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[mirror_ubuntu-zesty-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 <poll.h>
23 #include <pthread.h>
24 #include <semaphore.h>
25 #include <signal.h>
26 #include <stddef.h>
27 #include <stdbool.h>
28 #include <string.h>
29 #include <linux/elf.h>
30 #include <sys/uio.h>
31
32 #define _GNU_SOURCE
33 #include <unistd.h>
34 #include <sys/syscall.h>
35
36 #include "test_harness.h"
37
38 #ifndef PR_SET_PTRACER
39 # define PR_SET_PTRACER 0x59616d61
40 #endif
41
42 #ifndef PR_SET_NO_NEW_PRIVS
43 #define PR_SET_NO_NEW_PRIVS 38
44 #define PR_GET_NO_NEW_PRIVS 39
45 #endif
46
47 #ifndef PR_SECCOMP_EXT
48 #define PR_SECCOMP_EXT 43
49 #endif
50
51 #ifndef SECCOMP_EXT_ACT
52 #define SECCOMP_EXT_ACT 1
53 #endif
54
55 #ifndef SECCOMP_EXT_ACT_TSYNC
56 #define SECCOMP_EXT_ACT_TSYNC 1
57 #endif
58
59 #ifndef SECCOMP_MODE_STRICT
60 #define SECCOMP_MODE_STRICT 1
61 #endif
62
63 #ifndef SECCOMP_MODE_FILTER
64 #define SECCOMP_MODE_FILTER 2
65 #endif
66
67 #ifndef SECCOMP_RET_KILL
68 #define SECCOMP_RET_KILL 0x00000000U /* kill the task immediately */
69 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
70 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
71 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
72 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
73
74 /* Masks for the return value sections. */
75 #define SECCOMP_RET_ACTION 0x7fff0000U
76 #define SECCOMP_RET_DATA 0x0000ffffU
77
78 struct seccomp_data {
79 int nr;
80 __u32 arch;
81 __u64 instruction_pointer;
82 __u64 args[6];
83 };
84 #endif
85
86 #if __BYTE_ORDER == __LITTLE_ENDIAN
87 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
88 #elif __BYTE_ORDER == __BIG_ENDIAN
89 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
90 #else
91 #error "wut? Unknown __BYTE_ORDER?!"
92 #endif
93
94 #define SIBLING_EXIT_UNKILLED 0xbadbeef
95 #define SIBLING_EXIT_FAILURE 0xbadface
96 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
97
98 TEST(mode_strict_support)
99 {
100 long ret;
101
102 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
103 ASSERT_EQ(0, ret) {
104 TH_LOG("Kernel does not support CONFIG_SECCOMP");
105 }
106 syscall(__NR_exit, 1);
107 }
108
109 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
110 {
111 long ret;
112
113 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
114 ASSERT_EQ(0, ret) {
115 TH_LOG("Kernel does not support CONFIG_SECCOMP");
116 }
117 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
118 NULL, NULL, NULL);
119 EXPECT_FALSE(true) {
120 TH_LOG("Unreachable!");
121 }
122 }
123
124 /* Note! This doesn't test no new privs behavior */
125 TEST(no_new_privs_support)
126 {
127 long ret;
128
129 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
130 EXPECT_EQ(0, ret) {
131 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
132 }
133 }
134
135 /* Tests kernel support by checking for a copy_from_user() fault on * NULL. */
136 TEST(mode_filter_support)
137 {
138 long ret;
139
140 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
141 ASSERT_EQ(0, ret) {
142 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
143 }
144 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
145 EXPECT_EQ(-1, ret);
146 EXPECT_EQ(EFAULT, errno) {
147 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
148 }
149 }
150
151 TEST(mode_filter_without_nnp)
152 {
153 struct sock_filter filter[] = {
154 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
155 };
156 struct sock_fprog prog = {
157 .len = (unsigned short)ARRAY_SIZE(filter),
158 .filter = filter,
159 };
160 long ret;
161
162 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
163 ASSERT_LE(0, ret) {
164 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
165 }
166 errno = 0;
167 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
168 /* Succeeds with CAP_SYS_ADMIN, fails without */
169 /* TODO(wad) check caps not euid */
170 if (geteuid()) {
171 EXPECT_EQ(-1, ret);
172 EXPECT_EQ(EACCES, errno);
173 } else {
174 EXPECT_EQ(0, ret);
175 }
176 }
177
178 #define MAX_INSNS_PER_PATH 32768
179
180 TEST(filter_size_limits)
181 {
182 int i;
183 int count = BPF_MAXINSNS + 1;
184 struct sock_filter allow[] = {
185 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
186 };
187 struct sock_filter *filter;
188 struct sock_fprog prog = { };
189 long ret;
190
191 filter = calloc(count, sizeof(*filter));
192 ASSERT_NE(NULL, filter);
193
194 for (i = 0; i < count; i++)
195 filter[i] = allow[0];
196
197 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
198 ASSERT_EQ(0, ret);
199
200 prog.filter = filter;
201 prog.len = count;
202
203 /* Too many filter instructions in a single filter. */
204 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
205 ASSERT_NE(0, ret) {
206 TH_LOG("Installing %d insn filter was allowed", prog.len);
207 }
208
209 /* One less is okay, though. */
210 prog.len -= 1;
211 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
212 ASSERT_EQ(0, ret) {
213 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
214 }
215 }
216
217 TEST(filter_chain_limits)
218 {
219 int i;
220 int count = BPF_MAXINSNS;
221 struct sock_filter allow[] = {
222 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
223 };
224 struct sock_filter *filter;
225 struct sock_fprog prog = { };
226 long ret;
227
228 filter = calloc(count, sizeof(*filter));
229 ASSERT_NE(NULL, filter);
230
231 for (i = 0; i < count; i++)
232 filter[i] = allow[0];
233
234 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
235 ASSERT_EQ(0, ret);
236
237 prog.filter = filter;
238 prog.len = 1;
239
240 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
241 ASSERT_EQ(0, ret);
242
243 prog.len = count;
244
245 /* Too many total filter instructions. */
246 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
247 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
248 if (ret != 0)
249 break;
250 }
251 ASSERT_NE(0, ret) {
252 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
253 i, count, i * (count + 4));
254 }
255 }
256
257 TEST(mode_filter_cannot_move_to_strict)
258 {
259 struct sock_filter filter[] = {
260 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
261 };
262 struct sock_fprog prog = {
263 .len = (unsigned short)ARRAY_SIZE(filter),
264 .filter = filter,
265 };
266 long ret;
267
268 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
269 ASSERT_EQ(0, ret);
270
271 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
272 ASSERT_EQ(0, ret);
273
274 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
275 EXPECT_EQ(-1, ret);
276 EXPECT_EQ(EINVAL, errno);
277 }
278
279
280 TEST(mode_filter_get_seccomp)
281 {
282 struct sock_filter filter[] = {
283 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
284 };
285 struct sock_fprog prog = {
286 .len = (unsigned short)ARRAY_SIZE(filter),
287 .filter = filter,
288 };
289 long ret;
290
291 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
292 ASSERT_EQ(0, ret);
293
294 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
295 EXPECT_EQ(0, ret);
296
297 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
298 ASSERT_EQ(0, ret);
299
300 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
301 EXPECT_EQ(2, ret);
302 }
303
304
305 TEST(ALLOW_all)
306 {
307 struct sock_filter filter[] = {
308 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
309 };
310 struct sock_fprog prog = {
311 .len = (unsigned short)ARRAY_SIZE(filter),
312 .filter = filter,
313 };
314 long ret;
315
316 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
317 ASSERT_EQ(0, ret);
318
319 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
320 ASSERT_EQ(0, ret);
321 }
322
323 TEST(empty_prog)
324 {
325 struct sock_filter filter[] = {
326 };
327 struct sock_fprog prog = {
328 .len = (unsigned short)ARRAY_SIZE(filter),
329 .filter = filter,
330 };
331 long ret;
332
333 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
334 ASSERT_EQ(0, ret);
335
336 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
337 EXPECT_EQ(-1, ret);
338 EXPECT_EQ(EINVAL, errno);
339 }
340
341 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
342 {
343 struct sock_filter filter[] = {
344 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
345 };
346 struct sock_fprog prog = {
347 .len = (unsigned short)ARRAY_SIZE(filter),
348 .filter = filter,
349 };
350 long ret;
351
352 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
353 ASSERT_EQ(0, ret);
354
355 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
356 ASSERT_EQ(0, ret);
357 EXPECT_EQ(0, syscall(__NR_getpid)) {
358 TH_LOG("getpid() shouldn't ever return");
359 }
360 }
361
362 /* return code >= 0x80000000 is unused. */
363 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
364 {
365 struct sock_filter filter[] = {
366 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
367 };
368 struct sock_fprog prog = {
369 .len = (unsigned short)ARRAY_SIZE(filter),
370 .filter = filter,
371 };
372 long ret;
373
374 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
375 ASSERT_EQ(0, ret);
376
377 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
378 ASSERT_EQ(0, ret);
379 EXPECT_EQ(0, syscall(__NR_getpid)) {
380 TH_LOG("getpid() shouldn't ever return");
381 }
382 }
383
384 TEST_SIGNAL(KILL_all, SIGSYS)
385 {
386 struct sock_filter filter[] = {
387 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
388 };
389 struct sock_fprog prog = {
390 .len = (unsigned short)ARRAY_SIZE(filter),
391 .filter = filter,
392 };
393 long ret;
394
395 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
396 ASSERT_EQ(0, ret);
397
398 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
399 ASSERT_EQ(0, ret);
400 }
401
402 TEST_SIGNAL(KILL_one, SIGSYS)
403 {
404 struct sock_filter filter[] = {
405 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
406 offsetof(struct seccomp_data, nr)),
407 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
408 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
409 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
410 };
411 struct sock_fprog prog = {
412 .len = (unsigned short)ARRAY_SIZE(filter),
413 .filter = filter,
414 };
415 long ret;
416 pid_t parent = getppid();
417
418 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
419 ASSERT_EQ(0, ret);
420
421 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
422 ASSERT_EQ(0, ret);
423
424 EXPECT_EQ(parent, syscall(__NR_getppid));
425 /* getpid() should never return. */
426 EXPECT_EQ(0, syscall(__NR_getpid));
427 }
428
429 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
430 {
431 struct sock_filter filter[] = {
432 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
433 offsetof(struct seccomp_data, nr)),
434 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
435 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
436 /* Only both with lower 32-bit for now. */
437 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
438 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
439 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
440 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
441 };
442 struct sock_fprog prog = {
443 .len = (unsigned short)ARRAY_SIZE(filter),
444 .filter = filter,
445 };
446 long ret;
447 pid_t parent = getppid();
448 pid_t pid = getpid();
449
450 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
451 ASSERT_EQ(0, ret);
452
453 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
454 ASSERT_EQ(0, ret);
455
456 EXPECT_EQ(parent, syscall(__NR_getppid));
457 EXPECT_EQ(pid, syscall(__NR_getpid));
458 /* getpid() should never return. */
459 EXPECT_EQ(0, syscall(__NR_getpid, 0x0C0FFEE));
460 }
461
462 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
463 {
464 struct sock_filter filter[] = {
465 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
466 offsetof(struct seccomp_data, nr)),
467 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
468 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
469 /* Only both with lower 32-bit for now. */
470 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
471 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
472 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
473 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
474 };
475 struct sock_fprog prog = {
476 .len = (unsigned short)ARRAY_SIZE(filter),
477 .filter = filter,
478 };
479 long ret;
480 pid_t parent = getppid();
481 pid_t pid = getpid();
482
483 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
484 ASSERT_EQ(0, ret);
485
486 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
487 ASSERT_EQ(0, ret);
488
489 EXPECT_EQ(parent, syscall(__NR_getppid));
490 EXPECT_EQ(pid, syscall(__NR_getpid));
491 /* getpid() should never return. */
492 EXPECT_EQ(0, syscall(__NR_getpid, 1, 2, 3, 4, 5, 0x0C0FFEE));
493 }
494
495 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
496 TEST(arg_out_of_range)
497 {
498 struct sock_filter filter[] = {
499 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
500 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
501 };
502 struct sock_fprog prog = {
503 .len = (unsigned short)ARRAY_SIZE(filter),
504 .filter = filter,
505 };
506 long ret;
507
508 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
509 ASSERT_EQ(0, ret);
510
511 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
512 EXPECT_EQ(-1, ret);
513 EXPECT_EQ(EINVAL, errno);
514 }
515
516 TEST(ERRNO_valid)
517 {
518 struct sock_filter filter[] = {
519 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
520 offsetof(struct seccomp_data, nr)),
521 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
522 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | E2BIG),
523 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
524 };
525 struct sock_fprog prog = {
526 .len = (unsigned short)ARRAY_SIZE(filter),
527 .filter = filter,
528 };
529 long ret;
530 pid_t parent = getppid();
531
532 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
533 ASSERT_EQ(0, ret);
534
535 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
536 ASSERT_EQ(0, ret);
537
538 EXPECT_EQ(parent, syscall(__NR_getppid));
539 EXPECT_EQ(-1, read(0, NULL, 0));
540 EXPECT_EQ(E2BIG, errno);
541 }
542
543 TEST(ERRNO_zero)
544 {
545 struct sock_filter filter[] = {
546 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
547 offsetof(struct seccomp_data, nr)),
548 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
549 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 0),
550 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
551 };
552 struct sock_fprog prog = {
553 .len = (unsigned short)ARRAY_SIZE(filter),
554 .filter = filter,
555 };
556 long ret;
557 pid_t parent = getppid();
558
559 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
560 ASSERT_EQ(0, ret);
561
562 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
563 ASSERT_EQ(0, ret);
564
565 EXPECT_EQ(parent, syscall(__NR_getppid));
566 /* "errno" of 0 is ok. */
567 EXPECT_EQ(0, read(0, NULL, 0));
568 }
569
570 TEST(ERRNO_capped)
571 {
572 struct sock_filter filter[] = {
573 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
574 offsetof(struct seccomp_data, nr)),
575 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
576 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 4096),
577 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
578 };
579 struct sock_fprog prog = {
580 .len = (unsigned short)ARRAY_SIZE(filter),
581 .filter = filter,
582 };
583 long ret;
584 pid_t parent = getppid();
585
586 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
587 ASSERT_EQ(0, ret);
588
589 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
590 ASSERT_EQ(0, ret);
591
592 EXPECT_EQ(parent, syscall(__NR_getppid));
593 EXPECT_EQ(-1, read(0, NULL, 0));
594 EXPECT_EQ(4095, errno);
595 }
596
597 FIXTURE_DATA(TRAP) {
598 struct sock_fprog prog;
599 };
600
601 FIXTURE_SETUP(TRAP)
602 {
603 struct sock_filter filter[] = {
604 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
605 offsetof(struct seccomp_data, nr)),
606 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
607 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
608 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
609 };
610
611 memset(&self->prog, 0, sizeof(self->prog));
612 self->prog.filter = malloc(sizeof(filter));
613 ASSERT_NE(NULL, self->prog.filter);
614 memcpy(self->prog.filter, filter, sizeof(filter));
615 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
616 }
617
618 FIXTURE_TEARDOWN(TRAP)
619 {
620 if (self->prog.filter)
621 free(self->prog.filter);
622 }
623
624 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
625 {
626 long ret;
627
628 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
629 ASSERT_EQ(0, ret);
630
631 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
632 ASSERT_EQ(0, ret);
633 syscall(__NR_getpid);
634 }
635
636 /* Ensure that SIGSYS overrides SIG_IGN */
637 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
638 {
639 long ret;
640
641 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
642 ASSERT_EQ(0, ret);
643
644 signal(SIGSYS, SIG_IGN);
645
646 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
647 ASSERT_EQ(0, ret);
648 syscall(__NR_getpid);
649 }
650
651 static struct siginfo TRAP_info;
652 static volatile int TRAP_nr;
653 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
654 {
655 memcpy(&TRAP_info, info, sizeof(TRAP_info));
656 TRAP_nr = nr;
657 }
658
659 TEST_F(TRAP, handler)
660 {
661 int ret, test;
662 struct sigaction act;
663 sigset_t mask;
664
665 memset(&act, 0, sizeof(act));
666 sigemptyset(&mask);
667 sigaddset(&mask, SIGSYS);
668
669 act.sa_sigaction = &TRAP_action;
670 act.sa_flags = SA_SIGINFO;
671 ret = sigaction(SIGSYS, &act, NULL);
672 ASSERT_EQ(0, ret) {
673 TH_LOG("sigaction failed");
674 }
675 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
676 ASSERT_EQ(0, ret) {
677 TH_LOG("sigprocmask failed");
678 }
679
680 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
681 ASSERT_EQ(0, ret);
682 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
683 ASSERT_EQ(0, ret);
684 TRAP_nr = 0;
685 memset(&TRAP_info, 0, sizeof(TRAP_info));
686 /* Expect the registers to be rolled back. (nr = error) may vary
687 * based on arch. */
688 ret = syscall(__NR_getpid);
689 /* Silence gcc warning about volatile. */
690 test = TRAP_nr;
691 EXPECT_EQ(SIGSYS, test);
692 struct local_sigsys {
693 void *_call_addr; /* calling user insn */
694 int _syscall; /* triggering system call number */
695 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
696 } *sigsys = (struct local_sigsys *)
697 #ifdef si_syscall
698 &(TRAP_info.si_call_addr);
699 #else
700 &TRAP_info.si_pid;
701 #endif
702 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
703 /* Make sure arch is non-zero. */
704 EXPECT_NE(0, sigsys->_arch);
705 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
706 }
707
708 FIXTURE_DATA(precedence) {
709 struct sock_fprog allow;
710 struct sock_fprog trace;
711 struct sock_fprog error;
712 struct sock_fprog trap;
713 struct sock_fprog kill;
714 };
715
716 FIXTURE_SETUP(precedence)
717 {
718 struct sock_filter allow_insns[] = {
719 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
720 };
721 struct sock_filter trace_insns[] = {
722 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
723 offsetof(struct seccomp_data, nr)),
724 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
725 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
726 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
727 };
728 struct sock_filter error_insns[] = {
729 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
730 offsetof(struct seccomp_data, nr)),
731 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
732 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
733 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
734 };
735 struct sock_filter trap_insns[] = {
736 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
737 offsetof(struct seccomp_data, nr)),
738 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
739 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
740 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
741 };
742 struct sock_filter kill_insns[] = {
743 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
744 offsetof(struct seccomp_data, nr)),
745 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
746 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
747 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
748 };
749
750 memset(self, 0, sizeof(*self));
751 #define FILTER_ALLOC(_x) \
752 self->_x.filter = malloc(sizeof(_x##_insns)); \
753 ASSERT_NE(NULL, self->_x.filter); \
754 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
755 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
756 FILTER_ALLOC(allow);
757 FILTER_ALLOC(trace);
758 FILTER_ALLOC(error);
759 FILTER_ALLOC(trap);
760 FILTER_ALLOC(kill);
761 }
762
763 FIXTURE_TEARDOWN(precedence)
764 {
765 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
766 FILTER_FREE(allow);
767 FILTER_FREE(trace);
768 FILTER_FREE(error);
769 FILTER_FREE(trap);
770 FILTER_FREE(kill);
771 }
772
773 TEST_F(precedence, allow_ok)
774 {
775 pid_t parent, res = 0;
776 long ret;
777
778 parent = getppid();
779 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
780 ASSERT_EQ(0, ret);
781
782 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
783 ASSERT_EQ(0, ret);
784 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
785 ASSERT_EQ(0, ret);
786 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
787 ASSERT_EQ(0, ret);
788 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
789 ASSERT_EQ(0, ret);
790 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
791 ASSERT_EQ(0, ret);
792 /* Should work just fine. */
793 res = syscall(__NR_getppid);
794 EXPECT_EQ(parent, res);
795 }
796
797 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
798 {
799 pid_t parent, res = 0;
800 long ret;
801
802 parent = getppid();
803 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
804 ASSERT_EQ(0, ret);
805
806 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
807 ASSERT_EQ(0, ret);
808 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
809 ASSERT_EQ(0, ret);
810 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
811 ASSERT_EQ(0, ret);
812 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
813 ASSERT_EQ(0, ret);
814 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
815 ASSERT_EQ(0, ret);
816 /* Should work just fine. */
817 res = syscall(__NR_getppid);
818 EXPECT_EQ(parent, res);
819 /* getpid() should never return. */
820 res = syscall(__NR_getpid);
821 EXPECT_EQ(0, res);
822 }
823
824 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
825 {
826 pid_t parent;
827 long ret;
828
829 parent = getppid();
830 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
831 ASSERT_EQ(0, ret);
832
833 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
834 ASSERT_EQ(0, ret);
835 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
836 ASSERT_EQ(0, ret);
837 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
838 ASSERT_EQ(0, ret);
839 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
840 ASSERT_EQ(0, ret);
841 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
842 ASSERT_EQ(0, ret);
843 /* Should work just fine. */
844 EXPECT_EQ(parent, syscall(__NR_getppid));
845 /* getpid() should never return. */
846 EXPECT_EQ(0, syscall(__NR_getpid));
847 }
848
849 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
850 {
851 pid_t parent;
852 long ret;
853
854 parent = getppid();
855 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
856 ASSERT_EQ(0, ret);
857
858 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
859 ASSERT_EQ(0, ret);
860 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
861 ASSERT_EQ(0, ret);
862 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
863 ASSERT_EQ(0, ret);
864 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
865 ASSERT_EQ(0, ret);
866 /* Should work just fine. */
867 EXPECT_EQ(parent, syscall(__NR_getppid));
868 /* getpid() should never return. */
869 EXPECT_EQ(0, syscall(__NR_getpid));
870 }
871
872 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
873 {
874 pid_t parent;
875 long ret;
876
877 parent = getppid();
878 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
879 ASSERT_EQ(0, ret);
880
881 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
882 ASSERT_EQ(0, ret);
883 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
884 ASSERT_EQ(0, ret);
885 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
886 ASSERT_EQ(0, ret);
887 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
888 ASSERT_EQ(0, ret);
889 /* Should work just fine. */
890 EXPECT_EQ(parent, syscall(__NR_getppid));
891 /* getpid() should never return. */
892 EXPECT_EQ(0, syscall(__NR_getpid));
893 }
894
895 TEST_F(precedence, errno_is_third)
896 {
897 pid_t parent;
898 long ret;
899
900 parent = getppid();
901 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
902 ASSERT_EQ(0, ret);
903
904 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
905 ASSERT_EQ(0, ret);
906 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
907 ASSERT_EQ(0, ret);
908 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
909 ASSERT_EQ(0, ret);
910 /* Should work just fine. */
911 EXPECT_EQ(parent, syscall(__NR_getppid));
912 EXPECT_EQ(0, syscall(__NR_getpid));
913 }
914
915 TEST_F(precedence, errno_is_third_in_any_order)
916 {
917 pid_t parent;
918 long ret;
919
920 parent = getppid();
921 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
922 ASSERT_EQ(0, ret);
923
924 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
925 ASSERT_EQ(0, ret);
926 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
927 ASSERT_EQ(0, ret);
928 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
929 ASSERT_EQ(0, ret);
930 /* Should work just fine. */
931 EXPECT_EQ(parent, syscall(__NR_getppid));
932 EXPECT_EQ(0, syscall(__NR_getpid));
933 }
934
935 TEST_F(precedence, trace_is_fourth)
936 {
937 pid_t parent;
938 long ret;
939
940 parent = getppid();
941 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
942 ASSERT_EQ(0, ret);
943
944 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
945 ASSERT_EQ(0, ret);
946 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
947 ASSERT_EQ(0, ret);
948 /* Should work just fine. */
949 EXPECT_EQ(parent, syscall(__NR_getppid));
950 /* No ptracer */
951 EXPECT_EQ(-1, syscall(__NR_getpid));
952 }
953
954 TEST_F(precedence, trace_is_fourth_in_any_order)
955 {
956 pid_t parent;
957 long ret;
958
959 parent = getppid();
960 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
961 ASSERT_EQ(0, ret);
962
963 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
964 ASSERT_EQ(0, ret);
965 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
966 ASSERT_EQ(0, ret);
967 /* Should work just fine. */
968 EXPECT_EQ(parent, syscall(__NR_getppid));
969 /* No ptracer */
970 EXPECT_EQ(-1, syscall(__NR_getpid));
971 }
972
973 #ifndef PTRACE_O_TRACESECCOMP
974 #define PTRACE_O_TRACESECCOMP 0x00000080
975 #endif
976
977 /* Catch the Ubuntu 12.04 value error. */
978 #if PTRACE_EVENT_SECCOMP != 7
979 #undef PTRACE_EVENT_SECCOMP
980 #endif
981
982 #ifndef PTRACE_EVENT_SECCOMP
983 #define PTRACE_EVENT_SECCOMP 7
984 #endif
985
986 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
987 bool tracer_running;
988 void tracer_stop(int sig)
989 {
990 tracer_running = false;
991 }
992
993 typedef void tracer_func_t(struct __test_metadata *_metadata,
994 pid_t tracee, int status, void *args);
995
996 void tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
997 tracer_func_t tracer_func, void *args)
998 {
999 int ret = -1;
1000 struct sigaction action = {
1001 .sa_handler = tracer_stop,
1002 };
1003
1004 /* Allow external shutdown. */
1005 tracer_running = true;
1006 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1007
1008 errno = 0;
1009 while (ret == -1 && errno != EINVAL)
1010 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1011 ASSERT_EQ(0, ret) {
1012 kill(tracee, SIGKILL);
1013 }
1014 /* Wait for attach stop */
1015 wait(NULL);
1016
1017 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, PTRACE_O_TRACESECCOMP);
1018 ASSERT_EQ(0, ret) {
1019 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1020 kill(tracee, SIGKILL);
1021 }
1022 ptrace(PTRACE_CONT, tracee, NULL, 0);
1023
1024 /* Unblock the tracee */
1025 ASSERT_EQ(1, write(fd, "A", 1));
1026 ASSERT_EQ(0, close(fd));
1027
1028 /* Run until we're shut down. Must assert to stop execution. */
1029 while (tracer_running) {
1030 int status;
1031
1032 if (wait(&status) != tracee)
1033 continue;
1034 if (WIFSIGNALED(status) || WIFEXITED(status))
1035 /* Child is dead. Time to go. */
1036 return;
1037
1038 /* Make sure this is a seccomp event. */
1039 ASSERT_EQ(true, IS_SECCOMP_EVENT(status));
1040
1041 tracer_func(_metadata, tracee, status, args);
1042
1043 ret = ptrace(PTRACE_CONT, tracee, NULL, NULL);
1044 ASSERT_EQ(0, ret);
1045 }
1046 /* Directly report the status of our test harness results. */
1047 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1048 }
1049
1050 /* Common tracer setup/teardown functions. */
1051 void cont_handler(int num)
1052 { }
1053 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1054 tracer_func_t func, void *args)
1055 {
1056 char sync;
1057 int pipefd[2];
1058 pid_t tracer_pid;
1059 pid_t tracee = getpid();
1060
1061 /* Setup a pipe for clean synchronization. */
1062 ASSERT_EQ(0, pipe(pipefd));
1063
1064 /* Fork a child which we'll promote to tracer */
1065 tracer_pid = fork();
1066 ASSERT_LE(0, tracer_pid);
1067 signal(SIGALRM, cont_handler);
1068 if (tracer_pid == 0) {
1069 close(pipefd[0]);
1070 tracer(_metadata, pipefd[1], tracee, func, args);
1071 syscall(__NR_exit, 0);
1072 }
1073 close(pipefd[1]);
1074 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1075 read(pipefd[0], &sync, 1);
1076 close(pipefd[0]);
1077
1078 return tracer_pid;
1079 }
1080 void teardown_trace_fixture(struct __test_metadata *_metadata,
1081 pid_t tracer)
1082 {
1083 if (tracer) {
1084 int status;
1085 /*
1086 * Extract the exit code from the other process and
1087 * adopt it for ourselves in case its asserts failed.
1088 */
1089 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1090 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1091 if (WEXITSTATUS(status))
1092 _metadata->passed = 0;
1093 }
1094 }
1095
1096 /* "poke" tracer arguments and function. */
1097 struct tracer_args_poke_t {
1098 unsigned long poke_addr;
1099 };
1100
1101 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1102 void *args)
1103 {
1104 int ret;
1105 unsigned long msg;
1106 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1107
1108 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1109 EXPECT_EQ(0, ret);
1110 /* If this fails, don't try to recover. */
1111 ASSERT_EQ(0x1001, msg) {
1112 kill(tracee, SIGKILL);
1113 }
1114 /*
1115 * Poke in the message.
1116 * Registers are not touched to try to keep this relatively arch
1117 * agnostic.
1118 */
1119 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1120 EXPECT_EQ(0, ret);
1121 }
1122
1123 FIXTURE_DATA(TRACE_poke) {
1124 struct sock_fprog prog;
1125 pid_t tracer;
1126 long poked;
1127 struct tracer_args_poke_t tracer_args;
1128 };
1129
1130 FIXTURE_SETUP(TRACE_poke)
1131 {
1132 struct sock_filter filter[] = {
1133 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1134 offsetof(struct seccomp_data, nr)),
1135 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1136 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1137 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1138 };
1139
1140 self->poked = 0;
1141 memset(&self->prog, 0, sizeof(self->prog));
1142 self->prog.filter = malloc(sizeof(filter));
1143 ASSERT_NE(NULL, self->prog.filter);
1144 memcpy(self->prog.filter, filter, sizeof(filter));
1145 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1146
1147 /* Set up tracer args. */
1148 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1149
1150 /* Launch tracer. */
1151 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1152 &self->tracer_args);
1153 }
1154
1155 FIXTURE_TEARDOWN(TRACE_poke)
1156 {
1157 teardown_trace_fixture(_metadata, self->tracer);
1158 if (self->prog.filter)
1159 free(self->prog.filter);
1160 }
1161
1162 TEST_F(TRACE_poke, read_has_side_effects)
1163 {
1164 ssize_t ret;
1165
1166 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1167 ASSERT_EQ(0, ret);
1168
1169 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1170 ASSERT_EQ(0, ret);
1171
1172 EXPECT_EQ(0, self->poked);
1173 ret = read(-1, NULL, 0);
1174 EXPECT_EQ(-1, ret);
1175 EXPECT_EQ(0x1001, self->poked);
1176 }
1177
1178 TEST_F(TRACE_poke, getpid_runs_normally)
1179 {
1180 long ret;
1181
1182 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1183 ASSERT_EQ(0, ret);
1184
1185 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1186 ASSERT_EQ(0, ret);
1187
1188 EXPECT_EQ(0, self->poked);
1189 EXPECT_NE(0, syscall(__NR_getpid));
1190 EXPECT_EQ(0, self->poked);
1191 }
1192
1193 #if defined(__x86_64__)
1194 # define ARCH_REGS struct user_regs_struct
1195 # define SYSCALL_NUM orig_rax
1196 # define SYSCALL_RET rax
1197 #elif defined(__i386__)
1198 # define ARCH_REGS struct user_regs_struct
1199 # define SYSCALL_NUM orig_eax
1200 # define SYSCALL_RET eax
1201 #elif defined(__arm__)
1202 # define ARCH_REGS struct pt_regs
1203 # define SYSCALL_NUM ARM_r7
1204 # define SYSCALL_RET ARM_r0
1205 #elif defined(__aarch64__)
1206 # define ARCH_REGS struct user_pt_regs
1207 # define SYSCALL_NUM regs[8]
1208 # define SYSCALL_RET regs[0]
1209 #elif defined(__powerpc__)
1210 # define ARCH_REGS struct pt_regs
1211 # define SYSCALL_NUM gpr[0]
1212 # define SYSCALL_RET gpr[3]
1213 #elif defined(__s390__)
1214 # define ARCH_REGS s390_regs
1215 # define SYSCALL_NUM gprs[2]
1216 # define SYSCALL_RET gprs[2]
1217 #else
1218 # error "Do not know how to find your architecture's registers and syscalls"
1219 #endif
1220
1221 /* Architecture-specific syscall fetching routine. */
1222 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1223 {
1224 struct iovec iov;
1225 ARCH_REGS regs;
1226
1227 iov.iov_base = &regs;
1228 iov.iov_len = sizeof(regs);
1229 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1230 TH_LOG("PTRACE_GETREGSET failed");
1231 return -1;
1232 }
1233
1234 return regs.SYSCALL_NUM;
1235 }
1236
1237 /* Architecture-specific syscall changing routine. */
1238 void change_syscall(struct __test_metadata *_metadata,
1239 pid_t tracee, int syscall)
1240 {
1241 struct iovec iov;
1242 int ret;
1243 ARCH_REGS regs;
1244
1245 iov.iov_base = &regs;
1246 iov.iov_len = sizeof(regs);
1247 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1248 EXPECT_EQ(0, ret);
1249
1250 #if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__) || \
1251 defined(__powerpc__) || defined(__s390__)
1252 {
1253 regs.SYSCALL_NUM = syscall;
1254 }
1255
1256 #elif defined(__arm__)
1257 # ifndef PTRACE_SET_SYSCALL
1258 # define PTRACE_SET_SYSCALL 23
1259 # endif
1260 {
1261 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1262 EXPECT_EQ(0, ret);
1263 }
1264
1265 #else
1266 ASSERT_EQ(1, 0) {
1267 TH_LOG("How is the syscall changed on this architecture?");
1268 }
1269 #endif
1270
1271 /* If syscall is skipped, change return value. */
1272 if (syscall == -1)
1273 regs.SYSCALL_RET = 1;
1274
1275 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1276 EXPECT_EQ(0, ret);
1277 }
1278
1279 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1280 int status, void *args)
1281 {
1282 int ret;
1283 unsigned long msg;
1284
1285 /* Make sure we got the right message. */
1286 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1287 EXPECT_EQ(0, ret);
1288
1289 /* Validate and take action on expected syscalls. */
1290 switch (msg) {
1291 case 0x1002:
1292 /* change getpid to getppid. */
1293 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1294 change_syscall(_metadata, tracee, __NR_getppid);
1295 break;
1296 case 0x1003:
1297 /* skip gettid. */
1298 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1299 change_syscall(_metadata, tracee, -1);
1300 break;
1301 case 0x1004:
1302 /* do nothing (allow getppid) */
1303 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1304 break;
1305 default:
1306 EXPECT_EQ(0, msg) {
1307 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1308 kill(tracee, SIGKILL);
1309 }
1310 }
1311
1312 }
1313
1314 FIXTURE_DATA(TRACE_syscall) {
1315 struct sock_fprog prog;
1316 pid_t tracer, mytid, mypid, parent;
1317 };
1318
1319 FIXTURE_SETUP(TRACE_syscall)
1320 {
1321 struct sock_filter filter[] = {
1322 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1323 offsetof(struct seccomp_data, nr)),
1324 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1325 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1326 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1327 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1328 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1329 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1330 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1331 };
1332
1333 memset(&self->prog, 0, sizeof(self->prog));
1334 self->prog.filter = malloc(sizeof(filter));
1335 ASSERT_NE(NULL, self->prog.filter);
1336 memcpy(self->prog.filter, filter, sizeof(filter));
1337 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1338
1339 /* Prepare some testable syscall results. */
1340 self->mytid = syscall(__NR_gettid);
1341 ASSERT_GT(self->mytid, 0);
1342 ASSERT_NE(self->mytid, 1) {
1343 TH_LOG("Running this test as init is not supported. :)");
1344 }
1345
1346 self->mypid = getpid();
1347 ASSERT_GT(self->mypid, 0);
1348 ASSERT_EQ(self->mytid, self->mypid);
1349
1350 self->parent = getppid();
1351 ASSERT_GT(self->parent, 0);
1352 ASSERT_NE(self->parent, self->mypid);
1353
1354 /* Launch tracer. */
1355 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL);
1356 }
1357
1358 FIXTURE_TEARDOWN(TRACE_syscall)
1359 {
1360 teardown_trace_fixture(_metadata, self->tracer);
1361 if (self->prog.filter)
1362 free(self->prog.filter);
1363 }
1364
1365 TEST_F(TRACE_syscall, syscall_allowed)
1366 {
1367 long ret;
1368
1369 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1370 ASSERT_EQ(0, ret);
1371
1372 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1373 ASSERT_EQ(0, ret);
1374
1375 /* getppid works as expected (no changes). */
1376 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1377 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1378 }
1379
1380 TEST_F(TRACE_syscall, syscall_redirected)
1381 {
1382 long ret;
1383
1384 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1385 ASSERT_EQ(0, ret);
1386
1387 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1388 ASSERT_EQ(0, ret);
1389
1390 /* getpid has been redirected to getppid as expected. */
1391 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1392 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1393 }
1394
1395 TEST_F(TRACE_syscall, syscall_dropped)
1396 {
1397 long ret;
1398
1399 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1400 ASSERT_EQ(0, ret);
1401
1402 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1403 ASSERT_EQ(0, ret);
1404
1405 /* gettid has been skipped and an altered return value stored. */
1406 EXPECT_EQ(1, syscall(__NR_gettid));
1407 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1408 }
1409
1410 #ifndef __NR_seccomp
1411 # if defined(__i386__)
1412 # define __NR_seccomp 354
1413 # elif defined(__x86_64__)
1414 # define __NR_seccomp 317
1415 # elif defined(__arm__)
1416 # define __NR_seccomp 383
1417 # elif defined(__aarch64__)
1418 # define __NR_seccomp 277
1419 # elif defined(__powerpc__)
1420 # define __NR_seccomp 358
1421 # elif defined(__s390__)
1422 # define __NR_seccomp 348
1423 # else
1424 # warning "seccomp syscall number unknown for this architecture"
1425 # define __NR_seccomp 0xffff
1426 # endif
1427 #endif
1428
1429 #ifndef SECCOMP_SET_MODE_STRICT
1430 #define SECCOMP_SET_MODE_STRICT 0
1431 #endif
1432
1433 #ifndef SECCOMP_SET_MODE_FILTER
1434 #define SECCOMP_SET_MODE_FILTER 1
1435 #endif
1436
1437 #ifndef SECCOMP_FLAG_FILTER_TSYNC
1438 #define SECCOMP_FLAG_FILTER_TSYNC 1
1439 #endif
1440
1441 #ifndef seccomp
1442 int seccomp(unsigned int op, unsigned int flags, struct sock_fprog *filter)
1443 {
1444 errno = 0;
1445 return syscall(__NR_seccomp, op, flags, filter);
1446 }
1447 #endif
1448
1449 TEST(seccomp_syscall)
1450 {
1451 struct sock_filter filter[] = {
1452 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1453 };
1454 struct sock_fprog prog = {
1455 .len = (unsigned short)ARRAY_SIZE(filter),
1456 .filter = filter,
1457 };
1458 long ret;
1459
1460 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1461 ASSERT_EQ(0, ret) {
1462 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1463 }
1464
1465 /* Reject insane operation. */
1466 ret = seccomp(-1, 0, &prog);
1467 ASSERT_NE(ENOSYS, errno) {
1468 TH_LOG("Kernel does not support seccomp syscall!");
1469 }
1470 EXPECT_EQ(EINVAL, errno) {
1471 TH_LOG("Did not reject crazy op value!");
1472 }
1473
1474 /* Reject strict with flags or pointer. */
1475 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
1476 EXPECT_EQ(EINVAL, errno) {
1477 TH_LOG("Did not reject mode strict with flags!");
1478 }
1479 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
1480 EXPECT_EQ(EINVAL, errno) {
1481 TH_LOG("Did not reject mode strict with uargs!");
1482 }
1483
1484 /* Reject insane args for filter. */
1485 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
1486 EXPECT_EQ(EINVAL, errno) {
1487 TH_LOG("Did not reject crazy filter flags!");
1488 }
1489 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
1490 EXPECT_EQ(EFAULT, errno) {
1491 TH_LOG("Did not reject NULL filter!");
1492 }
1493
1494 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1495 EXPECT_EQ(0, errno) {
1496 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
1497 strerror(errno));
1498 }
1499 }
1500
1501 TEST(seccomp_syscall_mode_lock)
1502 {
1503 struct sock_filter filter[] = {
1504 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1505 };
1506 struct sock_fprog prog = {
1507 .len = (unsigned short)ARRAY_SIZE(filter),
1508 .filter = filter,
1509 };
1510 long ret;
1511
1512 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1513 ASSERT_EQ(0, ret) {
1514 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1515 }
1516
1517 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1518 ASSERT_NE(ENOSYS, errno) {
1519 TH_LOG("Kernel does not support seccomp syscall!");
1520 }
1521 EXPECT_EQ(0, ret) {
1522 TH_LOG("Could not install filter!");
1523 }
1524
1525 /* Make sure neither entry point will switch to strict. */
1526 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
1527 EXPECT_EQ(EINVAL, errno) {
1528 TH_LOG("Switched to mode strict!");
1529 }
1530
1531 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
1532 EXPECT_EQ(EINVAL, errno) {
1533 TH_LOG("Switched to mode strict!");
1534 }
1535 }
1536
1537 TEST(TSYNC_first)
1538 {
1539 struct sock_filter filter[] = {
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, NULL, 0, 0);
1549 ASSERT_EQ(0, ret) {
1550 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1551 }
1552
1553 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1554 &prog);
1555 ASSERT_NE(ENOSYS, errno) {
1556 TH_LOG("Kernel does not support seccomp syscall!");
1557 }
1558 EXPECT_EQ(0, ret) {
1559 TH_LOG("Could not install initial filter with TSYNC!");
1560 }
1561 }
1562
1563 #define TSYNC_SIBLINGS 2
1564 struct tsync_sibling {
1565 pthread_t tid;
1566 pid_t system_tid;
1567 sem_t *started;
1568 pthread_cond_t *cond;
1569 pthread_mutex_t *mutex;
1570 int diverge;
1571 int num_waits;
1572 struct sock_fprog *prog;
1573 struct __test_metadata *metadata;
1574 };
1575
1576 FIXTURE_DATA(TSYNC) {
1577 struct sock_fprog root_prog, apply_prog;
1578 struct tsync_sibling sibling[TSYNC_SIBLINGS];
1579 sem_t started;
1580 pthread_cond_t cond;
1581 pthread_mutex_t mutex;
1582 int sibling_count;
1583 };
1584
1585 FIXTURE_SETUP(TSYNC)
1586 {
1587 struct sock_filter root_filter[] = {
1588 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1589 };
1590 struct sock_filter apply_filter[] = {
1591 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1592 offsetof(struct seccomp_data, nr)),
1593 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1594 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1595 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1596 };
1597
1598 memset(&self->root_prog, 0, sizeof(self->root_prog));
1599 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
1600 memset(&self->sibling, 0, sizeof(self->sibling));
1601 self->root_prog.filter = malloc(sizeof(root_filter));
1602 ASSERT_NE(NULL, self->root_prog.filter);
1603 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
1604 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
1605
1606 self->apply_prog.filter = malloc(sizeof(apply_filter));
1607 ASSERT_NE(NULL, self->apply_prog.filter);
1608 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
1609 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
1610
1611 self->sibling_count = 0;
1612 pthread_mutex_init(&self->mutex, NULL);
1613 pthread_cond_init(&self->cond, NULL);
1614 sem_init(&self->started, 0, 0);
1615 self->sibling[0].tid = 0;
1616 self->sibling[0].cond = &self->cond;
1617 self->sibling[0].started = &self->started;
1618 self->sibling[0].mutex = &self->mutex;
1619 self->sibling[0].diverge = 0;
1620 self->sibling[0].num_waits = 1;
1621 self->sibling[0].prog = &self->root_prog;
1622 self->sibling[0].metadata = _metadata;
1623 self->sibling[1].tid = 0;
1624 self->sibling[1].cond = &self->cond;
1625 self->sibling[1].started = &self->started;
1626 self->sibling[1].mutex = &self->mutex;
1627 self->sibling[1].diverge = 0;
1628 self->sibling[1].prog = &self->root_prog;
1629 self->sibling[1].num_waits = 1;
1630 self->sibling[1].metadata = _metadata;
1631 }
1632
1633 FIXTURE_TEARDOWN(TSYNC)
1634 {
1635 int sib = 0;
1636
1637 if (self->root_prog.filter)
1638 free(self->root_prog.filter);
1639 if (self->apply_prog.filter)
1640 free(self->apply_prog.filter);
1641
1642 for ( ; sib < self->sibling_count; ++sib) {
1643 struct tsync_sibling *s = &self->sibling[sib];
1644 void *status;
1645
1646 if (!s->tid)
1647 continue;
1648 if (pthread_kill(s->tid, 0)) {
1649 pthread_cancel(s->tid);
1650 pthread_join(s->tid, &status);
1651 }
1652 }
1653 pthread_mutex_destroy(&self->mutex);
1654 pthread_cond_destroy(&self->cond);
1655 sem_destroy(&self->started);
1656 }
1657
1658 void *tsync_sibling(void *data)
1659 {
1660 long ret = 0;
1661 struct tsync_sibling *me = data;
1662
1663 me->system_tid = syscall(__NR_gettid);
1664
1665 pthread_mutex_lock(me->mutex);
1666 if (me->diverge) {
1667 /* Just re-apply the root prog to fork the tree */
1668 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
1669 me->prog, 0, 0);
1670 }
1671 sem_post(me->started);
1672 /* Return outside of started so parent notices failures. */
1673 if (ret) {
1674 pthread_mutex_unlock(me->mutex);
1675 return (void *)SIBLING_EXIT_FAILURE;
1676 }
1677 do {
1678 pthread_cond_wait(me->cond, me->mutex);
1679 me->num_waits = me->num_waits - 1;
1680 } while (me->num_waits);
1681 pthread_mutex_unlock(me->mutex);
1682
1683 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
1684 if (!ret)
1685 return (void *)SIBLING_EXIT_NEWPRIVS;
1686 read(0, NULL, 0);
1687 return (void *)SIBLING_EXIT_UNKILLED;
1688 }
1689
1690 void tsync_start_sibling(struct tsync_sibling *sibling)
1691 {
1692 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
1693 }
1694
1695 TEST_F(TSYNC, siblings_fail_prctl)
1696 {
1697 long ret;
1698 void *status;
1699 struct sock_filter filter[] = {
1700 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1701 offsetof(struct seccomp_data, nr)),
1702 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
1703 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
1704 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1705 };
1706 struct sock_fprog prog = {
1707 .len = (unsigned short)ARRAY_SIZE(filter),
1708 .filter = filter,
1709 };
1710
1711 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1712 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1713 }
1714
1715 /* Check prctl failure detection by requesting sib 0 diverge. */
1716 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1717 ASSERT_NE(ENOSYS, errno) {
1718 TH_LOG("Kernel does not support seccomp syscall!");
1719 }
1720 ASSERT_EQ(0, ret) {
1721 TH_LOG("setting filter failed");
1722 }
1723
1724 self->sibling[0].diverge = 1;
1725 tsync_start_sibling(&self->sibling[0]);
1726 tsync_start_sibling(&self->sibling[1]);
1727
1728 while (self->sibling_count < TSYNC_SIBLINGS) {
1729 sem_wait(&self->started);
1730 self->sibling_count++;
1731 }
1732
1733 /* Signal the threads to clean up*/
1734 pthread_mutex_lock(&self->mutex);
1735 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1736 TH_LOG("cond broadcast non-zero");
1737 }
1738 pthread_mutex_unlock(&self->mutex);
1739
1740 /* Ensure diverging sibling failed to call prctl. */
1741 pthread_join(self->sibling[0].tid, &status);
1742 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
1743 pthread_join(self->sibling[1].tid, &status);
1744 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1745 }
1746
1747 TEST_F(TSYNC, two_siblings_with_ancestor)
1748 {
1749 long ret;
1750 void *status;
1751
1752 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1753 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1754 }
1755
1756 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1757 ASSERT_NE(ENOSYS, errno) {
1758 TH_LOG("Kernel does not support seccomp syscall!");
1759 }
1760 ASSERT_EQ(0, ret) {
1761 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1762 }
1763 tsync_start_sibling(&self->sibling[0]);
1764 tsync_start_sibling(&self->sibling[1]);
1765
1766 while (self->sibling_count < TSYNC_SIBLINGS) {
1767 sem_wait(&self->started);
1768 self->sibling_count++;
1769 }
1770
1771 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1772 &self->apply_prog);
1773 ASSERT_EQ(0, ret) {
1774 TH_LOG("Could install filter on all threads!");
1775 }
1776 /* Tell the siblings to test the policy */
1777 pthread_mutex_lock(&self->mutex);
1778 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1779 TH_LOG("cond broadcast non-zero");
1780 }
1781 pthread_mutex_unlock(&self->mutex);
1782 /* Ensure they are both killed and don't exit cleanly. */
1783 pthread_join(self->sibling[0].tid, &status);
1784 EXPECT_EQ(0x0, (long)status);
1785 pthread_join(self->sibling[1].tid, &status);
1786 EXPECT_EQ(0x0, (long)status);
1787 }
1788
1789 TEST_F(TSYNC, two_sibling_want_nnp)
1790 {
1791 void *status;
1792
1793 /* start siblings before any prctl() operations */
1794 tsync_start_sibling(&self->sibling[0]);
1795 tsync_start_sibling(&self->sibling[1]);
1796 while (self->sibling_count < TSYNC_SIBLINGS) {
1797 sem_wait(&self->started);
1798 self->sibling_count++;
1799 }
1800
1801 /* Tell the siblings to test no policy */
1802 pthread_mutex_lock(&self->mutex);
1803 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1804 TH_LOG("cond broadcast non-zero");
1805 }
1806 pthread_mutex_unlock(&self->mutex);
1807
1808 /* Ensure they are both upset about lacking nnp. */
1809 pthread_join(self->sibling[0].tid, &status);
1810 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1811 pthread_join(self->sibling[1].tid, &status);
1812 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1813 }
1814
1815 TEST_F(TSYNC, two_siblings_with_no_filter)
1816 {
1817 long ret;
1818 void *status;
1819
1820 /* start siblings before any prctl() operations */
1821 tsync_start_sibling(&self->sibling[0]);
1822 tsync_start_sibling(&self->sibling[1]);
1823 while (self->sibling_count < TSYNC_SIBLINGS) {
1824 sem_wait(&self->started);
1825 self->sibling_count++;
1826 }
1827
1828 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1829 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1830 }
1831
1832 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1833 &self->apply_prog);
1834 ASSERT_NE(ENOSYS, errno) {
1835 TH_LOG("Kernel does not support seccomp syscall!");
1836 }
1837 ASSERT_EQ(0, ret) {
1838 TH_LOG("Could install filter on all threads!");
1839 }
1840
1841 /* Tell the siblings to test the policy */
1842 pthread_mutex_lock(&self->mutex);
1843 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1844 TH_LOG("cond broadcast non-zero");
1845 }
1846 pthread_mutex_unlock(&self->mutex);
1847
1848 /* Ensure they are both killed and don't exit cleanly. */
1849 pthread_join(self->sibling[0].tid, &status);
1850 EXPECT_EQ(0x0, (long)status);
1851 pthread_join(self->sibling[1].tid, &status);
1852 EXPECT_EQ(0x0, (long)status);
1853 }
1854
1855 TEST_F(TSYNC, two_siblings_with_one_divergence)
1856 {
1857 long ret;
1858 void *status;
1859
1860 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1861 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1862 }
1863
1864 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1865 ASSERT_NE(ENOSYS, errno) {
1866 TH_LOG("Kernel does not support seccomp syscall!");
1867 }
1868 ASSERT_EQ(0, ret) {
1869 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1870 }
1871 self->sibling[0].diverge = 1;
1872 tsync_start_sibling(&self->sibling[0]);
1873 tsync_start_sibling(&self->sibling[1]);
1874
1875 while (self->sibling_count < TSYNC_SIBLINGS) {
1876 sem_wait(&self->started);
1877 self->sibling_count++;
1878 }
1879
1880 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1881 &self->apply_prog);
1882 ASSERT_EQ(self->sibling[0].system_tid, ret) {
1883 TH_LOG("Did not fail on diverged sibling.");
1884 }
1885
1886 /* Wake the threads */
1887 pthread_mutex_lock(&self->mutex);
1888 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1889 TH_LOG("cond broadcast non-zero");
1890 }
1891 pthread_mutex_unlock(&self->mutex);
1892
1893 /* Ensure they are both unkilled. */
1894 pthread_join(self->sibling[0].tid, &status);
1895 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1896 pthread_join(self->sibling[1].tid, &status);
1897 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1898 }
1899
1900 TEST_F(TSYNC, two_siblings_not_under_filter)
1901 {
1902 long ret, sib;
1903 void *status;
1904
1905 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1906 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1907 }
1908
1909 /*
1910 * Sibling 0 will have its own seccomp policy
1911 * and Sibling 1 will not be under seccomp at
1912 * all. Sibling 1 will enter seccomp and 0
1913 * will cause failure.
1914 */
1915 self->sibling[0].diverge = 1;
1916 tsync_start_sibling(&self->sibling[0]);
1917 tsync_start_sibling(&self->sibling[1]);
1918
1919 while (self->sibling_count < TSYNC_SIBLINGS) {
1920 sem_wait(&self->started);
1921 self->sibling_count++;
1922 }
1923
1924 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1925 ASSERT_NE(ENOSYS, errno) {
1926 TH_LOG("Kernel does not support seccomp syscall!");
1927 }
1928 ASSERT_EQ(0, ret) {
1929 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1930 }
1931
1932 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1933 &self->apply_prog);
1934 ASSERT_EQ(ret, self->sibling[0].system_tid) {
1935 TH_LOG("Did not fail on diverged sibling.");
1936 }
1937 sib = 1;
1938 if (ret == self->sibling[0].system_tid)
1939 sib = 0;
1940
1941 pthread_mutex_lock(&self->mutex);
1942
1943 /* Increment the other siblings num_waits so we can clean up
1944 * the one we just saw.
1945 */
1946 self->sibling[!sib].num_waits += 1;
1947
1948 /* Signal the thread to clean up*/
1949 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1950 TH_LOG("cond broadcast non-zero");
1951 }
1952 pthread_mutex_unlock(&self->mutex);
1953 pthread_join(self->sibling[sib].tid, &status);
1954 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1955 /* Poll for actual task death. pthread_join doesn't guarantee it. */
1956 while (!kill(self->sibling[sib].system_tid, 0))
1957 sleep(0.1);
1958 /* Switch to the remaining sibling */
1959 sib = !sib;
1960
1961 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1962 &self->apply_prog);
1963 ASSERT_EQ(0, ret) {
1964 TH_LOG("Expected the remaining sibling to sync");
1965 };
1966
1967 pthread_mutex_lock(&self->mutex);
1968
1969 /* If remaining sibling didn't have a chance to wake up during
1970 * the first broadcast, manually reduce the num_waits now.
1971 */
1972 if (self->sibling[sib].num_waits > 1)
1973 self->sibling[sib].num_waits = 1;
1974 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1975 TH_LOG("cond broadcast non-zero");
1976 }
1977 pthread_mutex_unlock(&self->mutex);
1978 pthread_join(self->sibling[sib].tid, &status);
1979 EXPECT_EQ(0, (long)status);
1980 /* Poll for actual task death. pthread_join doesn't guarantee it. */
1981 while (!kill(self->sibling[sib].system_tid, 0))
1982 sleep(0.1);
1983
1984 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1985 &self->apply_prog);
1986 ASSERT_EQ(0, ret); /* just us chickens */
1987 }
1988
1989 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
1990 TEST(syscall_restart)
1991 {
1992 long ret;
1993 unsigned long msg;
1994 pid_t child_pid;
1995 int pipefd[2];
1996 int status;
1997 siginfo_t info = { };
1998 struct sock_filter filter[] = {
1999 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2000 offsetof(struct seccomp_data, nr)),
2001
2002 #ifdef __NR_sigreturn
2003 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2004 #endif
2005 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2006 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2007 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2008 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_poll, 4, 0),
2009 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2010
2011 /* Allow __NR_write for easy logging. */
2012 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2013 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2014 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2015 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), /* poll */
2016 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), /* restart */
2017 };
2018 struct sock_fprog prog = {
2019 .len = (unsigned short)ARRAY_SIZE(filter),
2020 .filter = filter,
2021 };
2022
2023 ASSERT_EQ(0, pipe(pipefd));
2024
2025 child_pid = fork();
2026 ASSERT_LE(0, child_pid);
2027 if (child_pid == 0) {
2028 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2029 char buf = ' ';
2030 struct pollfd fds = {
2031 .fd = pipefd[0],
2032 .events = POLLIN,
2033 };
2034
2035 /* Attach parent as tracer and stop. */
2036 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2037 EXPECT_EQ(0, raise(SIGSTOP));
2038
2039 EXPECT_EQ(0, close(pipefd[1]));
2040
2041 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2042 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2043 }
2044
2045 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2046 EXPECT_EQ(0, ret) {
2047 TH_LOG("Failed to install filter!");
2048 }
2049
2050 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2051 TH_LOG("Failed to read() sync from parent");
2052 }
2053 EXPECT_EQ('.', buf) {
2054 TH_LOG("Failed to get sync data from read()");
2055 }
2056
2057 /* Start poll to be interrupted. */
2058 errno = 0;
2059 EXPECT_EQ(1, poll(&fds, 1, -1)) {
2060 TH_LOG("Call to poll() failed (errno %d)", errno);
2061 }
2062
2063 /* Read final sync from parent. */
2064 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2065 TH_LOG("Failed final read() from parent");
2066 }
2067 EXPECT_EQ('!', buf) {
2068 TH_LOG("Failed to get final data from read()");
2069 }
2070
2071 /* Directly report the status of our test harness results. */
2072 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2073 : EXIT_FAILURE);
2074 }
2075 EXPECT_EQ(0, close(pipefd[0]));
2076
2077 /* Attach to child, setup options, and release. */
2078 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2079 ASSERT_EQ(true, WIFSTOPPED(status));
2080 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2081 PTRACE_O_TRACESECCOMP));
2082 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2083 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2084
2085 /* Wait for poll() to start. */
2086 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2087 ASSERT_EQ(true, WIFSTOPPED(status));
2088 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2089 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2090 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2091 ASSERT_EQ(0x100, msg);
2092 EXPECT_EQ(__NR_poll, get_syscall(_metadata, child_pid));
2093
2094 /* Might as well check siginfo for sanity while we're here. */
2095 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2096 ASSERT_EQ(SIGTRAP, info.si_signo);
2097 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2098 EXPECT_EQ(0, info.si_errno);
2099 EXPECT_EQ(getuid(), info.si_uid);
2100 /* Verify signal delivery came from child (seccomp-triggered). */
2101 EXPECT_EQ(child_pid, info.si_pid);
2102
2103 /* Interrupt poll with SIGSTOP (which we'll need to handle). */
2104 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2105 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2106 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2107 ASSERT_EQ(true, WIFSTOPPED(status));
2108 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2109 /* Verify signal delivery came from parent now. */
2110 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2111 EXPECT_EQ(getpid(), info.si_pid);
2112
2113 /* Restart poll with SIGCONT, which triggers restart_syscall. */
2114 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2115 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2116 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2117 ASSERT_EQ(true, WIFSTOPPED(status));
2118 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2119 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2120
2121 /* Wait for restart_syscall() to start. */
2122 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2123 ASSERT_EQ(true, WIFSTOPPED(status));
2124 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2125 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2126 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2127 ASSERT_EQ(0x200, msg);
2128 ret = get_syscall(_metadata, child_pid);
2129 #if defined(__arm__)
2130 /* FIXME: ARM does not expose true syscall in registers. */
2131 EXPECT_EQ(__NR_poll, ret);
2132 #else
2133 EXPECT_EQ(__NR_restart_syscall, ret);
2134 #endif
2135
2136 /* Write again to end poll. */
2137 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2138 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2139 EXPECT_EQ(0, close(pipefd[1]));
2140
2141 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2142 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2143 _metadata->passed = 0;
2144 }
2145
2146 /*
2147 * TODO:
2148 * - add microbenchmarks
2149 * - expand NNP testing
2150 * - better arch-specific TRACE and TRAP handlers.
2151 * - endianness checking when appropriate
2152 * - 64-bit arg prodding
2153 * - arch value testing (x86 modes especially)
2154 * - ...
2155 */
2156
2157 TEST_HARNESS_MAIN
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