?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
[linux/fpc-iii.git] / tools / testing / selftests / seccomp / seccomp_bpf.c
bloba004b4cce99ef3098005ea4b4607cc825f46b667
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 #else
1214 # error "Do not know how to find your architecture's registers and syscalls"
1215 #endif
1216
1217 /* Architecture-specific syscall fetching routine. */
1218 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1219 {
1220 struct iovec iov;
1221 ARCH_REGS regs;
1222
1223 iov.iov_base = &regs;
1224 iov.iov_len = sizeof(regs);
1225 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1226 TH_LOG("PTRACE_GETREGSET failed");
1227 return -1;
1228 }
1229
1230 return regs.SYSCALL_NUM;
1231 }
1232
1233 /* Architecture-specific syscall changing routine. */
1234 void change_syscall(struct __test_metadata *_metadata,
1235 pid_t tracee, int syscall)
1236 {
1237 struct iovec iov;
1238 int ret;
1239 ARCH_REGS regs;
1240
1241 iov.iov_base = &regs;
1242 iov.iov_len = sizeof(regs);
1243 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1244 EXPECT_EQ(0, ret);
1245
1246 #if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__) || defined(__powerpc__)
1247 {
1248 regs.SYSCALL_NUM = syscall;
1249 }
1250
1251 #elif defined(__arm__)
1252 # ifndef PTRACE_SET_SYSCALL
1253 # define PTRACE_SET_SYSCALL 23
1254 # endif
1255 {
1256 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1257 EXPECT_EQ(0, ret);
1258 }
1259
1260 #else
1261 ASSERT_EQ(1, 0) {
1262 TH_LOG("How is the syscall changed on this architecture?");
1263 }
1264 #endif
1265
1266 /* If syscall is skipped, change return value. */
1267 if (syscall == -1)
1268 regs.SYSCALL_RET = 1;
1269
1270 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1271 EXPECT_EQ(0, ret);
1272 }
1273
1274 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1275 int status, void *args)
1276 {
1277 int ret;
1278 unsigned long msg;
1279
1280 /* Make sure we got the right message. */
1281 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1282 EXPECT_EQ(0, ret);
1283
1284 switch (msg) {
1285 case 0x1002:
1286 /* change getpid to getppid. */
1287 change_syscall(_metadata, tracee, __NR_getppid);
1288 break;
1289 case 0x1003:
1290 /* skip gettid. */
1291 change_syscall(_metadata, tracee, -1);
1292 break;
1293 case 0x1004:
1294 /* do nothing (allow getppid) */
1295 break;
1296 default:
1297 EXPECT_EQ(0, msg) {
1298 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1299 kill(tracee, SIGKILL);
1300 }
1301 }
1302
1303 }
1304
1305 FIXTURE_DATA(TRACE_syscall) {
1306 struct sock_fprog prog;
1307 pid_t tracer, mytid, mypid, parent;
1308 };
1309
1310 FIXTURE_SETUP(TRACE_syscall)
1311 {
1312 struct sock_filter filter[] = {
1313 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1314 offsetof(struct seccomp_data, nr)),
1315 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1316 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1317 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1318 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1319 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1320 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1321 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1322 };
1323
1324 memset(&self->prog, 0, sizeof(self->prog));
1325 self->prog.filter = malloc(sizeof(filter));
1326 ASSERT_NE(NULL, self->prog.filter);
1327 memcpy(self->prog.filter, filter, sizeof(filter));
1328 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1329
1330 /* Prepare some testable syscall results. */
1331 self->mytid = syscall(__NR_gettid);
1332 ASSERT_GT(self->mytid, 0);
1333 ASSERT_NE(self->mytid, 1) {
1334 TH_LOG("Running this test as init is not supported. :)");
1335 }
1336
1337 self->mypid = getpid();
1338 ASSERT_GT(self->mypid, 0);
1339 ASSERT_EQ(self->mytid, self->mypid);
1340
1341 self->parent = getppid();
1342 ASSERT_GT(self->parent, 0);
1343 ASSERT_NE(self->parent, self->mypid);
1344
1345 /* Launch tracer. */
1346 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL);
1347 }
1348
1349 FIXTURE_TEARDOWN(TRACE_syscall)
1350 {
1351 teardown_trace_fixture(_metadata, self->tracer);
1352 if (self->prog.filter)
1353 free(self->prog.filter);
1354 }
1355
1356 TEST_F(TRACE_syscall, syscall_allowed)
1357 {
1358 long ret;
1359
1360 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1361 ASSERT_EQ(0, ret);
1362
1363 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1364 ASSERT_EQ(0, ret);
1365
1366 /* getppid works as expected (no changes). */
1367 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1368 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1369 }
1370
1371 TEST_F(TRACE_syscall, syscall_redirected)
1372 {
1373 long ret;
1374
1375 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1376 ASSERT_EQ(0, ret);
1377
1378 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1379 ASSERT_EQ(0, ret);
1380
1381 /* getpid has been redirected to getppid as expected. */
1382 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1383 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1384 }
1385
1386 TEST_F(TRACE_syscall, syscall_dropped)
1387 {
1388 long ret;
1389
1390 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1391 ASSERT_EQ(0, ret);
1392
1393 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1394 ASSERT_EQ(0, ret);
1395
1396 /* gettid has been skipped and an altered return value stored. */
1397 EXPECT_EQ(1, syscall(__NR_gettid));
1398 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1399 }
1400
1401 #ifndef __NR_seccomp
1402 # if defined(__i386__)
1403 # define __NR_seccomp 354
1404 # elif defined(__x86_64__)
1405 # define __NR_seccomp 317
1406 # elif defined(__arm__)
1407 # define __NR_seccomp 383
1408 # elif defined(__aarch64__)
1409 # define __NR_seccomp 277
1410 # elif defined(__powerpc__)
1411 # define __NR_seccomp 358
1412 # else
1413 # warning "seccomp syscall number unknown for this architecture"
1414 # define __NR_seccomp 0xffff
1415 # endif
1416 #endif
1417
1418 #ifndef SECCOMP_SET_MODE_STRICT
1419 #define SECCOMP_SET_MODE_STRICT 0
1420 #endif
1421
1422 #ifndef SECCOMP_SET_MODE_FILTER
1423 #define SECCOMP_SET_MODE_FILTER 1
1424 #endif
1425
1426 #ifndef SECCOMP_FLAG_FILTER_TSYNC
1427 #define SECCOMP_FLAG_FILTER_TSYNC 1
1428 #endif
1429
1430 #ifndef seccomp
1431 int seccomp(unsigned int op, unsigned int flags, struct sock_fprog *filter)
1432 {
1433 errno = 0;
1434 return syscall(__NR_seccomp, op, flags, filter);
1435 }
1436 #endif
1437
1438 TEST(seccomp_syscall)
1439 {
1440 struct sock_filter filter[] = {
1441 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1442 };
1443 struct sock_fprog prog = {
1444 .len = (unsigned short)ARRAY_SIZE(filter),
1445 .filter = filter,
1446 };
1447 long ret;
1448
1449 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1450 ASSERT_EQ(0, ret) {
1451 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1452 }
1453
1454 /* Reject insane operation. */
1455 ret = seccomp(-1, 0, &prog);
1456 EXPECT_EQ(EINVAL, errno) {
1457 TH_LOG("Did not reject crazy op value!");
1458 }
1459
1460 /* Reject strict with flags or pointer. */
1461 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
1462 EXPECT_EQ(EINVAL, errno) {
1463 TH_LOG("Did not reject mode strict with flags!");
1464 }
1465 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
1466 EXPECT_EQ(EINVAL, errno) {
1467 TH_LOG("Did not reject mode strict with uargs!");
1468 }
1469
1470 /* Reject insane args for filter. */
1471 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
1472 EXPECT_EQ(EINVAL, errno) {
1473 TH_LOG("Did not reject crazy filter flags!");
1474 }
1475 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
1476 EXPECT_EQ(EFAULT, errno) {
1477 TH_LOG("Did not reject NULL filter!");
1478 }
1479
1480 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1481 EXPECT_EQ(0, errno) {
1482 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
1483 strerror(errno));
1484 }
1485 }
1486
1487 TEST(seccomp_syscall_mode_lock)
1488 {
1489 struct sock_filter filter[] = {
1490 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1491 };
1492 struct sock_fprog prog = {
1493 .len = (unsigned short)ARRAY_SIZE(filter),
1494 .filter = filter,
1495 };
1496 long ret;
1497
1498 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1499 ASSERT_EQ(0, ret) {
1500 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1501 }
1502
1503 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1504 EXPECT_EQ(0, ret) {
1505 TH_LOG("Could not install filter!");
1506 }
1507
1508 /* Make sure neither entry point will switch to strict. */
1509 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
1510 EXPECT_EQ(EINVAL, errno) {
1511 TH_LOG("Switched to mode strict!");
1512 }
1513
1514 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
1515 EXPECT_EQ(EINVAL, errno) {
1516 TH_LOG("Switched to mode strict!");
1517 }
1518 }
1519
1520 TEST(TSYNC_first)
1521 {
1522 struct sock_filter filter[] = {
1523 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1524 };
1525 struct sock_fprog prog = {
1526 .len = (unsigned short)ARRAY_SIZE(filter),
1527 .filter = filter,
1528 };
1529 long ret;
1530
1531 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1532 ASSERT_EQ(0, ret) {
1533 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1534 }
1535
1536 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1537 &prog);
1538 EXPECT_EQ(0, ret) {
1539 TH_LOG("Could not install initial filter with TSYNC!");
1540 }
1541 }
1542
1543 #define TSYNC_SIBLINGS 2
1544 struct tsync_sibling {
1545 pthread_t tid;
1546 pid_t system_tid;
1547 sem_t *started;
1548 pthread_cond_t *cond;
1549 pthread_mutex_t *mutex;
1550 int diverge;
1551 int num_waits;
1552 struct sock_fprog *prog;
1553 struct __test_metadata *metadata;
1554 };
1555
1556 FIXTURE_DATA(TSYNC) {
1557 struct sock_fprog root_prog, apply_prog;
1558 struct tsync_sibling sibling[TSYNC_SIBLINGS];
1559 sem_t started;
1560 pthread_cond_t cond;
1561 pthread_mutex_t mutex;
1562 int sibling_count;
1563 };
1564
1565 FIXTURE_SETUP(TSYNC)
1566 {
1567 struct sock_filter root_filter[] = {
1568 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1569 };
1570 struct sock_filter apply_filter[] = {
1571 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1572 offsetof(struct seccomp_data, nr)),
1573 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1574 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1575 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1576 };
1577
1578 memset(&self->root_prog, 0, sizeof(self->root_prog));
1579 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
1580 memset(&self->sibling, 0, sizeof(self->sibling));
1581 self->root_prog.filter = malloc(sizeof(root_filter));
1582 ASSERT_NE(NULL, self->root_prog.filter);
1583 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
1584 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
1585
1586 self->apply_prog.filter = malloc(sizeof(apply_filter));
1587 ASSERT_NE(NULL, self->apply_prog.filter);
1588 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
1589 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
1590
1591 self->sibling_count = 0;
1592 pthread_mutex_init(&self->mutex, NULL);
1593 pthread_cond_init(&self->cond, NULL);
1594 sem_init(&self->started, 0, 0);
1595 self->sibling[0].tid = 0;
1596 self->sibling[0].cond = &self->cond;
1597 self->sibling[0].started = &self->started;
1598 self->sibling[0].mutex = &self->mutex;
1599 self->sibling[0].diverge = 0;
1600 self->sibling[0].num_waits = 1;
1601 self->sibling[0].prog = &self->root_prog;
1602 self->sibling[0].metadata = _metadata;
1603 self->sibling[1].tid = 0;
1604 self->sibling[1].cond = &self->cond;
1605 self->sibling[1].started = &self->started;
1606 self->sibling[1].mutex = &self->mutex;
1607 self->sibling[1].diverge = 0;
1608 self->sibling[1].prog = &self->root_prog;
1609 self->sibling[1].num_waits = 1;
1610 self->sibling[1].metadata = _metadata;
1611 }
1612
1613 FIXTURE_TEARDOWN(TSYNC)
1614 {
1615 int sib = 0;
1616
1617 if (self->root_prog.filter)
1618 free(self->root_prog.filter);
1619 if (self->apply_prog.filter)
1620 free(self->apply_prog.filter);
1621
1622 for ( ; sib < self->sibling_count; ++sib) {
1623 struct tsync_sibling *s = &self->sibling[sib];
1624 void *status;
1625
1626 if (!s->tid)
1627 continue;
1628 if (pthread_kill(s->tid, 0)) {
1629 pthread_cancel(s->tid);
1630 pthread_join(s->tid, &status);
1631 }
1632 }
1633 pthread_mutex_destroy(&self->mutex);
1634 pthread_cond_destroy(&self->cond);
1635 sem_destroy(&self->started);
1636 }
1637
1638 void *tsync_sibling(void *data)
1639 {
1640 long ret = 0;
1641 struct tsync_sibling *me = data;
1642
1643 me->system_tid = syscall(__NR_gettid);
1644
1645 pthread_mutex_lock(me->mutex);
1646 if (me->diverge) {
1647 /* Just re-apply the root prog to fork the tree */
1648 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
1649 me->prog, 0, 0);
1650 }
1651 sem_post(me->started);
1652 /* Return outside of started so parent notices failures. */
1653 if (ret) {
1654 pthread_mutex_unlock(me->mutex);
1655 return (void *)SIBLING_EXIT_FAILURE;
1656 }
1657 do {
1658 pthread_cond_wait(me->cond, me->mutex);
1659 me->num_waits = me->num_waits - 1;
1660 } while (me->num_waits);
1661 pthread_mutex_unlock(me->mutex);
1662
1663 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
1664 if (!ret)
1665 return (void *)SIBLING_EXIT_NEWPRIVS;
1666 read(0, NULL, 0);
1667 return (void *)SIBLING_EXIT_UNKILLED;
1668 }
1669
1670 void tsync_start_sibling(struct tsync_sibling *sibling)
1671 {
1672 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
1673 }
1674
1675 TEST_F(TSYNC, siblings_fail_prctl)
1676 {
1677 long ret;
1678 void *status;
1679 struct sock_filter filter[] = {
1680 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1681 offsetof(struct seccomp_data, nr)),
1682 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
1683 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
1684 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1685 };
1686 struct sock_fprog prog = {
1687 .len = (unsigned short)ARRAY_SIZE(filter),
1688 .filter = filter,
1689 };
1690
1691 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1692 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1693 }
1694
1695 /* Check prctl failure detection by requesting sib 0 diverge. */
1696 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1697 ASSERT_EQ(0, ret) {
1698 TH_LOG("setting filter failed");
1699 }
1700
1701 self->sibling[0].diverge = 1;
1702 tsync_start_sibling(&self->sibling[0]);
1703 tsync_start_sibling(&self->sibling[1]);
1704
1705 while (self->sibling_count < TSYNC_SIBLINGS) {
1706 sem_wait(&self->started);
1707 self->sibling_count++;
1708 }
1709
1710 /* Signal the threads to clean up*/
1711 pthread_mutex_lock(&self->mutex);
1712 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1713 TH_LOG("cond broadcast non-zero");
1714 }
1715 pthread_mutex_unlock(&self->mutex);
1716
1717 /* Ensure diverging sibling failed to call prctl. */
1718 pthread_join(self->sibling[0].tid, &status);
1719 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
1720 pthread_join(self->sibling[1].tid, &status);
1721 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1722 }
1723
1724 TEST_F(TSYNC, two_siblings_with_ancestor)
1725 {
1726 long ret;
1727 void *status;
1728
1729 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1730 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1731 }
1732
1733 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1734 ASSERT_EQ(0, ret) {
1735 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1736 }
1737 tsync_start_sibling(&self->sibling[0]);
1738 tsync_start_sibling(&self->sibling[1]);
1739
1740 while (self->sibling_count < TSYNC_SIBLINGS) {
1741 sem_wait(&self->started);
1742 self->sibling_count++;
1743 }
1744
1745 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1746 &self->apply_prog);
1747 ASSERT_EQ(0, ret) {
1748 TH_LOG("Could install filter on all threads!");
1749 }
1750 /* Tell the siblings to test the policy */
1751 pthread_mutex_lock(&self->mutex);
1752 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1753 TH_LOG("cond broadcast non-zero");
1754 }
1755 pthread_mutex_unlock(&self->mutex);
1756 /* Ensure they are both killed and don't exit cleanly. */
1757 pthread_join(self->sibling[0].tid, &status);
1758 EXPECT_EQ(0x0, (long)status);
1759 pthread_join(self->sibling[1].tid, &status);
1760 EXPECT_EQ(0x0, (long)status);
1761 }
1762
1763 TEST_F(TSYNC, two_sibling_want_nnp)
1764 {
1765 void *status;
1766
1767 /* start siblings before any prctl() operations */
1768 tsync_start_sibling(&self->sibling[0]);
1769 tsync_start_sibling(&self->sibling[1]);
1770 while (self->sibling_count < TSYNC_SIBLINGS) {
1771 sem_wait(&self->started);
1772 self->sibling_count++;
1773 }
1774
1775 /* Tell the siblings to test no policy */
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 they are both upset about lacking nnp. */
1783 pthread_join(self->sibling[0].tid, &status);
1784 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1785 pthread_join(self->sibling[1].tid, &status);
1786 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1787 }
1788
1789 TEST_F(TSYNC, two_siblings_with_no_filter)
1790 {
1791 long ret;
1792 void *status;
1793
1794 /* start siblings before any prctl() operations */
1795 tsync_start_sibling(&self->sibling[0]);
1796 tsync_start_sibling(&self->sibling[1]);
1797 while (self->sibling_count < TSYNC_SIBLINGS) {
1798 sem_wait(&self->started);
1799 self->sibling_count++;
1800 }
1801
1802 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1803 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1804 }
1805
1806 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1807 &self->apply_prog);
1808 ASSERT_EQ(0, ret) {
1809 TH_LOG("Could install filter on all threads!");
1810 }
1811
1812 /* Tell the siblings to test the policy */
1813 pthread_mutex_lock(&self->mutex);
1814 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1815 TH_LOG("cond broadcast non-zero");
1816 }
1817 pthread_mutex_unlock(&self->mutex);
1818
1819 /* Ensure they are both killed and don't exit cleanly. */
1820 pthread_join(self->sibling[0].tid, &status);
1821 EXPECT_EQ(0x0, (long)status);
1822 pthread_join(self->sibling[1].tid, &status);
1823 EXPECT_EQ(0x0, (long)status);
1824 }
1825
1826 TEST_F(TSYNC, two_siblings_with_one_divergence)
1827 {
1828 long ret;
1829 void *status;
1830
1831 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1832 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1833 }
1834
1835 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1836 ASSERT_EQ(0, ret) {
1837 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1838 }
1839 self->sibling[0].diverge = 1;
1840 tsync_start_sibling(&self->sibling[0]);
1841 tsync_start_sibling(&self->sibling[1]);
1842
1843 while (self->sibling_count < TSYNC_SIBLINGS) {
1844 sem_wait(&self->started);
1845 self->sibling_count++;
1846 }
1847
1848 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1849 &self->apply_prog);
1850 ASSERT_EQ(self->sibling[0].system_tid, ret) {
1851 TH_LOG("Did not fail on diverged sibling.");
1852 }
1853
1854 /* Wake the threads */
1855 pthread_mutex_lock(&self->mutex);
1856 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1857 TH_LOG("cond broadcast non-zero");
1858 }
1859 pthread_mutex_unlock(&self->mutex);
1860
1861 /* Ensure they are both unkilled. */
1862 pthread_join(self->sibling[0].tid, &status);
1863 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1864 pthread_join(self->sibling[1].tid, &status);
1865 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1866 }
1867
1868 TEST_F(TSYNC, two_siblings_not_under_filter)
1869 {
1870 long ret, sib;
1871 void *status;
1872
1873 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1874 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1875 }
1876
1877 /*
1878 * Sibling 0 will have its own seccomp policy
1879 * and Sibling 1 will not be under seccomp at
1880 * all. Sibling 1 will enter seccomp and 0
1881 * will cause failure.
1882 */
1883 self->sibling[0].diverge = 1;
1884 tsync_start_sibling(&self->sibling[0]);
1885 tsync_start_sibling(&self->sibling[1]);
1886
1887 while (self->sibling_count < TSYNC_SIBLINGS) {
1888 sem_wait(&self->started);
1889 self->sibling_count++;
1890 }
1891
1892 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1893 ASSERT_EQ(0, ret) {
1894 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1895 }
1896
1897 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1898 &self->apply_prog);
1899 ASSERT_EQ(ret, self->sibling[0].system_tid) {
1900 TH_LOG("Did not fail on diverged sibling.");
1901 }
1902 sib = 1;
1903 if (ret == self->sibling[0].system_tid)
1904 sib = 0;
1905
1906 pthread_mutex_lock(&self->mutex);
1907
1908 /* Increment the other siblings num_waits so we can clean up
1909 * the one we just saw.
1910 */
1911 self->sibling[!sib].num_waits += 1;
1912
1913 /* Signal the thread to clean up*/
1914 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1915 TH_LOG("cond broadcast non-zero");
1916 }
1917 pthread_mutex_unlock(&self->mutex);
1918 pthread_join(self->sibling[sib].tid, &status);
1919 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1920 /* Poll for actual task death. pthread_join doesn't guarantee it. */
1921 while (!kill(self->sibling[sib].system_tid, 0))
1922 sleep(0.1);
1923 /* Switch to the remaining sibling */
1924 sib = !sib;
1925
1926 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1927 &self->apply_prog);
1928 ASSERT_EQ(0, ret) {
1929 TH_LOG("Expected the remaining sibling to sync");
1930 };
1931
1932 pthread_mutex_lock(&self->mutex);
1933
1934 /* If remaining sibling didn't have a chance to wake up during
1935 * the first broadcast, manually reduce the num_waits now.
1936 */
1937 if (self->sibling[sib].num_waits > 1)
1938 self->sibling[sib].num_waits = 1;
1939 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1940 TH_LOG("cond broadcast non-zero");
1941 }
1942 pthread_mutex_unlock(&self->mutex);
1943 pthread_join(self->sibling[sib].tid, &status);
1944 EXPECT_EQ(0, (long)status);
1945 /* Poll for actual task death. pthread_join doesn't guarantee it. */
1946 while (!kill(self->sibling[sib].system_tid, 0))
1947 sleep(0.1);
1948
1949 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1950 &self->apply_prog);
1951 ASSERT_EQ(0, ret); /* just us chickens */
1952 }
1953
1954 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
1955 TEST(syscall_restart)
1956 {
1957 long ret;
1958 unsigned long msg;
1959 pid_t child_pid;
1960 int pipefd[2];
1961 int status;
1962 siginfo_t info = { };
1963 struct sock_filter filter[] = {
1964 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1965 offsetof(struct seccomp_data, nr)),
1966
1967 #ifdef __NR_sigreturn
1968 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
1969 #endif
1970 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
1971 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
1972 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
1973 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_poll, 4, 0),
1974 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
1975
1976 /* Allow __NR_write for easy logging. */
1977 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
1978 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1979 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1980 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), /* poll */
1981 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), /* restart */
1982 };
1983 struct sock_fprog prog = {
1984 .len = (unsigned short)ARRAY_SIZE(filter),
1985 .filter = filter,
1986 };
1987
1988 ASSERT_EQ(0, pipe(pipefd));
1989
1990 child_pid = fork();
1991 ASSERT_LE(0, child_pid);
1992 if (child_pid == 0) {
1993 /* Child uses EXPECT not ASSERT to deliver status correctly. */
1994 char buf = ' ';
1995 struct pollfd fds = {
1996 .fd = pipefd[0],
1997 .events = POLLIN,
1998 };
1999
2000 /* Attach parent as tracer and stop. */
2001 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2002 EXPECT_EQ(0, raise(SIGSTOP));
2003
2004 EXPECT_EQ(0, close(pipefd[1]));
2005
2006 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2007 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2008 }
2009
2010 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2011 EXPECT_EQ(0, ret) {
2012 TH_LOG("Failed to install filter!");
2013 }
2014
2015 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2016 TH_LOG("Failed to read() sync from parent");
2017 }
2018 EXPECT_EQ('.', buf) {
2019 TH_LOG("Failed to get sync data from read()");
2020 }
2021
2022 /* Start poll to be interrupted. */
2023 errno = 0;
2024 EXPECT_EQ(1, poll(&fds, 1, -1)) {
2025 TH_LOG("Call to poll() failed (errno %d)", errno);
2026 }
2027
2028 /* Read final sync from parent. */
2029 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2030 TH_LOG("Failed final read() from parent");
2031 }
2032 EXPECT_EQ('!', buf) {
2033 TH_LOG("Failed to get final data from read()");
2034 }
2035
2036 /* Directly report the status of our test harness results. */
2037 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2038 : EXIT_FAILURE);
2039 }
2040 EXPECT_EQ(0, close(pipefd[0]));
2041
2042 /* Attach to child, setup options, and release. */
2043 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2044 ASSERT_EQ(true, WIFSTOPPED(status));
2045 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2046 PTRACE_O_TRACESECCOMP));
2047 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2048 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2049
2050 /* Wait for poll() to start. */
2051 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2052 ASSERT_EQ(true, WIFSTOPPED(status));
2053 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2054 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2055 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2056 ASSERT_EQ(0x100, msg);
2057 EXPECT_EQ(__NR_poll, get_syscall(_metadata, child_pid));
2058
2059 /* Might as well check siginfo for sanity while we're here. */
2060 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2061 ASSERT_EQ(SIGTRAP, info.si_signo);
2062 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2063 EXPECT_EQ(0, info.si_errno);
2064 EXPECT_EQ(getuid(), info.si_uid);
2065 /* Verify signal delivery came from child (seccomp-triggered). */
2066 EXPECT_EQ(child_pid, info.si_pid);
2067
2068 /* Interrupt poll with SIGSTOP (which we'll need to handle). */
2069 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2070 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2071 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2072 ASSERT_EQ(true, WIFSTOPPED(status));
2073 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2074 /* Verify signal delivery came from parent now. */
2075 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2076 EXPECT_EQ(getpid(), info.si_pid);
2077
2078 /* Restart poll with SIGCONT, which triggers restart_syscall. */
2079 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2080 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2081 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2082 ASSERT_EQ(true, WIFSTOPPED(status));
2083 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2084 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2085
2086 /* Wait for restart_syscall() to start. */
2087 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2088 ASSERT_EQ(true, WIFSTOPPED(status));
2089 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2090 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2091 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2092 ASSERT_EQ(0x200, msg);
2093 ret = get_syscall(_metadata, child_pid);
2094 #if defined(__arm__)
2095 /* FIXME: ARM does not expose true syscall in registers. */
2096 EXPECT_EQ(__NR_poll, ret);
2097 #else
2098 EXPECT_EQ(__NR_restart_syscall, ret);
2099 #endif
2100
2101 /* Write again to end poll. */
2102 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2103 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2104 EXPECT_EQ(0, close(pipefd[1]));
2105
2106 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2107 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2108 _metadata->passed = 0;
2109 }
2110
2111 /*
2112 * TODO:
2113 * - add microbenchmarks
2114 * - expand NNP testing
2115 * - better arch-specific TRACE and TRAP handlers.
2116 * - endianness checking when appropriate
2117 * - 64-bit arg prodding
2118 * - arch value testing (x86 modes especially)
2119 * - ...
2120 */
2121
2122 TEST_HARNESS_MAIN
Linux with added FPC-III support