATUS(status))
3108 _metadata->passed = 0;
3109 }
3110
TEST_SIGNAL(filter_flag_log,SIGSYS)3111 TEST_SIGNAL(filter_flag_log, SIGSYS)
3112 {
3113 struct sock_filter allow_filter[] = {
3114 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3115 };
3116 struct sock_filter kill_filter[] = {
3117 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3118 offsetof(struct seccomp_data, nr)),
3119 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
3120 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
3121 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3122 };
3123 struct sock_fprog allow_prog = {
3124 .len = (unsigned short)ARRAY_SIZE(allow_filter),
3125 .filter = allow_filter,
3126 };
3127 struct sock_fprog kill_prog = {
3128 .len = (unsigned short)ARRAY_SIZE(kill_filter),
3129 .filter = kill_filter,
3130 };
3131 long ret;
3132 pid_t parent = getppid();
3133
3134 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3135 ASSERT_EQ(0, ret);
3136
3137 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
3138 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
3139 &allow_prog);
3140 ASSERT_NE(ENOSYS, errno) {
3141 TH_LOG("Kernel does not support seccomp syscall!");
3142 }
3143 EXPECT_NE(0, ret) {
3144 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
3145 }
3146 EXPECT_EQ(EINVAL, errno) {
3147 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
3148 }
3149
3150 /* Verify that a simple, permissive filter can be added with no flags */
3151 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
3152 EXPECT_EQ(0, ret);
3153
3154 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
3155 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3156 &allow_prog);
3157 ASSERT_NE(EINVAL, errno) {
3158 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
3159 }
3160 EXPECT_EQ(0, ret);
3161
3162 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
3163 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3164 &kill_prog);
3165 EXPECT_EQ(0, ret);
3166
3167 EXPECT_EQ(parent, syscall(__NR_getppid));
3168 /* getpid() should never return. */
3169 EXPECT_EQ(0, syscall(__NR_getpid));
3170 }
3171
TEST(get_action_avail)3172 TEST(get_action_avail)
3173 {
3174 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
3175 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
3176 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
3177 __u32 unknown_action = 0x10000000U;
3178 int i;
3179 long ret;
3180
3181 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
3182 ASSERT_NE(ENOSYS, errno) {
3183 TH_LOG("Kernel does not support seccomp syscall!");
3184 }
3185 ASSERT_NE(EINVAL, errno) {
3186 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
3187 }
3188 EXPECT_EQ(ret, 0);
3189
3190 for (i = 0; i < ARRAY_SIZE(actions); i++) {
3191 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
3192 EXPECT_EQ(ret, 0) {
3193 TH_LOG("Expected action (0x%X) not available!",
3194 actions[i]);
3195 }
3196 }
3197
3198 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
3199 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
3200 EXPECT_EQ(ret, -1);
3201 EXPECT_EQ(errno, EOPNOTSUPP);
3202 }
3203
TEST(get_metadata)3204 TEST(get_metadata)
3205 {
3206 pid_t pid;
3207 int pipefd[2];
3208 char buf;
3209 struct seccomp_metadata md;
3210 long ret;
3211
3212 /* Only real root can get metadata. */
3213 if (geteuid()) {
3214 SKIP(return, "get_metadata requires real root");
3215 return;
3216 }
3217
3218 ASSERT_EQ(0, pipe(pipefd));
3219
3220 pid = fork();
3221 ASSERT_GE(pid, 0);
3222 if (pid == 0) {
3223 struct sock_filter filter[] = {
3224 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3225 };
3226 struct sock_fprog prog = {
3227 .len = (unsigned short)ARRAY_SIZE(filter),
3228 .filter = filter,
3229 };
3230
3231 /* one with log, one without */
3232 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3233 SECCOMP_FILTER_FLAG_LOG, &prog));
3234 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3235
3236 EXPECT_EQ(0, close(pipefd[0]));
3237 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3238 ASSERT_EQ(0, close(pipefd[1]));
3239
3240 while (1)
3241 sleep(100);
3242 }
3243
3244 ASSERT_EQ(0, close(pipefd[1]));
3245 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3246
3247 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3248 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3249
3250 /* Past here must not use ASSERT or child process is never killed. */
3251
3252 md.filter_off = 0;
3253 errno = 0;
3254 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3255 EXPECT_EQ(sizeof(md), ret) {
3256 if (errno == EINVAL)
3257 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3258 }
3259
3260 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3261 EXPECT_EQ(md.filter_off, 0);
3262
3263 md.filter_off = 1;
3264 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3265 EXPECT_EQ(sizeof(md), ret);
3266 EXPECT_EQ(md.flags, 0);
3267 EXPECT_EQ(md.filter_off, 1);
3268
3269 skip:
3270 ASSERT_EQ(0, kill(pid, SIGKILL));
3271 }
3272
user_notif_syscall(int nr,unsigned int flags)3273 static int user_notif_syscall(int nr, unsigned int flags)
3274 {
3275 struct sock_filter filter[] = {
3276 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3277 offsetof(struct seccomp_data, nr)),
3278 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
3279 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
3280 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3281 };
3282
3283 struct sock_fprog prog = {
3284 .len = (unsigned short)ARRAY_SIZE(filter),
3285 .filter = filter,
3286 };
3287
3288 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3289 }
3290
3291 #define USER_NOTIF_MAGIC INT_MAX
TEST(user_notification_basic)3292 TEST(user_notification_basic)
3293 {
3294 pid_t pid;
3295 long ret;
3296 int status, listener;
3297 struct seccomp_notif req = {};
3298 struct seccomp_notif_resp resp = {};
3299 struct pollfd pollfd;
3300
3301 struct sock_filter filter[] = {
3302 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3303 };
3304 struct sock_fprog prog = {
3305 .len = (unsigned short)ARRAY_SIZE(filter),
3306 .filter = filter,
3307 };
3308
3309 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3310 ASSERT_EQ(0, ret) {
3311 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3312 }
3313
3314 pid = fork();
3315 ASSERT_GE(pid, 0);
3316
3317 /* Check that we get -ENOSYS with no listener attached */
3318 if (pid == 0) {
3319 if (user_notif_syscall(__NR_getppid, 0) < 0)
3320 exit(1);
3321 ret = syscall(__NR_getppid);
3322 exit(ret >= 0 || errno != ENOSYS);
3323 }
3324
3325 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3326 EXPECT_EQ(true, WIFEXITED(status));
3327 EXPECT_EQ(0, WEXITSTATUS(status));
3328
3329 /* Add some no-op filters for grins. */
3330 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3331 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3332 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3333 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3334
3335 /* Check that the basic notification machinery works */
3336 listener = user_notif_syscall(__NR_getppid,
3337 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3338 ASSERT_GE(listener, 0);
3339
3340 /* Installing a second listener in the chain should EBUSY */
3341 EXPECT_EQ(user_notif_syscall(__NR_getppid,
3342 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3343 -1);
3344 EXPECT_EQ(errno, EBUSY);
3345
3346 pid = fork();
3347 ASSERT_GE(pid, 0);
3348
3349 if (pid == 0) {
3350 ret = syscall(__NR_getppid);
3351 exit(ret != USER_NOTIF_MAGIC);
3352 }
3353
3354 pollfd.fd = listener;
3355 pollfd.events = POLLIN | POLLOUT;
3356
3357 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3358 EXPECT_EQ(pollfd.revents, POLLIN);
3359
3360 /* Test that we can't pass garbage to the kernel. */
3361 memset(&req, 0, sizeof(req));
3362 req.pid = -1;
3363 errno = 0;
3364 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
3365 EXPECT_EQ(-1, ret);
3366 EXPECT_EQ(EINVAL, errno);
3367
3368 if (ret) {
3369 req.pid = 0;
3370 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3371 }
3372
3373 pollfd.fd = listener;
3374 pollfd.events = POLLIN | POLLOUT;
3375
3376 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3377 EXPECT_EQ(pollfd.revents, POLLOUT);
3378
3379 EXPECT_EQ(req.data.nr, __NR_getppid);
3380
3381 resp.id = req.id;
3382 resp.error = 0;
3383 resp.val = USER_NOTIF_MAGIC;
3384
3385 /* check that we make sure flags == 0 */
3386 resp.flags = 1;
3387 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3388 EXPECT_EQ(errno, EINVAL);
3389
3390 resp.flags = 0;
3391 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3392
3393 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3394 EXPECT_EQ(true, WIFEXITED(status));
3395 EXPECT_EQ(0, WEXITSTATUS(status));
3396 }
3397
TEST(user_notification_with_tsync)3398 TEST(user_notification_with_tsync)
3399 {
3400 int ret;
3401 unsigned int flags;
3402
3403 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3404 ASSERT_EQ(0, ret) {
3405 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3406 }
3407
3408 /* these were exclusive */
3409 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
3410 SECCOMP_FILTER_FLAG_TSYNC;
3411 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags));
3412 ASSERT_EQ(EINVAL, errno);
3413
3414 /* but now they're not */
3415 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
3416 ret = user_notif_syscall(__NR_getppid, flags);
3417 close(ret);
3418 ASSERT_LE(0, ret);
3419 }
3420
TEST(user_notification_kill_in_middle)3421 TEST(user_notification_kill_in_middle)
3422 {
3423 pid_t pid;
3424 long ret;
3425 int listener;
3426 struct seccomp_notif req = {};
3427 struct seccomp_notif_resp resp = {};
3428
3429 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3430 ASSERT_EQ(0, ret) {
3431 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3432 }
3433
3434 listener = user_notif_syscall(__NR_getppid,
3435 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3436 ASSERT_GE(listener, 0);
3437
3438 /*
3439 * Check that nothing bad happens when we kill the task in the middle
3440 * of a syscall.
3441 */
3442 pid = fork();
3443 ASSERT_GE(pid, 0);
3444
3445 if (pid == 0) {
3446 ret = syscall(__NR_getppid);
3447 exit(ret != USER_NOTIF_MAGIC);
3448 }
3449
3450 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3451 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3452
3453 EXPECT_EQ(kill(pid, SIGKILL), 0);
3454 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3455
3456 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3457
3458 resp.id = req.id;
3459 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3460 EXPECT_EQ(ret, -1);
3461 EXPECT_EQ(errno, ENOENT);
3462 }
3463
3464 static int handled = -1;
3465
signal_handler(int signal)3466 static void signal_handler(int signal)
3467 {
3468 if (write(handled, "c", 1) != 1)
3469 perror("write from signal");
3470 }
3471
TEST(user_notification_signal)3472 TEST(user_notification_signal)
3473 {
3474 pid_t pid;
3475 long ret;
3476 int status, listener, sk_pair[2];
3477 struct seccomp_notif req = {};
3478 struct seccomp_notif_resp resp = {};
3479 char c;
3480
3481 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3482 ASSERT_EQ(0, ret) {
3483 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3484 }
3485
3486 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3487
3488 listener = user_notif_syscall(__NR_gettid,
3489 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3490 ASSERT_GE(listener, 0);
3491
3492 pid = fork();
3493 ASSERT_GE(pid, 0);
3494
3495 if (pid == 0) {
3496 close(sk_pair[0]);
3497 handled = sk_pair[1];
3498 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3499 perror("signal");
3500 exit(1);
3501 }
3502 /*
3503 * ERESTARTSYS behavior is a bit hard to test, because we need
3504 * to rely on a signal that has not yet been handled. Let's at
3505 * least check that the error code gets propagated through, and
3506 * hope that it doesn't break when there is actually a signal :)
3507 */
3508 ret = syscall(__NR_gettid);
3509 exit(!(ret == -1 && errno == 512));
3510 }
3511
3512 close(sk_pair[1]);
3513
3514 memset(&req, 0, sizeof(req));
3515 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3516
3517 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3518
3519 /*
3520 * Make sure the signal really is delivered, which means we're not
3521 * stuck in the user notification code any more and the notification
3522 * should be dead.
3523 */
3524 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3525
3526 resp.id = req.id;
3527 resp.error = -EPERM;
3528 resp.val = 0;
3529
3530 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3531 EXPECT_EQ(errno, ENOENT);
3532
3533 memset(&req, 0, sizeof(req));
3534 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3535
3536 resp.id = req.id;
3537 resp.error = -512; /* -ERESTARTSYS */
3538 resp.val = 0;
3539
3540 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3541
3542 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3543 EXPECT_EQ(true, WIFEXITED(status));
3544 EXPECT_EQ(0, WEXITSTATUS(status));
3545 }
3546
TEST(user_notification_closed_listener)3547 TEST(user_notification_closed_listener)
3548 {
3549 pid_t pid;
3550 long ret;
3551 int status, listener;
3552
3553 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3554 ASSERT_EQ(0, ret) {
3555 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3556 }
3557
3558 listener = user_notif_syscall(__NR_getppid,
3559 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3560 ASSERT_GE(listener, 0);
3561
3562 /*
3563 * Check that we get an ENOSYS when the listener is closed.
3564 */
3565 pid = fork();
3566 ASSERT_GE(pid, 0);
3567 if (pid == 0) {
3568 close(listener);
3569 ret = syscall(__NR_getppid);
3570 exit(ret != -1 && errno != ENOSYS);
3571 }
3572
3573 close(listener);
3574
3575 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3576 EXPECT_EQ(true, WIFEXITED(status));
3577 EXPECT_EQ(0, WEXITSTATUS(status));
3578 }
3579
3580 /*
3581 * Check that a pid in a child namespace still shows up as valid in ours.
3582 */
TEST(user_notification_child_pid_ns)3583 TEST(user_notification_child_pid_ns)
3584 {
3585 pid_t pid;
3586 int status, listener;
3587 struct seccomp_notif req = {};
3588 struct seccomp_notif_resp resp = {};
3589
3590 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
3591 if (errno == EINVAL)
3592 SKIP(return, "kernel missing CLONE_NEWUSER support");
3593 };
3594
3595 listener = user_notif_syscall(__NR_getppid,
3596 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3597 ASSERT_GE(listener, 0);
3598
3599 pid = fork();
3600 ASSERT_GE(pid, 0);
3601
3602 if (pid == 0)
3603 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3604
3605 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3606 EXPECT_EQ(req.pid, pid);
3607
3608 resp.id = req.id;
3609 resp.error = 0;
3610 resp.val = USER_NOTIF_MAGIC;
3611
3612 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3613
3614 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3615 EXPECT_EQ(true, WIFEXITED(status));
3616 EXPECT_EQ(0, WEXITSTATUS(status));
3617 close(listener);
3618 }
3619
3620 /*
3621 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3622 * invalid.
3623 */
TEST(user_notification_sibling_pid_ns)3624 TEST(user_notification_sibling_pid_ns)
3625 {
3626 pid_t pid, pid2;
3627 int status, listener;
3628 struct seccomp_notif req = {};
3629 struct seccomp_notif_resp resp = {};
3630
3631 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3632 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3633 }
3634
3635 listener = user_notif_syscall(__NR_getppid,
3636 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3637 ASSERT_GE(listener, 0);
3638
3639 pid = fork();
3640 ASSERT_GE(pid, 0);
3641
3642 if (pid == 0) {
3643 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3644
3645 pid2 = fork();
3646 ASSERT_GE(pid2, 0);
3647
3648 if (pid2 == 0)
3649 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3650
3651 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3652 EXPECT_EQ(true, WIFEXITED(status));
3653 EXPECT_EQ(0, WEXITSTATUS(status));
3654 exit(WEXITSTATUS(status));
3655 }
3656
3657 /* Create the sibling ns, and sibling in it. */
3658 ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
3659 if (errno == EPERM)
3660 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
3661 }
3662 ASSERT_EQ(errno, 0);
3663
3664 pid2 = fork();
3665 ASSERT_GE(pid2, 0);
3666
3667 if (pid2 == 0) {
3668 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3669 /*
3670 * The pid should be 0, i.e. the task is in some namespace that
3671 * we can't "see".
3672 */
3673 EXPECT_EQ(req.pid, 0);
3674
3675 resp.id = req.id;
3676 resp.error = 0;
3677 resp.val = USER_NOTIF_MAGIC;
3678
3679 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3680 exit(0);
3681 }
3682
3683 close(listener);
3684
3685 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3686 EXPECT_EQ(true, WIFEXITED(status));
3687 EXPECT_EQ(0, WEXITSTATUS(status));
3688
3689 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3690 EXPECT_EQ(true, WIFEXITED(status));
3691 EXPECT_EQ(0, WEXITSTATUS(status));
3692 }
3693
TEST(user_notification_fault_recv)3694 TEST(user_notification_fault_recv)
3695 {
3696 pid_t pid;
3697 int status, listener;
3698 struct seccomp_notif req = {};
3699 struct seccomp_notif_resp resp = {};
3700
3701 ASSERT_EQ(unshare(CLONE_NEWUSER), 0);
3702
3703 listener = user_notif_syscall(__NR_getppid,
3704 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3705 ASSERT_GE(listener, 0);
3706
3707 pid = fork();
3708 ASSERT_GE(pid, 0);
3709
3710 if (pid == 0)
3711 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3712
3713 /* Do a bad recv() */
3714 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3715 EXPECT_EQ(errno, EFAULT);
3716
3717 /* We should still be able to receive this notification, though. */
3718 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3719 EXPECT_EQ(req.pid, pid);
3720
3721 resp.id = req.id;
3722 resp.error = 0;
3723 resp.val = USER_NOTIF_MAGIC;
3724
3725 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3726
3727 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3728 EXPECT_EQ(true, WIFEXITED(status));
3729 EXPECT_EQ(0, WEXITSTATUS(status));
3730 }
3731
TEST(seccomp_get_notif_sizes)3732 TEST(seccomp_get_notif_sizes)
3733 {
3734 struct seccomp_notif_sizes sizes;
3735
3736 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3737 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3738 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3739 }
3740
TEST(user_notification_continue)3741 TEST(user_notification_continue)
3742 {
3743 pid_t pid;
3744 long ret;
3745 int status, listener;
3746 struct seccomp_notif req = {};
3747 struct seccomp_notif_resp resp = {};
3748 struct pollfd pollfd;
3749
3750 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3751 ASSERT_EQ(0, ret) {
3752 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3753 }
3754
3755 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3756 ASSERT_GE(listener, 0);
3757
3758 pid = fork();
3759 ASSERT_GE(pid, 0);
3760
3761 if (pid == 0) {
3762 int dup_fd, pipe_fds[2];
3763 pid_t self;
3764
3765 ASSERT_GE(pipe(pipe_fds), 0);
3766
3767 dup_fd = dup(pipe_fds[0]);
3768 ASSERT_GE(dup_fd, 0);
3769 EXPECT_NE(pipe_fds[0], dup_fd);
3770
3771 self = getpid();
3772 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
3773 exit(0);
3774 }
3775
3776 pollfd.fd = listener;
3777 pollfd.events = POLLIN | POLLOUT;
3778
3779 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3780 EXPECT_EQ(pollfd.revents, POLLIN);
3781
3782 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3783
3784 pollfd.fd = listener;
3785 pollfd.events = POLLIN | POLLOUT;
3786
3787 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3788 EXPECT_EQ(pollfd.revents, POLLOUT);
3789
3790 EXPECT_EQ(req.data.nr, __NR_dup);
3791
3792 resp.id = req.id;
3793 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
3794
3795 /*
3796 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
3797 * args be set to 0.
3798 */
3799 resp.error = 0;
3800 resp.val = USER_NOTIF_MAGIC;
3801 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3802 EXPECT_EQ(errno, EINVAL);
3803
3804 resp.error = USER_NOTIF_MAGIC;
3805 resp.val = 0;
3806 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3807 EXPECT_EQ(errno, EINVAL);
3808
3809 resp.error = 0;
3810 resp.val = 0;
3811 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
3812 if (errno == EINVAL)
3813 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
3814 }
3815
3816 skip:
3817 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3818 EXPECT_EQ(true, WIFEXITED(status));
3819 EXPECT_EQ(0, WEXITSTATUS(status)) {
3820 if (WEXITSTATUS(status) == 2) {
3821 SKIP(return, "Kernel does not support kcmp() syscall");
3822 return;
3823 }
3824 }
3825 }
3826
TEST(user_notification_filter_empty)3827 TEST(user_notification_filter_empty)
3828 {
3829 pid_t pid;
3830 long ret;
3831 int status;
3832 struct pollfd pollfd;
3833 struct __clone_args args = {
3834 .flags = CLONE_FILES,
3835 .exit_signal = SIGCHLD,
3836 };
3837
3838 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3839 ASSERT_EQ(0, ret) {
3840 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3841 }
3842
3843 pid = sys_clone3(&args, sizeof(args));
3844 ASSERT_GE(pid, 0);
3845
3846 if (pid == 0) {
3847 int listener;
3848
3849 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3850 if (listener < 0)
3851 _exit(EXIT_FAILURE);
3852
3853 if (dup2(listener, 200) != 200)
3854 _exit(EXIT_FAILURE);
3855
3856 close(listener);
3857
3858 _exit(EXIT_SUCCESS);
3859 }
3860
3861 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3862 EXPECT_EQ(true, WIFEXITED(status));
3863 EXPECT_EQ(0, WEXITSTATUS(status));
3864
3865 /*
3866 * The seccomp filter has become unused so we should be notified once
3867 * the kernel gets around to cleaning up task struct.
3868 */
3869 pollfd.fd = 200;
3870 pollfd.events = POLLHUP;
3871
3872 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
3873 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
3874 }
3875
do_thread(void * data)3876 static void *do_thread(void *data)
3877 {
3878 return NULL;
3879 }
3880
TEST(user_notification_filter_empty_threaded)3881 TEST(user_notification_filter_empty_threaded)
3882 {
3883 pid_t pid;
3884 long ret;
3885 int status;
3886 struct pollfd pollfd;
3887 struct __clone_args args = {
3888 .flags = CLONE_FILES,
3889 .exit_signal = SIGCHLD,
3890 };
3891
3892 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3893 ASSERT_EQ(0, ret) {
3894 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3895 }
3896
3897 pid = sys_clone3(&args, sizeof(args));
3898 ASSERT_GE(pid, 0);
3899
3900 if (pid == 0) {
3901 pid_t pid1, pid2;
3902 int listener, status;
3903 pthread_t thread;
3904
3905 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3906 if (listener < 0)
3907 _exit(EXIT_FAILURE);
3908
3909 if (dup2(listener, 200) != 200)
3910 _exit(EXIT_FAILURE);
3911
3912 close(listener);
3913
3914 pid1 = fork();
3915 if (pid1 < 0)
3916 _exit(EXIT_FAILURE);
3917
3918 if (pid1 == 0)
3919 _exit(EXIT_SUCCESS);
3920
3921 pid2 = fork();
3922 if (pid2 < 0)
3923 _exit(EXIT_FAILURE);
3924
3925 if (pid2 == 0)
3926 _exit(EXIT_SUCCESS);
3927
3928 if (pthread_create(&thread, NULL, do_thread, NULL) ||
3929 pthread_join(thread, NULL))
3930 _exit(EXIT_FAILURE);
3931
3932 if (pthread_create(&thread, NULL, do_thread, NULL) ||
3933 pthread_join(thread, NULL))
3934 _exit(EXIT_FAILURE);
3935
3936 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) ||
3937 WEXITSTATUS(status))
3938 _exit(EXIT_FAILURE);
3939
3940 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) ||
3941 WEXITSTATUS(status))
3942 _exit(EXIT_FAILURE);
3943
3944 exit(EXIT_SUCCESS);
3945 }
3946
3947 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3948 EXPECT_EQ(true, WIFEXITED(status));
3949 EXPECT_EQ(0, WEXITSTATUS(status));
3950
3951 /*
3952 * The seccomp filter has become unused so we should be notified once
3953 * the kernel gets around to cleaning up task struct.
3954 */
3955 pollfd.fd = 200;
3956 pollfd.events = POLLHUP;
3957
3958 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
3959 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
3960 }
3961
TEST(user_notification_addfd)3962 TEST(user_notification_addfd)
3963 {
3964 pid_t pid;
3965 long ret;
3966 int status, listener, memfd, fd, nextfd;
3967 struct seccomp_notif_addfd addfd = {};
3968 struct seccomp_notif_addfd_small small = {};
3969 struct seccomp_notif_addfd_big big = {};
3970 struct seccomp_notif req = {};
3971 struct seccomp_notif_resp resp = {};
3972 /* 100 ms */
3973 struct timespec delay = { .tv_nsec = 100000000 };
3974
3975 /* There may be arbitrary already-open fds at test start. */
3976 memfd = memfd_create("test", 0);
3977 ASSERT_GE(memfd, 0);
3978 nextfd = memfd + 1;
3979
3980 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3981 ASSERT_EQ(0, ret) {
3982 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3983 }
3984
3985 /* fd: 4 */
3986 /* Check that the basic notification machinery works */
3987 listener = user_notif_syscall(__NR_getppid,
3988 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3989 ASSERT_EQ(listener, nextfd++);
3990
3991 pid = fork();
3992 ASSERT_GE(pid, 0);
3993
3994 if (pid == 0) {
3995 /* fds will be added and this value is expected */
3996 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC)
3997 exit(1);
3998
3999 /* Atomic addfd+send is received here. Check it is a valid fd */
4000 if (fcntl(syscall(__NR_getppid), F_GETFD) == -1)
4001 exit(1);
4002
4003 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4004 }
4005
4006 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4007
4008 addfd.srcfd = memfd;
4009 addfd.newfd = 0;
4010 addfd.id = req.id;
4011 addfd.flags = 0x0;
4012
4013 /* Verify bad newfd_flags cannot be set */
4014 addfd.newfd_flags = ~O_CLOEXEC;
4015 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4016 EXPECT_EQ(errno, EINVAL);
4017 addfd.newfd_flags = O_CLOEXEC;
4018
4019 /* Verify bad flags cannot be set */
4020 addfd.flags = 0xff;
4021 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4022 EXPECT_EQ(errno, EINVAL);
4023 addfd.flags = 0;
4024
4025 /* Verify that remote_fd cannot be set without setting flags */
4026 addfd.newfd = 1;
4027 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4028 EXPECT_EQ(errno, EINVAL);
4029 addfd.newfd = 0;
4030
4031 /* Verify small size cannot be set */
4032 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1);
4033 EXPECT_EQ(errno, EINVAL);
4034
4035 /* Verify we can't send bits filled in unknown buffer area */
4036 memset(&big, 0xAA, sizeof(big));
4037 big.addfd = addfd;
4038 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1);
4039 EXPECT_EQ(errno, E2BIG);
4040
4041
4042 /* Verify we can set an arbitrary remote fd */
4043 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4044 EXPECT_EQ(fd, nextfd++);
4045 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4046
4047 /* Verify we can set an arbitrary remote fd with large size */
4048 memset(&big, 0x0, sizeof(big));
4049 big.addfd = addfd;
4050 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
4051 EXPECT_EQ(fd, nextfd++);
4052
4053 /* Verify we can set a specific remote fd */
4054 addfd.newfd = 42;
4055 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4056 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4057 EXPECT_EQ(fd, 42);
4058 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4059
4060 /* Resume syscall */
4061 resp.id = req.id;
4062 resp.error = 0;
4063 resp.val = USER_NOTIF_MAGIC;
4064 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4065
4066 /*
4067 * This sets the ID of the ADD FD to the last request plus 1. The
4068 * notification ID increments 1 per notification.
4069 */
4070 addfd.id = req.id + 1;
4071
4072 /* This spins until the underlying notification is generated */
4073 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4074 errno != -EINPROGRESS)
4075 nanosleep(&delay, NULL);
4076
4077 memset(&req, 0, sizeof(req));
4078 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4079 ASSERT_EQ(addfd.id, req.id);
4080
4081 /* Verify we can do an atomic addfd and send */
4082 addfd.newfd = 0;
4083 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4084 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4085 /*
4086 * Child has earlier "low" fds and now 42, so we expect the next
4087 * lowest available fd to be assigned here.
4088 */
4089 EXPECT_EQ(fd, nextfd++);
4090 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4091
4092 /*
4093 * This sets the ID of the ADD FD to the last request plus 1. The
4094 * notification ID increments 1 per notification.
4095 */
4096 addfd.id = req.id + 1;
4097
4098 /* This spins until the underlying notification is generated */
4099 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4100 errno != -EINPROGRESS)
4101 nanosleep(&delay, NULL);
4102
4103 memset(&req, 0, sizeof(req));
4104 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4105 ASSERT_EQ(addfd.id, req.id);
4106
4107 resp.id = req.id;
4108 resp.error = 0;
4109 resp.val = USER_NOTIF_MAGIC;
4110 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4111
4112 /* Wait for child to finish. */
4113 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4114 EXPECT_EQ(true, WIFEXITED(status));
4115 EXPECT_EQ(0, WEXITSTATUS(status));
4116
4117 close(memfd);
4118 }
4119
TEST(user_notification_addfd_rlimit)4120 TEST(user_notification_addfd_rlimit)
4121 {
4122 pid_t pid;
4123 long ret;
4124 int status, listener, memfd;
4125 struct seccomp_notif_addfd addfd = {};
4126 struct seccomp_notif req = {};
4127 struct seccomp_notif_resp resp = {};
4128 const struct rlimit lim = {
4129 .rlim_cur = 0,
4130 .rlim_max = 0,
4131 };
4132
4133 memfd = memfd_create("test", 0);
4134 ASSERT_GE(memfd, 0);
4135
4136 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4137 ASSERT_EQ(0, ret) {
4138 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4139 }
4140
4141 /* Check that the basic notification machinery works */
4142 listener = user_notif_syscall(__NR_getppid,
4143 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4144 ASSERT_GE(listener, 0);
4145
4146 pid = fork();
4147 ASSERT_GE(pid, 0);
4148
4149 if (pid == 0)
4150 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4151
4152
4153 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4154
4155 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0);
4156
4157 addfd.srcfd = memfd;
4158 addfd.newfd_flags = O_CLOEXEC;
4159 addfd.newfd = 0;
4160 addfd.id = req.id;
4161 addfd.flags = 0;
4162
4163 /* Should probably spot check /proc/sys/fs/file-nr */
4164 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4165 EXPECT_EQ(errno, EMFILE);
4166
4167 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4168 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4169 EXPECT_EQ(errno, EMFILE);
4170
4171 addfd.newfd = 100;
4172 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4173 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4174 EXPECT_EQ(errno, EBADF);
4175
4176 resp.id = req.id;
4177 resp.error = 0;
4178 resp.val = USER_NOTIF_MAGIC;
4179
4180 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4181
4182 /* Wait for child to finish. */
4183 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4184 EXPECT_EQ(true, WIFEXITED(status));
4185 EXPECT_EQ(0, WEXITSTATUS(status));
4186
4187 close(memfd);
4188 }
4189
4190 /*
4191 * TODO:
4192 * - expand NNP testing
4193 * - better arch-specific TRACE and TRAP handlers.
4194 * - endianness checking when appropriate
4195 * - 64-bit arg prodding
4196 * - arch value testing (x86 modes especially)
4197 * - verify that FILTER_FLAG_LOG filters generate log messages
4198 * - verify that RET_LOG generates log messages
4199 */
4200
4201 TEST_HARNESS_MAIN
4202
