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[mirror_ubuntu-artful-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 <asm/siginfo.h>
9 #define __have_siginfo_t 1
10 #define __have_sigval_t 1
11 #define __have_sigevent_t 1
12
13 #include <errno.h>
14 #include <linux/filter.h>
15 #include <sys/prctl.h>
16 #include <sys/ptrace.h>
17 #include <sys/types.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 "test_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, 1);
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 tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1025 tracer_func_t tracer_func, void *args)
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_O_TRACESECCOMP);
1046 ASSERT_EQ(0, ret) {
1047 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1048 kill(tracee, SIGKILL);
1049 }
1050 ptrace(PTRACE_CONT, tracee, NULL, 0);
1051
1052 /* Unblock the tracee */
1053 ASSERT_EQ(1, write(fd, "A", 1));
1054 ASSERT_EQ(0, close(fd));
1055
1056 /* Run until we're shut down. Must assert to stop execution. */
1057 while (tracer_running) {
1058 int status;
1059
1060 if (wait(&status) != tracee)
1061 continue;
1062 if (WIFSIGNALED(status) || WIFEXITED(status))
1063 /* Child is dead. Time to go. */
1064 return;
1065
1066 /* Make sure this is a seccomp event. */
1067 ASSERT_EQ(true, IS_SECCOMP_EVENT(status));
1068
1069 tracer_func(_metadata, tracee, status, args);
1070
1071 ret = ptrace(PTRACE_CONT, tracee, NULL, NULL);
1072 ASSERT_EQ(0, ret);
1073 }
1074 /* Directly report the status of our test harness results. */
1075 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1076 }
1077
1078 /* Common tracer setup/teardown functions. */
1079 void cont_handler(int num)
1080 { }
1081 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1082 tracer_func_t func, void *args)
1083 {
1084 char sync;
1085 int pipefd[2];
1086 pid_t tracer_pid;
1087 pid_t tracee = getpid();
1088
1089 /* Setup a pipe for clean synchronization. */
1090 ASSERT_EQ(0, pipe(pipefd));
1091
1092 /* Fork a child which we'll promote to tracer */
1093 tracer_pid = fork();
1094 ASSERT_LE(0, tracer_pid);
1095 signal(SIGALRM, cont_handler);
1096 if (tracer_pid == 0) {
1097 close(pipefd[0]);
1098 tracer(_metadata, pipefd[1], tracee, func, args);
1099 syscall(__NR_exit, 0);
1100 }
1101 close(pipefd[1]);
1102 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1103 read(pipefd[0], &sync, 1);
1104 close(pipefd[0]);
1105
1106 return tracer_pid;
1107 }
1108 void teardown_trace_fixture(struct __test_metadata *_metadata,
1109 pid_t tracer)
1110 {
1111 if (tracer) {
1112 int status;
1113 /*
1114 * Extract the exit code from the other process and
1115 * adopt it for ourselves in case its asserts failed.
1116 */
1117 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1118 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1119 if (WEXITSTATUS(status))
1120 _metadata->passed = 0;
1121 }
1122 }
1123
1124 /* "poke" tracer arguments and function. */
1125 struct tracer_args_poke_t {
1126 unsigned long poke_addr;
1127 };
1128
1129 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1130 void *args)
1131 {
1132 int ret;
1133 unsigned long msg;
1134 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1135
1136 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1137 EXPECT_EQ(0, ret);
1138 /* If this fails, don't try to recover. */
1139 ASSERT_EQ(0x1001, msg) {
1140 kill(tracee, SIGKILL);
1141 }
1142 /*
1143 * Poke in the message.
1144 * Registers are not touched to try to keep this relatively arch
1145 * agnostic.
1146 */
1147 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1148 EXPECT_EQ(0, ret);
1149 }
1150
1151 FIXTURE_DATA(TRACE_poke) {
1152 struct sock_fprog prog;
1153 pid_t tracer;
1154 long poked;
1155 struct tracer_args_poke_t tracer_args;
1156 };
1157
1158 FIXTURE_SETUP(TRACE_poke)
1159 {
1160 struct sock_filter filter[] = {
1161 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1162 offsetof(struct seccomp_data, nr)),
1163 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1164 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1165 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1166 };
1167
1168 self->poked = 0;
1169 memset(&self->prog, 0, sizeof(self->prog));
1170 self->prog.filter = malloc(sizeof(filter));
1171 ASSERT_NE(NULL, self->prog.filter);
1172 memcpy(self->prog.filter, filter, sizeof(filter));
1173 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1174
1175 /* Set up tracer args. */
1176 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1177
1178 /* Launch tracer. */
1179 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1180 &self->tracer_args);
1181 }
1182
1183 FIXTURE_TEARDOWN(TRACE_poke)
1184 {
1185 teardown_trace_fixture(_metadata, self->tracer);
1186 if (self->prog.filter)
1187 free(self->prog.filter);
1188 }
1189
1190 TEST_F(TRACE_poke, read_has_side_effects)
1191 {
1192 ssize_t ret;
1193
1194 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1195 ASSERT_EQ(0, ret);
1196
1197 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1198 ASSERT_EQ(0, ret);
1199
1200 EXPECT_EQ(0, self->poked);
1201 ret = read(-1, NULL, 0);
1202 EXPECT_EQ(-1, ret);
1203 EXPECT_EQ(0x1001, self->poked);
1204 }
1205
1206 TEST_F(TRACE_poke, getpid_runs_normally)
1207 {
1208 long ret;
1209
1210 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1211 ASSERT_EQ(0, ret);
1212
1213 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1214 ASSERT_EQ(0, ret);
1215
1216 EXPECT_EQ(0, self->poked);
1217 EXPECT_NE(0, syscall(__NR_getpid));
1218 EXPECT_EQ(0, self->poked);
1219 }
1220
1221 #if defined(__x86_64__)
1222 # define ARCH_REGS struct user_regs_struct
1223 # define SYSCALL_NUM orig_rax
1224 # define SYSCALL_RET rax
1225 #elif defined(__i386__)
1226 # define ARCH_REGS struct user_regs_struct
1227 # define SYSCALL_NUM orig_eax
1228 # define SYSCALL_RET eax
1229 #elif defined(__arm__)
1230 # define ARCH_REGS struct pt_regs
1231 # define SYSCALL_NUM ARM_r7
1232 # define SYSCALL_RET ARM_r0
1233 #elif defined(__aarch64__)
1234 # define ARCH_REGS struct user_pt_regs
1235 # define SYSCALL_NUM regs[8]
1236 # define SYSCALL_RET regs[0]
1237 #elif defined(__powerpc__)
1238 # define ARCH_REGS struct pt_regs
1239 # define SYSCALL_NUM gpr[0]
1240 # define SYSCALL_RET gpr[3]
1241 #elif defined(__s390__)
1242 # define ARCH_REGS s390_regs
1243 # define SYSCALL_NUM gprs[2]
1244 # define SYSCALL_RET gprs[2]
1245 #else
1246 # error "Do not know how to find your architecture's registers and syscalls"
1247 #endif
1248
1249 /* Architecture-specific syscall fetching routine. */
1250 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1251 {
1252 struct iovec iov;
1253 ARCH_REGS regs;
1254
1255 iov.iov_base = &regs;
1256 iov.iov_len = sizeof(regs);
1257 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1258 TH_LOG("PTRACE_GETREGSET failed");
1259 return -1;
1260 }
1261
1262 return regs.SYSCALL_NUM;
1263 }
1264
1265 /* Architecture-specific syscall changing routine. */
1266 void change_syscall(struct __test_metadata *_metadata,
1267 pid_t tracee, int syscall)
1268 {
1269 struct iovec iov;
1270 int ret;
1271 ARCH_REGS regs;
1272
1273 iov.iov_base = &regs;
1274 iov.iov_len = sizeof(regs);
1275 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1276 EXPECT_EQ(0, ret);
1277
1278 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1279 defined(__s390__)
1280 {
1281 regs.SYSCALL_NUM = syscall;
1282 }
1283
1284 #elif defined(__arm__)
1285 # ifndef PTRACE_SET_SYSCALL
1286 # define PTRACE_SET_SYSCALL 23
1287 # endif
1288 {
1289 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1290 EXPECT_EQ(0, ret);
1291 }
1292
1293 #elif defined(__aarch64__)
1294 # ifndef NT_ARM_SYSTEM_CALL
1295 # define NT_ARM_SYSTEM_CALL 0x404
1296 # endif
1297 {
1298 iov.iov_base = &syscall;
1299 iov.iov_len = sizeof(syscall);
1300 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1301 &iov);
1302 EXPECT_EQ(0, ret);
1303 }
1304
1305 #else
1306 ASSERT_EQ(1, 0) {
1307 TH_LOG("How is the syscall changed on this architecture?");
1308 }
1309 #endif
1310
1311 /* If syscall is skipped, change return value. */
1312 if (syscall == -1)
1313 regs.SYSCALL_RET = 1;
1314
1315 iov.iov_base = &regs;
1316 iov.iov_len = sizeof(regs);
1317 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1318 EXPECT_EQ(0, ret);
1319 }
1320
1321 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1322 int status, void *args)
1323 {
1324 int ret;
1325 unsigned long msg;
1326
1327 /* Make sure we got the right message. */
1328 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1329 EXPECT_EQ(0, ret);
1330
1331 /* Validate and take action on expected syscalls. */
1332 switch (msg) {
1333 case 0x1002:
1334 /* change getpid to getppid. */
1335 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1336 change_syscall(_metadata, tracee, __NR_getppid);
1337 break;
1338 case 0x1003:
1339 /* skip gettid. */
1340 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1341 change_syscall(_metadata, tracee, -1);
1342 break;
1343 case 0x1004:
1344 /* do nothing (allow getppid) */
1345 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1346 break;
1347 default:
1348 EXPECT_EQ(0, msg) {
1349 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1350 kill(tracee, SIGKILL);
1351 }
1352 }
1353
1354 }
1355
1356 FIXTURE_DATA(TRACE_syscall) {
1357 struct sock_fprog prog;
1358 pid_t tracer, mytid, mypid, parent;
1359 };
1360
1361 FIXTURE_SETUP(TRACE_syscall)
1362 {
1363 struct sock_filter filter[] = {
1364 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1365 offsetof(struct seccomp_data, nr)),
1366 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1367 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1368 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1369 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1370 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1371 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1372 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1373 };
1374
1375 memset(&self->prog, 0, sizeof(self->prog));
1376 self->prog.filter = malloc(sizeof(filter));
1377 ASSERT_NE(NULL, self->prog.filter);
1378 memcpy(self->prog.filter, filter, sizeof(filter));
1379 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1380
1381 /* Prepare some testable syscall results. */
1382 self->mytid = syscall(__NR_gettid);
1383 ASSERT_GT(self->mytid, 0);
1384 ASSERT_NE(self->mytid, 1) {
1385 TH_LOG("Running this test as init is not supported. :)");
1386 }
1387
1388 self->mypid = getpid();
1389 ASSERT_GT(self->mypid, 0);
1390 ASSERT_EQ(self->mytid, self->mypid);
1391
1392 self->parent = getppid();
1393 ASSERT_GT(self->parent, 0);
1394 ASSERT_NE(self->parent, self->mypid);
1395
1396 /* Launch tracer. */
1397 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL);
1398 }
1399
1400 FIXTURE_TEARDOWN(TRACE_syscall)
1401 {
1402 teardown_trace_fixture(_metadata, self->tracer);
1403 if (self->prog.filter)
1404 free(self->prog.filter);
1405 }
1406
1407 TEST_F(TRACE_syscall, syscall_allowed)
1408 {
1409 long ret;
1410
1411 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1412 ASSERT_EQ(0, ret);
1413
1414 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1415 ASSERT_EQ(0, ret);
1416
1417 /* getppid works as expected (no changes). */
1418 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1419 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1420 }
1421
1422 TEST_F(TRACE_syscall, syscall_redirected)
1423 {
1424 long ret;
1425
1426 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1427 ASSERT_EQ(0, ret);
1428
1429 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1430 ASSERT_EQ(0, ret);
1431
1432 /* getpid has been redirected to getppid as expected. */
1433 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1434 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1435 }
1436
1437 TEST_F(TRACE_syscall, syscall_dropped)
1438 {
1439 long ret;
1440
1441 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1442 ASSERT_EQ(0, ret);
1443
1444 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1445 ASSERT_EQ(0, ret);
1446
1447 /* gettid has been skipped and an altered return value stored. */
1448 EXPECT_EQ(1, syscall(__NR_gettid));
1449 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1450 }
1451
1452 #ifndef __NR_seccomp
1453 # if defined(__i386__)
1454 # define __NR_seccomp 354
1455 # elif defined(__x86_64__)
1456 # define __NR_seccomp 317
1457 # elif defined(__arm__)
1458 # define __NR_seccomp 383
1459 # elif defined(__aarch64__)
1460 # define __NR_seccomp 277
1461 # elif defined(__powerpc__)
1462 # define __NR_seccomp 358
1463 # elif defined(__s390__)
1464 # define __NR_seccomp 348
1465 # else
1466 # warning "seccomp syscall number unknown for this architecture"
1467 # define __NR_seccomp 0xffff
1468 # endif
1469 #endif
1470
1471 #ifndef SECCOMP_SET_MODE_STRICT
1472 #define SECCOMP_SET_MODE_STRICT 0
1473 #endif
1474
1475 #ifndef SECCOMP_SET_MODE_FILTER
1476 #define SECCOMP_SET_MODE_FILTER 1
1477 #endif
1478
1479 #ifndef SECCOMP_FLAG_FILTER_TSYNC
1480 #define SECCOMP_FLAG_FILTER_TSYNC 1
1481 #endif
1482
1483 #ifndef seccomp
1484 int seccomp(unsigned int op, unsigned int flags, struct sock_fprog *filter)
1485 {
1486 errno = 0;
1487 return syscall(__NR_seccomp, op, flags, filter);
1488 }
1489 #endif
1490
1491 TEST(seccomp_syscall)
1492 {
1493 struct sock_filter filter[] = {
1494 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1495 };
1496 struct sock_fprog prog = {
1497 .len = (unsigned short)ARRAY_SIZE(filter),
1498 .filter = filter,
1499 };
1500 long ret;
1501
1502 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1503 ASSERT_EQ(0, ret) {
1504 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1505 }
1506
1507 /* Reject insane operation. */
1508 ret = seccomp(-1, 0, &prog);
1509 ASSERT_NE(ENOSYS, errno) {
1510 TH_LOG("Kernel does not support seccomp syscall!");
1511 }
1512 EXPECT_EQ(EINVAL, errno) {
1513 TH_LOG("Did not reject crazy op value!");
1514 }
1515
1516 /* Reject strict with flags or pointer. */
1517 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
1518 EXPECT_EQ(EINVAL, errno) {
1519 TH_LOG("Did not reject mode strict with flags!");
1520 }
1521 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
1522 EXPECT_EQ(EINVAL, errno) {
1523 TH_LOG("Did not reject mode strict with uargs!");
1524 }
1525
1526 /* Reject insane args for filter. */
1527 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
1528 EXPECT_EQ(EINVAL, errno) {
1529 TH_LOG("Did not reject crazy filter flags!");
1530 }
1531 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
1532 EXPECT_EQ(EFAULT, errno) {
1533 TH_LOG("Did not reject NULL filter!");
1534 }
1535
1536 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1537 EXPECT_EQ(0, errno) {
1538 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
1539 strerror(errno));
1540 }
1541 }
1542
1543 TEST(seccomp_syscall_mode_lock)
1544 {
1545 struct sock_filter filter[] = {
1546 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1547 };
1548 struct sock_fprog prog = {
1549 .len = (unsigned short)ARRAY_SIZE(filter),
1550 .filter = filter,
1551 };
1552 long ret;
1553
1554 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1555 ASSERT_EQ(0, ret) {
1556 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1557 }
1558
1559 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1560 ASSERT_NE(ENOSYS, errno) {
1561 TH_LOG("Kernel does not support seccomp syscall!");
1562 }
1563 EXPECT_EQ(0, ret) {
1564 TH_LOG("Could not install filter!");
1565 }
1566
1567 /* Make sure neither entry point will switch to strict. */
1568 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
1569 EXPECT_EQ(EINVAL, errno) {
1570 TH_LOG("Switched to mode strict!");
1571 }
1572
1573 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
1574 EXPECT_EQ(EINVAL, errno) {
1575 TH_LOG("Switched to mode strict!");
1576 }
1577 }
1578
1579 TEST(TSYNC_first)
1580 {
1581 struct sock_filter filter[] = {
1582 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1583 };
1584 struct sock_fprog prog = {
1585 .len = (unsigned short)ARRAY_SIZE(filter),
1586 .filter = filter,
1587 };
1588 long ret;
1589
1590 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1591 ASSERT_EQ(0, ret) {
1592 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1593 }
1594
1595 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1596 &prog);
1597 ASSERT_NE(ENOSYS, errno) {
1598 TH_LOG("Kernel does not support seccomp syscall!");
1599 }
1600 EXPECT_EQ(0, ret) {
1601 TH_LOG("Could not install initial filter with TSYNC!");
1602 }
1603 }
1604
1605 #define TSYNC_SIBLINGS 2
1606 struct tsync_sibling {
1607 pthread_t tid;
1608 pid_t system_tid;
1609 sem_t *started;
1610 pthread_cond_t *cond;
1611 pthread_mutex_t *mutex;
1612 int diverge;
1613 int num_waits;
1614 struct sock_fprog *prog;
1615 struct __test_metadata *metadata;
1616 };
1617
1618 FIXTURE_DATA(TSYNC) {
1619 struct sock_fprog root_prog, apply_prog;
1620 struct tsync_sibling sibling[TSYNC_SIBLINGS];
1621 sem_t started;
1622 pthread_cond_t cond;
1623 pthread_mutex_t mutex;
1624 int sibling_count;
1625 };
1626
1627 FIXTURE_SETUP(TSYNC)
1628 {
1629 struct sock_filter root_filter[] = {
1630 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1631 };
1632 struct sock_filter apply_filter[] = {
1633 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1634 offsetof(struct seccomp_data, nr)),
1635 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1636 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1637 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1638 };
1639
1640 memset(&self->root_prog, 0, sizeof(self->root_prog));
1641 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
1642 memset(&self->sibling, 0, sizeof(self->sibling));
1643 self->root_prog.filter = malloc(sizeof(root_filter));
1644 ASSERT_NE(NULL, self->root_prog.filter);
1645 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
1646 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
1647
1648 self->apply_prog.filter = malloc(sizeof(apply_filter));
1649 ASSERT_NE(NULL, self->apply_prog.filter);
1650 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
1651 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
1652
1653 self->sibling_count = 0;
1654 pthread_mutex_init(&self->mutex, NULL);
1655 pthread_cond_init(&self->cond, NULL);
1656 sem_init(&self->started, 0, 0);
1657 self->sibling[0].tid = 0;
1658 self->sibling[0].cond = &self->cond;
1659 self->sibling[0].started = &self->started;
1660 self->sibling[0].mutex = &self->mutex;
1661 self->sibling[0].diverge = 0;
1662 self->sibling[0].num_waits = 1;
1663 self->sibling[0].prog = &self->root_prog;
1664 self->sibling[0].metadata = _metadata;
1665 self->sibling[1].tid = 0;
1666 self->sibling[1].cond = &self->cond;
1667 self->sibling[1].started = &self->started;
1668 self->sibling[1].mutex = &self->mutex;
1669 self->sibling[1].diverge = 0;
1670 self->sibling[1].prog = &self->root_prog;
1671 self->sibling[1].num_waits = 1;
1672 self->sibling[1].metadata = _metadata;
1673 }
1674
1675 FIXTURE_TEARDOWN(TSYNC)
1676 {
1677 int sib = 0;
1678
1679 if (self->root_prog.filter)
1680 free(self->root_prog.filter);
1681 if (self->apply_prog.filter)
1682 free(self->apply_prog.filter);
1683
1684 for ( ; sib < self->sibling_count; ++sib) {
1685 struct tsync_sibling *s = &self->sibling[sib];
1686 void *status;
1687
1688 if (!s->tid)
1689 continue;
1690 if (pthread_kill(s->tid, 0)) {
1691 pthread_cancel(s->tid);
1692 pthread_join(s->tid, &status);
1693 }
1694 }
1695 pthread_mutex_destroy(&self->mutex);
1696 pthread_cond_destroy(&self->cond);
1697 sem_destroy(&self->started);
1698 }
1699
1700 void *tsync_sibling(void *data)
1701 {
1702 long ret = 0;
1703 struct tsync_sibling *me = data;
1704
1705 me->system_tid = syscall(__NR_gettid);
1706
1707 pthread_mutex_lock(me->mutex);
1708 if (me->diverge) {
1709 /* Just re-apply the root prog to fork the tree */
1710 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
1711 me->prog, 0, 0);
1712 }
1713 sem_post(me->started);
1714 /* Return outside of started so parent notices failures. */
1715 if (ret) {
1716 pthread_mutex_unlock(me->mutex);
1717 return (void *)SIBLING_EXIT_FAILURE;
1718 }
1719 do {
1720 pthread_cond_wait(me->cond, me->mutex);
1721 me->num_waits = me->num_waits - 1;
1722 } while (me->num_waits);
1723 pthread_mutex_unlock(me->mutex);
1724
1725 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
1726 if (!ret)
1727 return (void *)SIBLING_EXIT_NEWPRIVS;
1728 read(0, NULL, 0);
1729 return (void *)SIBLING_EXIT_UNKILLED;
1730 }
1731
1732 void tsync_start_sibling(struct tsync_sibling *sibling)
1733 {
1734 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
1735 }
1736
1737 TEST_F(TSYNC, siblings_fail_prctl)
1738 {
1739 long ret;
1740 void *status;
1741 struct sock_filter filter[] = {
1742 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1743 offsetof(struct seccomp_data, nr)),
1744 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
1745 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
1746 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1747 };
1748 struct sock_fprog prog = {
1749 .len = (unsigned short)ARRAY_SIZE(filter),
1750 .filter = filter,
1751 };
1752
1753 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1754 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1755 }
1756
1757 /* Check prctl failure detection by requesting sib 0 diverge. */
1758 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1759 ASSERT_NE(ENOSYS, errno) {
1760 TH_LOG("Kernel does not support seccomp syscall!");
1761 }
1762 ASSERT_EQ(0, ret) {
1763 TH_LOG("setting filter failed");
1764 }
1765
1766 self->sibling[0].diverge = 1;
1767 tsync_start_sibling(&self->sibling[0]);
1768 tsync_start_sibling(&self->sibling[1]);
1769
1770 while (self->sibling_count < TSYNC_SIBLINGS) {
1771 sem_wait(&self->started);
1772 self->sibling_count++;
1773 }
1774
1775 /* Signal the threads to clean up*/
1776 pthread_mutex_lock(&self->mutex);
1777 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1778 TH_LOG("cond broadcast non-zero");
1779 }
1780 pthread_mutex_unlock(&self->mutex);
1781
1782 /* Ensure diverging sibling failed to call prctl. */
1783 pthread_join(self->sibling[0].tid, &status);
1784 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
1785 pthread_join(self->sibling[1].tid, &status);
1786 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1787 }
1788
1789 TEST_F(TSYNC, two_siblings_with_ancestor)
1790 {
1791 long ret;
1792 void *status;
1793
1794 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1795 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1796 }
1797
1798 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1799 ASSERT_NE(ENOSYS, errno) {
1800 TH_LOG("Kernel does not support seccomp syscall!");
1801 }
1802 ASSERT_EQ(0, ret) {
1803 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1804 }
1805 tsync_start_sibling(&self->sibling[0]);
1806 tsync_start_sibling(&self->sibling[1]);
1807
1808 while (self->sibling_count < TSYNC_SIBLINGS) {
1809 sem_wait(&self->started);
1810 self->sibling_count++;
1811 }
1812
1813 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1814 &self->apply_prog);
1815 ASSERT_EQ(0, ret) {
1816 TH_LOG("Could install filter on all threads!");
1817 }
1818 /* Tell the siblings to test the policy */
1819 pthread_mutex_lock(&self->mutex);
1820 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1821 TH_LOG("cond broadcast non-zero");
1822 }
1823 pthread_mutex_unlock(&self->mutex);
1824 /* Ensure they are both killed and don't exit cleanly. */
1825 pthread_join(self->sibling[0].tid, &status);
1826 EXPECT_EQ(0x0, (long)status);
1827 pthread_join(self->sibling[1].tid, &status);
1828 EXPECT_EQ(0x0, (long)status);
1829 }
1830
1831 TEST_F(TSYNC, two_sibling_want_nnp)
1832 {
1833 void *status;
1834
1835 /* start siblings before any prctl() operations */
1836 tsync_start_sibling(&self->sibling[0]);
1837 tsync_start_sibling(&self->sibling[1]);
1838 while (self->sibling_count < TSYNC_SIBLINGS) {
1839 sem_wait(&self->started);
1840 self->sibling_count++;
1841 }
1842
1843 /* Tell the siblings to test no policy */
1844 pthread_mutex_lock(&self->mutex);
1845 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1846 TH_LOG("cond broadcast non-zero");
1847 }
1848 pthread_mutex_unlock(&self->mutex);
1849
1850 /* Ensure they are both upset about lacking nnp. */
1851 pthread_join(self->sibling[0].tid, &status);
1852 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1853 pthread_join(self->sibling[1].tid, &status);
1854 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1855 }
1856
1857 TEST_F(TSYNC, two_siblings_with_no_filter)
1858 {
1859 long ret;
1860 void *status;
1861
1862 /* start siblings before any prctl() operations */
1863 tsync_start_sibling(&self->sibling[0]);
1864 tsync_start_sibling(&self->sibling[1]);
1865 while (self->sibling_count < TSYNC_SIBLINGS) {
1866 sem_wait(&self->started);
1867 self->sibling_count++;
1868 }
1869
1870 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1871 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1872 }
1873
1874 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1875 &self->apply_prog);
1876 ASSERT_NE(ENOSYS, errno) {
1877 TH_LOG("Kernel does not support seccomp syscall!");
1878 }
1879 ASSERT_EQ(0, ret) {
1880 TH_LOG("Could install filter on all threads!");
1881 }
1882
1883 /* Tell the siblings to test the policy */
1884 pthread_mutex_lock(&self->mutex);
1885 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1886 TH_LOG("cond broadcast non-zero");
1887 }
1888 pthread_mutex_unlock(&self->mutex);
1889
1890 /* Ensure they are both killed and don't exit cleanly. */
1891 pthread_join(self->sibling[0].tid, &status);
1892 EXPECT_EQ(0x0, (long)status);
1893 pthread_join(self->sibling[1].tid, &status);
1894 EXPECT_EQ(0x0, (long)status);
1895 }
1896
1897 TEST_F(TSYNC, two_siblings_with_one_divergence)
1898 {
1899 long ret;
1900 void *status;
1901
1902 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1903 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1904 }
1905
1906 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1907 ASSERT_NE(ENOSYS, errno) {
1908 TH_LOG("Kernel does not support seccomp syscall!");
1909 }
1910 ASSERT_EQ(0, ret) {
1911 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1912 }
1913 self->sibling[0].diverge = 1;
1914 tsync_start_sibling(&self->sibling[0]);
1915 tsync_start_sibling(&self->sibling[1]);
1916
1917 while (self->sibling_count < TSYNC_SIBLINGS) {
1918 sem_wait(&self->started);
1919 self->sibling_count++;
1920 }
1921
1922 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1923 &self->apply_prog);
1924 ASSERT_EQ(self->sibling[0].system_tid, ret) {
1925 TH_LOG("Did not fail on diverged sibling.");
1926 }
1927
1928 /* Wake the threads */
1929 pthread_mutex_lock(&self->mutex);
1930 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1931 TH_LOG("cond broadcast non-zero");
1932 }
1933 pthread_mutex_unlock(&self->mutex);
1934
1935 /* Ensure they are both unkilled. */
1936 pthread_join(self->sibling[0].tid, &status);
1937 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1938 pthread_join(self->sibling[1].tid, &status);
1939 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1940 }
1941
1942 TEST_F(TSYNC, two_siblings_not_under_filter)
1943 {
1944 long ret, sib;
1945 void *status;
1946
1947 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1948 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1949 }
1950
1951 /*
1952 * Sibling 0 will have its own seccomp policy
1953 * and Sibling 1 will not be under seccomp at
1954 * all. Sibling 1 will enter seccomp and 0
1955 * will cause failure.
1956 */
1957 self->sibling[0].diverge = 1;
1958 tsync_start_sibling(&self->sibling[0]);
1959 tsync_start_sibling(&self->sibling[1]);
1960
1961 while (self->sibling_count < TSYNC_SIBLINGS) {
1962 sem_wait(&self->started);
1963 self->sibling_count++;
1964 }
1965
1966 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1967 ASSERT_NE(ENOSYS, errno) {
1968 TH_LOG("Kernel does not support seccomp syscall!");
1969 }
1970 ASSERT_EQ(0, ret) {
1971 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1972 }
1973
1974 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1975 &self->apply_prog);
1976 ASSERT_EQ(ret, self->sibling[0].system_tid) {
1977 TH_LOG("Did not fail on diverged sibling.");
1978 }
1979 sib = 1;
1980 if (ret == self->sibling[0].system_tid)
1981 sib = 0;
1982
1983 pthread_mutex_lock(&self->mutex);
1984
1985 /* Increment the other siblings num_waits so we can clean up
1986 * the one we just saw.
1987 */
1988 self->sibling[!sib].num_waits += 1;
1989
1990 /* Signal the thread to clean up*/
1991 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1992 TH_LOG("cond broadcast non-zero");
1993 }
1994 pthread_mutex_unlock(&self->mutex);
1995 pthread_join(self->sibling[sib].tid, &status);
1996 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1997 /* Poll for actual task death. pthread_join doesn't guarantee it. */
1998 while (!kill(self->sibling[sib].system_tid, 0))
1999 sleep(0.1);
2000 /* Switch to the remaining sibling */
2001 sib = !sib;
2002
2003 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
2004 &self->apply_prog);
2005 ASSERT_EQ(0, ret) {
2006 TH_LOG("Expected the remaining sibling to sync");
2007 };
2008
2009 pthread_mutex_lock(&self->mutex);
2010
2011 /* If remaining sibling didn't have a chance to wake up during
2012 * the first broadcast, manually reduce the num_waits now.
2013 */
2014 if (self->sibling[sib].num_waits > 1)
2015 self->sibling[sib].num_waits = 1;
2016 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2017 TH_LOG("cond broadcast non-zero");
2018 }
2019 pthread_mutex_unlock(&self->mutex);
2020 pthread_join(self->sibling[sib].tid, &status);
2021 EXPECT_EQ(0, (long)status);
2022 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2023 while (!kill(self->sibling[sib].system_tid, 0))
2024 sleep(0.1);
2025
2026 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
2027 &self->apply_prog);
2028 ASSERT_EQ(0, ret); /* just us chickens */
2029 }
2030
2031 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2032 TEST(syscall_restart)
2033 {
2034 long ret;
2035 unsigned long msg;
2036 pid_t child_pid;
2037 int pipefd[2];
2038 int status;
2039 siginfo_t info = { };
2040 struct sock_filter filter[] = {
2041 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2042 offsetof(struct seccomp_data, nr)),
2043
2044 #ifdef __NR_sigreturn
2045 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2046 #endif
2047 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2048 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2049 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2050 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2051 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2052
2053 /* Allow __NR_write for easy logging. */
2054 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2055 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2056 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2057 /* The nanosleep jump target. */
2058 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2059 /* The restart_syscall jump target. */
2060 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2061 };
2062 struct sock_fprog prog = {
2063 .len = (unsigned short)ARRAY_SIZE(filter),
2064 .filter = filter,
2065 };
2066 #if defined(__arm__)
2067 struct utsname utsbuf;
2068 #endif
2069
2070 ASSERT_EQ(0, pipe(pipefd));
2071
2072 child_pid = fork();
2073 ASSERT_LE(0, child_pid);
2074 if (child_pid == 0) {
2075 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2076 char buf = ' ';
2077 struct timespec timeout = { };
2078
2079 /* Attach parent as tracer and stop. */
2080 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2081 EXPECT_EQ(0, raise(SIGSTOP));
2082
2083 EXPECT_EQ(0, close(pipefd[1]));
2084
2085 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2086 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2087 }
2088
2089 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2090 EXPECT_EQ(0, ret) {
2091 TH_LOG("Failed to install filter!");
2092 }
2093
2094 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2095 TH_LOG("Failed to read() sync from parent");
2096 }
2097 EXPECT_EQ('.', buf) {
2098 TH_LOG("Failed to get sync data from read()");
2099 }
2100
2101 /* Start nanosleep to be interrupted. */
2102 timeout.tv_sec = 1;
2103 errno = 0;
2104 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2105 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2106 }
2107
2108 /* Read final sync from parent. */
2109 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2110 TH_LOG("Failed final read() from parent");
2111 }
2112 EXPECT_EQ('!', buf) {
2113 TH_LOG("Failed to get final data from read()");
2114 }
2115
2116 /* Directly report the status of our test harness results. */
2117 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2118 : EXIT_FAILURE);
2119 }
2120 EXPECT_EQ(0, close(pipefd[0]));
2121
2122 /* Attach to child, setup options, and release. */
2123 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2124 ASSERT_EQ(true, WIFSTOPPED(status));
2125 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2126 PTRACE_O_TRACESECCOMP));
2127 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2128 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2129
2130 /* Wait for nanosleep() to start. */
2131 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2132 ASSERT_EQ(true, WIFSTOPPED(status));
2133 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2134 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2135 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2136 ASSERT_EQ(0x100, msg);
2137 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2138
2139 /* Might as well check siginfo for sanity while we're here. */
2140 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2141 ASSERT_EQ(SIGTRAP, info.si_signo);
2142 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2143 EXPECT_EQ(0, info.si_errno);
2144 EXPECT_EQ(getuid(), info.si_uid);
2145 /* Verify signal delivery came from child (seccomp-triggered). */
2146 EXPECT_EQ(child_pid, info.si_pid);
2147
2148 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2149 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2150 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2151 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2152 ASSERT_EQ(true, WIFSTOPPED(status));
2153 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2154 /* Verify signal delivery came from parent now. */
2155 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2156 EXPECT_EQ(getpid(), info.si_pid);
2157
2158 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2159 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2160 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2161 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2162 ASSERT_EQ(true, WIFSTOPPED(status));
2163 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2164 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2165
2166 /* Wait for restart_syscall() to start. */
2167 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2168 ASSERT_EQ(true, WIFSTOPPED(status));
2169 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2170 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2171 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2172
2173 ASSERT_EQ(0x200, msg);
2174 ret = get_syscall(_metadata, child_pid);
2175 #if defined(__arm__)
2176 /*
2177 * FIXME:
2178 * - native ARM registers do NOT expose true syscall.
2179 * - compat ARM registers on ARM64 DO expose true syscall.
2180 */
2181 ASSERT_EQ(0, uname(&utsbuf));
2182 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2183 EXPECT_EQ(__NR_nanosleep, ret);
2184 } else
2185 #endif
2186 {
2187 EXPECT_EQ(__NR_restart_syscall, ret);
2188 }
2189
2190 /* Write again to end test. */
2191 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2192 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2193 EXPECT_EQ(0, close(pipefd[1]));
2194
2195 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2196 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2197 _metadata->passed = 0;
2198 }
2199
2200 /*
2201 * TODO:
2202 * - add microbenchmarks
2203 * - expand NNP testing
2204 * - better arch-specific TRACE and TRAP handlers.
2205 * - endianness checking when appropriate
2206 * - 64-bit arg prodding
2207 * - arch value testing (x86 modes especially)
2208 * - ...
2209 */
2210
2211 TEST_HARNESS_MAIN
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