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Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[cris-mirror.git] / tools / testing / selftests / seccomp / seccomp_bpf.c
blob5df609950a666f8000307653a0b1e8d4368549a2
1 /*
2 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
3 * Use of this source code is governed by the GPLv2 license.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #include <sys/types.h>
9
10 /*
11 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
12 * we need to use the kernel's siginfo.h file and trick glibc
13 * into accepting it.
14 */
15 #if !__GLIBC_PREREQ(2, 26)
16 # include <asm/siginfo.h>
17 # define __have_siginfo_t 1
18 # define __have_sigval_t 1
19 # define __have_sigevent_t 1
20 #endif
21
22 #include <errno.h>
23 #include <linux/filter.h>
24 #include <sys/prctl.h>
25 #include <sys/ptrace.h>
26 #include <sys/user.h>
27 #include <linux/prctl.h>
28 #include <linux/ptrace.h>
29 #include <linux/seccomp.h>
30 #include <pthread.h>
31 #include <semaphore.h>
32 #include <signal.h>
33 #include <stddef.h>
34 #include <stdbool.h>
35 #include <string.h>
36 #include <time.h>
37 #include <linux/elf.h>
38 #include <sys/uio.h>
39 #include <sys/utsname.h>
40 #include <sys/fcntl.h>
41 #include <sys/mman.h>
42 #include <sys/times.h>
43
44 #define _GNU_SOURCE
45 #include <unistd.h>
46 #include <sys/syscall.h>
47
48 #include "../kselftest_harness.h"
49
50 #ifndef PR_SET_PTRACER
51 # define PR_SET_PTRACER 0x59616d61
52 #endif
53
54 #ifndef PR_SET_NO_NEW_PRIVS
55 #define PR_SET_NO_NEW_PRIVS 38
56 #define PR_GET_NO_NEW_PRIVS 39
57 #endif
58
59 #ifndef PR_SECCOMP_EXT
60 #define PR_SECCOMP_EXT 43
61 #endif
62
63 #ifndef SECCOMP_EXT_ACT
64 #define SECCOMP_EXT_ACT 1
65 #endif
66
67 #ifndef SECCOMP_EXT_ACT_TSYNC
68 #define SECCOMP_EXT_ACT_TSYNC 1
69 #endif
70
71 #ifndef SECCOMP_MODE_STRICT
72 #define SECCOMP_MODE_STRICT 1
73 #endif
74
75 #ifndef SECCOMP_MODE_FILTER
76 #define SECCOMP_MODE_FILTER 2
77 #endif
78
79 #ifndef SECCOMP_RET_ALLOW
80 struct seccomp_data {
81 int nr;
82 __u32 arch;
83 __u64 instruction_pointer;
84 __u64 args[6];
85 };
86 #endif
87
88 #ifndef SECCOMP_RET_KILL_PROCESS
89 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
90 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
91 #endif
92 #ifndef SECCOMP_RET_KILL
93 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
94 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
95 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
96 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
97 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
98 #endif
99 #ifndef SECCOMP_RET_LOG
100 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
101 #endif
102
103 #ifndef __NR_seccomp
104 # if defined(__i386__)
105 # define __NR_seccomp 354
106 # elif defined(__x86_64__)
107 # define __NR_seccomp 317
108 # elif defined(__arm__)
109 # define __NR_seccomp 383
110 # elif defined(__aarch64__)
111 # define __NR_seccomp 277
112 # elif defined(__hppa__)
113 # define __NR_seccomp 338
114 # elif defined(__powerpc__)
115 # define __NR_seccomp 358
116 # elif defined(__s390__)
117 # define __NR_seccomp 348
118 # else
119 # warning "seccomp syscall number unknown for this architecture"
120 # define __NR_seccomp 0xffff
121 # endif
122 #endif
123
124 #ifndef SECCOMP_SET_MODE_STRICT
125 #define SECCOMP_SET_MODE_STRICT 0
126 #endif
127
128 #ifndef SECCOMP_SET_MODE_FILTER
129 #define SECCOMP_SET_MODE_FILTER 1
130 #endif
131
132 #ifndef SECCOMP_GET_ACTION_AVAIL
133 #define SECCOMP_GET_ACTION_AVAIL 2
134 #endif
135
136 #ifndef SECCOMP_FILTER_FLAG_TSYNC
137 #define SECCOMP_FILTER_FLAG_TSYNC 1
138 #endif
139
140 #ifndef SECCOMP_FILTER_FLAG_LOG
141 #define SECCOMP_FILTER_FLAG_LOG 2
142 #endif
143
144 #ifndef PTRACE_SECCOMP_GET_METADATA
145 #define PTRACE_SECCOMP_GET_METADATA 0x420d
146
147 struct seccomp_metadata {
148 __u64 filter_off; /* Input: which filter */
149 __u64 flags; /* Output: filter's flags */
150 };
151 #endif
152
153 #ifndef seccomp
154 int seccomp(unsigned int op, unsigned int flags, void *args)
155 {
156 errno = 0;
157 return syscall(__NR_seccomp, op, flags, args);
158 }
159 #endif
160
161 #if __BYTE_ORDER == __LITTLE_ENDIAN
162 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
163 #elif __BYTE_ORDER == __BIG_ENDIAN
164 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
165 #else
166 #error "wut? Unknown __BYTE_ORDER?!"
167 #endif
168
169 #define SIBLING_EXIT_UNKILLED 0xbadbeef
170 #define SIBLING_EXIT_FAILURE 0xbadface
171 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
172
173 TEST(mode_strict_support)
174 {
175 long ret;
176
177 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
178 ASSERT_EQ(0, ret) {
179 TH_LOG("Kernel does not support CONFIG_SECCOMP");
180 }
181 syscall(__NR_exit, 0);
182 }
183
184 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
185 {
186 long ret;
187
188 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
189 ASSERT_EQ(0, ret) {
190 TH_LOG("Kernel does not support CONFIG_SECCOMP");
191 }
192 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
193 NULL, NULL, NULL);
194 EXPECT_FALSE(true) {
195 TH_LOG("Unreachable!");
196 }
197 }
198
199 /* Note! This doesn't test no new privs behavior */
200 TEST(no_new_privs_support)
201 {
202 long ret;
203
204 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
205 EXPECT_EQ(0, ret) {
206 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
207 }
208 }
209
210 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
211 TEST(mode_filter_support)
212 {
213 long ret;
214
215 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
216 ASSERT_EQ(0, ret) {
217 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
218 }
219 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
220 EXPECT_EQ(-1, ret);
221 EXPECT_EQ(EFAULT, errno) {
222 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
223 }
224 }
225
226 TEST(mode_filter_without_nnp)
227 {
228 struct sock_filter filter[] = {
229 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
230 };
231 struct sock_fprog prog = {
232 .len = (unsigned short)ARRAY_SIZE(filter),
233 .filter = filter,
234 };
235 long ret;
236
237 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
238 ASSERT_LE(0, ret) {
239 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
240 }
241 errno = 0;
242 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
243 /* Succeeds with CAP_SYS_ADMIN, fails without */
244 /* TODO(wad) check caps not euid */
245 if (geteuid()) {
246 EXPECT_EQ(-1, ret);
247 EXPECT_EQ(EACCES, errno);
248 } else {
249 EXPECT_EQ(0, ret);
250 }
251 }
252
253 #define MAX_INSNS_PER_PATH 32768
254
255 TEST(filter_size_limits)
256 {
257 int i;
258 int count = BPF_MAXINSNS + 1;
259 struct sock_filter allow[] = {
260 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
261 };
262 struct sock_filter *filter;
263 struct sock_fprog prog = { };
264 long ret;
265
266 filter = calloc(count, sizeof(*filter));
267 ASSERT_NE(NULL, filter);
268
269 for (i = 0; i < count; i++)
270 filter[i] = allow[0];
271
272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
273 ASSERT_EQ(0, ret);
274
275 prog.filter = filter;
276 prog.len = count;
277
278 /* Too many filter instructions in a single filter. */
279 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
280 ASSERT_NE(0, ret) {
281 TH_LOG("Installing %d insn filter was allowed", prog.len);
282 }
283
284 /* One less is okay, though. */
285 prog.len -= 1;
286 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
287 ASSERT_EQ(0, ret) {
288 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
289 }
290 }
291
292 TEST(filter_chain_limits)
293 {
294 int i;
295 int count = BPF_MAXINSNS;
296 struct sock_filter allow[] = {
297 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
298 };
299 struct sock_filter *filter;
300 struct sock_fprog prog = { };
301 long ret;
302
303 filter = calloc(count, sizeof(*filter));
304 ASSERT_NE(NULL, filter);
305
306 for (i = 0; i < count; i++)
307 filter[i] = allow[0];
308
309 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
310 ASSERT_EQ(0, ret);
311
312 prog.filter = filter;
313 prog.len = 1;
314
315 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
316 ASSERT_EQ(0, ret);
317
318 prog.len = count;
319
320 /* Too many total filter instructions. */
321 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
322 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
323 if (ret != 0)
324 break;
325 }
326 ASSERT_NE(0, ret) {
327 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
328 i, count, i * (count + 4));
329 }
330 }
331
332 TEST(mode_filter_cannot_move_to_strict)
333 {
334 struct sock_filter filter[] = {
335 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
336 };
337 struct sock_fprog prog = {
338 .len = (unsigned short)ARRAY_SIZE(filter),
339 .filter = filter,
340 };
341 long ret;
342
343 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
344 ASSERT_EQ(0, ret);
345
346 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
347 ASSERT_EQ(0, ret);
348
349 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
350 EXPECT_EQ(-1, ret);
351 EXPECT_EQ(EINVAL, errno);
352 }
353
354
355 TEST(mode_filter_get_seccomp)
356 {
357 struct sock_filter filter[] = {
358 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
359 };
360 struct sock_fprog prog = {
361 .len = (unsigned short)ARRAY_SIZE(filter),
362 .filter = filter,
363 };
364 long ret;
365
366 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
367 ASSERT_EQ(0, ret);
368
369 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
370 EXPECT_EQ(0, ret);
371
372 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
373 ASSERT_EQ(0, ret);
374
375 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
376 EXPECT_EQ(2, ret);
377 }
378
379
380 TEST(ALLOW_all)
381 {
382 struct sock_filter filter[] = {
383 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
384 };
385 struct sock_fprog prog = {
386 .len = (unsigned short)ARRAY_SIZE(filter),
387 .filter = filter,
388 };
389 long ret;
390
391 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
392 ASSERT_EQ(0, ret);
393
394 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
395 ASSERT_EQ(0, ret);
396 }
397
398 TEST(empty_prog)
399 {
400 struct sock_filter filter[] = {
401 };
402 struct sock_fprog prog = {
403 .len = (unsigned short)ARRAY_SIZE(filter),
404 .filter = filter,
405 };
406 long ret;
407
408 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
409 ASSERT_EQ(0, ret);
410
411 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
412 EXPECT_EQ(-1, ret);
413 EXPECT_EQ(EINVAL, errno);
414 }
415
416 TEST(log_all)
417 {
418 struct sock_filter filter[] = {
419 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
420 };
421 struct sock_fprog prog = {
422 .len = (unsigned short)ARRAY_SIZE(filter),
423 .filter = filter,
424 };
425 long ret;
426 pid_t parent = getppid();
427
428 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
429 ASSERT_EQ(0, ret);
430
431 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
432 ASSERT_EQ(0, ret);
433
434 /* getppid() should succeed and be logged (no check for logging) */
435 EXPECT_EQ(parent, syscall(__NR_getppid));
436 }
437
438 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
439 {
440 struct sock_filter filter[] = {
441 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
442 };
443 struct sock_fprog prog = {
444 .len = (unsigned short)ARRAY_SIZE(filter),
445 .filter = filter,
446 };
447 long ret;
448
449 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
450 ASSERT_EQ(0, ret);
451
452 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
453 ASSERT_EQ(0, ret);
454 EXPECT_EQ(0, syscall(__NR_getpid)) {
455 TH_LOG("getpid() shouldn't ever return");
456 }
457 }
458
459 /* return code >= 0x80000000 is unused. */
460 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
461 {
462 struct sock_filter filter[] = {
463 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
464 };
465 struct sock_fprog prog = {
466 .len = (unsigned short)ARRAY_SIZE(filter),
467 .filter = filter,
468 };
469 long ret;
470
471 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
472 ASSERT_EQ(0, ret);
473
474 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
475 ASSERT_EQ(0, ret);
476 EXPECT_EQ(0, syscall(__NR_getpid)) {
477 TH_LOG("getpid() shouldn't ever return");
478 }
479 }
480
481 TEST_SIGNAL(KILL_all, SIGSYS)
482 {
483 struct sock_filter filter[] = {
484 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
485 };
486 struct sock_fprog prog = {
487 .len = (unsigned short)ARRAY_SIZE(filter),
488 .filter = filter,
489 };
490 long ret;
491
492 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
493 ASSERT_EQ(0, ret);
494
495 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
496 ASSERT_EQ(0, ret);
497 }
498
499 TEST_SIGNAL(KILL_one, SIGSYS)
500 {
501 struct sock_filter filter[] = {
502 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
503 offsetof(struct seccomp_data, nr)),
504 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
505 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
506 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
507 };
508 struct sock_fprog prog = {
509 .len = (unsigned short)ARRAY_SIZE(filter),
510 .filter = filter,
511 };
512 long ret;
513 pid_t parent = getppid();
514
515 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
516 ASSERT_EQ(0, ret);
517
518 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
519 ASSERT_EQ(0, ret);
520
521 EXPECT_EQ(parent, syscall(__NR_getppid));
522 /* getpid() should never return. */
523 EXPECT_EQ(0, syscall(__NR_getpid));
524 }
525
526 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
527 {
528 void *fatal_address;
529 struct sock_filter filter[] = {
530 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
531 offsetof(struct seccomp_data, nr)),
532 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
533 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
534 /* Only both with lower 32-bit for now. */
535 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
536 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
537 (unsigned long)&fatal_address, 0, 1),
538 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
539 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
540 };
541 struct sock_fprog prog = {
542 .len = (unsigned short)ARRAY_SIZE(filter),
543 .filter = filter,
544 };
545 long ret;
546 pid_t parent = getppid();
547 struct tms timebuf;
548 clock_t clock = times(&timebuf);
549
550 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
551 ASSERT_EQ(0, ret);
552
553 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
554 ASSERT_EQ(0, ret);
555
556 EXPECT_EQ(parent, syscall(__NR_getppid));
557 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
558 /* times() should never return. */
559 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
560 }
561
562 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
563 {
564 #ifndef __NR_mmap2
565 int sysno = __NR_mmap;
566 #else
567 int sysno = __NR_mmap2;
568 #endif
569 struct sock_filter filter[] = {
570 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
571 offsetof(struct seccomp_data, nr)),
572 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
573 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
574 /* Only both with lower 32-bit for now. */
575 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
576 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
577 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
578 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
579 };
580 struct sock_fprog prog = {
581 .len = (unsigned short)ARRAY_SIZE(filter),
582 .filter = filter,
583 };
584 long ret;
585 pid_t parent = getppid();
586 int fd;
587 void *map1, *map2;
588 int page_size = sysconf(_SC_PAGESIZE);
589
590 ASSERT_LT(0, page_size);
591
592 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
593 ASSERT_EQ(0, ret);
594
595 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
596 ASSERT_EQ(0, ret);
597
598 fd = open("/dev/zero", O_RDONLY);
599 ASSERT_NE(-1, fd);
600
601 EXPECT_EQ(parent, syscall(__NR_getppid));
602 map1 = (void *)syscall(sysno,
603 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
604 EXPECT_NE(MAP_FAILED, map1);
605 /* mmap2() should never return. */
606 map2 = (void *)syscall(sysno,
607 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
608 EXPECT_EQ(MAP_FAILED, map2);
609
610 /* The test failed, so clean up the resources. */
611 munmap(map1, page_size);
612 munmap(map2, page_size);
613 close(fd);
614 }
615
616 /* This is a thread task to die via seccomp filter violation. */
617 void *kill_thread(void *data)
618 {
619 bool die = (bool)data;
620
621 if (die) {
622 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
623 return (void *)SIBLING_EXIT_FAILURE;
624 }
625
626 return (void *)SIBLING_EXIT_UNKILLED;
627 }
628
629 /* Prepare a thread that will kill itself or both of us. */
630 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
631 {
632 pthread_t thread;
633 void *status;
634 /* Kill only when calling __NR_prctl. */
635 struct sock_filter filter_thread[] = {
636 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
637 offsetof(struct seccomp_data, nr)),
638 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
639 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
640 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
641 };
642 struct sock_fprog prog_thread = {
643 .len = (unsigned short)ARRAY_SIZE(filter_thread),
644 .filter = filter_thread,
645 };
646 struct sock_filter filter_process[] = {
647 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
648 offsetof(struct seccomp_data, nr)),
649 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
650 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
651 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
652 };
653 struct sock_fprog prog_process = {
654 .len = (unsigned short)ARRAY_SIZE(filter_process),
655 .filter = filter_process,
656 };
657
658 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
659 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
660 }
661
662 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
663 kill_process ? &prog_process : &prog_thread));
664
665 /*
666 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
667 * flag cannot be downgraded by a new filter.
668 */
669 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
670
671 /* Start a thread that will exit immediately. */
672 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
673 ASSERT_EQ(0, pthread_join(thread, &status));
674 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
675
676 /* Start a thread that will die immediately. */
677 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
678 ASSERT_EQ(0, pthread_join(thread, &status));
679 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
680
681 /*
682 * If we get here, only the spawned thread died. Let the parent know
683 * the whole process didn't die (i.e. this thread, the spawner,
684 * stayed running).
685 */
686 exit(42);
687 }
688
689 TEST(KILL_thread)
690 {
691 int status;
692 pid_t child_pid;
693
694 child_pid = fork();
695 ASSERT_LE(0, child_pid);
696 if (child_pid == 0) {
697 kill_thread_or_group(_metadata, false);
698 _exit(38);
699 }
700
701 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
702
703 /* If only the thread was killed, we'll see exit 42. */
704 ASSERT_TRUE(WIFEXITED(status));
705 ASSERT_EQ(42, WEXITSTATUS(status));
706 }
707
708 TEST(KILL_process)
709 {
710 int status;
711 pid_t child_pid;
712
713 child_pid = fork();
714 ASSERT_LE(0, child_pid);
715 if (child_pid == 0) {
716 kill_thread_or_group(_metadata, true);
717 _exit(38);
718 }
719
720 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
721
722 /* If the entire process was killed, we'll see SIGSYS. */
723 ASSERT_TRUE(WIFSIGNALED(status));
724 ASSERT_EQ(SIGSYS, WTERMSIG(status));
725 }
726
727 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
728 TEST(arg_out_of_range)
729 {
730 struct sock_filter filter[] = {
731 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
732 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
733 };
734 struct sock_fprog prog = {
735 .len = (unsigned short)ARRAY_SIZE(filter),
736 .filter = filter,
737 };
738 long ret;
739
740 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
741 ASSERT_EQ(0, ret);
742
743 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
744 EXPECT_EQ(-1, ret);
745 EXPECT_EQ(EINVAL, errno);
746 }
747
748 #define ERRNO_FILTER(name, errno) \
749 struct sock_filter _read_filter_##name[] = { \
750 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
751 offsetof(struct seccomp_data, nr)), \
752 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
754 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
755 }; \
756 struct sock_fprog prog_##name = { \
757 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
758 .filter = _read_filter_##name, \
759 }
760
761 /* Make sure basic errno values are correctly passed through a filter. */
762 TEST(ERRNO_valid)
763 {
764 ERRNO_FILTER(valid, E2BIG);
765 long ret;
766 pid_t parent = getppid();
767
768 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
769 ASSERT_EQ(0, ret);
770
771 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
772 ASSERT_EQ(0, ret);
773
774 EXPECT_EQ(parent, syscall(__NR_getppid));
775 EXPECT_EQ(-1, read(0, NULL, 0));
776 EXPECT_EQ(E2BIG, errno);
777 }
778
779 /* Make sure an errno of zero is correctly handled by the arch code. */
780 TEST(ERRNO_zero)
781 {
782 ERRNO_FILTER(zero, 0);
783 long ret;
784 pid_t parent = getppid();
785
786 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
787 ASSERT_EQ(0, ret);
788
789 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
790 ASSERT_EQ(0, ret);
791
792 EXPECT_EQ(parent, syscall(__NR_getppid));
793 /* "errno" of 0 is ok. */
794 EXPECT_EQ(0, read(0, NULL, 0));
795 }
796
797 /*
798 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
799 * This tests that the errno value gets capped correctly, fixed by
800 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
801 */
802 TEST(ERRNO_capped)
803 {
804 ERRNO_FILTER(capped, 4096);
805 long ret;
806 pid_t parent = getppid();
807
808 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
809 ASSERT_EQ(0, ret);
810
811 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
812 ASSERT_EQ(0, ret);
813
814 EXPECT_EQ(parent, syscall(__NR_getppid));
815 EXPECT_EQ(-1, read(0, NULL, 0));
816 EXPECT_EQ(4095, errno);
817 }
818
819 /*
820 * Filters are processed in reverse order: last applied is executed first.
821 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
822 * SECCOMP_RET_DATA mask results will follow the most recently applied
823 * matching filter return (and not the lowest or highest value).
824 */
825 TEST(ERRNO_order)
826 {
827 ERRNO_FILTER(first, 11);
828 ERRNO_FILTER(second, 13);
829 ERRNO_FILTER(third, 12);
830 long ret;
831 pid_t parent = getppid();
832
833 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
834 ASSERT_EQ(0, ret);
835
836 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
837 ASSERT_EQ(0, ret);
838
839 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
840 ASSERT_EQ(0, ret);
841
842 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
843 ASSERT_EQ(0, ret);
844
845 EXPECT_EQ(parent, syscall(__NR_getppid));
846 EXPECT_EQ(-1, read(0, NULL, 0));
847 EXPECT_EQ(12, errno);
848 }
849
850 FIXTURE_DATA(TRAP) {
851 struct sock_fprog prog;
852 };
853
854 FIXTURE_SETUP(TRAP)
855 {
856 struct sock_filter filter[] = {
857 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
858 offsetof(struct seccomp_data, nr)),
859 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
860 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
861 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
862 };
863
864 memset(&self->prog, 0, sizeof(self->prog));
865 self->prog.filter = malloc(sizeof(filter));
866 ASSERT_NE(NULL, self->prog.filter);
867 memcpy(self->prog.filter, filter, sizeof(filter));
868 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
869 }
870
871 FIXTURE_TEARDOWN(TRAP)
872 {
873 if (self->prog.filter)
874 free(self->prog.filter);
875 }
876
877 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
878 {
879 long ret;
880
881 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
882 ASSERT_EQ(0, ret);
883
884 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
885 ASSERT_EQ(0, ret);
886 syscall(__NR_getpid);
887 }
888
889 /* Ensure that SIGSYS overrides SIG_IGN */
890 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
891 {
892 long ret;
893
894 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
895 ASSERT_EQ(0, ret);
896
897 signal(SIGSYS, SIG_IGN);
898
899 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
900 ASSERT_EQ(0, ret);
901 syscall(__NR_getpid);
902 }
903
904 static siginfo_t TRAP_info;
905 static volatile int TRAP_nr;
906 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
907 {
908 memcpy(&TRAP_info, info, sizeof(TRAP_info));
909 TRAP_nr = nr;
910 }
911
912 TEST_F(TRAP, handler)
913 {
914 int ret, test;
915 struct sigaction act;
916 sigset_t mask;
917
918 memset(&act, 0, sizeof(act));
919 sigemptyset(&mask);
920 sigaddset(&mask, SIGSYS);
921
922 act.sa_sigaction = &TRAP_action;
923 act.sa_flags = SA_SIGINFO;
924 ret = sigaction(SIGSYS, &act, NULL);
925 ASSERT_EQ(0, ret) {
926 TH_LOG("sigaction failed");
927 }
928 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
929 ASSERT_EQ(0, ret) {
930 TH_LOG("sigprocmask failed");
931 }
932
933 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
934 ASSERT_EQ(0, ret);
935 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
936 ASSERT_EQ(0, ret);
937 TRAP_nr = 0;
938 memset(&TRAP_info, 0, sizeof(TRAP_info));
939 /* Expect the registers to be rolled back. (nr = error) may vary
940 * based on arch. */
941 ret = syscall(__NR_getpid);
942 /* Silence gcc warning about volatile. */
943 test = TRAP_nr;
944 EXPECT_EQ(SIGSYS, test);
945 struct local_sigsys {
946 void *_call_addr; /* calling user insn */
947 int _syscall; /* triggering system call number */
948 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
949 } *sigsys = (struct local_sigsys *)
950 #ifdef si_syscall
951 &(TRAP_info.si_call_addr);
952 #else
953 &TRAP_info.si_pid;
954 #endif
955 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
956 /* Make sure arch is non-zero. */
957 EXPECT_NE(0, sigsys->_arch);
958 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
959 }
960
961 FIXTURE_DATA(precedence) {
962 struct sock_fprog allow;
963 struct sock_fprog log;
964 struct sock_fprog trace;
965 struct sock_fprog error;
966 struct sock_fprog trap;
967 struct sock_fprog kill;
968 };
969
970 FIXTURE_SETUP(precedence)
971 {
972 struct sock_filter allow_insns[] = {
973 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
974 };
975 struct sock_filter log_insns[] = {
976 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
977 offsetof(struct seccomp_data, nr)),
978 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
979 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
980 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
981 };
982 struct sock_filter trace_insns[] = {
983 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
984 offsetof(struct seccomp_data, nr)),
985 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
986 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
987 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
988 };
989 struct sock_filter error_insns[] = {
990 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
991 offsetof(struct seccomp_data, nr)),
992 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
993 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
994 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
995 };
996 struct sock_filter trap_insns[] = {
997 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
998 offsetof(struct seccomp_data, nr)),
999 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1000 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1001 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1002 };
1003 struct sock_filter kill_insns[] = {
1004 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1005 offsetof(struct seccomp_data, nr)),
1006 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1007 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1008 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1009 };
1010
1011 memset(self, 0, sizeof(*self));
1012 #define FILTER_ALLOC(_x) \
1013 self->_x.filter = malloc(sizeof(_x##_insns)); \
1014 ASSERT_NE(NULL, self->_x.filter); \
1015 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1016 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1017 FILTER_ALLOC(allow);
1018 FILTER_ALLOC(log);
1019 FILTER_ALLOC(trace);
1020 FILTER_ALLOC(error);
1021 FILTER_ALLOC(trap);
1022 FILTER_ALLOC(kill);
1023 }
1024
1025 FIXTURE_TEARDOWN(precedence)
1026 {
1027 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1028 FILTER_FREE(allow);
1029 FILTER_FREE(log);
1030 FILTER_FREE(trace);
1031 FILTER_FREE(error);
1032 FILTER_FREE(trap);
1033 FILTER_FREE(kill);
1034 }
1035
1036 TEST_F(precedence, allow_ok)
1037 {
1038 pid_t parent, res = 0;
1039 long ret;
1040
1041 parent = getppid();
1042 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1043 ASSERT_EQ(0, ret);
1044
1045 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1046 ASSERT_EQ(0, ret);
1047 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1048 ASSERT_EQ(0, ret);
1049 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1050 ASSERT_EQ(0, ret);
1051 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1052 ASSERT_EQ(0, ret);
1053 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1054 ASSERT_EQ(0, ret);
1055 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1056 ASSERT_EQ(0, ret);
1057 /* Should work just fine. */
1058 res = syscall(__NR_getppid);
1059 EXPECT_EQ(parent, res);
1060 }
1061
1062 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1063 {
1064 pid_t parent, res = 0;
1065 long ret;
1066
1067 parent = getppid();
1068 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1069 ASSERT_EQ(0, ret);
1070
1071 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1072 ASSERT_EQ(0, ret);
1073 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1074 ASSERT_EQ(0, ret);
1075 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1076 ASSERT_EQ(0, ret);
1077 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1078 ASSERT_EQ(0, ret);
1079 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1080 ASSERT_EQ(0, ret);
1081 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1082 ASSERT_EQ(0, ret);
1083 /* Should work just fine. */
1084 res = syscall(__NR_getppid);
1085 EXPECT_EQ(parent, res);
1086 /* getpid() should never return. */
1087 res = syscall(__NR_getpid);
1088 EXPECT_EQ(0, res);
1089 }
1090
1091 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1092 {
1093 pid_t parent;
1094 long ret;
1095
1096 parent = getppid();
1097 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1098 ASSERT_EQ(0, ret);
1099
1100 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1101 ASSERT_EQ(0, ret);
1102 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1103 ASSERT_EQ(0, ret);
1104 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1105 ASSERT_EQ(0, ret);
1106 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1107 ASSERT_EQ(0, ret);
1108 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1109 ASSERT_EQ(0, ret);
1110 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1111 ASSERT_EQ(0, ret);
1112 /* Should work just fine. */
1113 EXPECT_EQ(parent, syscall(__NR_getppid));
1114 /* getpid() should never return. */
1115 EXPECT_EQ(0, syscall(__NR_getpid));
1116 }
1117
1118 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1119 {
1120 pid_t parent;
1121 long ret;
1122
1123 parent = getppid();
1124 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1125 ASSERT_EQ(0, ret);
1126
1127 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1128 ASSERT_EQ(0, ret);
1129 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1130 ASSERT_EQ(0, ret);
1131 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1132 ASSERT_EQ(0, ret);
1133 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1134 ASSERT_EQ(0, ret);
1135 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1136 ASSERT_EQ(0, ret);
1137 /* Should work just fine. */
1138 EXPECT_EQ(parent, syscall(__NR_getppid));
1139 /* getpid() should never return. */
1140 EXPECT_EQ(0, syscall(__NR_getpid));
1141 }
1142
1143 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1144 {
1145 pid_t parent;
1146 long ret;
1147
1148 parent = getppid();
1149 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1150 ASSERT_EQ(0, ret);
1151
1152 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1153 ASSERT_EQ(0, ret);
1154 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1155 ASSERT_EQ(0, ret);
1156 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1157 ASSERT_EQ(0, ret);
1158 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1159 ASSERT_EQ(0, ret);
1160 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1161 ASSERT_EQ(0, ret);
1162 /* Should work just fine. */
1163 EXPECT_EQ(parent, syscall(__NR_getppid));
1164 /* getpid() should never return. */
1165 EXPECT_EQ(0, syscall(__NR_getpid));
1166 }
1167
1168 TEST_F(precedence, errno_is_third)
1169 {
1170 pid_t parent;
1171 long ret;
1172
1173 parent = getppid();
1174 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1175 ASSERT_EQ(0, ret);
1176
1177 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1178 ASSERT_EQ(0, ret);
1179 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1180 ASSERT_EQ(0, ret);
1181 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1182 ASSERT_EQ(0, ret);
1183 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1184 ASSERT_EQ(0, ret);
1185 /* Should work just fine. */
1186 EXPECT_EQ(parent, syscall(__NR_getppid));
1187 EXPECT_EQ(0, syscall(__NR_getpid));
1188 }
1189
1190 TEST_F(precedence, errno_is_third_in_any_order)
1191 {
1192 pid_t parent;
1193 long ret;
1194
1195 parent = getppid();
1196 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1197 ASSERT_EQ(0, ret);
1198
1199 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1200 ASSERT_EQ(0, ret);
1201 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1202 ASSERT_EQ(0, ret);
1203 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1204 ASSERT_EQ(0, ret);
1205 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1206 ASSERT_EQ(0, ret);
1207 /* Should work just fine. */
1208 EXPECT_EQ(parent, syscall(__NR_getppid));
1209 EXPECT_EQ(0, syscall(__NR_getpid));
1210 }
1211
1212 TEST_F(precedence, trace_is_fourth)
1213 {
1214 pid_t parent;
1215 long ret;
1216
1217 parent = getppid();
1218 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1219 ASSERT_EQ(0, ret);
1220
1221 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1222 ASSERT_EQ(0, ret);
1223 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1224 ASSERT_EQ(0, ret);
1225 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1226 ASSERT_EQ(0, ret);
1227 /* Should work just fine. */
1228 EXPECT_EQ(parent, syscall(__NR_getppid));
1229 /* No ptracer */
1230 EXPECT_EQ(-1, syscall(__NR_getpid));
1231 }
1232
1233 TEST_F(precedence, trace_is_fourth_in_any_order)
1234 {
1235 pid_t parent;
1236 long ret;
1237
1238 parent = getppid();
1239 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1240 ASSERT_EQ(0, ret);
1241
1242 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1243 ASSERT_EQ(0, ret);
1244 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1245 ASSERT_EQ(0, ret);
1246 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1247 ASSERT_EQ(0, ret);
1248 /* Should work just fine. */
1249 EXPECT_EQ(parent, syscall(__NR_getppid));
1250 /* No ptracer */
1251 EXPECT_EQ(-1, syscall(__NR_getpid));
1252 }
1253
1254 TEST_F(precedence, log_is_fifth)
1255 {
1256 pid_t mypid, parent;
1257 long ret;
1258
1259 mypid = getpid();
1260 parent = getppid();
1261 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1262 ASSERT_EQ(0, ret);
1263
1264 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1265 ASSERT_EQ(0, ret);
1266 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1267 ASSERT_EQ(0, ret);
1268 /* Should work just fine. */
1269 EXPECT_EQ(parent, syscall(__NR_getppid));
1270 /* Should also work just fine */
1271 EXPECT_EQ(mypid, syscall(__NR_getpid));
1272 }
1273
1274 TEST_F(precedence, log_is_fifth_in_any_order)
1275 {
1276 pid_t mypid, parent;
1277 long ret;
1278
1279 mypid = getpid();
1280 parent = getppid();
1281 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1282 ASSERT_EQ(0, ret);
1283
1284 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1285 ASSERT_EQ(0, ret);
1286 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1287 ASSERT_EQ(0, ret);
1288 /* Should work just fine. */
1289 EXPECT_EQ(parent, syscall(__NR_getppid));
1290 /* Should also work just fine */
1291 EXPECT_EQ(mypid, syscall(__NR_getpid));
1292 }
1293
1294 #ifndef PTRACE_O_TRACESECCOMP
1295 #define PTRACE_O_TRACESECCOMP 0x00000080
1296 #endif
1297
1298 /* Catch the Ubuntu 12.04 value error. */
1299 #if PTRACE_EVENT_SECCOMP != 7
1300 #undef PTRACE_EVENT_SECCOMP
1301 #endif
1302
1303 #ifndef PTRACE_EVENT_SECCOMP
1304 #define PTRACE_EVENT_SECCOMP 7
1305 #endif
1306
1307 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1308 bool tracer_running;
1309 void tracer_stop(int sig)
1310 {
1311 tracer_running = false;
1312 }
1313
1314 typedef void tracer_func_t(struct __test_metadata *_metadata,
1315 pid_t tracee, int status, void *args);
1316
1317 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1318 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1319 {
1320 int ret = -1;
1321 struct sigaction action = {
1322 .sa_handler = tracer_stop,
1323 };
1324
1325 /* Allow external shutdown. */
1326 tracer_running = true;
1327 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1328
1329 errno = 0;
1330 while (ret == -1 && errno != EINVAL)
1331 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1332 ASSERT_EQ(0, ret) {
1333 kill(tracee, SIGKILL);
1334 }
1335 /* Wait for attach stop */
1336 wait(NULL);
1337
1338 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1339 PTRACE_O_TRACESYSGOOD :
1340 PTRACE_O_TRACESECCOMP);
1341 ASSERT_EQ(0, ret) {
1342 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1343 kill(tracee, SIGKILL);
1344 }
1345 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1346 tracee, NULL, 0);
1347 ASSERT_EQ(0, ret);
1348
1349 /* Unblock the tracee */
1350 ASSERT_EQ(1, write(fd, "A", 1));
1351 ASSERT_EQ(0, close(fd));
1352
1353 /* Run until we're shut down. Must assert to stop execution. */
1354 while (tracer_running) {
1355 int status;
1356
1357 if (wait(&status) != tracee)
1358 continue;
1359 if (WIFSIGNALED(status) || WIFEXITED(status))
1360 /* Child is dead. Time to go. */
1361 return;
1362
1363 /* Check if this is a seccomp event. */
1364 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1365
1366 tracer_func(_metadata, tracee, status, args);
1367
1368 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1369 tracee, NULL, 0);
1370 ASSERT_EQ(0, ret);
1371 }
1372 /* Directly report the status of our test harness results. */
1373 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1374 }
1375
1376 /* Common tracer setup/teardown functions. */
1377 void cont_handler(int num)
1378 { }
1379 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1380 tracer_func_t func, void *args, bool ptrace_syscall)
1381 {
1382 char sync;
1383 int pipefd[2];
1384 pid_t tracer_pid;
1385 pid_t tracee = getpid();
1386
1387 /* Setup a pipe for clean synchronization. */
1388 ASSERT_EQ(0, pipe(pipefd));
1389
1390 /* Fork a child which we'll promote to tracer */
1391 tracer_pid = fork();
1392 ASSERT_LE(0, tracer_pid);
1393 signal(SIGALRM, cont_handler);
1394 if (tracer_pid == 0) {
1395 close(pipefd[0]);
1396 start_tracer(_metadata, pipefd[1], tracee, func, args,
1397 ptrace_syscall);
1398 syscall(__NR_exit, 0);
1399 }
1400 close(pipefd[1]);
1401 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1402 read(pipefd[0], &sync, 1);
1403 close(pipefd[0]);
1404
1405 return tracer_pid;
1406 }
1407 void teardown_trace_fixture(struct __test_metadata *_metadata,
1408 pid_t tracer)
1409 {
1410 if (tracer) {
1411 int status;
1412 /*
1413 * Extract the exit code from the other process and
1414 * adopt it for ourselves in case its asserts failed.
1415 */
1416 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1417 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1418 if (WEXITSTATUS(status))
1419 _metadata->passed = 0;
1420 }
1421 }
1422
1423 /* "poke" tracer arguments and function. */
1424 struct tracer_args_poke_t {
1425 unsigned long poke_addr;
1426 };
1427
1428 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1429 void *args)
1430 {
1431 int ret;
1432 unsigned long msg;
1433 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1434
1435 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1436 EXPECT_EQ(0, ret);
1437 /* If this fails, don't try to recover. */
1438 ASSERT_EQ(0x1001, msg) {
1439 kill(tracee, SIGKILL);
1440 }
1441 /*
1442 * Poke in the message.
1443 * Registers are not touched to try to keep this relatively arch
1444 * agnostic.
1445 */
1446 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1447 EXPECT_EQ(0, ret);
1448 }
1449
1450 FIXTURE_DATA(TRACE_poke) {
1451 struct sock_fprog prog;
1452 pid_t tracer;
1453 long poked;
1454 struct tracer_args_poke_t tracer_args;
1455 };
1456
1457 FIXTURE_SETUP(TRACE_poke)
1458 {
1459 struct sock_filter filter[] = {
1460 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1461 offsetof(struct seccomp_data, nr)),
1462 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1463 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1464 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1465 };
1466
1467 self->poked = 0;
1468 memset(&self->prog, 0, sizeof(self->prog));
1469 self->prog.filter = malloc(sizeof(filter));
1470 ASSERT_NE(NULL, self->prog.filter);
1471 memcpy(self->prog.filter, filter, sizeof(filter));
1472 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1473
1474 /* Set up tracer args. */
1475 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1476
1477 /* Launch tracer. */
1478 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1479 &self->tracer_args, false);
1480 }
1481
1482 FIXTURE_TEARDOWN(TRACE_poke)
1483 {
1484 teardown_trace_fixture(_metadata, self->tracer);
1485 if (self->prog.filter)
1486 free(self->prog.filter);
1487 }
1488
1489 TEST_F(TRACE_poke, read_has_side_effects)
1490 {
1491 ssize_t ret;
1492
1493 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1494 ASSERT_EQ(0, ret);
1495
1496 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1497 ASSERT_EQ(0, ret);
1498
1499 EXPECT_EQ(0, self->poked);
1500 ret = read(-1, NULL, 0);
1501 EXPECT_EQ(-1, ret);
1502 EXPECT_EQ(0x1001, self->poked);
1503 }
1504
1505 TEST_F(TRACE_poke, getpid_runs_normally)
1506 {
1507 long ret;
1508
1509 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1510 ASSERT_EQ(0, ret);
1511
1512 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1513 ASSERT_EQ(0, ret);
1514
1515 EXPECT_EQ(0, self->poked);
1516 EXPECT_NE(0, syscall(__NR_getpid));
1517 EXPECT_EQ(0, self->poked);
1518 }
1519
1520 #if defined(__x86_64__)
1521 # define ARCH_REGS struct user_regs_struct
1522 # define SYSCALL_NUM orig_rax
1523 # define SYSCALL_RET rax
1524 #elif defined(__i386__)
1525 # define ARCH_REGS struct user_regs_struct
1526 # define SYSCALL_NUM orig_eax
1527 # define SYSCALL_RET eax
1528 #elif defined(__arm__)
1529 # define ARCH_REGS struct pt_regs
1530 # define SYSCALL_NUM ARM_r7
1531 # define SYSCALL_RET ARM_r0
1532 #elif defined(__aarch64__)
1533 # define ARCH_REGS struct user_pt_regs
1534 # define SYSCALL_NUM regs[8]
1535 # define SYSCALL_RET regs[0]
1536 #elif defined(__hppa__)
1537 # define ARCH_REGS struct user_regs_struct
1538 # define SYSCALL_NUM gr[20]
1539 # define SYSCALL_RET gr[28]
1540 #elif defined(__powerpc__)
1541 # define ARCH_REGS struct pt_regs
1542 # define SYSCALL_NUM gpr[0]
1543 # define SYSCALL_RET gpr[3]
1544 #elif defined(__s390__)
1545 # define ARCH_REGS s390_regs
1546 # define SYSCALL_NUM gprs[2]
1547 # define SYSCALL_RET gprs[2]
1548 #elif defined(__mips__)
1549 # define ARCH_REGS struct pt_regs
1550 # define SYSCALL_NUM regs[2]
1551 # define SYSCALL_SYSCALL_NUM regs[4]
1552 # define SYSCALL_RET regs[2]
1553 # define SYSCALL_NUM_RET_SHARE_REG
1554 #else
1555 # error "Do not know how to find your architecture's registers and syscalls"
1556 #endif
1557
1558 /* When the syscall return can't be changed, stub out the tests for it. */
1559 #ifdef SYSCALL_NUM_RET_SHARE_REG
1560 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1561 #else
1562 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(val, action)
1563 #endif
1564
1565 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1566 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1567 */
1568 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1569 #define HAVE_GETREGS
1570 #endif
1571
1572 /* Architecture-specific syscall fetching routine. */
1573 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1574 {
1575 ARCH_REGS regs;
1576 #ifdef HAVE_GETREGS
1577 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
1578 TH_LOG("PTRACE_GETREGS failed");
1579 return -1;
1580 }
1581 #else
1582 struct iovec iov;
1583
1584 iov.iov_base = &regs;
1585 iov.iov_len = sizeof(regs);
1586 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1587 TH_LOG("PTRACE_GETREGSET failed");
1588 return -1;
1589 }
1590 #endif
1591
1592 #if defined(__mips__)
1593 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1594 return regs.SYSCALL_SYSCALL_NUM;
1595 #endif
1596 return regs.SYSCALL_NUM;
1597 }
1598
1599 /* Architecture-specific syscall changing routine. */
1600 void change_syscall(struct __test_metadata *_metadata,
1601 pid_t tracee, int syscall)
1602 {
1603 int ret;
1604 ARCH_REGS regs;
1605 #ifdef HAVE_GETREGS
1606 ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
1607 #else
1608 struct iovec iov;
1609 iov.iov_base = &regs;
1610 iov.iov_len = sizeof(regs);
1611 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1612 #endif
1613 EXPECT_EQ(0, ret) {}
1614
1615 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1616 defined(__s390__) || defined(__hppa__)
1617 {
1618 regs.SYSCALL_NUM = syscall;
1619 }
1620 #elif defined(__mips__)
1621 {
1622 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1623 regs.SYSCALL_SYSCALL_NUM = syscall;
1624 else
1625 regs.SYSCALL_NUM = syscall;
1626 }
1627
1628 #elif defined(__arm__)
1629 # ifndef PTRACE_SET_SYSCALL
1630 # define PTRACE_SET_SYSCALL 23
1631 # endif
1632 {
1633 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1634 EXPECT_EQ(0, ret);
1635 }
1636
1637 #elif defined(__aarch64__)
1638 # ifndef NT_ARM_SYSTEM_CALL
1639 # define NT_ARM_SYSTEM_CALL 0x404
1640 # endif
1641 {
1642 iov.iov_base = &syscall;
1643 iov.iov_len = sizeof(syscall);
1644 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1645 &iov);
1646 EXPECT_EQ(0, ret);
1647 }
1648
1649 #else
1650 ASSERT_EQ(1, 0) {
1651 TH_LOG("How is the syscall changed on this architecture?");
1652 }
1653 #endif
1654
1655 /* If syscall is skipped, change return value. */
1656 if (syscall == -1)
1657 #ifdef SYSCALL_NUM_RET_SHARE_REG
1658 TH_LOG("Can't modify syscall return on this architecture");
1659 #else
1660 regs.SYSCALL_RET = EPERM;
1661 #endif
1662
1663 #ifdef HAVE_GETREGS
1664 ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
1665 #else
1666 iov.iov_base = &regs;
1667 iov.iov_len = sizeof(regs);
1668 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1669 #endif
1670 EXPECT_EQ(0, ret);
1671 }
1672
1673 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1674 int status, void *args)
1675 {
1676 int ret;
1677 unsigned long msg;
1678
1679 /* Make sure we got the right message. */
1680 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1681 EXPECT_EQ(0, ret);
1682
1683 /* Validate and take action on expected syscalls. */
1684 switch (msg) {
1685 case 0x1002:
1686 /* change getpid to getppid. */
1687 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1688 change_syscall(_metadata, tracee, __NR_getppid);
1689 break;
1690 case 0x1003:
1691 /* skip gettid. */
1692 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1693 change_syscall(_metadata, tracee, -1);
1694 break;
1695 case 0x1004:
1696 /* do nothing (allow getppid) */
1697 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1698 break;
1699 default:
1700 EXPECT_EQ(0, msg) {
1701 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1702 kill(tracee, SIGKILL);
1703 }
1704 }
1705
1706 }
1707
1708 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1709 int status, void *args)
1710 {
1711 int ret, nr;
1712 unsigned long msg;
1713 static bool entry;
1714
1715 /* Make sure we got an empty message. */
1716 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1717 EXPECT_EQ(0, ret);
1718 EXPECT_EQ(0, msg);
1719
1720 /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */
1721 entry = !entry;
1722 if (!entry)
1723 return;
1724
1725 nr = get_syscall(_metadata, tracee);
1726
1727 if (nr == __NR_getpid)
1728 change_syscall(_metadata, tracee, __NR_getppid);
1729 if (nr == __NR_openat)
1730 change_syscall(_metadata, tracee, -1);
1731 }
1732
1733 FIXTURE_DATA(TRACE_syscall) {
1734 struct sock_fprog prog;
1735 pid_t tracer, mytid, mypid, parent;
1736 };
1737
1738 FIXTURE_SETUP(TRACE_syscall)
1739 {
1740 struct sock_filter filter[] = {
1741 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1742 offsetof(struct seccomp_data, nr)),
1743 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1744 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1745 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1746 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1747 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1748 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1749 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1750 };
1751
1752 memset(&self->prog, 0, sizeof(self->prog));
1753 self->prog.filter = malloc(sizeof(filter));
1754 ASSERT_NE(NULL, self->prog.filter);
1755 memcpy(self->prog.filter, filter, sizeof(filter));
1756 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1757
1758 /* Prepare some testable syscall results. */
1759 self->mytid = syscall(__NR_gettid);
1760 ASSERT_GT(self->mytid, 0);
1761 ASSERT_NE(self->mytid, 1) {
1762 TH_LOG("Running this test as init is not supported. :)");
1763 }
1764
1765 self->mypid = getpid();
1766 ASSERT_GT(self->mypid, 0);
1767 ASSERT_EQ(self->mytid, self->mypid);
1768
1769 self->parent = getppid();
1770 ASSERT_GT(self->parent, 0);
1771 ASSERT_NE(self->parent, self->mypid);
1772
1773 /* Launch tracer. */
1774 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1775 false);
1776 }
1777
1778 FIXTURE_TEARDOWN(TRACE_syscall)
1779 {
1780 teardown_trace_fixture(_metadata, self->tracer);
1781 if (self->prog.filter)
1782 free(self->prog.filter);
1783 }
1784
1785 TEST_F(TRACE_syscall, ptrace_syscall_redirected)
1786 {
1787 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1788 teardown_trace_fixture(_metadata, self->tracer);
1789 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1790 true);
1791
1792 /* Tracer will redirect getpid to getppid. */
1793 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1794 }
1795
1796 TEST_F(TRACE_syscall, ptrace_syscall_dropped)
1797 {
1798 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1799 teardown_trace_fixture(_metadata, self->tracer);
1800 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1801 true);
1802
1803 /* Tracer should skip the open syscall, resulting in EPERM. */
1804 EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_openat));
1805 }
1806
1807 TEST_F(TRACE_syscall, syscall_allowed)
1808 {
1809 long ret;
1810
1811 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1812 ASSERT_EQ(0, ret);
1813
1814 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1815 ASSERT_EQ(0, ret);
1816
1817 /* getppid works as expected (no changes). */
1818 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1819 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1820 }
1821
1822 TEST_F(TRACE_syscall, syscall_redirected)
1823 {
1824 long ret;
1825
1826 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1827 ASSERT_EQ(0, ret);
1828
1829 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1830 ASSERT_EQ(0, ret);
1831
1832 /* getpid has been redirected to getppid as expected. */
1833 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1834 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1835 }
1836
1837 TEST_F(TRACE_syscall, syscall_dropped)
1838 {
1839 long ret;
1840
1841 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1842 ASSERT_EQ(0, ret);
1843
1844 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1845 ASSERT_EQ(0, ret);
1846
1847 /* gettid has been skipped and an altered return value stored. */
1848 EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_gettid));
1849 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1850 }
1851
1852 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1853 {
1854 struct sock_filter filter[] = {
1855 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1856 offsetof(struct seccomp_data, nr)),
1857 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1858 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1859 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1860 };
1861 struct sock_fprog prog = {
1862 .len = (unsigned short)ARRAY_SIZE(filter),
1863 .filter = filter,
1864 };
1865 long ret;
1866
1867 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1868 ASSERT_EQ(0, ret);
1869
1870 /* Install fixture filter. */
1871 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1872 ASSERT_EQ(0, ret);
1873
1874 /* Install "errno on getppid" filter. */
1875 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1876 ASSERT_EQ(0, ret);
1877
1878 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1879 errno = 0;
1880 EXPECT_EQ(-1, syscall(__NR_getpid));
1881 EXPECT_EQ(EPERM, errno);
1882 }
1883
1884 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1885 {
1886 struct sock_filter filter[] = {
1887 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1888 offsetof(struct seccomp_data, nr)),
1889 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1890 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1891 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1892 };
1893 struct sock_fprog prog = {
1894 .len = (unsigned short)ARRAY_SIZE(filter),
1895 .filter = filter,
1896 };
1897 long ret;
1898
1899 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1900 ASSERT_EQ(0, ret);
1901
1902 /* Install fixture filter. */
1903 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1904 ASSERT_EQ(0, ret);
1905
1906 /* Install "death on getppid" filter. */
1907 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1908 ASSERT_EQ(0, ret);
1909
1910 /* Tracer will redirect getpid to getppid, and we should die. */
1911 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1912 }
1913
1914 TEST_F(TRACE_syscall, skip_after_ptrace)
1915 {
1916 struct sock_filter filter[] = {
1917 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1918 offsetof(struct seccomp_data, nr)),
1919 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1920 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1921 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1922 };
1923 struct sock_fprog prog = {
1924 .len = (unsigned short)ARRAY_SIZE(filter),
1925 .filter = filter,
1926 };
1927 long ret;
1928
1929 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1930 teardown_trace_fixture(_metadata, self->tracer);
1931 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1932 true);
1933
1934 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1935 ASSERT_EQ(0, ret);
1936
1937 /* Install "errno on getppid" filter. */
1938 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1939 ASSERT_EQ(0, ret);
1940
1941 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1942 EXPECT_EQ(-1, syscall(__NR_getpid));
1943 EXPECT_EQ(EPERM, errno);
1944 }
1945
1946 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
1947 {
1948 struct sock_filter filter[] = {
1949 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1950 offsetof(struct seccomp_data, nr)),
1951 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1952 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1953 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1954 };
1955 struct sock_fprog prog = {
1956 .len = (unsigned short)ARRAY_SIZE(filter),
1957 .filter = filter,
1958 };
1959 long ret;
1960
1961 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1962 teardown_trace_fixture(_metadata, self->tracer);
1963 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1964 true);
1965
1966 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1967 ASSERT_EQ(0, ret);
1968
1969 /* Install "death on getppid" filter. */
1970 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1971 ASSERT_EQ(0, ret);
1972
1973 /* Tracer will redirect getpid to getppid, and we should die. */
1974 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1975 }
1976
1977 TEST(seccomp_syscall)
1978 {
1979 struct sock_filter filter[] = {
1980 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1981 };
1982 struct sock_fprog prog = {
1983 .len = (unsigned short)ARRAY_SIZE(filter),
1984 .filter = filter,
1985 };
1986 long ret;
1987
1988 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1989 ASSERT_EQ(0, ret) {
1990 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1991 }
1992
1993 /* Reject insane operation. */
1994 ret = seccomp(-1, 0, &prog);
1995 ASSERT_NE(ENOSYS, errno) {
1996 TH_LOG("Kernel does not support seccomp syscall!");
1997 }
1998 EXPECT_EQ(EINVAL, errno) {
1999 TH_LOG("Did not reject crazy op value!");
2000 }
2001
2002 /* Reject strict with flags or pointer. */
2003 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2004 EXPECT_EQ(EINVAL, errno) {
2005 TH_LOG("Did not reject mode strict with flags!");
2006 }
2007 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2008 EXPECT_EQ(EINVAL, errno) {
2009 TH_LOG("Did not reject mode strict with uargs!");
2010 }
2011
2012 /* Reject insane args for filter. */
2013 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2014 EXPECT_EQ(EINVAL, errno) {
2015 TH_LOG("Did not reject crazy filter flags!");
2016 }
2017 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2018 EXPECT_EQ(EFAULT, errno) {
2019 TH_LOG("Did not reject NULL filter!");
2020 }
2021
2022 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2023 EXPECT_EQ(0, errno) {
2024 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2025 strerror(errno));
2026 }
2027 }
2028
2029 TEST(seccomp_syscall_mode_lock)
2030 {
2031 struct sock_filter filter[] = {
2032 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2033 };
2034 struct sock_fprog prog = {
2035 .len = (unsigned short)ARRAY_SIZE(filter),
2036 .filter = filter,
2037 };
2038 long ret;
2039
2040 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2041 ASSERT_EQ(0, ret) {
2042 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2043 }
2044
2045 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2046 ASSERT_NE(ENOSYS, errno) {
2047 TH_LOG("Kernel does not support seccomp syscall!");
2048 }
2049 EXPECT_EQ(0, ret) {
2050 TH_LOG("Could not install filter!");
2051 }
2052
2053 /* Make sure neither entry point will switch to strict. */
2054 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2055 EXPECT_EQ(EINVAL, errno) {
2056 TH_LOG("Switched to mode strict!");
2057 }
2058
2059 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2060 EXPECT_EQ(EINVAL, errno) {
2061 TH_LOG("Switched to mode strict!");
2062 }
2063 }
2064
2065 /*
2066 * Test detection of known and unknown filter flags. Userspace needs to be able
2067 * to check if a filter flag is supported by the current kernel and a good way
2068 * of doing that is by attempting to enter filter mode, with the flag bit in
2069 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2070 * that the flag is valid and EINVAL indicates that the flag is invalid.
2071 */
2072 TEST(detect_seccomp_filter_flags)
2073 {
2074 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2075 SECCOMP_FILTER_FLAG_LOG };
2076 unsigned int flag, all_flags;
2077 int i;
2078 long ret;
2079
2080 /* Test detection of known-good filter flags */
2081 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2082 flag = flags[i];
2083 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2084 ASSERT_NE(ENOSYS, errno) {
2085 TH_LOG("Kernel does not support seccomp syscall!");
2086 }
2087 EXPECT_EQ(-1, ret);
2088 EXPECT_EQ(EFAULT, errno) {
2089 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2090 flag);
2091 }
2092
2093 all_flags |= flag;
2094 }
2095
2096 /* Test detection of all known-good filter flags */
2097 ret = seccomp(SECCOMP_SET_MODE_FILTER, all_flags, NULL);
2098 EXPECT_EQ(-1, ret);
2099 EXPECT_EQ(EFAULT, errno) {
2100 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2101 all_flags);
2102 }
2103
2104 /* Test detection of an unknown filter flag */
2105 flag = -1;
2106 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2107 EXPECT_EQ(-1, ret);
2108 EXPECT_EQ(EINVAL, errno) {
2109 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2110 flag);
2111 }
2112
2113 /*
2114 * Test detection of an unknown filter flag that may simply need to be
2115 * added to this test
2116 */
2117 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2118 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2119 EXPECT_EQ(-1, ret);
2120 EXPECT_EQ(EINVAL, errno) {
2121 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?",
2122 flag);
2123 }
2124 }
2125
2126 TEST(TSYNC_first)
2127 {
2128 struct sock_filter filter[] = {
2129 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2130 };
2131 struct sock_fprog prog = {
2132 .len = (unsigned short)ARRAY_SIZE(filter),
2133 .filter = filter,
2134 };
2135 long ret;
2136
2137 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2138 ASSERT_EQ(0, ret) {
2139 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2140 }
2141
2142 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2143 &prog);
2144 ASSERT_NE(ENOSYS, errno) {
2145 TH_LOG("Kernel does not support seccomp syscall!");
2146 }
2147 EXPECT_EQ(0, ret) {
2148 TH_LOG("Could not install initial filter with TSYNC!");
2149 }
2150 }
2151
2152 #define TSYNC_SIBLINGS 2
2153 struct tsync_sibling {
2154 pthread_t tid;
2155 pid_t system_tid;
2156 sem_t *started;
2157 pthread_cond_t *cond;
2158 pthread_mutex_t *mutex;
2159 int diverge;
2160 int num_waits;
2161 struct sock_fprog *prog;
2162 struct __test_metadata *metadata;
2163 };
2164
2165 /*
2166 * To avoid joining joined threads (which is not allowed by Bionic),
2167 * make sure we both successfully join and clear the tid to skip a
2168 * later join attempt during fixture teardown. Any remaining threads
2169 * will be directly killed during teardown.
2170 */
2171 #define PTHREAD_JOIN(tid, status) \
2172 do { \
2173 int _rc = pthread_join(tid, status); \
2174 if (_rc) { \
2175 TH_LOG("pthread_join of tid %u failed: %d\n", \
2176 (unsigned int)tid, _rc); \
2177 } else { \
2178 tid = 0; \
2179 } \
2180 } while (0)
2181
2182 FIXTURE_DATA(TSYNC) {
2183 struct sock_fprog root_prog, apply_prog;
2184 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2185 sem_t started;
2186 pthread_cond_t cond;
2187 pthread_mutex_t mutex;
2188 int sibling_count;
2189 };
2190
2191 FIXTURE_SETUP(TSYNC)
2192 {
2193 struct sock_filter root_filter[] = {
2194 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2195 };
2196 struct sock_filter apply_filter[] = {
2197 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2198 offsetof(struct seccomp_data, nr)),
2199 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2200 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2201 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2202 };
2203
2204 memset(&self->root_prog, 0, sizeof(self->root_prog));
2205 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2206 memset(&self->sibling, 0, sizeof(self->sibling));
2207 self->root_prog.filter = malloc(sizeof(root_filter));
2208 ASSERT_NE(NULL, self->root_prog.filter);
2209 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2210 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2211
2212 self->apply_prog.filter = malloc(sizeof(apply_filter));
2213 ASSERT_NE(NULL, self->apply_prog.filter);
2214 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2215 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2216
2217 self->sibling_count = 0;
2218 pthread_mutex_init(&self->mutex, NULL);
2219 pthread_cond_init(&self->cond, NULL);
2220 sem_init(&self->started, 0, 0);
2221 self->sibling[0].tid = 0;
2222 self->sibling[0].cond = &self->cond;
2223 self->sibling[0].started = &self->started;
2224 self->sibling[0].mutex = &self->mutex;
2225 self->sibling[0].diverge = 0;
2226 self->sibling[0].num_waits = 1;
2227 self->sibling[0].prog = &self->root_prog;
2228 self->sibling[0].metadata = _metadata;
2229 self->sibling[1].tid = 0;
2230 self->sibling[1].cond = &self->cond;
2231 self->sibling[1].started = &self->started;
2232 self->sibling[1].mutex = &self->mutex;
2233 self->sibling[1].diverge = 0;
2234 self->sibling[1].prog = &self->root_prog;
2235 self->sibling[1].num_waits = 1;
2236 self->sibling[1].metadata = _metadata;
2237 }
2238
2239 FIXTURE_TEARDOWN(TSYNC)
2240 {
2241 int sib = 0;
2242
2243 if (self->root_prog.filter)
2244 free(self->root_prog.filter);
2245 if (self->apply_prog.filter)
2246 free(self->apply_prog.filter);
2247
2248 for ( ; sib < self->sibling_count; ++sib) {
2249 struct tsync_sibling *s = &self->sibling[sib];
2250
2251 if (!s->tid)
2252 continue;
2253 /*
2254 * If a thread is still running, it may be stuck, so hit
2255 * it over the head really hard.
2256 */
2257 pthread_kill(s->tid, 9);
2258 }
2259 pthread_mutex_destroy(&self->mutex);
2260 pthread_cond_destroy(&self->cond);
2261 sem_destroy(&self->started);
2262 }
2263
2264 void *tsync_sibling(void *data)
2265 {
2266 long ret = 0;
2267 struct tsync_sibling *me = data;
2268
2269 me->system_tid = syscall(__NR_gettid);
2270
2271 pthread_mutex_lock(me->mutex);
2272 if (me->diverge) {
2273 /* Just re-apply the root prog to fork the tree */
2274 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2275 me->prog, 0, 0);
2276 }
2277 sem_post(me->started);
2278 /* Return outside of started so parent notices failures. */
2279 if (ret) {
2280 pthread_mutex_unlock(me->mutex);
2281 return (void *)SIBLING_EXIT_FAILURE;
2282 }
2283 do {
2284 pthread_cond_wait(me->cond, me->mutex);
2285 me->num_waits = me->num_waits - 1;
2286 } while (me->num_waits);
2287 pthread_mutex_unlock(me->mutex);
2288
2289 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2290 if (!ret)
2291 return (void *)SIBLING_EXIT_NEWPRIVS;
2292 read(0, NULL, 0);
2293 return (void *)SIBLING_EXIT_UNKILLED;
2294 }
2295
2296 void tsync_start_sibling(struct tsync_sibling *sibling)
2297 {
2298 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2299 }
2300
2301 TEST_F(TSYNC, siblings_fail_prctl)
2302 {
2303 long ret;
2304 void *status;
2305 struct sock_filter filter[] = {
2306 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2307 offsetof(struct seccomp_data, nr)),
2308 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2309 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2310 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2311 };
2312 struct sock_fprog prog = {
2313 .len = (unsigned short)ARRAY_SIZE(filter),
2314 .filter = filter,
2315 };
2316
2317 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2318 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2319 }
2320
2321 /* Check prctl failure detection by requesting sib 0 diverge. */
2322 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2323 ASSERT_NE(ENOSYS, errno) {
2324 TH_LOG("Kernel does not support seccomp syscall!");
2325 }
2326 ASSERT_EQ(0, ret) {
2327 TH_LOG("setting filter failed");
2328 }
2329
2330 self->sibling[0].diverge = 1;
2331 tsync_start_sibling(&self->sibling[0]);
2332 tsync_start_sibling(&self->sibling[1]);
2333
2334 while (self->sibling_count < TSYNC_SIBLINGS) {
2335 sem_wait(&self->started);
2336 self->sibling_count++;
2337 }
2338
2339 /* Signal the threads to clean up*/
2340 pthread_mutex_lock(&self->mutex);
2341 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2342 TH_LOG("cond broadcast non-zero");
2343 }
2344 pthread_mutex_unlock(&self->mutex);
2345
2346 /* Ensure diverging sibling failed to call prctl. */
2347 PTHREAD_JOIN(self->sibling[0].tid, &status);
2348 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2349 PTHREAD_JOIN(self->sibling[1].tid, &status);
2350 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2351 }
2352
2353 TEST_F(TSYNC, two_siblings_with_ancestor)
2354 {
2355 long ret;
2356 void *status;
2357
2358 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2359 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2360 }
2361
2362 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2363 ASSERT_NE(ENOSYS, errno) {
2364 TH_LOG("Kernel does not support seccomp syscall!");
2365 }
2366 ASSERT_EQ(0, ret) {
2367 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2368 }
2369 tsync_start_sibling(&self->sibling[0]);
2370 tsync_start_sibling(&self->sibling[1]);
2371
2372 while (self->sibling_count < TSYNC_SIBLINGS) {
2373 sem_wait(&self->started);
2374 self->sibling_count++;
2375 }
2376
2377 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2378 &self->apply_prog);
2379 ASSERT_EQ(0, ret) {
2380 TH_LOG("Could install filter on all threads!");
2381 }
2382 /* Tell the siblings to test the policy */
2383 pthread_mutex_lock(&self->mutex);
2384 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2385 TH_LOG("cond broadcast non-zero");
2386 }
2387 pthread_mutex_unlock(&self->mutex);
2388 /* Ensure they are both killed and don't exit cleanly. */
2389 PTHREAD_JOIN(self->sibling[0].tid, &status);
2390 EXPECT_EQ(0x0, (long)status);
2391 PTHREAD_JOIN(self->sibling[1].tid, &status);
2392 EXPECT_EQ(0x0, (long)status);
2393 }
2394
2395 TEST_F(TSYNC, two_sibling_want_nnp)
2396 {
2397 void *status;
2398
2399 /* start siblings before any prctl() operations */
2400 tsync_start_sibling(&self->sibling[0]);
2401 tsync_start_sibling(&self->sibling[1]);
2402 while (self->sibling_count < TSYNC_SIBLINGS) {
2403 sem_wait(&self->started);
2404 self->sibling_count++;
2405 }
2406
2407 /* Tell the siblings to test no policy */
2408 pthread_mutex_lock(&self->mutex);
2409 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2410 TH_LOG("cond broadcast non-zero");
2411 }
2412 pthread_mutex_unlock(&self->mutex);
2413
2414 /* Ensure they are both upset about lacking nnp. */
2415 PTHREAD_JOIN(self->sibling[0].tid, &status);
2416 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2417 PTHREAD_JOIN(self->sibling[1].tid, &status);
2418 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2419 }
2420
2421 TEST_F(TSYNC, two_siblings_with_no_filter)
2422 {
2423 long ret;
2424 void *status;
2425
2426 /* start siblings before any prctl() operations */
2427 tsync_start_sibling(&self->sibling[0]);
2428 tsync_start_sibling(&self->sibling[1]);
2429 while (self->sibling_count < TSYNC_SIBLINGS) {
2430 sem_wait(&self->started);
2431 self->sibling_count++;
2432 }
2433
2434 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2435 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2436 }
2437
2438 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2439 &self->apply_prog);
2440 ASSERT_NE(ENOSYS, errno) {
2441 TH_LOG("Kernel does not support seccomp syscall!");
2442 }
2443 ASSERT_EQ(0, ret) {
2444 TH_LOG("Could install filter on all threads!");
2445 }
2446
2447 /* Tell the siblings to test the policy */
2448 pthread_mutex_lock(&self->mutex);
2449 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2450 TH_LOG("cond broadcast non-zero");
2451 }
2452 pthread_mutex_unlock(&self->mutex);
2453
2454 /* Ensure they are both killed and don't exit cleanly. */
2455 PTHREAD_JOIN(self->sibling[0].tid, &status);
2456 EXPECT_EQ(0x0, (long)status);
2457 PTHREAD_JOIN(self->sibling[1].tid, &status);
2458 EXPECT_EQ(0x0, (long)status);
2459 }
2460
2461 TEST_F(TSYNC, two_siblings_with_one_divergence)
2462 {
2463 long ret;
2464 void *status;
2465
2466 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2467 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2468 }
2469
2470 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2471 ASSERT_NE(ENOSYS, errno) {
2472 TH_LOG("Kernel does not support seccomp syscall!");
2473 }
2474 ASSERT_EQ(0, ret) {
2475 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2476 }
2477 self->sibling[0].diverge = 1;
2478 tsync_start_sibling(&self->sibling[0]);
2479 tsync_start_sibling(&self->sibling[1]);
2480
2481 while (self->sibling_count < TSYNC_SIBLINGS) {
2482 sem_wait(&self->started);
2483 self->sibling_count++;
2484 }
2485
2486 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2487 &self->apply_prog);
2488 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2489 TH_LOG("Did not fail on diverged sibling.");
2490 }
2491
2492 /* Wake the threads */
2493 pthread_mutex_lock(&self->mutex);
2494 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2495 TH_LOG("cond broadcast non-zero");
2496 }
2497 pthread_mutex_unlock(&self->mutex);
2498
2499 /* Ensure they are both unkilled. */
2500 PTHREAD_JOIN(self->sibling[0].tid, &status);
2501 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2502 PTHREAD_JOIN(self->sibling[1].tid, &status);
2503 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2504 }
2505
2506 TEST_F(TSYNC, two_siblings_not_under_filter)
2507 {
2508 long ret, sib;
2509 void *status;
2510
2511 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2512 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2513 }
2514
2515 /*
2516 * Sibling 0 will have its own seccomp policy
2517 * and Sibling 1 will not be under seccomp at
2518 * all. Sibling 1 will enter seccomp and 0
2519 * will cause failure.
2520 */
2521 self->sibling[0].diverge = 1;
2522 tsync_start_sibling(&self->sibling[0]);
2523 tsync_start_sibling(&self->sibling[1]);
2524
2525 while (self->sibling_count < TSYNC_SIBLINGS) {
2526 sem_wait(&self->started);
2527 self->sibling_count++;
2528 }
2529
2530 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2531 ASSERT_NE(ENOSYS, errno) {
2532 TH_LOG("Kernel does not support seccomp syscall!");
2533 }
2534 ASSERT_EQ(0, ret) {
2535 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2536 }
2537
2538 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2539 &self->apply_prog);
2540 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2541 TH_LOG("Did not fail on diverged sibling.");
2542 }
2543 sib = 1;
2544 if (ret == self->sibling[0].system_tid)
2545 sib = 0;
2546
2547 pthread_mutex_lock(&self->mutex);
2548
2549 /* Increment the other siblings num_waits so we can clean up
2550 * the one we just saw.
2551 */
2552 self->sibling[!sib].num_waits += 1;
2553
2554 /* Signal the thread to clean up*/
2555 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2556 TH_LOG("cond broadcast non-zero");
2557 }
2558 pthread_mutex_unlock(&self->mutex);
2559 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2560 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2561 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2562 while (!kill(self->sibling[sib].system_tid, 0))
2563 sleep(0.1);
2564 /* Switch to the remaining sibling */
2565 sib = !sib;
2566
2567 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2568 &self->apply_prog);
2569 ASSERT_EQ(0, ret) {
2570 TH_LOG("Expected the remaining sibling to sync");
2571 };
2572
2573 pthread_mutex_lock(&self->mutex);
2574
2575 /* If remaining sibling didn't have a chance to wake up during
2576 * the first broadcast, manually reduce the num_waits now.
2577 */
2578 if (self->sibling[sib].num_waits > 1)
2579 self->sibling[sib].num_waits = 1;
2580 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2581 TH_LOG("cond broadcast non-zero");
2582 }
2583 pthread_mutex_unlock(&self->mutex);
2584 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2585 EXPECT_EQ(0, (long)status);
2586 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2587 while (!kill(self->sibling[sib].system_tid, 0))
2588 sleep(0.1);
2589
2590 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2591 &self->apply_prog);
2592 ASSERT_EQ(0, ret); /* just us chickens */
2593 }
2594
2595 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2596 TEST(syscall_restart)
2597 {
2598 long ret;
2599 unsigned long msg;
2600 pid_t child_pid;
2601 int pipefd[2];
2602 int status;
2603 siginfo_t info = { };
2604 struct sock_filter filter[] = {
2605 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2606 offsetof(struct seccomp_data, nr)),
2607
2608 #ifdef __NR_sigreturn
2609 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2610 #endif
2611 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2612 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2613 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2614 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2615 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2616
2617 /* Allow __NR_write for easy logging. */
2618 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2619 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2620 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2621 /* The nanosleep jump target. */
2622 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2623 /* The restart_syscall jump target. */
2624 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2625 };
2626 struct sock_fprog prog = {
2627 .len = (unsigned short)ARRAY_SIZE(filter),
2628 .filter = filter,
2629 };
2630 #if defined(__arm__)
2631 struct utsname utsbuf;
2632 #endif
2633
2634 ASSERT_EQ(0, pipe(pipefd));
2635
2636 child_pid = fork();
2637 ASSERT_LE(0, child_pid);
2638 if (child_pid == 0) {
2639 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2640 char buf = ' ';
2641 struct timespec timeout = { };
2642
2643 /* Attach parent as tracer and stop. */
2644 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2645 EXPECT_EQ(0, raise(SIGSTOP));
2646
2647 EXPECT_EQ(0, close(pipefd[1]));
2648
2649 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2650 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2651 }
2652
2653 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2654 EXPECT_EQ(0, ret) {
2655 TH_LOG("Failed to install filter!");
2656 }
2657
2658 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2659 TH_LOG("Failed to read() sync from parent");
2660 }
2661 EXPECT_EQ('.', buf) {
2662 TH_LOG("Failed to get sync data from read()");
2663 }
2664
2665 /* Start nanosleep to be interrupted. */
2666 timeout.tv_sec = 1;
2667 errno = 0;
2668 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2669 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2670 }
2671
2672 /* Read final sync from parent. */
2673 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2674 TH_LOG("Failed final read() from parent");
2675 }
2676 EXPECT_EQ('!', buf) {
2677 TH_LOG("Failed to get final data from read()");
2678 }
2679
2680 /* Directly report the status of our test harness results. */
2681 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2682 : EXIT_FAILURE);
2683 }
2684 EXPECT_EQ(0, close(pipefd[0]));
2685
2686 /* Attach to child, setup options, and release. */
2687 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2688 ASSERT_EQ(true, WIFSTOPPED(status));
2689 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2690 PTRACE_O_TRACESECCOMP));
2691 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2692 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2693
2694 /* Wait for nanosleep() to start. */
2695 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2696 ASSERT_EQ(true, WIFSTOPPED(status));
2697 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2698 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2699 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2700 ASSERT_EQ(0x100, msg);
2701 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2702
2703 /* Might as well check siginfo for sanity while we're here. */
2704 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2705 ASSERT_EQ(SIGTRAP, info.si_signo);
2706 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2707 EXPECT_EQ(0, info.si_errno);
2708 EXPECT_EQ(getuid(), info.si_uid);
2709 /* Verify signal delivery came from child (seccomp-triggered). */
2710 EXPECT_EQ(child_pid, info.si_pid);
2711
2712 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2713 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2714 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2715 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2716 ASSERT_EQ(true, WIFSTOPPED(status));
2717 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2718 /* Verify signal delivery came from parent now. */
2719 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2720 EXPECT_EQ(getpid(), info.si_pid);
2721
2722 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2723 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2724 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2725 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2726 ASSERT_EQ(true, WIFSTOPPED(status));
2727 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2728 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2729
2730 /* Wait for restart_syscall() to start. */
2731 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2732 ASSERT_EQ(true, WIFSTOPPED(status));
2733 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2734 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2735 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2736
2737 ASSERT_EQ(0x200, msg);
2738 ret = get_syscall(_metadata, child_pid);
2739 #if defined(__arm__)
2740 /*
2741 * FIXME:
2742 * - native ARM registers do NOT expose true syscall.
2743 * - compat ARM registers on ARM64 DO expose true syscall.
2744 */
2745 ASSERT_EQ(0, uname(&utsbuf));
2746 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2747 EXPECT_EQ(__NR_nanosleep, ret);
2748 } else
2749 #endif
2750 {
2751 EXPECT_EQ(__NR_restart_syscall, ret);
2752 }
2753
2754 /* Write again to end test. */
2755 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2756 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2757 EXPECT_EQ(0, close(pipefd[1]));
2758
2759 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2760 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2761 _metadata->passed = 0;
2762 }
2763
2764 TEST_SIGNAL(filter_flag_log, SIGSYS)
2765 {
2766 struct sock_filter allow_filter[] = {
2767 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2768 };
2769 struct sock_filter kill_filter[] = {
2770 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2771 offsetof(struct seccomp_data, nr)),
2772 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2773 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2774 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2775 };
2776 struct sock_fprog allow_prog = {
2777 .len = (unsigned short)ARRAY_SIZE(allow_filter),
2778 .filter = allow_filter,
2779 };
2780 struct sock_fprog kill_prog = {
2781 .len = (unsigned short)ARRAY_SIZE(kill_filter),
2782 .filter = kill_filter,
2783 };
2784 long ret;
2785 pid_t parent = getppid();
2786
2787 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2788 ASSERT_EQ(0, ret);
2789
2790 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
2791 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
2792 &allow_prog);
2793 ASSERT_NE(ENOSYS, errno) {
2794 TH_LOG("Kernel does not support seccomp syscall!");
2795 }
2796 EXPECT_NE(0, ret) {
2797 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
2798 }
2799 EXPECT_EQ(EINVAL, errno) {
2800 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
2801 }
2802
2803 /* Verify that a simple, permissive filter can be added with no flags */
2804 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
2805 EXPECT_EQ(0, ret);
2806
2807 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
2808 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2809 &allow_prog);
2810 ASSERT_NE(EINVAL, errno) {
2811 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
2812 }
2813 EXPECT_EQ(0, ret);
2814
2815 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
2816 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2817 &kill_prog);
2818 EXPECT_EQ(0, ret);
2819
2820 EXPECT_EQ(parent, syscall(__NR_getppid));
2821 /* getpid() should never return. */
2822 EXPECT_EQ(0, syscall(__NR_getpid));
2823 }
2824
2825 TEST(get_action_avail)
2826 {
2827 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
2828 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
2829 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
2830 __u32 unknown_action = 0x10000000U;
2831 int i;
2832 long ret;
2833
2834 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
2835 ASSERT_NE(ENOSYS, errno) {
2836 TH_LOG("Kernel does not support seccomp syscall!");
2837 }
2838 ASSERT_NE(EINVAL, errno) {
2839 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
2840 }
2841 EXPECT_EQ(ret, 0);
2842
2843 for (i = 0; i < ARRAY_SIZE(actions); i++) {
2844 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
2845 EXPECT_EQ(ret, 0) {
2846 TH_LOG("Expected action (0x%X) not available!",
2847 actions[i]);
2848 }
2849 }
2850
2851 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
2852 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
2853 EXPECT_EQ(ret, -1);
2854 EXPECT_EQ(errno, EOPNOTSUPP);
2855 }
2856
2857 TEST(get_metadata)
2858 {
2859 pid_t pid;
2860 int pipefd[2];
2861 char buf;
2862 struct seccomp_metadata md;
2863
2864 ASSERT_EQ(0, pipe(pipefd));
2865
2866 pid = fork();
2867 ASSERT_GE(pid, 0);
2868 if (pid == 0) {
2869 struct sock_filter filter[] = {
2870 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2871 };
2872 struct sock_fprog prog = {
2873 .len = (unsigned short)ARRAY_SIZE(filter),
2874 .filter = filter,
2875 };
2876
2877 /* one with log, one without */
2878 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
2879 SECCOMP_FILTER_FLAG_LOG, &prog));
2880 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
2881
2882 ASSERT_EQ(0, close(pipefd[0]));
2883 ASSERT_EQ(1, write(pipefd[1], "1", 1));
2884 ASSERT_EQ(0, close(pipefd[1]));
2885
2886 while (1)
2887 sleep(100);
2888 }
2889
2890 ASSERT_EQ(0, close(pipefd[1]));
2891 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
2892
2893 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
2894 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
2895
2896 md.filter_off = 0;
2897 ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
2898 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
2899 EXPECT_EQ(md.filter_off, 0);
2900
2901 md.filter_off = 1;
2902 ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
2903 EXPECT_EQ(md.flags, 0);
2904 EXPECT_EQ(md.filter_off, 1);
2905
2906 ASSERT_EQ(0, kill(pid, SIGKILL));
2907 }
2908
2909 /*
2910 * TODO:
2911 * - add microbenchmarks
2912 * - expand NNP testing
2913 * - better arch-specific TRACE and TRAP handlers.
2914 * - endianness checking when appropriate
2915 * - 64-bit arg prodding
2916 * - arch value testing (x86 modes especially)
2917 * - verify that FILTER_FLAG_LOG filters generate log messages
2918 * - verify that RET_LOG generates log messages
2919 * - ...
2920 */
2921
2922 TEST_HARNESS_MAIN
CRIS linux kernel tree