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Merge tag 'mmc-v4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc
[mirror_ubuntu-disco-kernel.git] / tools / testing / selftests / seccomp / seccomp_bpf.c
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 #include <asm/siginfo.h>
10 #define __have_siginfo_t 1
11 #define __have_sigval_t 1
12 #define __have_sigevent_t 1
13
14 #include <errno.h>
15 #include <linux/filter.h>
16 #include <sys/prctl.h>
17 #include <sys/ptrace.h>
18 #include <sys/user.h>
19 #include <linux/prctl.h>
20 #include <linux/ptrace.h>
21 #include <linux/seccomp.h>
22 #include <pthread.h>
23 #include <semaphore.h>
24 #include <signal.h>
25 #include <stddef.h>
26 #include <stdbool.h>
27 #include <string.h>
28 #include <time.h>
29 #include <linux/elf.h>
30 #include <sys/uio.h>
31 #include <sys/utsname.h>
32 #include <sys/fcntl.h>
33 #include <sys/mman.h>
34 #include <sys/times.h>
35
36 #define _GNU_SOURCE
37 #include <unistd.h>
38 #include <sys/syscall.h>
39
40 #include "../kselftest_harness.h"
41
42 #ifndef PR_SET_PTRACER
43 # define PR_SET_PTRACER 0x59616d61
44 #endif
45
46 #ifndef PR_SET_NO_NEW_PRIVS
47 #define PR_SET_NO_NEW_PRIVS 38
48 #define PR_GET_NO_NEW_PRIVS 39
49 #endif
50
51 #ifndef PR_SECCOMP_EXT
52 #define PR_SECCOMP_EXT 43
53 #endif
54
55 #ifndef SECCOMP_EXT_ACT
56 #define SECCOMP_EXT_ACT 1
57 #endif
58
59 #ifndef SECCOMP_EXT_ACT_TSYNC
60 #define SECCOMP_EXT_ACT_TSYNC 1
61 #endif
62
63 #ifndef SECCOMP_MODE_STRICT
64 #define SECCOMP_MODE_STRICT 1
65 #endif
66
67 #ifndef SECCOMP_MODE_FILTER
68 #define SECCOMP_MODE_FILTER 2
69 #endif
70
71 #ifndef SECCOMP_RET_KILL
72 #define SECCOMP_RET_KILL 0x00000000U /* kill the task immediately */
73 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
74 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
75 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
76 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
77
78 /* Masks for the return value sections. */
79 #define SECCOMP_RET_ACTION 0x7fff0000U
80 #define SECCOMP_RET_DATA 0x0000ffffU
81
82 struct seccomp_data {
83 int nr;
84 __u32 arch;
85 __u64 instruction_pointer;
86 __u64 args[6];
87 };
88 #endif
89
90 #if __BYTE_ORDER == __LITTLE_ENDIAN
91 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
92 #elif __BYTE_ORDER == __BIG_ENDIAN
93 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
94 #else
95 #error "wut? Unknown __BYTE_ORDER?!"
96 #endif
97
98 #define SIBLING_EXIT_UNKILLED 0xbadbeef
99 #define SIBLING_EXIT_FAILURE 0xbadface
100 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
101
102 TEST(mode_strict_support)
103 {
104 long ret;
105
106 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
107 ASSERT_EQ(0, ret) {
108 TH_LOG("Kernel does not support CONFIG_SECCOMP");
109 }
110 syscall(__NR_exit, 0);
111 }
112
113 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
114 {
115 long ret;
116
117 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
118 ASSERT_EQ(0, ret) {
119 TH_LOG("Kernel does not support CONFIG_SECCOMP");
120 }
121 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
122 NULL, NULL, NULL);
123 EXPECT_FALSE(true) {
124 TH_LOG("Unreachable!");
125 }
126 }
127
128 /* Note! This doesn't test no new privs behavior */
129 TEST(no_new_privs_support)
130 {
131 long ret;
132
133 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
134 EXPECT_EQ(0, ret) {
135 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
136 }
137 }
138
139 /* Tests kernel support by checking for a copy_from_user() fault on * NULL. */
140 TEST(mode_filter_support)
141 {
142 long ret;
143
144 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
145 ASSERT_EQ(0, ret) {
146 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
147 }
148 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
149 EXPECT_EQ(-1, ret);
150 EXPECT_EQ(EFAULT, errno) {
151 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
152 }
153 }
154
155 TEST(mode_filter_without_nnp)
156 {
157 struct sock_filter filter[] = {
158 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
159 };
160 struct sock_fprog prog = {
161 .len = (unsigned short)ARRAY_SIZE(filter),
162 .filter = filter,
163 };
164 long ret;
165
166 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
167 ASSERT_LE(0, ret) {
168 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
169 }
170 errno = 0;
171 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
172 /* Succeeds with CAP_SYS_ADMIN, fails without */
173 /* TODO(wad) check caps not euid */
174 if (geteuid()) {
175 EXPECT_EQ(-1, ret);
176 EXPECT_EQ(EACCES, errno);
177 } else {
178 EXPECT_EQ(0, ret);
179 }
180 }
181
182 #define MAX_INSNS_PER_PATH 32768
183
184 TEST(filter_size_limits)
185 {
186 int i;
187 int count = BPF_MAXINSNS + 1;
188 struct sock_filter allow[] = {
189 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
190 };
191 struct sock_filter *filter;
192 struct sock_fprog prog = { };
193 long ret;
194
195 filter = calloc(count, sizeof(*filter));
196 ASSERT_NE(NULL, filter);
197
198 for (i = 0; i < count; i++)
199 filter[i] = allow[0];
200
201 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
202 ASSERT_EQ(0, ret);
203
204 prog.filter = filter;
205 prog.len = count;
206
207 /* Too many filter instructions in a single filter. */
208 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
209 ASSERT_NE(0, ret) {
210 TH_LOG("Installing %d insn filter was allowed", prog.len);
211 }
212
213 /* One less is okay, though. */
214 prog.len -= 1;
215 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
216 ASSERT_EQ(0, ret) {
217 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
218 }
219 }
220
221 TEST(filter_chain_limits)
222 {
223 int i;
224 int count = BPF_MAXINSNS;
225 struct sock_filter allow[] = {
226 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
227 };
228 struct sock_filter *filter;
229 struct sock_fprog prog = { };
230 long ret;
231
232 filter = calloc(count, sizeof(*filter));
233 ASSERT_NE(NULL, filter);
234
235 for (i = 0; i < count; i++)
236 filter[i] = allow[0];
237
238 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
239 ASSERT_EQ(0, ret);
240
241 prog.filter = filter;
242 prog.len = 1;
243
244 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
245 ASSERT_EQ(0, ret);
246
247 prog.len = count;
248
249 /* Too many total filter instructions. */
250 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
251 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
252 if (ret != 0)
253 break;
254 }
255 ASSERT_NE(0, ret) {
256 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
257 i, count, i * (count + 4));
258 }
259 }
260
261 TEST(mode_filter_cannot_move_to_strict)
262 {
263 struct sock_filter filter[] = {
264 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
265 };
266 struct sock_fprog prog = {
267 .len = (unsigned short)ARRAY_SIZE(filter),
268 .filter = filter,
269 };
270 long ret;
271
272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
273 ASSERT_EQ(0, ret);
274
275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
276 ASSERT_EQ(0, ret);
277
278 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
279 EXPECT_EQ(-1, ret);
280 EXPECT_EQ(EINVAL, errno);
281 }
282
283
284 TEST(mode_filter_get_seccomp)
285 {
286 struct sock_filter filter[] = {
287 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
288 };
289 struct sock_fprog prog = {
290 .len = (unsigned short)ARRAY_SIZE(filter),
291 .filter = filter,
292 };
293 long ret;
294
295 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
296 ASSERT_EQ(0, ret);
297
298 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
299 EXPECT_EQ(0, ret);
300
301 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
302 ASSERT_EQ(0, ret);
303
304 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
305 EXPECT_EQ(2, ret);
306 }
307
308
309 TEST(ALLOW_all)
310 {
311 struct sock_filter filter[] = {
312 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
313 };
314 struct sock_fprog prog = {
315 .len = (unsigned short)ARRAY_SIZE(filter),
316 .filter = filter,
317 };
318 long ret;
319
320 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
321 ASSERT_EQ(0, ret);
322
323 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
324 ASSERT_EQ(0, ret);
325 }
326
327 TEST(empty_prog)
328 {
329 struct sock_filter filter[] = {
330 };
331 struct sock_fprog prog = {
332 .len = (unsigned short)ARRAY_SIZE(filter),
333 .filter = filter,
334 };
335 long ret;
336
337 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
338 ASSERT_EQ(0, ret);
339
340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
341 EXPECT_EQ(-1, ret);
342 EXPECT_EQ(EINVAL, errno);
343 }
344
345 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
346 {
347 struct sock_filter filter[] = {
348 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
349 };
350 struct sock_fprog prog = {
351 .len = (unsigned short)ARRAY_SIZE(filter),
352 .filter = filter,
353 };
354 long ret;
355
356 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
357 ASSERT_EQ(0, ret);
358
359 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
360 ASSERT_EQ(0, ret);
361 EXPECT_EQ(0, syscall(__NR_getpid)) {
362 TH_LOG("getpid() shouldn't ever return");
363 }
364 }
365
366 /* return code >= 0x80000000 is unused. */
367 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
368 {
369 struct sock_filter filter[] = {
370 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
371 };
372 struct sock_fprog prog = {
373 .len = (unsigned short)ARRAY_SIZE(filter),
374 .filter = filter,
375 };
376 long ret;
377
378 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
379 ASSERT_EQ(0, ret);
380
381 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
382 ASSERT_EQ(0, ret);
383 EXPECT_EQ(0, syscall(__NR_getpid)) {
384 TH_LOG("getpid() shouldn't ever return");
385 }
386 }
387
388 TEST_SIGNAL(KILL_all, SIGSYS)
389 {
390 struct sock_filter filter[] = {
391 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
392 };
393 struct sock_fprog prog = {
394 .len = (unsigned short)ARRAY_SIZE(filter),
395 .filter = filter,
396 };
397 long ret;
398
399 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
400 ASSERT_EQ(0, ret);
401
402 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
403 ASSERT_EQ(0, ret);
404 }
405
406 TEST_SIGNAL(KILL_one, SIGSYS)
407 {
408 struct sock_filter filter[] = {
409 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
410 offsetof(struct seccomp_data, nr)),
411 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
412 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
413 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
414 };
415 struct sock_fprog prog = {
416 .len = (unsigned short)ARRAY_SIZE(filter),
417 .filter = filter,
418 };
419 long ret;
420 pid_t parent = getppid();
421
422 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
423 ASSERT_EQ(0, ret);
424
425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
426 ASSERT_EQ(0, ret);
427
428 EXPECT_EQ(parent, syscall(__NR_getppid));
429 /* getpid() should never return. */
430 EXPECT_EQ(0, syscall(__NR_getpid));
431 }
432
433 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
434 {
435 void *fatal_address;
436 struct sock_filter filter[] = {
437 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
438 offsetof(struct seccomp_data, nr)),
439 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
440 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
441 /* Only both with lower 32-bit for now. */
442 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
443 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
444 (unsigned long)&fatal_address, 0, 1),
445 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
446 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
447 };
448 struct sock_fprog prog = {
449 .len = (unsigned short)ARRAY_SIZE(filter),
450 .filter = filter,
451 };
452 long ret;
453 pid_t parent = getppid();
454 struct tms timebuf;
455 clock_t clock = times(&timebuf);
456
457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
458 ASSERT_EQ(0, ret);
459
460 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
461 ASSERT_EQ(0, ret);
462
463 EXPECT_EQ(parent, syscall(__NR_getppid));
464 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
465 /* times() should never return. */
466 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
467 }
468
469 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
470 {
471 #ifndef __NR_mmap2
472 int sysno = __NR_mmap;
473 #else
474 int sysno = __NR_mmap2;
475 #endif
476 struct sock_filter filter[] = {
477 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
478 offsetof(struct seccomp_data, nr)),
479 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
480 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
481 /* Only both with lower 32-bit for now. */
482 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
483 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
484 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
485 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
486 };
487 struct sock_fprog prog = {
488 .len = (unsigned short)ARRAY_SIZE(filter),
489 .filter = filter,
490 };
491 long ret;
492 pid_t parent = getppid();
493 int fd;
494 void *map1, *map2;
495 int page_size = sysconf(_SC_PAGESIZE);
496
497 ASSERT_LT(0, page_size);
498
499 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
500 ASSERT_EQ(0, ret);
501
502 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
503 ASSERT_EQ(0, ret);
504
505 fd = open("/dev/zero", O_RDONLY);
506 ASSERT_NE(-1, fd);
507
508 EXPECT_EQ(parent, syscall(__NR_getppid));
509 map1 = (void *)syscall(sysno,
510 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
511 EXPECT_NE(MAP_FAILED, map1);
512 /* mmap2() should never return. */
513 map2 = (void *)syscall(sysno,
514 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
515 EXPECT_EQ(MAP_FAILED, map2);
516
517 /* The test failed, so clean up the resources. */
518 munmap(map1, page_size);
519 munmap(map2, page_size);
520 close(fd);
521 }
522
523 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
524 TEST(arg_out_of_range)
525 {
526 struct sock_filter filter[] = {
527 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
528 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
529 };
530 struct sock_fprog prog = {
531 .len = (unsigned short)ARRAY_SIZE(filter),
532 .filter = filter,
533 };
534 long ret;
535
536 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
537 ASSERT_EQ(0, ret);
538
539 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
540 EXPECT_EQ(-1, ret);
541 EXPECT_EQ(EINVAL, errno);
542 }
543
544 TEST(ERRNO_valid)
545 {
546 struct sock_filter filter[] = {
547 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
548 offsetof(struct seccomp_data, nr)),
549 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
550 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | E2BIG),
551 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
552 };
553 struct sock_fprog prog = {
554 .len = (unsigned short)ARRAY_SIZE(filter),
555 .filter = filter,
556 };
557 long ret;
558 pid_t parent = getppid();
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 ASSERT_EQ(0, ret);
565
566 EXPECT_EQ(parent, syscall(__NR_getppid));
567 EXPECT_EQ(-1, read(0, NULL, 0));
568 EXPECT_EQ(E2BIG, errno);
569 }
570
571 TEST(ERRNO_zero)
572 {
573 struct sock_filter filter[] = {
574 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
575 offsetof(struct seccomp_data, nr)),
576 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
577 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 0),
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
587 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
588 ASSERT_EQ(0, ret);
589
590 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
591 ASSERT_EQ(0, ret);
592
593 EXPECT_EQ(parent, syscall(__NR_getppid));
594 /* "errno" of 0 is ok. */
595 EXPECT_EQ(0, read(0, NULL, 0));
596 }
597
598 TEST(ERRNO_capped)
599 {
600 struct sock_filter filter[] = {
601 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
602 offsetof(struct seccomp_data, nr)),
603 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
604 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 4096),
605 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
606 };
607 struct sock_fprog prog = {
608 .len = (unsigned short)ARRAY_SIZE(filter),
609 .filter = filter,
610 };
611 long ret;
612 pid_t parent = getppid();
613
614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
615 ASSERT_EQ(0, ret);
616
617 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
618 ASSERT_EQ(0, ret);
619
620 EXPECT_EQ(parent, syscall(__NR_getppid));
621 EXPECT_EQ(-1, read(0, NULL, 0));
622 EXPECT_EQ(4095, errno);
623 }
624
625 FIXTURE_DATA(TRAP) {
626 struct sock_fprog prog;
627 };
628
629 FIXTURE_SETUP(TRAP)
630 {
631 struct sock_filter filter[] = {
632 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
633 offsetof(struct seccomp_data, nr)),
634 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
635 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
636 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
637 };
638
639 memset(&self->prog, 0, sizeof(self->prog));
640 self->prog.filter = malloc(sizeof(filter));
641 ASSERT_NE(NULL, self->prog.filter);
642 memcpy(self->prog.filter, filter, sizeof(filter));
643 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
644 }
645
646 FIXTURE_TEARDOWN(TRAP)
647 {
648 if (self->prog.filter)
649 free(self->prog.filter);
650 }
651
652 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
653 {
654 long ret;
655
656 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
657 ASSERT_EQ(0, ret);
658
659 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
660 ASSERT_EQ(0, ret);
661 syscall(__NR_getpid);
662 }
663
664 /* Ensure that SIGSYS overrides SIG_IGN */
665 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
666 {
667 long ret;
668
669 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
670 ASSERT_EQ(0, ret);
671
672 signal(SIGSYS, SIG_IGN);
673
674 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
675 ASSERT_EQ(0, ret);
676 syscall(__NR_getpid);
677 }
678
679 static struct siginfo TRAP_info;
680 static volatile int TRAP_nr;
681 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
682 {
683 memcpy(&TRAP_info, info, sizeof(TRAP_info));
684 TRAP_nr = nr;
685 }
686
687 TEST_F(TRAP, handler)
688 {
689 int ret, test;
690 struct sigaction act;
691 sigset_t mask;
692
693 memset(&act, 0, sizeof(act));
694 sigemptyset(&mask);
695 sigaddset(&mask, SIGSYS);
696
697 act.sa_sigaction = &TRAP_action;
698 act.sa_flags = SA_SIGINFO;
699 ret = sigaction(SIGSYS, &act, NULL);
700 ASSERT_EQ(0, ret) {
701 TH_LOG("sigaction failed");
702 }
703 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
704 ASSERT_EQ(0, ret) {
705 TH_LOG("sigprocmask failed");
706 }
707
708 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
709 ASSERT_EQ(0, ret);
710 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
711 ASSERT_EQ(0, ret);
712 TRAP_nr = 0;
713 memset(&TRAP_info, 0, sizeof(TRAP_info));
714 /* Expect the registers to be rolled back. (nr = error) may vary
715 * based on arch. */
716 ret = syscall(__NR_getpid);
717 /* Silence gcc warning about volatile. */
718 test = TRAP_nr;
719 EXPECT_EQ(SIGSYS, test);
720 struct local_sigsys {
721 void *_call_addr; /* calling user insn */
722 int _syscall; /* triggering system call number */
723 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
724 } *sigsys = (struct local_sigsys *)
725 #ifdef si_syscall
726 &(TRAP_info.si_call_addr);
727 #else
728 &TRAP_info.si_pid;
729 #endif
730 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
731 /* Make sure arch is non-zero. */
732 EXPECT_NE(0, sigsys->_arch);
733 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
734 }
735
736 FIXTURE_DATA(precedence) {
737 struct sock_fprog allow;
738 struct sock_fprog trace;
739 struct sock_fprog error;
740 struct sock_fprog trap;
741 struct sock_fprog kill;
742 };
743
744 FIXTURE_SETUP(precedence)
745 {
746 struct sock_filter allow_insns[] = {
747 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
748 };
749 struct sock_filter trace_insns[] = {
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_getpid, 1, 0),
753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
754 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
755 };
756 struct sock_filter error_insns[] = {
757 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
758 offsetof(struct seccomp_data, nr)),
759 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
760 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
761 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
762 };
763 struct sock_filter trap_insns[] = {
764 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
765 offsetof(struct seccomp_data, nr)),
766 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
767 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
768 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
769 };
770 struct sock_filter kill_insns[] = {
771 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
772 offsetof(struct seccomp_data, nr)),
773 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
774 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
775 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
776 };
777
778 memset(self, 0, sizeof(*self));
779 #define FILTER_ALLOC(_x) \
780 self->_x.filter = malloc(sizeof(_x##_insns)); \
781 ASSERT_NE(NULL, self->_x.filter); \
782 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
783 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
784 FILTER_ALLOC(allow);
785 FILTER_ALLOC(trace);
786 FILTER_ALLOC(error);
787 FILTER_ALLOC(trap);
788 FILTER_ALLOC(kill);
789 }
790
791 FIXTURE_TEARDOWN(precedence)
792 {
793 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
794 FILTER_FREE(allow);
795 FILTER_FREE(trace);
796 FILTER_FREE(error);
797 FILTER_FREE(trap);
798 FILTER_FREE(kill);
799 }
800
801 TEST_F(precedence, allow_ok)
802 {
803 pid_t parent, res = 0;
804 long ret;
805
806 parent = getppid();
807 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
808 ASSERT_EQ(0, ret);
809
810 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
811 ASSERT_EQ(0, ret);
812 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
813 ASSERT_EQ(0, ret);
814 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
815 ASSERT_EQ(0, ret);
816 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
817 ASSERT_EQ(0, ret);
818 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
819 ASSERT_EQ(0, ret);
820 /* Should work just fine. */
821 res = syscall(__NR_getppid);
822 EXPECT_EQ(parent, res);
823 }
824
825 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
826 {
827 pid_t parent, res = 0;
828 long ret;
829
830 parent = getppid();
831 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
832 ASSERT_EQ(0, ret);
833
834 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
835 ASSERT_EQ(0, ret);
836 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
837 ASSERT_EQ(0, ret);
838 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
839 ASSERT_EQ(0, ret);
840 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
841 ASSERT_EQ(0, ret);
842 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
843 ASSERT_EQ(0, ret);
844 /* Should work just fine. */
845 res = syscall(__NR_getppid);
846 EXPECT_EQ(parent, res);
847 /* getpid() should never return. */
848 res = syscall(__NR_getpid);
849 EXPECT_EQ(0, res);
850 }
851
852 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
853 {
854 pid_t parent;
855 long ret;
856
857 parent = getppid();
858 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
859 ASSERT_EQ(0, ret);
860
861 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
862 ASSERT_EQ(0, ret);
863 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
864 ASSERT_EQ(0, ret);
865 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
866 ASSERT_EQ(0, ret);
867 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
868 ASSERT_EQ(0, ret);
869 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
870 ASSERT_EQ(0, ret);
871 /* Should work just fine. */
872 EXPECT_EQ(parent, syscall(__NR_getppid));
873 /* getpid() should never return. */
874 EXPECT_EQ(0, syscall(__NR_getpid));
875 }
876
877 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
878 {
879 pid_t parent;
880 long ret;
881
882 parent = getppid();
883 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
884 ASSERT_EQ(0, ret);
885
886 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
887 ASSERT_EQ(0, ret);
888 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
889 ASSERT_EQ(0, ret);
890 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
891 ASSERT_EQ(0, ret);
892 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
893 ASSERT_EQ(0, ret);
894 /* Should work just fine. */
895 EXPECT_EQ(parent, syscall(__NR_getppid));
896 /* getpid() should never return. */
897 EXPECT_EQ(0, syscall(__NR_getpid));
898 }
899
900 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
901 {
902 pid_t parent;
903 long ret;
904
905 parent = getppid();
906 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
907 ASSERT_EQ(0, ret);
908
909 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
910 ASSERT_EQ(0, ret);
911 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
912 ASSERT_EQ(0, ret);
913 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
914 ASSERT_EQ(0, ret);
915 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
916 ASSERT_EQ(0, ret);
917 /* Should work just fine. */
918 EXPECT_EQ(parent, syscall(__NR_getppid));
919 /* getpid() should never return. */
920 EXPECT_EQ(0, syscall(__NR_getpid));
921 }
922
923 TEST_F(precedence, errno_is_third)
924 {
925 pid_t parent;
926 long ret;
927
928 parent = getppid();
929 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
930 ASSERT_EQ(0, ret);
931
932 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
933 ASSERT_EQ(0, ret);
934 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
935 ASSERT_EQ(0, ret);
936 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
937 ASSERT_EQ(0, ret);
938 /* Should work just fine. */
939 EXPECT_EQ(parent, syscall(__NR_getppid));
940 EXPECT_EQ(0, syscall(__NR_getpid));
941 }
942
943 TEST_F(precedence, errno_is_third_in_any_order)
944 {
945 pid_t parent;
946 long ret;
947
948 parent = getppid();
949 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
950 ASSERT_EQ(0, ret);
951
952 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
953 ASSERT_EQ(0, ret);
954 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
955 ASSERT_EQ(0, ret);
956 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
957 ASSERT_EQ(0, ret);
958 /* Should work just fine. */
959 EXPECT_EQ(parent, syscall(__NR_getppid));
960 EXPECT_EQ(0, syscall(__NR_getpid));
961 }
962
963 TEST_F(precedence, trace_is_fourth)
964 {
965 pid_t parent;
966 long ret;
967
968 parent = getppid();
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, &self->allow);
973 ASSERT_EQ(0, ret);
974 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
975 ASSERT_EQ(0, ret);
976 /* Should work just fine. */
977 EXPECT_EQ(parent, syscall(__NR_getppid));
978 /* No ptracer */
979 EXPECT_EQ(-1, syscall(__NR_getpid));
980 }
981
982 TEST_F(precedence, trace_is_fourth_in_any_order)
983 {
984 pid_t parent;
985 long ret;
986
987 parent = getppid();
988 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
989 ASSERT_EQ(0, ret);
990
991 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
992 ASSERT_EQ(0, ret);
993 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
994 ASSERT_EQ(0, ret);
995 /* Should work just fine. */
996 EXPECT_EQ(parent, syscall(__NR_getppid));
997 /* No ptracer */
998 EXPECT_EQ(-1, syscall(__NR_getpid));
999 }
1000
1001 #ifndef PTRACE_O_TRACESECCOMP
1002 #define PTRACE_O_TRACESECCOMP 0x00000080
1003 #endif
1004
1005 /* Catch the Ubuntu 12.04 value error. */
1006 #if PTRACE_EVENT_SECCOMP != 7
1007 #undef PTRACE_EVENT_SECCOMP
1008 #endif
1009
1010 #ifndef PTRACE_EVENT_SECCOMP
1011 #define PTRACE_EVENT_SECCOMP 7
1012 #endif
1013
1014 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1015 bool tracer_running;
1016 void tracer_stop(int sig)
1017 {
1018 tracer_running = false;
1019 }
1020
1021 typedef void tracer_func_t(struct __test_metadata *_metadata,
1022 pid_t tracee, int status, void *args);
1023
1024 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1025 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1026 {
1027 int ret = -1;
1028 struct sigaction action = {
1029 .sa_handler = tracer_stop,
1030 };
1031
1032 /* Allow external shutdown. */
1033 tracer_running = true;
1034 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1035
1036 errno = 0;
1037 while (ret == -1 && errno != EINVAL)
1038 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1039 ASSERT_EQ(0, ret) {
1040 kill(tracee, SIGKILL);
1041 }
1042 /* Wait for attach stop */
1043 wait(NULL);
1044
1045 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1046 PTRACE_O_TRACESYSGOOD :
1047 PTRACE_O_TRACESECCOMP);
1048 ASSERT_EQ(0, ret) {
1049 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1050 kill(tracee, SIGKILL);
1051 }
1052 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1053 tracee, NULL, 0);
1054 ASSERT_EQ(0, ret);
1055
1056 /* Unblock the tracee */
1057 ASSERT_EQ(1, write(fd, "A", 1));
1058 ASSERT_EQ(0, close(fd));
1059
1060 /* Run until we're shut down. Must assert to stop execution. */
1061 while (tracer_running) {
1062 int status;
1063
1064 if (wait(&status) != tracee)
1065 continue;
1066 if (WIFSIGNALED(status) || WIFEXITED(status))
1067 /* Child is dead. Time to go. */
1068 return;
1069
1070 /* Check if this is a seccomp event. */
1071 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1072
1073 tracer_func(_metadata, tracee, status, args);
1074
1075 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1076 tracee, NULL, 0);
1077 ASSERT_EQ(0, ret);
1078 }
1079 /* Directly report the status of our test harness results. */
1080 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1081 }
1082
1083 /* Common tracer setup/teardown functions. */
1084 void cont_handler(int num)
1085 { }
1086 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1087 tracer_func_t func, void *args, bool ptrace_syscall)
1088 {
1089 char sync;
1090 int pipefd[2];
1091 pid_t tracer_pid;
1092 pid_t tracee = getpid();
1093
1094 /* Setup a pipe for clean synchronization. */
1095 ASSERT_EQ(0, pipe(pipefd));
1096
1097 /* Fork a child which we'll promote to tracer */
1098 tracer_pid = fork();
1099 ASSERT_LE(0, tracer_pid);
1100 signal(SIGALRM, cont_handler);
1101 if (tracer_pid == 0) {
1102 close(pipefd[0]);
1103 start_tracer(_metadata, pipefd[1], tracee, func, args,
1104 ptrace_syscall);
1105 syscall(__NR_exit, 0);
1106 }
1107 close(pipefd[1]);
1108 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1109 read(pipefd[0], &sync, 1);
1110 close(pipefd[0]);
1111
1112 return tracer_pid;
1113 }
1114 void teardown_trace_fixture(struct __test_metadata *_metadata,
1115 pid_t tracer)
1116 {
1117 if (tracer) {
1118 int status;
1119 /*
1120 * Extract the exit code from the other process and
1121 * adopt it for ourselves in case its asserts failed.
1122 */
1123 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1124 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1125 if (WEXITSTATUS(status))
1126 _metadata->passed = 0;
1127 }
1128 }
1129
1130 /* "poke" tracer arguments and function. */
1131 struct tracer_args_poke_t {
1132 unsigned long poke_addr;
1133 };
1134
1135 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1136 void *args)
1137 {
1138 int ret;
1139 unsigned long msg;
1140 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1141
1142 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1143 EXPECT_EQ(0, ret);
1144 /* If this fails, don't try to recover. */
1145 ASSERT_EQ(0x1001, msg) {
1146 kill(tracee, SIGKILL);
1147 }
1148 /*
1149 * Poke in the message.
1150 * Registers are not touched to try to keep this relatively arch
1151 * agnostic.
1152 */
1153 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1154 EXPECT_EQ(0, ret);
1155 }
1156
1157 FIXTURE_DATA(TRACE_poke) {
1158 struct sock_fprog prog;
1159 pid_t tracer;
1160 long poked;
1161 struct tracer_args_poke_t tracer_args;
1162 };
1163
1164 FIXTURE_SETUP(TRACE_poke)
1165 {
1166 struct sock_filter filter[] = {
1167 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1168 offsetof(struct seccomp_data, nr)),
1169 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1170 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1171 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1172 };
1173
1174 self->poked = 0;
1175 memset(&self->prog, 0, sizeof(self->prog));
1176 self->prog.filter = malloc(sizeof(filter));
1177 ASSERT_NE(NULL, self->prog.filter);
1178 memcpy(self->prog.filter, filter, sizeof(filter));
1179 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1180
1181 /* Set up tracer args. */
1182 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1183
1184 /* Launch tracer. */
1185 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1186 &self->tracer_args, false);
1187 }
1188
1189 FIXTURE_TEARDOWN(TRACE_poke)
1190 {
1191 teardown_trace_fixture(_metadata, self->tracer);
1192 if (self->prog.filter)
1193 free(self->prog.filter);
1194 }
1195
1196 TEST_F(TRACE_poke, read_has_side_effects)
1197 {
1198 ssize_t ret;
1199
1200 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1201 ASSERT_EQ(0, ret);
1202
1203 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1204 ASSERT_EQ(0, ret);
1205
1206 EXPECT_EQ(0, self->poked);
1207 ret = read(-1, NULL, 0);
1208 EXPECT_EQ(-1, ret);
1209 EXPECT_EQ(0x1001, self->poked);
1210 }
1211
1212 TEST_F(TRACE_poke, getpid_runs_normally)
1213 {
1214 long ret;
1215
1216 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1217 ASSERT_EQ(0, ret);
1218
1219 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1220 ASSERT_EQ(0, ret);
1221
1222 EXPECT_EQ(0, self->poked);
1223 EXPECT_NE(0, syscall(__NR_getpid));
1224 EXPECT_EQ(0, self->poked);
1225 }
1226
1227 #if defined(__x86_64__)
1228 # define ARCH_REGS struct user_regs_struct
1229 # define SYSCALL_NUM orig_rax
1230 # define SYSCALL_RET rax
1231 #elif defined(__i386__)
1232 # define ARCH_REGS struct user_regs_struct
1233 # define SYSCALL_NUM orig_eax
1234 # define SYSCALL_RET eax
1235 #elif defined(__arm__)
1236 # define ARCH_REGS struct pt_regs
1237 # define SYSCALL_NUM ARM_r7
1238 # define SYSCALL_RET ARM_r0
1239 #elif defined(__aarch64__)
1240 # define ARCH_REGS struct user_pt_regs
1241 # define SYSCALL_NUM regs[8]
1242 # define SYSCALL_RET regs[0]
1243 #elif defined(__hppa__)
1244 # define ARCH_REGS struct user_regs_struct
1245 # define SYSCALL_NUM gr[20]
1246 # define SYSCALL_RET gr[28]
1247 #elif defined(__powerpc__)
1248 # define ARCH_REGS struct pt_regs
1249 # define SYSCALL_NUM gpr[0]
1250 # define SYSCALL_RET gpr[3]
1251 #elif defined(__s390__)
1252 # define ARCH_REGS s390_regs
1253 # define SYSCALL_NUM gprs[2]
1254 # define SYSCALL_RET gprs[2]
1255 #elif defined(__mips__)
1256 # define ARCH_REGS struct pt_regs
1257 # define SYSCALL_NUM regs[2]
1258 # define SYSCALL_SYSCALL_NUM regs[4]
1259 # define SYSCALL_RET regs[2]
1260 # define SYSCALL_NUM_RET_SHARE_REG
1261 #else
1262 # error "Do not know how to find your architecture's registers and syscalls"
1263 #endif
1264
1265 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1266 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1267 */
1268 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1269 #define HAVE_GETREGS
1270 #endif
1271
1272 /* Architecture-specific syscall fetching routine. */
1273 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1274 {
1275 ARCH_REGS regs;
1276 #ifdef HAVE_GETREGS
1277 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
1278 TH_LOG("PTRACE_GETREGS failed");
1279 return -1;
1280 }
1281 #else
1282 struct iovec iov;
1283
1284 iov.iov_base = &regs;
1285 iov.iov_len = sizeof(regs);
1286 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1287 TH_LOG("PTRACE_GETREGSET failed");
1288 return -1;
1289 }
1290 #endif
1291
1292 #if defined(__mips__)
1293 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1294 return regs.SYSCALL_SYSCALL_NUM;
1295 #endif
1296 return regs.SYSCALL_NUM;
1297 }
1298
1299 /* Architecture-specific syscall changing routine. */
1300 void change_syscall(struct __test_metadata *_metadata,
1301 pid_t tracee, int syscall)
1302 {
1303 int ret;
1304 ARCH_REGS regs;
1305 #ifdef HAVE_GETREGS
1306 ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
1307 #else
1308 struct iovec iov;
1309 iov.iov_base = &regs;
1310 iov.iov_len = sizeof(regs);
1311 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1312 #endif
1313 EXPECT_EQ(0, ret) {}
1314
1315 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1316 defined(__s390__) || defined(__hppa__)
1317 {
1318 regs.SYSCALL_NUM = syscall;
1319 }
1320 #elif defined(__mips__)
1321 {
1322 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1323 regs.SYSCALL_SYSCALL_NUM = syscall;
1324 else
1325 regs.SYSCALL_NUM = syscall;
1326 }
1327
1328 #elif defined(__arm__)
1329 # ifndef PTRACE_SET_SYSCALL
1330 # define PTRACE_SET_SYSCALL 23
1331 # endif
1332 {
1333 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1334 EXPECT_EQ(0, ret);
1335 }
1336
1337 #elif defined(__aarch64__)
1338 # ifndef NT_ARM_SYSTEM_CALL
1339 # define NT_ARM_SYSTEM_CALL 0x404
1340 # endif
1341 {
1342 iov.iov_base = &syscall;
1343 iov.iov_len = sizeof(syscall);
1344 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1345 &iov);
1346 EXPECT_EQ(0, ret);
1347 }
1348
1349 #else
1350 ASSERT_EQ(1, 0) {
1351 TH_LOG("How is the syscall changed on this architecture?");
1352 }
1353 #endif
1354
1355 /* If syscall is skipped, change return value. */
1356 if (syscall == -1)
1357 #ifdef SYSCALL_NUM_RET_SHARE_REG
1358 TH_LOG("Can't modify syscall return on this architecture");
1359 #else
1360 regs.SYSCALL_RET = 1;
1361 #endif
1362
1363 #ifdef HAVE_GETREGS
1364 ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
1365 #else
1366 iov.iov_base = &regs;
1367 iov.iov_len = sizeof(regs);
1368 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1369 #endif
1370 EXPECT_EQ(0, ret);
1371 }
1372
1373 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1374 int status, void *args)
1375 {
1376 int ret;
1377 unsigned long msg;
1378
1379 /* Make sure we got the right message. */
1380 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1381 EXPECT_EQ(0, ret);
1382
1383 /* Validate and take action on expected syscalls. */
1384 switch (msg) {
1385 case 0x1002:
1386 /* change getpid to getppid. */
1387 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1388 change_syscall(_metadata, tracee, __NR_getppid);
1389 break;
1390 case 0x1003:
1391 /* skip gettid. */
1392 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1393 change_syscall(_metadata, tracee, -1);
1394 break;
1395 case 0x1004:
1396 /* do nothing (allow getppid) */
1397 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1398 break;
1399 default:
1400 EXPECT_EQ(0, msg) {
1401 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1402 kill(tracee, SIGKILL);
1403 }
1404 }
1405
1406 }
1407
1408 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1409 int status, void *args)
1410 {
1411 int ret, nr;
1412 unsigned long msg;
1413 static bool entry;
1414
1415 /* Make sure we got an empty message. */
1416 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1417 EXPECT_EQ(0, ret);
1418 EXPECT_EQ(0, msg);
1419
1420 /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */
1421 entry = !entry;
1422 if (!entry)
1423 return;
1424
1425 nr = get_syscall(_metadata, tracee);
1426
1427 if (nr == __NR_getpid)
1428 change_syscall(_metadata, tracee, __NR_getppid);
1429 }
1430
1431 FIXTURE_DATA(TRACE_syscall) {
1432 struct sock_fprog prog;
1433 pid_t tracer, mytid, mypid, parent;
1434 };
1435
1436 FIXTURE_SETUP(TRACE_syscall)
1437 {
1438 struct sock_filter filter[] = {
1439 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1440 offsetof(struct seccomp_data, nr)),
1441 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1442 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1443 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1444 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1445 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1446 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1447 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1448 };
1449
1450 memset(&self->prog, 0, sizeof(self->prog));
1451 self->prog.filter = malloc(sizeof(filter));
1452 ASSERT_NE(NULL, self->prog.filter);
1453 memcpy(self->prog.filter, filter, sizeof(filter));
1454 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1455
1456 /* Prepare some testable syscall results. */
1457 self->mytid = syscall(__NR_gettid);
1458 ASSERT_GT(self->mytid, 0);
1459 ASSERT_NE(self->mytid, 1) {
1460 TH_LOG("Running this test as init is not supported. :)");
1461 }
1462
1463 self->mypid = getpid();
1464 ASSERT_GT(self->mypid, 0);
1465 ASSERT_EQ(self->mytid, self->mypid);
1466
1467 self->parent = getppid();
1468 ASSERT_GT(self->parent, 0);
1469 ASSERT_NE(self->parent, self->mypid);
1470
1471 /* Launch tracer. */
1472 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1473 false);
1474 }
1475
1476 FIXTURE_TEARDOWN(TRACE_syscall)
1477 {
1478 teardown_trace_fixture(_metadata, self->tracer);
1479 if (self->prog.filter)
1480 free(self->prog.filter);
1481 }
1482
1483 TEST_F(TRACE_syscall, syscall_allowed)
1484 {
1485 long ret;
1486
1487 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1488 ASSERT_EQ(0, ret);
1489
1490 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1491 ASSERT_EQ(0, ret);
1492
1493 /* getppid works as expected (no changes). */
1494 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1495 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1496 }
1497
1498 TEST_F(TRACE_syscall, syscall_redirected)
1499 {
1500 long ret;
1501
1502 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1503 ASSERT_EQ(0, ret);
1504
1505 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1506 ASSERT_EQ(0, ret);
1507
1508 /* getpid has been redirected to getppid as expected. */
1509 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1510 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1511 }
1512
1513 TEST_F(TRACE_syscall, syscall_dropped)
1514 {
1515 long ret;
1516
1517 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1518 ASSERT_EQ(0, ret);
1519
1520 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1521 ASSERT_EQ(0, ret);
1522
1523 #ifdef SYSCALL_NUM_RET_SHARE_REG
1524 /* gettid has been skipped */
1525 EXPECT_EQ(-1, syscall(__NR_gettid));
1526 #else
1527 /* gettid has been skipped and an altered return value stored. */
1528 EXPECT_EQ(1, syscall(__NR_gettid));
1529 #endif
1530 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1531 }
1532
1533 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1534 {
1535 struct sock_filter filter[] = {
1536 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1537 offsetof(struct seccomp_data, nr)),
1538 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1539 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1540 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1541 };
1542 struct sock_fprog prog = {
1543 .len = (unsigned short)ARRAY_SIZE(filter),
1544 .filter = filter,
1545 };
1546 long ret;
1547
1548 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1549 ASSERT_EQ(0, ret);
1550
1551 /* Install fixture filter. */
1552 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1553 ASSERT_EQ(0, ret);
1554
1555 /* Install "errno on getppid" filter. */
1556 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1557 ASSERT_EQ(0, ret);
1558
1559 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1560 EXPECT_EQ(-1, syscall(__NR_getpid));
1561 EXPECT_EQ(EPERM, errno);
1562 }
1563
1564 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1565 {
1566 struct sock_filter filter[] = {
1567 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1568 offsetof(struct seccomp_data, nr)),
1569 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1570 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1571 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1572 };
1573 struct sock_fprog prog = {
1574 .len = (unsigned short)ARRAY_SIZE(filter),
1575 .filter = filter,
1576 };
1577 long ret;
1578
1579 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1580 ASSERT_EQ(0, ret);
1581
1582 /* Install fixture filter. */
1583 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1584 ASSERT_EQ(0, ret);
1585
1586 /* Install "death on getppid" filter. */
1587 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1588 ASSERT_EQ(0, ret);
1589
1590 /* Tracer will redirect getpid to getppid, and we should die. */
1591 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1592 }
1593
1594 TEST_F(TRACE_syscall, skip_after_ptrace)
1595 {
1596 struct sock_filter filter[] = {
1597 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1598 offsetof(struct seccomp_data, nr)),
1599 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1600 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1601 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1602 };
1603 struct sock_fprog prog = {
1604 .len = (unsigned short)ARRAY_SIZE(filter),
1605 .filter = filter,
1606 };
1607 long ret;
1608
1609 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1610 teardown_trace_fixture(_metadata, self->tracer);
1611 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1612 true);
1613
1614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1615 ASSERT_EQ(0, ret);
1616
1617 /* Install "errno on getppid" filter. */
1618 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1619 ASSERT_EQ(0, ret);
1620
1621 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1622 EXPECT_EQ(-1, syscall(__NR_getpid));
1623 EXPECT_EQ(EPERM, errno);
1624 }
1625
1626 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
1627 {
1628 struct sock_filter filter[] = {
1629 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1630 offsetof(struct seccomp_data, nr)),
1631 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1632 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1633 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1634 };
1635 struct sock_fprog prog = {
1636 .len = (unsigned short)ARRAY_SIZE(filter),
1637 .filter = filter,
1638 };
1639 long ret;
1640
1641 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1642 teardown_trace_fixture(_metadata, self->tracer);
1643 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1644 true);
1645
1646 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1647 ASSERT_EQ(0, ret);
1648
1649 /* Install "death on getppid" filter. */
1650 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1651 ASSERT_EQ(0, ret);
1652
1653 /* Tracer will redirect getpid to getppid, and we should die. */
1654 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1655 }
1656
1657 #ifndef __NR_seccomp
1658 # if defined(__i386__)
1659 # define __NR_seccomp 354
1660 # elif defined(__x86_64__)
1661 # define __NR_seccomp 317
1662 # elif defined(__arm__)
1663 # define __NR_seccomp 383
1664 # elif defined(__aarch64__)
1665 # define __NR_seccomp 277
1666 # elif defined(__hppa__)
1667 # define __NR_seccomp 338
1668 # elif defined(__powerpc__)
1669 # define __NR_seccomp 358
1670 # elif defined(__s390__)
1671 # define __NR_seccomp 348
1672 # else
1673 # warning "seccomp syscall number unknown for this architecture"
1674 # define __NR_seccomp 0xffff
1675 # endif
1676 #endif
1677
1678 #ifndef SECCOMP_SET_MODE_STRICT
1679 #define SECCOMP_SET_MODE_STRICT 0
1680 #endif
1681
1682 #ifndef SECCOMP_SET_MODE_FILTER
1683 #define SECCOMP_SET_MODE_FILTER 1
1684 #endif
1685
1686 #ifndef SECCOMP_FILTER_FLAG_TSYNC
1687 #define SECCOMP_FILTER_FLAG_TSYNC 1
1688 #endif
1689
1690 #ifndef seccomp
1691 int seccomp(unsigned int op, unsigned int flags, void *args)
1692 {
1693 errno = 0;
1694 return syscall(__NR_seccomp, op, flags, args);
1695 }
1696 #endif
1697
1698 TEST(seccomp_syscall)
1699 {
1700 struct sock_filter filter[] = {
1701 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1702 };
1703 struct sock_fprog prog = {
1704 .len = (unsigned short)ARRAY_SIZE(filter),
1705 .filter = filter,
1706 };
1707 long ret;
1708
1709 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1710 ASSERT_EQ(0, ret) {
1711 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1712 }
1713
1714 /* Reject insane operation. */
1715 ret = seccomp(-1, 0, &prog);
1716 ASSERT_NE(ENOSYS, errno) {
1717 TH_LOG("Kernel does not support seccomp syscall!");
1718 }
1719 EXPECT_EQ(EINVAL, errno) {
1720 TH_LOG("Did not reject crazy op value!");
1721 }
1722
1723 /* Reject strict with flags or pointer. */
1724 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
1725 EXPECT_EQ(EINVAL, errno) {
1726 TH_LOG("Did not reject mode strict with flags!");
1727 }
1728 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
1729 EXPECT_EQ(EINVAL, errno) {
1730 TH_LOG("Did not reject mode strict with uargs!");
1731 }
1732
1733 /* Reject insane args for filter. */
1734 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
1735 EXPECT_EQ(EINVAL, errno) {
1736 TH_LOG("Did not reject crazy filter flags!");
1737 }
1738 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
1739 EXPECT_EQ(EFAULT, errno) {
1740 TH_LOG("Did not reject NULL filter!");
1741 }
1742
1743 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1744 EXPECT_EQ(0, errno) {
1745 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
1746 strerror(errno));
1747 }
1748 }
1749
1750 TEST(seccomp_syscall_mode_lock)
1751 {
1752 struct sock_filter filter[] = {
1753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1754 };
1755 struct sock_fprog prog = {
1756 .len = (unsigned short)ARRAY_SIZE(filter),
1757 .filter = filter,
1758 };
1759 long ret;
1760
1761 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1762 ASSERT_EQ(0, ret) {
1763 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1764 }
1765
1766 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1767 ASSERT_NE(ENOSYS, errno) {
1768 TH_LOG("Kernel does not support seccomp syscall!");
1769 }
1770 EXPECT_EQ(0, ret) {
1771 TH_LOG("Could not install filter!");
1772 }
1773
1774 /* Make sure neither entry point will switch to strict. */
1775 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
1776 EXPECT_EQ(EINVAL, errno) {
1777 TH_LOG("Switched to mode strict!");
1778 }
1779
1780 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
1781 EXPECT_EQ(EINVAL, errno) {
1782 TH_LOG("Switched to mode strict!");
1783 }
1784 }
1785
1786 TEST(TSYNC_first)
1787 {
1788 struct sock_filter filter[] = {
1789 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1790 };
1791 struct sock_fprog prog = {
1792 .len = (unsigned short)ARRAY_SIZE(filter),
1793 .filter = filter,
1794 };
1795 long ret;
1796
1797 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1798 ASSERT_EQ(0, ret) {
1799 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1800 }
1801
1802 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
1803 &prog);
1804 ASSERT_NE(ENOSYS, errno) {
1805 TH_LOG("Kernel does not support seccomp syscall!");
1806 }
1807 EXPECT_EQ(0, ret) {
1808 TH_LOG("Could not install initial filter with TSYNC!");
1809 }
1810 }
1811
1812 #define TSYNC_SIBLINGS 2
1813 struct tsync_sibling {
1814 pthread_t tid;
1815 pid_t system_tid;
1816 sem_t *started;
1817 pthread_cond_t *cond;
1818 pthread_mutex_t *mutex;
1819 int diverge;
1820 int num_waits;
1821 struct sock_fprog *prog;
1822 struct __test_metadata *metadata;
1823 };
1824
1825 /*
1826 * To avoid joining joined threads (which is not allowed by Bionic),
1827 * make sure we both successfully join and clear the tid to skip a
1828 * later join attempt during fixture teardown. Any remaining threads
1829 * will be directly killed during teardown.
1830 */
1831 #define PTHREAD_JOIN(tid, status) \
1832 do { \
1833 int _rc = pthread_join(tid, status); \
1834 if (_rc) { \
1835 TH_LOG("pthread_join of tid %u failed: %d\n", \
1836 (unsigned int)tid, _rc); \
1837 } else { \
1838 tid = 0; \
1839 } \
1840 } while (0)
1841
1842 FIXTURE_DATA(TSYNC) {
1843 struct sock_fprog root_prog, apply_prog;
1844 struct tsync_sibling sibling[TSYNC_SIBLINGS];
1845 sem_t started;
1846 pthread_cond_t cond;
1847 pthread_mutex_t mutex;
1848 int sibling_count;
1849 };
1850
1851 FIXTURE_SETUP(TSYNC)
1852 {
1853 struct sock_filter root_filter[] = {
1854 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1855 };
1856 struct sock_filter apply_filter[] = {
1857 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1858 offsetof(struct seccomp_data, nr)),
1859 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1860 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1861 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1862 };
1863
1864 memset(&self->root_prog, 0, sizeof(self->root_prog));
1865 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
1866 memset(&self->sibling, 0, sizeof(self->sibling));
1867 self->root_prog.filter = malloc(sizeof(root_filter));
1868 ASSERT_NE(NULL, self->root_prog.filter);
1869 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
1870 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
1871
1872 self->apply_prog.filter = malloc(sizeof(apply_filter));
1873 ASSERT_NE(NULL, self->apply_prog.filter);
1874 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
1875 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
1876
1877 self->sibling_count = 0;
1878 pthread_mutex_init(&self->mutex, NULL);
1879 pthread_cond_init(&self->cond, NULL);
1880 sem_init(&self->started, 0, 0);
1881 self->sibling[0].tid = 0;
1882 self->sibling[0].cond = &self->cond;
1883 self->sibling[0].started = &self->started;
1884 self->sibling[0].mutex = &self->mutex;
1885 self->sibling[0].diverge = 0;
1886 self->sibling[0].num_waits = 1;
1887 self->sibling[0].prog = &self->root_prog;
1888 self->sibling[0].metadata = _metadata;
1889 self->sibling[1].tid = 0;
1890 self->sibling[1].cond = &self->cond;
1891 self->sibling[1].started = &self->started;
1892 self->sibling[1].mutex = &self->mutex;
1893 self->sibling[1].diverge = 0;
1894 self->sibling[1].prog = &self->root_prog;
1895 self->sibling[1].num_waits = 1;
1896 self->sibling[1].metadata = _metadata;
1897 }
1898
1899 FIXTURE_TEARDOWN(TSYNC)
1900 {
1901 int sib = 0;
1902
1903 if (self->root_prog.filter)
1904 free(self->root_prog.filter);
1905 if (self->apply_prog.filter)
1906 free(self->apply_prog.filter);
1907
1908 for ( ; sib < self->sibling_count; ++sib) {
1909 struct tsync_sibling *s = &self->sibling[sib];
1910
1911 if (!s->tid)
1912 continue;
1913 /*
1914 * If a thread is still running, it may be stuck, so hit
1915 * it over the head really hard.
1916 */
1917 pthread_kill(s->tid, 9);
1918 }
1919 pthread_mutex_destroy(&self->mutex);
1920 pthread_cond_destroy(&self->cond);
1921 sem_destroy(&self->started);
1922 }
1923
1924 void *tsync_sibling(void *data)
1925 {
1926 long ret = 0;
1927 struct tsync_sibling *me = data;
1928
1929 me->system_tid = syscall(__NR_gettid);
1930
1931 pthread_mutex_lock(me->mutex);
1932 if (me->diverge) {
1933 /* Just re-apply the root prog to fork the tree */
1934 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
1935 me->prog, 0, 0);
1936 }
1937 sem_post(me->started);
1938 /* Return outside of started so parent notices failures. */
1939 if (ret) {
1940 pthread_mutex_unlock(me->mutex);
1941 return (void *)SIBLING_EXIT_FAILURE;
1942 }
1943 do {
1944 pthread_cond_wait(me->cond, me->mutex);
1945 me->num_waits = me->num_waits - 1;
1946 } while (me->num_waits);
1947 pthread_mutex_unlock(me->mutex);
1948
1949 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
1950 if (!ret)
1951 return (void *)SIBLING_EXIT_NEWPRIVS;
1952 read(0, NULL, 0);
1953 return (void *)SIBLING_EXIT_UNKILLED;
1954 }
1955
1956 void tsync_start_sibling(struct tsync_sibling *sibling)
1957 {
1958 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
1959 }
1960
1961 TEST_F(TSYNC, siblings_fail_prctl)
1962 {
1963 long ret;
1964 void *status;
1965 struct sock_filter filter[] = {
1966 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1967 offsetof(struct seccomp_data, nr)),
1968 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
1969 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
1970 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1971 };
1972 struct sock_fprog prog = {
1973 .len = (unsigned short)ARRAY_SIZE(filter),
1974 .filter = filter,
1975 };
1976
1977 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1978 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1979 }
1980
1981 /* Check prctl failure detection by requesting sib 0 diverge. */
1982 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1983 ASSERT_NE(ENOSYS, errno) {
1984 TH_LOG("Kernel does not support seccomp syscall!");
1985 }
1986 ASSERT_EQ(0, ret) {
1987 TH_LOG("setting filter failed");
1988 }
1989
1990 self->sibling[0].diverge = 1;
1991 tsync_start_sibling(&self->sibling[0]);
1992 tsync_start_sibling(&self->sibling[1]);
1993
1994 while (self->sibling_count < TSYNC_SIBLINGS) {
1995 sem_wait(&self->started);
1996 self->sibling_count++;
1997 }
1998
1999 /* Signal the threads to clean up*/
2000 pthread_mutex_lock(&self->mutex);
2001 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2002 TH_LOG("cond broadcast non-zero");
2003 }
2004 pthread_mutex_unlock(&self->mutex);
2005
2006 /* Ensure diverging sibling failed to call prctl. */
2007 PTHREAD_JOIN(self->sibling[0].tid, &status);
2008 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2009 PTHREAD_JOIN(self->sibling[1].tid, &status);
2010 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2011 }
2012
2013 TEST_F(TSYNC, two_siblings_with_ancestor)
2014 {
2015 long ret;
2016 void *status;
2017
2018 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2019 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2020 }
2021
2022 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2023 ASSERT_NE(ENOSYS, errno) {
2024 TH_LOG("Kernel does not support seccomp syscall!");
2025 }
2026 ASSERT_EQ(0, ret) {
2027 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2028 }
2029 tsync_start_sibling(&self->sibling[0]);
2030 tsync_start_sibling(&self->sibling[1]);
2031
2032 while (self->sibling_count < TSYNC_SIBLINGS) {
2033 sem_wait(&self->started);
2034 self->sibling_count++;
2035 }
2036
2037 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2038 &self->apply_prog);
2039 ASSERT_EQ(0, ret) {
2040 TH_LOG("Could install filter on all threads!");
2041 }
2042 /* Tell the siblings to test the policy */
2043 pthread_mutex_lock(&self->mutex);
2044 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2045 TH_LOG("cond broadcast non-zero");
2046 }
2047 pthread_mutex_unlock(&self->mutex);
2048 /* Ensure they are both killed and don't exit cleanly. */
2049 PTHREAD_JOIN(self->sibling[0].tid, &status);
2050 EXPECT_EQ(0x0, (long)status);
2051 PTHREAD_JOIN(self->sibling[1].tid, &status);
2052 EXPECT_EQ(0x0, (long)status);
2053 }
2054
2055 TEST_F(TSYNC, two_sibling_want_nnp)
2056 {
2057 void *status;
2058
2059 /* start siblings before any prctl() operations */
2060 tsync_start_sibling(&self->sibling[0]);
2061 tsync_start_sibling(&self->sibling[1]);
2062 while (self->sibling_count < TSYNC_SIBLINGS) {
2063 sem_wait(&self->started);
2064 self->sibling_count++;
2065 }
2066
2067 /* Tell the siblings to test no policy */
2068 pthread_mutex_lock(&self->mutex);
2069 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2070 TH_LOG("cond broadcast non-zero");
2071 }
2072 pthread_mutex_unlock(&self->mutex);
2073
2074 /* Ensure they are both upset about lacking nnp. */
2075 PTHREAD_JOIN(self->sibling[0].tid, &status);
2076 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2077 PTHREAD_JOIN(self->sibling[1].tid, &status);
2078 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2079 }
2080
2081 TEST_F(TSYNC, two_siblings_with_no_filter)
2082 {
2083 long ret;
2084 void *status;
2085
2086 /* start siblings before any prctl() operations */
2087 tsync_start_sibling(&self->sibling[0]);
2088 tsync_start_sibling(&self->sibling[1]);
2089 while (self->sibling_count < TSYNC_SIBLINGS) {
2090 sem_wait(&self->started);
2091 self->sibling_count++;
2092 }
2093
2094 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2095 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2096 }
2097
2098 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2099 &self->apply_prog);
2100 ASSERT_NE(ENOSYS, errno) {
2101 TH_LOG("Kernel does not support seccomp syscall!");
2102 }
2103 ASSERT_EQ(0, ret) {
2104 TH_LOG("Could install filter on all threads!");
2105 }
2106
2107 /* Tell the siblings to test the policy */
2108 pthread_mutex_lock(&self->mutex);
2109 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2110 TH_LOG("cond broadcast non-zero");
2111 }
2112 pthread_mutex_unlock(&self->mutex);
2113
2114 /* Ensure they are both killed and don't exit cleanly. */
2115 PTHREAD_JOIN(self->sibling[0].tid, &status);
2116 EXPECT_EQ(0x0, (long)status);
2117 PTHREAD_JOIN(self->sibling[1].tid, &status);
2118 EXPECT_EQ(0x0, (long)status);
2119 }
2120
2121 TEST_F(TSYNC, two_siblings_with_one_divergence)
2122 {
2123 long ret;
2124 void *status;
2125
2126 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2127 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2128 }
2129
2130 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2131 ASSERT_NE(ENOSYS, errno) {
2132 TH_LOG("Kernel does not support seccomp syscall!");
2133 }
2134 ASSERT_EQ(0, ret) {
2135 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2136 }
2137 self->sibling[0].diverge = 1;
2138 tsync_start_sibling(&self->sibling[0]);
2139 tsync_start_sibling(&self->sibling[1]);
2140
2141 while (self->sibling_count < TSYNC_SIBLINGS) {
2142 sem_wait(&self->started);
2143 self->sibling_count++;
2144 }
2145
2146 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2147 &self->apply_prog);
2148 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2149 TH_LOG("Did not fail on diverged sibling.");
2150 }
2151
2152 /* Wake the threads */
2153 pthread_mutex_lock(&self->mutex);
2154 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2155 TH_LOG("cond broadcast non-zero");
2156 }
2157 pthread_mutex_unlock(&self->mutex);
2158
2159 /* Ensure they are both unkilled. */
2160 PTHREAD_JOIN(self->sibling[0].tid, &status);
2161 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2162 PTHREAD_JOIN(self->sibling[1].tid, &status);
2163 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2164 }
2165
2166 TEST_F(TSYNC, two_siblings_not_under_filter)
2167 {
2168 long ret, sib;
2169 void *status;
2170
2171 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2172 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2173 }
2174
2175 /*
2176 * Sibling 0 will have its own seccomp policy
2177 * and Sibling 1 will not be under seccomp at
2178 * all. Sibling 1 will enter seccomp and 0
2179 * will cause failure.
2180 */
2181 self->sibling[0].diverge = 1;
2182 tsync_start_sibling(&self->sibling[0]);
2183 tsync_start_sibling(&self->sibling[1]);
2184
2185 while (self->sibling_count < TSYNC_SIBLINGS) {
2186 sem_wait(&self->started);
2187 self->sibling_count++;
2188 }
2189
2190 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2191 ASSERT_NE(ENOSYS, errno) {
2192 TH_LOG("Kernel does not support seccomp syscall!");
2193 }
2194 ASSERT_EQ(0, ret) {
2195 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2196 }
2197
2198 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2199 &self->apply_prog);
2200 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2201 TH_LOG("Did not fail on diverged sibling.");
2202 }
2203 sib = 1;
2204 if (ret == self->sibling[0].system_tid)
2205 sib = 0;
2206
2207 pthread_mutex_lock(&self->mutex);
2208
2209 /* Increment the other siblings num_waits so we can clean up
2210 * the one we just saw.
2211 */
2212 self->sibling[!sib].num_waits += 1;
2213
2214 /* Signal the thread to clean up*/
2215 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2216 TH_LOG("cond broadcast non-zero");
2217 }
2218 pthread_mutex_unlock(&self->mutex);
2219 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2220 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2221 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2222 while (!kill(self->sibling[sib].system_tid, 0))
2223 sleep(0.1);
2224 /* Switch to the remaining sibling */
2225 sib = !sib;
2226
2227 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2228 &self->apply_prog);
2229 ASSERT_EQ(0, ret) {
2230 TH_LOG("Expected the remaining sibling to sync");
2231 };
2232
2233 pthread_mutex_lock(&self->mutex);
2234
2235 /* If remaining sibling didn't have a chance to wake up during
2236 * the first broadcast, manually reduce the num_waits now.
2237 */
2238 if (self->sibling[sib].num_waits > 1)
2239 self->sibling[sib].num_waits = 1;
2240 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2241 TH_LOG("cond broadcast non-zero");
2242 }
2243 pthread_mutex_unlock(&self->mutex);
2244 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2245 EXPECT_EQ(0, (long)status);
2246 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2247 while (!kill(self->sibling[sib].system_tid, 0))
2248 sleep(0.1);
2249
2250 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2251 &self->apply_prog);
2252 ASSERT_EQ(0, ret); /* just us chickens */
2253 }
2254
2255 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2256 TEST(syscall_restart)
2257 {
2258 long ret;
2259 unsigned long msg;
2260 pid_t child_pid;
2261 int pipefd[2];
2262 int status;
2263 siginfo_t info = { };
2264 struct sock_filter filter[] = {
2265 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2266 offsetof(struct seccomp_data, nr)),
2267
2268 #ifdef __NR_sigreturn
2269 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2270 #endif
2271 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2272 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2273 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2274 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2275 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2276
2277 /* Allow __NR_write for easy logging. */
2278 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2279 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2280 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2281 /* The nanosleep jump target. */
2282 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2283 /* The restart_syscall jump target. */
2284 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2285 };
2286 struct sock_fprog prog = {
2287 .len = (unsigned short)ARRAY_SIZE(filter),
2288 .filter = filter,
2289 };
2290 #if defined(__arm__)
2291 struct utsname utsbuf;
2292 #endif
2293
2294 ASSERT_EQ(0, pipe(pipefd));
2295
2296 child_pid = fork();
2297 ASSERT_LE(0, child_pid);
2298 if (child_pid == 0) {
2299 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2300 char buf = ' ';
2301 struct timespec timeout = { };
2302
2303 /* Attach parent as tracer and stop. */
2304 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2305 EXPECT_EQ(0, raise(SIGSTOP));
2306
2307 EXPECT_EQ(0, close(pipefd[1]));
2308
2309 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2310 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2311 }
2312
2313 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2314 EXPECT_EQ(0, ret) {
2315 TH_LOG("Failed to install filter!");
2316 }
2317
2318 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2319 TH_LOG("Failed to read() sync from parent");
2320 }
2321 EXPECT_EQ('.', buf) {
2322 TH_LOG("Failed to get sync data from read()");
2323 }
2324
2325 /* Start nanosleep to be interrupted. */
2326 timeout.tv_sec = 1;
2327 errno = 0;
2328 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2329 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2330 }
2331
2332 /* Read final sync from parent. */
2333 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2334 TH_LOG("Failed final read() from parent");
2335 }
2336 EXPECT_EQ('!', buf) {
2337 TH_LOG("Failed to get final data from read()");
2338 }
2339
2340 /* Directly report the status of our test harness results. */
2341 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2342 : EXIT_FAILURE);
2343 }
2344 EXPECT_EQ(0, close(pipefd[0]));
2345
2346 /* Attach to child, setup options, and release. */
2347 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2348 ASSERT_EQ(true, WIFSTOPPED(status));
2349 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2350 PTRACE_O_TRACESECCOMP));
2351 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2352 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2353
2354 /* Wait for nanosleep() to start. */
2355 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2356 ASSERT_EQ(true, WIFSTOPPED(status));
2357 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2358 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2359 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2360 ASSERT_EQ(0x100, msg);
2361 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2362
2363 /* Might as well check siginfo for sanity while we're here. */
2364 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2365 ASSERT_EQ(SIGTRAP, info.si_signo);
2366 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2367 EXPECT_EQ(0, info.si_errno);
2368 EXPECT_EQ(getuid(), info.si_uid);
2369 /* Verify signal delivery came from child (seccomp-triggered). */
2370 EXPECT_EQ(child_pid, info.si_pid);
2371
2372 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2373 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2374 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2375 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2376 ASSERT_EQ(true, WIFSTOPPED(status));
2377 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2378 /* Verify signal delivery came from parent now. */
2379 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2380 EXPECT_EQ(getpid(), info.si_pid);
2381
2382 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2383 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2384 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2385 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2386 ASSERT_EQ(true, WIFSTOPPED(status));
2387 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2388 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2389
2390 /* Wait for restart_syscall() to start. */
2391 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2392 ASSERT_EQ(true, WIFSTOPPED(status));
2393 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2394 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2395 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2396
2397 ASSERT_EQ(0x200, msg);
2398 ret = get_syscall(_metadata, child_pid);
2399 #if defined(__arm__)
2400 /*
2401 * FIXME:
2402 * - native ARM registers do NOT expose true syscall.
2403 * - compat ARM registers on ARM64 DO expose true syscall.
2404 */
2405 ASSERT_EQ(0, uname(&utsbuf));
2406 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2407 EXPECT_EQ(__NR_nanosleep, ret);
2408 } else
2409 #endif
2410 {
2411 EXPECT_EQ(__NR_restart_syscall, ret);
2412 }
2413
2414 /* Write again to end test. */
2415 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2416 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2417 EXPECT_EQ(0, close(pipefd[1]));
2418
2419 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2420 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2421 _metadata->passed = 0;
2422 }
2423
2424 /*
2425 * TODO:
2426 * - add microbenchmarks
2427 * - expand NNP testing
2428 * - better arch-specific TRACE and TRAP handlers.
2429 * - endianness checking when appropriate
2430 * - 64-bit arg prodding
2431 * - arch value testing (x86 modes especially)
2432 * - ...
2433 */
2434
2435 TEST_HARNESS_MAIN
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