1 /*
2 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
3 * Use of this source code is governed by the GPLv2 license.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #include <sys/types.h>
9
10 /*
11 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
12 * we need to use the kernel's siginfo.h file and trick glibc
13 * into accepting it.
14 */
15 #if defined(__GLIBC_PREREQ)
16 #if !__GLIBC_PREREQ(2, 26)
17 # include <asm/siginfo.h>
18 # define __have_siginfo_t 1
19 # define __have_sigval_t 1
20 # define __have_sigevent_t 1
21 #endif
22 #endif
23
24 #include <errno.h>
25 #include <linux/filter.h>
26 #include <sys/prctl.h>
27 #include <sys/ptrace.h>
28 #include <sys/user.h>
29 #include <linux/prctl.h>
30 #include <linux/ptrace.h>
31 #include <linux/seccomp.h>
32 #include <pthread.h>
33 #include <semaphore.h>
34 #include <signal.h>
35 #include <stddef.h>
36 #include <stdbool.h>
37 #include <string.h>
38 #include <time.h>
39 #include <linux/elf.h>
40 #include <sys/uio.h>
41 #include <sys/utsname.h>
42 #include <sys/fcntl.h>
43 #include <sys/mman.h>
44 #include <sys/times.h>
45
46 #define _GNU_SOURCE
47 #include <unistd.h>
48 #include <sys/syscall.h>
49
50 #include "../kselftest_harness.h"
51
52 #ifndef PR_SET_PTRACER
53 # define PR_SET_PTRACER 0x59616d61
54 #endif
55
56 #ifndef PR_SET_NO_NEW_PRIVS
57 #define PR_SET_NO_NEW_PRIVS 38
58 #define PR_GET_NO_NEW_PRIVS 39
59 #endif
60
61 #ifndef PR_SECCOMP_EXT
62 #define PR_SECCOMP_EXT 43
63 #endif
64
65 #ifndef SECCOMP_EXT_ACT
66 #define SECCOMP_EXT_ACT 1
67 #endif
68
69 #ifndef SECCOMP_EXT_ACT_TSYNC
70 #define SECCOMP_EXT_ACT_TSYNC 1
71 #endif
72
73 #ifndef SECCOMP_MODE_STRICT
74 #define SECCOMP_MODE_STRICT 1
75 #endif
76
77 #ifndef SECCOMP_MODE_FILTER
78 #define SECCOMP_MODE_FILTER 2
79 #endif
80
81 #ifndef SECCOMP_RET_ALLOW
82 struct seccomp_data {
83 int nr;
84 __u32 arch;
85 __u64 instruction_pointer;
86 __u64 args[6];
87 };
88 #endif
89
90 #ifndef SECCOMP_RET_KILL_PROCESS
91 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
92 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
93 #endif
94 #ifndef SECCOMP_RET_KILL
95 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
96 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
97 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
98 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
99 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
100 #endif
101 #ifndef SECCOMP_RET_LOG
102 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
103 #endif
104
105 #ifndef __NR_seccomp
106 # if defined(__i386__)
107 # define __NR_seccomp 354
108 # elif defined(__x86_64__)
109 # define __NR_seccomp 317
110 # elif defined(__arm__)
111 # define __NR_seccomp 383
112 # elif defined(__aarch64__)
113 # define __NR_seccomp 277
114 # elif defined(__hppa__)
115 # define __NR_seccomp 338
116 # elif defined(__powerpc__)
117 # define __NR_seccomp 358
118 # elif defined(__s390__)
119 # define __NR_seccomp 348
120 # else
121 # warning "seccomp syscall number unknown for this architecture"
122 # define __NR_seccomp 0xffff
123 # endif
124 #endif
125
126 #ifndef SECCOMP_SET_MODE_STRICT
127 #define SECCOMP_SET_MODE_STRICT 0
128 #endif
129
130 #ifndef SECCOMP_SET_MODE_FILTER
131 #define SECCOMP_SET_MODE_FILTER 1
132 #endif
133
134 #ifndef SECCOMP_GET_ACTION_AVAIL
135 #define SECCOMP_GET_ACTION_AVAIL 2
136 #endif
137
138 #ifndef SECCOMP_FILTER_FLAG_TSYNC
139 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
140 #endif
141
142 #ifndef SECCOMP_FILTER_FLAG_LOG
143 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
144 #endif
145
146 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
147 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
148 #endif
149
150 #ifndef PTRACE_SECCOMP_GET_METADATA
151 #define PTRACE_SECCOMP_GET_METADATA 0x420d
152
153 struct seccomp_metadata {
154 __u64 filter_off; /* Input: which filter */
155 __u64 flags; /* Output: filter's flags */
156 };
157 #endif
158
159 #ifndef seccomp
seccomp(unsigned int op,unsigned int flags,void * args)160 int seccomp(unsigned int op, unsigned int flags, void *args)
161 {
162 errno = 0;
163 return syscall(__NR_seccomp, op, flags, args);
164 }
165 #endif
166
167 #if __BYTE_ORDER == __LITTLE_ENDIAN
168 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
169 #elif __BYTE_ORDER == __BIG_ENDIAN
170 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
171 #else
172 #error "wut? Unknown __BYTE_ORDER?!"
173 #endif
174
175 #define SIBLING_EXIT_UNKILLED 0xbadbeef
176 #define SIBLING_EXIT_FAILURE 0xbadface
177 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
178
TEST(mode_strict_support)179 TEST(mode_strict_support)
180 {
181 long ret;
182
183 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
184 ASSERT_EQ(0, ret) {
185 TH_LOG("Kernel does not support CONFIG_SECCOMP");
186 }
187 syscall(__NR_exit, 0);
188 }
189
TEST_SIGNAL(mode_strict_cannot_call_prctl,SIGKILL)190 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
191 {
192 long ret;
193
194 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
195 ASSERT_EQ(0, ret) {
196 TH_LOG("Kernel does not support CONFIG_SECCOMP");
197 }
198 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
199 NULL, NULL, NULL);
200 EXPECT_FALSE(true) {
201 TH_LOG("Unreachable!");
202 }
203 }
204
205 /* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)206 TEST(no_new_privs_support)
207 {
208 long ret;
209
210 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
211 EXPECT_EQ(0, ret) {
212 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
213 }
214 }
215
216 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)217 TEST(mode_filter_support)
218 {
219 long ret;
220
221 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
222 ASSERT_EQ(0, ret) {
223 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
224 }
225 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
226 EXPECT_EQ(-1, ret);
227 EXPECT_EQ(EFAULT, errno) {
228 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
229 }
230 }
231
TEST(mode_filter_without_nnp)232 TEST(mode_filter_without_nnp)
233 {
234 struct sock_filter filter[] = {
235 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
236 };
237 struct sock_fprog prog = {
238 .len = (unsigned short)ARRAY_SIZE(filter),
239 .filter = filter,
240 };
241 long ret;
242
243 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
244 ASSERT_LE(0, ret) {
245 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
246 }
247 errno = 0;
248 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
249 /* Succeeds with CAP_SYS_ADMIN, fails without */
250 /* TODO(wad) check caps not euid */
251 if (geteuid()) {
252 EXPECT_EQ(-1, ret);
253 EXPECT_EQ(EACCES, errno);
254 } else {
255 EXPECT_EQ(0, ret);
256 }
257 }
258
259 #define MAX_INSNS_PER_PATH 32768
260
TEST(filter_size_limits)261 TEST(filter_size_limits)
262 {
263 int i;
264 int count = BPF_MAXINSNS + 1;
265 struct sock_filter allow[] = {
266 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
267 };
268 struct sock_filter *filter;
269 struct sock_fprog prog = { };
270 long ret;
271
272 filter = calloc(count, sizeof(*filter));
273 ASSERT_NE(NULL, filter);
274
275 for (i = 0; i < count; i++)
276 filter[i] = allow[0];
277
278 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
279 ASSERT_EQ(0, ret);
280
281 prog.filter = filter;
282 prog.len = count;
283
284 /* Too many filter instructions in a single filter. */
285 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
286 ASSERT_NE(0, ret) {
287 TH_LOG("Installing %d insn filter was allowed", prog.len);
288 }
289
290 /* One less is okay, though. */
291 prog.len -= 1;
292 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
293 ASSERT_EQ(0, ret) {
294 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
295 }
296 }
297
TEST(filter_chain_limits)298 TEST(filter_chain_limits)
299 {
300 int i;
301 int count = BPF_MAXINSNS;
302 struct sock_filter allow[] = {
303 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
304 };
305 struct sock_filter *filter;
306 struct sock_fprog prog = { };
307 long ret;
308
309 filter = calloc(count, sizeof(*filter));
310 ASSERT_NE(NULL, filter);
311
312 for (i = 0; i < count; i++)
313 filter[i] = allow[0];
314
315 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
316 ASSERT_EQ(0, ret);
317
318 prog.filter = filter;
319 prog.len = 1;
320
321 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
322 ASSERT_EQ(0, ret);
323
324 prog.len = count;
325
326 /* Too many total filter instructions. */
327 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
328 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
329 if (ret != 0)
330 break;
331 }
332 ASSERT_NE(0, ret) {
333 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
334 i, count, i * (count + 4));
335 }
336 }
337
TEST(mode_filter_cannot_move_to_strict)338 TEST(mode_filter_cannot_move_to_strict)
339 {
340 struct sock_filter filter[] = {
341 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
342 };
343 struct sock_fprog prog = {
344 .len = (unsigned short)ARRAY_SIZE(filter),
345 .filter = filter,
346 };
347 long ret;
348
349 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
350 ASSERT_EQ(0, ret);
351
352 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
353 ASSERT_EQ(0, ret);
354
355 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
356 EXPECT_EQ(-1, ret);
357 EXPECT_EQ(EINVAL, errno);
358 }
359
360
TEST(mode_filter_get_seccomp)361 TEST(mode_filter_get_seccomp)
362 {
363 struct sock_filter filter[] = {
364 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
365 };
366 struct sock_fprog prog = {
367 .len = (unsigned short)ARRAY_SIZE(filter),
368 .filter = filter,
369 };
370 long ret;
371
372 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
373 ASSERT_EQ(0, ret);
374
375 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
376 EXPECT_EQ(0, ret);
377
378 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
379 ASSERT_EQ(0, ret);
380
381 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
382 EXPECT_EQ(2, ret);
383 }
384
385
TEST(ALLOW_all)386 TEST(ALLOW_all)
387 {
388 struct sock_filter filter[] = {
389 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
390 };
391 struct sock_fprog prog = {
392 .len = (unsigned short)ARRAY_SIZE(filter),
393 .filter = filter,
394 };
395 long ret;
396
397 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
398 ASSERT_EQ(0, ret);
399
400 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
401 ASSERT_EQ(0, ret);
402 }
403
TEST(empty_prog)404 TEST(empty_prog)
405 {
406 struct sock_filter filter[] = {
407 };
408 struct sock_fprog prog = {
409 .len = (unsigned short)ARRAY_SIZE(filter),
410 .filter = filter,
411 };
412 long ret;
413
414 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
415 ASSERT_EQ(0, ret);
416
417 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
418 EXPECT_EQ(-1, ret);
419 EXPECT_EQ(EINVAL, errno);
420 }
421
422 #if 0
423 TEST(log_all)
424 {
425 struct sock_filter filter[] = {
426 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
427 };
428 struct sock_fprog prog = {
429 .len = (unsigned short)ARRAY_SIZE(filter),
430 .filter = filter,
431 };
432 long ret;
433 pid_t parent = getppid();
434
435 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
436 ASSERT_EQ(0, ret);
437
438 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
439 ASSERT_EQ(0, ret);
440
441 /* getppid() should succeed and be logged (no check for logging) */
442 EXPECT_EQ(parent, syscall(__NR_getppid));
443 }
444 #endif
445
TEST_SIGNAL(unknown_ret_is_kill_inside,SIGSYS)446 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
447 {
448 struct sock_filter filter[] = {
449 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
450 };
451 struct sock_fprog prog = {
452 .len = (unsigned short)ARRAY_SIZE(filter),
453 .filter = filter,
454 };
455 long ret;
456
457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
458 ASSERT_EQ(0, ret);
459
460 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
461 ASSERT_EQ(0, ret);
462 EXPECT_EQ(0, syscall(__NR_getpid)) {
463 TH_LOG("getpid() shouldn't ever return");
464 }
465 }
466
467 /* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow,SIGSYS)468 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
469 {
470 struct sock_filter filter[] = {
471 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
472 };
473 struct sock_fprog prog = {
474 .len = (unsigned short)ARRAY_SIZE(filter),
475 .filter = filter,
476 };
477 long ret;
478
479 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
480 ASSERT_EQ(0, ret);
481
482 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
483 ASSERT_EQ(0, ret);
484 EXPECT_EQ(0, syscall(__NR_getpid)) {
485 TH_LOG("getpid() shouldn't ever return");
486 }
487 }
488
TEST_SIGNAL(KILL_all,SIGSYS)489 TEST_SIGNAL(KILL_all, SIGSYS)
490 {
491 struct sock_filter filter[] = {
492 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
493 };
494 struct sock_fprog prog = {
495 .len = (unsigned short)ARRAY_SIZE(filter),
496 .filter = filter,
497 };
498 long ret;
499
500 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
501 ASSERT_EQ(0, ret);
502
503 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
504 ASSERT_EQ(0, ret);
505 }
506
TEST_SIGNAL(KILL_one,SIGSYS)507 TEST_SIGNAL(KILL_one, SIGSYS)
508 {
509 struct sock_filter filter[] = {
510 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
511 offsetof(struct seccomp_data, nr)),
512 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
513 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
514 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
515 };
516 struct sock_fprog prog = {
517 .len = (unsigned short)ARRAY_SIZE(filter),
518 .filter = filter,
519 };
520 long ret;
521 pid_t parent = getppid();
522
523 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
524 ASSERT_EQ(0, ret);
525
526 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
527 ASSERT_EQ(0, ret);
528
529 EXPECT_EQ(parent, syscall(__NR_getppid));
530 /* getpid() should never return. */
531 EXPECT_EQ(0, syscall(__NR_getpid));
532 }
533
TEST_SIGNAL(KILL_one_arg_one,SIGSYS)534 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
535 {
536 void *fatal_address;
537 struct sock_filter filter[] = {
538 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
539 offsetof(struct seccomp_data, nr)),
540 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
541 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
542 /* Only both with lower 32-bit for now. */
543 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
544 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
545 (unsigned long)&fatal_address, 0, 1),
546 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
547 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
548 };
549 struct sock_fprog prog = {
550 .len = (unsigned short)ARRAY_SIZE(filter),
551 .filter = filter,
552 };
553 long ret;
554 pid_t parent = getppid();
555 struct tms timebuf;
556 clock_t clock = times(&timebuf);
557
558 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
559 ASSERT_EQ(0, ret);
560
561 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
562 ASSERT_EQ(0, ret);
563
564 EXPECT_EQ(parent, syscall(__NR_getppid));
565 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
566 /* times() should never return. */
567 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
568 }
569
TEST_SIGNAL(KILL_one_arg_six,SIGSYS)570 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
571 {
572 #ifndef __NR_mmap2
573 int sysno = __NR_mmap;
574 #else
575 int sysno = __NR_mmap2;
576 #endif
577 struct sock_filter filter[] = {
578 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
579 offsetof(struct seccomp_data, nr)),
580 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
581 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
582 /* Only both with lower 32-bit for now. */
583 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
584 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
585 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
586 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
587 };
588 struct sock_fprog prog = {
589 .len = (unsigned short)ARRAY_SIZE(filter),
590 .filter = filter,
591 };
592 long ret;
593 pid_t parent = getppid();
594 int fd;
595 void *map1, *map2;
596 int page_size = sysconf(_SC_PAGESIZE);
597
598 ASSERT_LT(0, page_size);
599
600 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
601 ASSERT_EQ(0, ret);
602
603 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
604 ASSERT_EQ(0, ret);
605
606 fd = open("/dev/zero", O_RDONLY);
607 ASSERT_NE(-1, fd);
608
609 EXPECT_EQ(parent, syscall(__NR_getppid));
610 map1 = (void *)syscall(sysno,
611 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
612 EXPECT_NE(MAP_FAILED, map1);
613 /* mmap2() should never return. */
614 map2 = (void *)syscall(sysno,
615 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
616 EXPECT_EQ(MAP_FAILED, map2);
617
618 /* The test failed, so clean up the resources. */
619 munmap(map1, page_size);
620 munmap(map2, page_size);
621 close(fd);
622 }
623
624 /* This is a thread task to die via seccomp filter violation. */
kill_thread(void * data)625 void *kill_thread(void *data)
626 {
627 bool die = (bool)data;
628
629 if (die) {
630 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
631 return (void *)SIBLING_EXIT_FAILURE;
632 }
633
634 return (void *)SIBLING_EXIT_UNKILLED;
635 }
636
637 /* Prepare a thread that will kill itself or both of us. */
kill_thread_or_group(struct __test_metadata * _metadata,bool kill_process)638 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
639 {
640 pthread_t thread;
641 void *status;
642 /* Kill only when calling __NR_prctl. */
643 struct sock_filter filter_thread[] = {
644 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
645 offsetof(struct seccomp_data, nr)),
646 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
647 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
648 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
649 };
650 struct sock_fprog prog_thread = {
651 .len = (unsigned short)ARRAY_SIZE(filter_thread),
652 .filter = filter_thread,
653 };
654 struct sock_filter filter_process[] = {
655 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
656 offsetof(struct seccomp_data, nr)),
657 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
658 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
659 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
660 };
661 struct sock_fprog prog_process = {
662 .len = (unsigned short)ARRAY_SIZE(filter_process),
663 .filter = filter_process,
664 };
665
666 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
667 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
668 }
669
670 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
671 kill_process ? &prog_process : &prog_thread));
672
673 /*
674 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
675 * flag cannot be downgraded by a new filter.
676 */
677 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
678
679 /* Start a thread that will exit immediately. */
680 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
681 ASSERT_EQ(0, pthread_join(thread, &status));
682 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
683
684 /* Start a thread that will die immediately. */
685 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
686 ASSERT_EQ(0, pthread_join(thread, &status));
687 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
688
689 /*
690 * If we get here, only the spawned thread died. Let the parent know
691 * the whole process didn't die (i.e. this thread, the spawner,
692 * stayed running).
693 */
694 exit(42);
695 }
696
697 #if 0
698 TEST(KILL_thread)
699 {
700 int status;
701 pid_t child_pid;
702
703 child_pid = fork();
704 ASSERT_LE(0, child_pid);
705 if (child_pid == 0) {
706 kill_thread_or_group(_metadata, false);
707 _exit(38);
708 }
709
710 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
711
712 /* If only the thread was killed, we'll see exit 42. */
713 ASSERT_TRUE(WIFEXITED(status));
714 ASSERT_EQ(42, WEXITSTATUS(status));
715 }
716 #endif
717
TEST(KILL_process)718 TEST(KILL_process)
719 {
720 int status;
721 pid_t child_pid;
722
723 child_pid = fork();
724 ASSERT_LE(0, child_pid);
725 if (child_pid == 0) {
726 kill_thread_or_group(_metadata, true);
727 _exit(38);
728 }
729
730 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
731
732 /* If the entire process was killed, we'll see SIGSYS. */
733 ASSERT_TRUE(WIFSIGNALED(status));
734 ASSERT_EQ(SIGSYS, WTERMSIG(status));
735 }
736
737 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)738 TEST(arg_out_of_range)
739 {
740 struct sock_filter filter[] = {
741 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
742 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
743 };
744 struct sock_fprog prog = {
745 .len = (unsigned short)ARRAY_SIZE(filter),
746 .filter = filter,
747 };
748 long ret;
749
750 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
751 ASSERT_EQ(0, ret);
752
753 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
754 EXPECT_EQ(-1, ret);
755 EXPECT_EQ(EINVAL, errno);
756 }
757
758 #define ERRNO_FILTER(name, errno) \
759 struct sock_filter _read_filter_##name[] = { \
760 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
761 offsetof(struct seccomp_data, nr)), \
762 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
763 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
764 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
765 }; \
766 struct sock_fprog prog_##name = { \
767 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
768 .filter = _read_filter_##name, \
769 }
770
771 /* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)772 TEST(ERRNO_valid)
773 {
774 ERRNO_FILTER(valid, E2BIG);
775 long ret;
776 pid_t parent = getppid();
777
778 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
779 ASSERT_EQ(0, ret);
780
781 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
782 ASSERT_EQ(0, ret);
783
784 EXPECT_EQ(parent, syscall(__NR_getppid));
785 EXPECT_EQ(-1, read(0, NULL, 0));
786 EXPECT_EQ(E2BIG, errno);
787 }
788
789 /* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)790 TEST(ERRNO_zero)
791 {
792 ERRNO_FILTER(zero, 0);
793 long ret;
794 pid_t parent = getppid();
795
796 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
797 ASSERT_EQ(0, ret);
798
799 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
800 ASSERT_EQ(0, ret);
801
802 EXPECT_EQ(parent, syscall(__NR_getppid));
803 /* "errno" of 0 is ok. */
804 EXPECT_EQ(0, read(0, NULL, 0));
805 }
806
807 /*
808 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
809 * This tests that the errno value gets capped correctly, fixed by
810 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
811 */
TEST(ERRNO_capped)812 TEST(ERRNO_capped)
813 {
814 ERRNO_FILTER(capped, 4096);
815 long ret;
816 pid_t parent = getppid();
817
818 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
819 ASSERT_EQ(0, ret);
820
821 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
822 ASSERT_EQ(0, ret);
823
824 EXPECT_EQ(parent, syscall(__NR_getppid));
825 EXPECT_EQ(-1, read(0, NULL, 0));
826 EXPECT_EQ(4095, errno);
827 }
828
829 /*
830 * Filters are processed in reverse order: last applied is executed first.
831 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
832 * SECCOMP_RET_DATA mask results will follow the most recently applied
833 * matching filter return (and not the lowest or highest value).
834 */
TEST(ERRNO_order)835 TEST(ERRNO_order)
836 {
837 ERRNO_FILTER(first, 11);
838 ERRNO_FILTER(second, 13);
839 ERRNO_FILTER(third, 12);
840 long ret;
841 pid_t parent = getppid();
842
843 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
844 ASSERT_EQ(0, ret);
845
846 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
847 ASSERT_EQ(0, ret);
848
849 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
850 ASSERT_EQ(0, ret);
851
852 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
853 ASSERT_EQ(0, ret);
854
855 EXPECT_EQ(parent, syscall(__NR_getppid));
856 EXPECT_EQ(-1, read(0, NULL, 0));
857 EXPECT_EQ(12, errno);
858 }
859
FIXTURE_DATA(TRAP)860 FIXTURE_DATA(TRAP) {
861 struct sock_fprog prog;
862 };
863
FIXTURE_SETUP(TRAP)864 FIXTURE_SETUP(TRAP)
865 {
866 struct sock_filter filter[] = {
867 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
868 offsetof(struct seccomp_data, nr)),
869 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
870 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
871 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
872 };
873
874 memset(&self->prog, 0, sizeof(self->prog));
875 self->prog.filter = malloc(sizeof(filter));
876 ASSERT_NE(NULL, self->prog.filter);
877 memcpy(self->prog.filter, filter, sizeof(filter));
878 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
879 }
880
FIXTURE_TEARDOWN(TRAP)881 FIXTURE_TEARDOWN(TRAP)
882 {
883 if (self->prog.filter)
884 free(self->prog.filter);
885 }
886
TEST_F_SIGNAL(TRAP,dfl,SIGSYS)887 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
888 {
889 long ret;
890
891 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
892 ASSERT_EQ(0, ret);
893
894 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
895 ASSERT_EQ(0, ret);
896 syscall(__NR_getpid);
897 }
898
899 /* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP,ign,SIGSYS)900 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
901 {
902 long ret;
903
904 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
905 ASSERT_EQ(0, ret);
906
907 signal(SIGSYS, SIG_IGN);
908
909 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
910 ASSERT_EQ(0, ret);
911 syscall(__NR_getpid);
912 }
913
914 static siginfo_t TRAP_info;
915 static volatile int TRAP_nr;
TRAP_action(int nr,siginfo_t * info,void * void_context)916 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
917 {
918 memcpy(&TRAP_info, info, sizeof(TRAP_info));
919 TRAP_nr = nr;
920 }
921
TEST_F(TRAP,handler)922 TEST_F(TRAP, handler)
923 {
924 int ret, test;
925 struct sigaction act;
926 sigset_t mask;
927
928 memset(&act, 0, sizeof(act));
929 sigemptyset(&mask);
930 sigaddset(&mask, SIGSYS);
931
932 act.sa_sigaction = &TRAP_action;
933 act.sa_flags = SA_SIGINFO;
934 ret = sigaction(SIGSYS, &act, NULL);
935 ASSERT_EQ(0, ret) {
936 TH_LOG("sigaction failed");
937 }
938 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
939 ASSERT_EQ(0, ret) {
940 TH_LOG("sigprocmask failed");
941 }
942
943 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
944 ASSERT_EQ(0, ret);
945 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
946 ASSERT_EQ(0, ret);
947 TRAP_nr = 0;
948 memset(&TRAP_info, 0, sizeof(TRAP_info));
949 /* Expect the registers to be rolled back. (nr = error) may vary
950 * based on arch. */
951 ret = syscall(__NR_getpid);
952 /* Silence gcc warning about volatile. */
953 test = TRAP_nr;
954 EXPECT_EQ(SIGSYS, test);
955 struct local_sigsys {
956 void *_call_addr; /* calling user insn */
957 int _syscall; /* triggering system call number */
958 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
959 } *sigsys = (struct local_sigsys *)
960 #ifdef si_syscall
961 &(TRAP_info.si_call_addr);
962 #else
963 &TRAP_info.si_pid;
964 #endif
965 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
966 /* Make sure arch is non-zero. */
967 EXPECT_NE(0, sigsys->_arch);
968 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
969 }
970
FIXTURE_DATA(precedence)971 FIXTURE_DATA(precedence) {
972 struct sock_fprog allow;
973 struct sock_fprog log;
974 struct sock_fprog trace;
975 struct sock_fprog error;
976 struct sock_fprog trap;
977 struct sock_fprog kill;
978 };
979
FIXTURE_SETUP(precedence)980 FIXTURE_SETUP(precedence)
981 {
982 struct sock_filter allow_insns[] = {
983 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
984 };
985 struct sock_filter log_insns[] = {
986 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
987 offsetof(struct seccomp_data, nr)),
988 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
989 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
990 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
991 };
992 struct sock_filter trace_insns[] = {
993 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
994 offsetof(struct seccomp_data, nr)),
995 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
996 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
997 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
998 };
999 struct sock_filter error_insns[] = {
1000 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1001 offsetof(struct seccomp_data, nr)),
1002 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1003 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1004 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1005 };
1006 struct sock_filter trap_insns[] = {
1007 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1008 offsetof(struct seccomp_data, nr)),
1009 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1010 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1011 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1012 };
1013 struct sock_filter kill_insns[] = {
1014 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1015 offsetof(struct seccomp_data, nr)),
1016 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1017 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1018 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1019 };
1020
1021 memset(self, 0, sizeof(*self));
1022 #define FILTER_ALLOC(_x) \
1023 self->_x.filter = malloc(sizeof(_x##_insns)); \
1024 ASSERT_NE(NULL, self->_x.filter); \
1025 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1026 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1027 FILTER_ALLOC(allow);
1028 FILTER_ALLOC(log);
1029 FILTER_ALLOC(trace);
1030 FILTER_ALLOC(error);
1031 FILTER_ALLOC(trap);
1032 FILTER_ALLOC(kill);
1033 }
1034
FIXTURE_TEARDOWN(precedence)1035 FIXTURE_TEARDOWN(precedence)
1036 {
1037 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1038 FILTER_FREE(allow);
1039 FILTER_FREE(log);
1040 FILTER_FREE(trace);
1041 FILTER_FREE(error);
1042 FILTER_FREE(trap);
1043 FILTER_FREE(kill);
1044 }
1045
TEST_F(precedence,allow_ok)1046 TEST_F(precedence, allow_ok)
1047 {
1048 pid_t parent, res = 0;
1049 long ret;
1050
1051 parent = getppid();
1052 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1053 ASSERT_EQ(0, ret);
1054
1055 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1056 ASSERT_EQ(0, ret);
1057 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1058 ASSERT_EQ(0, ret);
1059 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1060 ASSERT_EQ(0, ret);
1061 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1062 ASSERT_EQ(0, ret);
1063 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1064 ASSERT_EQ(0, ret);
1065 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1066 ASSERT_EQ(0, ret);
1067 /* Should work just fine. */
1068 res = syscall(__NR_getppid);
1069 EXPECT_EQ(parent, res);
1070 }
1071
TEST_F_SIGNAL(precedence,kill_is_highest,SIGSYS)1072 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1073 {
1074 pid_t parent, res = 0;
1075 long ret;
1076
1077 parent = getppid();
1078 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1079 ASSERT_EQ(0, ret);
1080
1081 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1082 ASSERT_EQ(0, ret);
1083 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1084 ASSERT_EQ(0, ret);
1085 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1086 ASSERT_EQ(0, ret);
1087 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1088 ASSERT_EQ(0, ret);
1089 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1090 ASSERT_EQ(0, ret);
1091 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1092 ASSERT_EQ(0, ret);
1093 /* Should work just fine. */
1094 res = syscall(__NR_getppid);
1095 EXPECT_EQ(parent, res);
1096 /* getpid() should never return. */
1097 res = syscall(__NR_getpid);
1098 EXPECT_EQ(0, res);
1099 }
1100
TEST_F_SIGNAL(precedence,kill_is_highest_in_any_order,SIGSYS)1101 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1102 {
1103 pid_t parent;
1104 long ret;
1105
1106 parent = getppid();
1107 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1108 ASSERT_EQ(0, ret);
1109
1110 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1111 ASSERT_EQ(0, ret);
1112 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1113 ASSERT_EQ(0, ret);
1114 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1115 ASSERT_EQ(0, ret);
1116 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1117 ASSERT_EQ(0, ret);
1118 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1119 ASSERT_EQ(0, ret);
1120 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1121 ASSERT_EQ(0, ret);
1122 /* Should work just fine. */
1123 EXPECT_EQ(parent, syscall(__NR_getppid));
1124 /* getpid() should never return. */
1125 EXPECT_EQ(0, syscall(__NR_getpid));
1126 }
1127
TEST_F_SIGNAL(precedence,trap_is_second,SIGSYS)1128 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1129 {
1130 pid_t parent;
1131 long ret;
1132
1133 parent = getppid();
1134 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1135 ASSERT_EQ(0, ret);
1136
1137 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1138 ASSERT_EQ(0, ret);
1139 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1140 ASSERT_EQ(0, ret);
1141 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1142 ASSERT_EQ(0, ret);
1143 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1144 ASSERT_EQ(0, ret);
1145 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1146 ASSERT_EQ(0, ret);
1147 /* Should work just fine. */
1148 EXPECT_EQ(parent, syscall(__NR_getppid));
1149 /* getpid() should never return. */
1150 EXPECT_EQ(0, syscall(__NR_getpid));
1151 }
1152
TEST_F_SIGNAL(precedence,trap_is_second_in_any_order,SIGSYS)1153 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1154 {
1155 pid_t parent;
1156 long ret;
1157
1158 parent = getppid();
1159 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1160 ASSERT_EQ(0, ret);
1161
1162 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1163 ASSERT_EQ(0, ret);
1164 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1165 ASSERT_EQ(0, ret);
1166 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1167 ASSERT_EQ(0, ret);
1168 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1169 ASSERT_EQ(0, ret);
1170 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1171 ASSERT_EQ(0, ret);
1172 /* Should work just fine. */
1173 EXPECT_EQ(parent, syscall(__NR_getppid));
1174 /* getpid() should never return. */
1175 EXPECT_EQ(0, syscall(__NR_getpid));
1176 }
1177
TEST_F(precedence,errno_is_third)1178 TEST_F(precedence, errno_is_third)
1179 {
1180 pid_t parent;
1181 long ret;
1182
1183 parent = getppid();
1184 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1185 ASSERT_EQ(0, ret);
1186
1187 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1188 ASSERT_EQ(0, ret);
1189 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1190 ASSERT_EQ(0, ret);
1191 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1192 ASSERT_EQ(0, ret);
1193 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1194 ASSERT_EQ(0, ret);
1195 /* Should work just fine. */
1196 EXPECT_EQ(parent, syscall(__NR_getppid));
1197 EXPECT_EQ(0, syscall(__NR_getpid));
1198 }
1199
TEST_F(precedence,errno_is_third_in_any_order)1200 TEST_F(precedence, errno_is_third_in_any_order)
1201 {
1202 pid_t parent;
1203 long ret;
1204
1205 parent = getppid();
1206 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1207 ASSERT_EQ(0, ret);
1208
1209 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1210 ASSERT_EQ(0, ret);
1211 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1212 ASSERT_EQ(0, ret);
1213 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1214 ASSERT_EQ(0, ret);
1215 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1216 ASSERT_EQ(0, ret);
1217 /* Should work just fine. */
1218 EXPECT_EQ(parent, syscall(__NR_getppid));
1219 EXPECT_EQ(0, syscall(__NR_getpid));
1220 }
1221
TEST_F(precedence,trace_is_fourth)1222 TEST_F(precedence, trace_is_fourth)
1223 {
1224 pid_t parent;
1225 long ret;
1226
1227 parent = getppid();
1228 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1229 ASSERT_EQ(0, ret);
1230
1231 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1232 ASSERT_EQ(0, ret);
1233 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1234 ASSERT_EQ(0, ret);
1235 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1236 ASSERT_EQ(0, ret);
1237 /* Should work just fine. */
1238 EXPECT_EQ(parent, syscall(__NR_getppid));
1239 /* No ptracer */
1240 EXPECT_EQ(-1, syscall(__NR_getpid));
1241 }
1242
TEST_F(precedence,trace_is_fourth_in_any_order)1243 TEST_F(precedence, trace_is_fourth_in_any_order)
1244 {
1245 pid_t parent;
1246 long ret;
1247
1248 parent = getppid();
1249 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1250 ASSERT_EQ(0, ret);
1251
1252 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1253 ASSERT_EQ(0, ret);
1254 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1255 ASSERT_EQ(0, ret);
1256 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1257 ASSERT_EQ(0, ret);
1258 /* Should work just fine. */
1259 EXPECT_EQ(parent, syscall(__NR_getppid));
1260 /* No ptracer */
1261 EXPECT_EQ(-1, syscall(__NR_getpid));
1262 }
1263
1264 #if 0
1265 TEST_F(precedence, log_is_fifth)
1266 {
1267 pid_t mypid, parent;
1268 long ret;
1269
1270 mypid = getpid();
1271 parent = getppid();
1272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1273 ASSERT_EQ(0, ret);
1274
1275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1276 ASSERT_EQ(0, ret);
1277 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1278 ASSERT_EQ(0, ret);
1279 /* Should work just fine. */
1280 EXPECT_EQ(parent, syscall(__NR_getppid));
1281 /* Should also work just fine */
1282 EXPECT_EQ(mypid, syscall(__NR_getpid));
1283 }
1284
1285 TEST_F(precedence, log_is_fifth_in_any_order)
1286 {
1287 pid_t mypid, parent;
1288 long ret;
1289
1290 mypid = getpid();
1291 parent = getppid();
1292 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1293 ASSERT_EQ(0, ret);
1294
1295 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1296 ASSERT_EQ(0, ret);
1297 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1298 ASSERT_EQ(0, ret);
1299 /* Should work just fine. */
1300 EXPECT_EQ(parent, syscall(__NR_getppid));
1301 /* Should also work just fine */
1302 EXPECT_EQ(mypid, syscall(__NR_getpid));
1303 }
1304 #endif
1305
1306 #ifndef PTRACE_O_TRACESECCOMP
1307 #define PTRACE_O_TRACESECCOMP 0x00000080
1308 #endif
1309
1310 /* Catch the Ubuntu 12.04 value error. */
1311 #if PTRACE_EVENT_SECCOMP != 7
1312 #undef PTRACE_EVENT_SECCOMP
1313 #endif
1314
1315 #ifndef PTRACE_EVENT_SECCOMP
1316 #define PTRACE_EVENT_SECCOMP 7
1317 #endif
1318
1319 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1320 bool tracer_running;
tracer_stop(int sig)1321 void tracer_stop(int sig)
1322 {
1323 tracer_running = false;
1324 }
1325
1326 typedef void tracer_func_t(struct __test_metadata *_metadata,
1327 pid_t tracee, int status, void *args);
1328
start_tracer(struct __test_metadata * _metadata,int fd,pid_t tracee,tracer_func_t tracer_func,void * args,bool ptrace_syscall)1329 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1330 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1331 {
1332 int ret = -1;
1333 struct sigaction action = {
1334 .sa_handler = tracer_stop,
1335 };
1336
1337 /* Allow external shutdown. */
1338 tracer_running = true;
1339 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1340
1341 errno = 0;
1342 while (ret == -1 && errno != EINVAL)
1343 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1344 ASSERT_EQ(0, ret) {
1345 kill(tracee, SIGKILL);
1346 }
1347 /* Wait for attach stop */
1348 wait(NULL);
1349
1350 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1351 PTRACE_O_TRACESYSGOOD :
1352 PTRACE_O_TRACESECCOMP);
1353 ASSERT_EQ(0, ret) {
1354 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1355 kill(tracee, SIGKILL);
1356 }
1357 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1358 tracee, NULL, 0);
1359 ASSERT_EQ(0, ret);
1360
1361 /* Unblock the tracee */
1362 ASSERT_EQ(1, write(fd, "A", 1));
1363 ASSERT_EQ(0, close(fd));
1364
1365 /* Run until we're shut down. Must assert to stop execution. */
1366 while (tracer_running) {
1367 int status;
1368
1369 if (wait(&status) != tracee)
1370 continue;
1371 if (WIFSIGNALED(status) || WIFEXITED(status))
1372 /* Child is dead. Time to go. */
1373 return;
1374
1375 /* Check if this is a seccomp event. */
1376 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1377
1378 tracer_func(_metadata, tracee, status, args);
1379
1380 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1381 tracee, NULL, 0);
1382 ASSERT_EQ(0, ret);
1383 }
1384 /* Directly report the status of our test harness results. */
1385 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1386 }
1387
1388 /* Common tracer setup/teardown functions. */
cont_handler(int num)1389 void cont_handler(int num)
1390 { }
setup_trace_fixture(struct __test_metadata * _metadata,tracer_func_t func,void * args,bool ptrace_syscall)1391 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1392 tracer_func_t func, void *args, bool ptrace_syscall)
1393 {
1394 char sync;
1395 int pipefd[2];
1396 pid_t tracer_pid;
1397 pid_t tracee = getpid();
1398
1399 /* Setup a pipe for clean synchronization. */
1400 ASSERT_EQ(0, pipe(pipefd));
1401
1402 /* Fork a child which we'll promote to tracer */
1403 tracer_pid = fork();
1404 ASSERT_LE(0, tracer_pid);
1405 signal(SIGALRM, cont_handler);
1406 if (tracer_pid == 0) {
1407 close(pipefd[0]);
1408 start_tracer(_metadata, pipefd[1], tracee, func, args,
1409 ptrace_syscall);
1410 syscall(__NR_exit, 0);
1411 }
1412 close(pipefd[1]);
1413 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1414 read(pipefd[0], &sync, 1);
1415 close(pipefd[0]);
1416
1417 return tracer_pid;
1418 }
teardown_trace_fixture(struct __test_metadata * _metadata,pid_t tracer)1419 void teardown_trace_fixture(struct __test_metadata *_metadata,
1420 pid_t tracer)
1421 {
1422 if (tracer) {
1423 int status;
1424 /*
1425 * Extract the exit code from the other process and
1426 * adopt it for ourselves in case its asserts failed.
1427 */
1428 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1429 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1430 if (WEXITSTATUS(status))
1431 _metadata->passed = 0;
1432 }
1433 }
1434
1435 /* "poke" tracer arguments and function. */
1436 struct tracer_args_poke_t {
1437 unsigned long poke_addr;
1438 };
1439
tracer_poke(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1440 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1441 void *args)
1442 {
1443 int ret;
1444 unsigned long msg;
1445 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1446
1447 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1448 EXPECT_EQ(0, ret);
1449 /* If this fails, don't try to recover. */
1450 ASSERT_EQ(0x1001, msg) {
1451 kill(tracee, SIGKILL);
1452 }
1453 /*
1454 * Poke in the message.
1455 * Registers are not touched to try to keep this relatively arch
1456 * agnostic.
1457 */
1458 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1459 EXPECT_EQ(0, ret);
1460 }
1461
FIXTURE_DATA(TRACE_poke)1462 FIXTURE_DATA(TRACE_poke) {
1463 struct sock_fprog prog;
1464 pid_t tracer;
1465 long poked;
1466 struct tracer_args_poke_t tracer_args;
1467 };
1468
FIXTURE_SETUP(TRACE_poke)1469 FIXTURE_SETUP(TRACE_poke)
1470 {
1471 struct sock_filter filter[] = {
1472 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1473 offsetof(struct seccomp_data, nr)),
1474 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1475 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1476 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1477 };
1478
1479 self->poked = 0;
1480 memset(&self->prog, 0, sizeof(self->prog));
1481 self->prog.filter = malloc(sizeof(filter));
1482 ASSERT_NE(NULL, self->prog.filter);
1483 memcpy(self->prog.filter, filter, sizeof(filter));
1484 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1485
1486 /* Set up tracer args. */
1487 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1488
1489 /* Launch tracer. */
1490 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1491 &self->tracer_args, false);
1492 }
1493
FIXTURE_TEARDOWN(TRACE_poke)1494 FIXTURE_TEARDOWN(TRACE_poke)
1495 {
1496 teardown_trace_fixture(_metadata, self->tracer);
1497 if (self->prog.filter)
1498 free(self->prog.filter);
1499 }
1500
TEST_F(TRACE_poke,read_has_side_effects)1501 TEST_F(TRACE_poke, read_has_side_effects)
1502 {
1503 ssize_t ret;
1504
1505 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1506 ASSERT_EQ(0, ret);
1507
1508 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1509 ASSERT_EQ(0, ret);
1510
1511 EXPECT_EQ(0, self->poked);
1512 ret = read(-1, NULL, 0);
1513 EXPECT_EQ(-1, ret);
1514 EXPECT_EQ(0x1001, self->poked);
1515 }
1516
TEST_F(TRACE_poke,getpid_runs_normally)1517 TEST_F(TRACE_poke, getpid_runs_normally)
1518 {
1519 long ret;
1520
1521 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1522 ASSERT_EQ(0, ret);
1523
1524 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1525 ASSERT_EQ(0, ret);
1526
1527 EXPECT_EQ(0, self->poked);
1528 EXPECT_NE(0, syscall(__NR_getpid));
1529 EXPECT_EQ(0, self->poked);
1530 }
1531
1532 #if defined(__x86_64__)
1533 # define ARCH_REGS struct user_regs_struct
1534 # define SYSCALL_NUM orig_rax
1535 # define SYSCALL_RET rax
1536 #elif defined(__i386__)
1537 # define ARCH_REGS struct user_regs_struct
1538 # define SYSCALL_NUM orig_eax
1539 # define SYSCALL_RET eax
1540 #elif defined(__arm__)
1541 # define ARCH_REGS struct pt_regs
1542 # define SYSCALL_NUM ARM_r7
1543 # define SYSCALL_RET ARM_r0
1544 #elif defined(__aarch64__)
1545 # define ARCH_REGS struct user_pt_regs
1546 # define SYSCALL_NUM regs[8]
1547 # define SYSCALL_RET regs[0]
1548 #elif defined(__hppa__)
1549 # define ARCH_REGS struct user_regs_struct
1550 # define SYSCALL_NUM gr[20]
1551 # define SYSCALL_RET gr[28]
1552 #elif defined(__powerpc__)
1553 # define ARCH_REGS struct pt_regs
1554 # define SYSCALL_NUM gpr[0]
1555 # define SYSCALL_RET gpr[3]
1556 #elif defined(__s390__)
1557 # define ARCH_REGS s390_regs
1558 # define SYSCALL_NUM gprs[2]
1559 # define SYSCALL_RET gprs[2]
1560 #elif defined(__mips__)
1561 # define ARCH_REGS struct pt_regs
1562 # define SYSCALL_NUM regs[2]
1563 # define SYSCALL_SYSCALL_NUM regs[4]
1564 # define SYSCALL_RET regs[2]
1565 # define SYSCALL_NUM_RET_SHARE_REG
1566 #else
1567 # error "Do not know how to find your architecture's registers and syscalls"
1568 #endif
1569
1570 /* When the syscall return can't be changed, stub out the tests for it. */
1571 #ifdef SYSCALL_NUM_RET_SHARE_REG
1572 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1573 #else
1574 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(val, action)
1575 #endif
1576
1577 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1578 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1579 */
1580 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1581 #define HAVE_GETREGS
1582 #endif
1583
1584 /* Architecture-specific syscall fetching routine. */
get_syscall(struct __test_metadata * _metadata,pid_t tracee)1585 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1586 {
1587 ARCH_REGS regs;
1588 #ifdef HAVE_GETREGS
1589 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, ®s)) {
1590 TH_LOG("PTRACE_GETREGS failed");
1591 return -1;
1592 }
1593 #else
1594 struct iovec iov;
1595
1596 iov.iov_base = ®s;
1597 iov.iov_len = sizeof(regs);
1598 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1599 TH_LOG("PTRACE_GETREGSET failed");
1600 return -1;
1601 }
1602 #endif
1603
1604 #if defined(__mips__)
1605 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1606 return regs.SYSCALL_SYSCALL_NUM;
1607 #endif
1608 return regs.SYSCALL_NUM;
1609 }
1610
1611 /* Architecture-specific syscall changing routine. */
change_syscall(struct __test_metadata * _metadata,pid_t tracee,int syscall)1612 void change_syscall(struct __test_metadata *_metadata,
1613 pid_t tracee, int syscall)
1614 {
1615 int ret;
1616 ARCH_REGS regs;
1617 #ifdef HAVE_GETREGS
1618 ret = ptrace(PTRACE_GETREGS, tracee, 0, ®s);
1619 #else
1620 struct iovec iov;
1621 iov.iov_base = ®s;
1622 iov.iov_len = sizeof(regs);
1623 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1624 #endif
1625 EXPECT_EQ(0, ret) {}
1626
1627 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1628 defined(__s390__) || defined(__hppa__)
1629 {
1630 regs.SYSCALL_NUM = syscall;
1631 }
1632 #elif defined(__mips__)
1633 {
1634 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1635 regs.SYSCALL_SYSCALL_NUM = syscall;
1636 else
1637 regs.SYSCALL_NUM = syscall;
1638 }
1639
1640 #elif defined(__arm__)
1641 # ifndef PTRACE_SET_SYSCALL
1642 # define PTRACE_SET_SYSCALL 23
1643 # endif
1644 {
1645 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1646 EXPECT_EQ(0, ret);
1647 }
1648
1649 #elif defined(__aarch64__)
1650 # ifndef NT_ARM_SYSTEM_CALL
1651 # define NT_ARM_SYSTEM_CALL 0x404
1652 # endif
1653 {
1654 iov.iov_base = &syscall;
1655 iov.iov_len = sizeof(syscall);
1656 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1657 &iov);
1658 EXPECT_EQ(0, ret);
1659 }
1660
1661 #else
1662 ASSERT_EQ(1, 0) {
1663 TH_LOG("How is the syscall changed on this architecture?");
1664 }
1665 #endif
1666
1667 /* If syscall is skipped, change return value. */
1668 if (syscall == -1)
1669 #ifdef SYSCALL_NUM_RET_SHARE_REG
1670 TH_LOG("Can't modify syscall return on this architecture");
1671 #else
1672 regs.SYSCALL_RET = EPERM;
1673 #endif
1674
1675 #ifdef HAVE_GETREGS
1676 ret = ptrace(PTRACE_SETREGS, tracee, 0, ®s);
1677 #else
1678 iov.iov_base = ®s;
1679 iov.iov_len = sizeof(regs);
1680 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1681 #endif
1682 EXPECT_EQ(0, ret);
1683 }
1684
tracer_syscall(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1685 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1686 int status, void *args)
1687 {
1688 int ret;
1689 unsigned long msg;
1690
1691 /* Make sure we got the right message. */
1692 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1693 EXPECT_EQ(0, ret);
1694
1695 /* Validate and take action on expected syscalls. */
1696 switch (msg) {
1697 case 0x1002:
1698 /* change getpid to getppid. */
1699 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1700 change_syscall(_metadata, tracee, __NR_getppid);
1701 break;
1702 case 0x1003:
1703 /* skip gettid. */
1704 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1705 change_syscall(_metadata, tracee, -1);
1706 break;
1707 case 0x1004:
1708 /* do nothing (allow getppid) */
1709 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1710 break;
1711 default:
1712 EXPECT_EQ(0, msg) {
1713 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1714 kill(tracee, SIGKILL);
1715 }
1716 }
1717
1718 }
1719
tracer_ptrace(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1720 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1721 int status, void *args)
1722 {
1723 int ret, nr;
1724 unsigned long msg;
1725 static bool entry;
1726
1727 /* Make sure we got an empty message. */
1728 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1729 EXPECT_EQ(0, ret);
1730 EXPECT_EQ(0, msg);
1731
1732 /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */
1733 entry = !entry;
1734 if (!entry)
1735 return;
1736
1737 nr = get_syscall(_metadata, tracee);
1738
1739 if (nr == __NR_getpid)
1740 change_syscall(_metadata, tracee, __NR_getppid);
1741 if (nr == __NR_openat)
1742 change_syscall(_metadata, tracee, -1);
1743 }
1744
FIXTURE_DATA(TRACE_syscall)1745 FIXTURE_DATA(TRACE_syscall) {
1746 struct sock_fprog prog;
1747 pid_t tracer, mytid, mypid, parent;
1748 };
1749
FIXTURE_SETUP(TRACE_syscall)1750 FIXTURE_SETUP(TRACE_syscall)
1751 {
1752 struct sock_filter filter[] = {
1753 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1754 offsetof(struct seccomp_data, nr)),
1755 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1756 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1757 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1758 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1759 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1760 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1761 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1762 };
1763
1764 memset(&self->prog, 0, sizeof(self->prog));
1765 self->prog.filter = malloc(sizeof(filter));
1766 ASSERT_NE(NULL, self->prog.filter);
1767 memcpy(self->prog.filter, filter, sizeof(filter));
1768 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1769
1770 /* Prepare some testable syscall results. */
1771 self->mytid = syscall(__NR_gettid);
1772 ASSERT_GT(self->mytid, 0);
1773 ASSERT_NE(self->mytid, 1) {
1774 TH_LOG("Running this test as init is not supported. :)");
1775 }
1776
1777 self->mypid = getpid();
1778 ASSERT_GT(self->mypid, 0);
1779 ASSERT_EQ(self->mytid, self->mypid);
1780
1781 self->parent = getppid();
1782 ASSERT_GT(self->parent, 0);
1783 ASSERT_NE(self->parent, self->mypid);
1784
1785 /* Launch tracer. */
1786 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1787 false);
1788 }
1789
FIXTURE_TEARDOWN(TRACE_syscall)1790 FIXTURE_TEARDOWN(TRACE_syscall)
1791 {
1792 teardown_trace_fixture(_metadata, self->tracer);
1793 if (self->prog.filter)
1794 free(self->prog.filter);
1795 }
1796
TEST_F(TRACE_syscall,ptrace_syscall_redirected)1797 TEST_F(TRACE_syscall, ptrace_syscall_redirected)
1798 {
1799 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1800 teardown_trace_fixture(_metadata, self->tracer);
1801 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1802 true);
1803
1804 /* Tracer will redirect getpid to getppid. */
1805 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1806 }
1807
1808 #ifdef __NR_open
TEST_F(TRACE_syscall,ptrace_syscall_dropped)1809 TEST_F(TRACE_syscall, ptrace_syscall_dropped)
1810 {
1811 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1812 teardown_trace_fixture(_metadata, self->tracer);
1813 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1814 true);
1815
1816 /* Tracer should skip the open syscall, resulting in EPERM. */
1817 EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_openat));
1818 }
1819 #endif
1820
TEST_F(TRACE_syscall,syscall_allowed)1821 TEST_F(TRACE_syscall, syscall_allowed)
1822 {
1823 long ret;
1824
1825 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1826 ASSERT_EQ(0, ret);
1827
1828 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1829 ASSERT_EQ(0, ret);
1830
1831 /* getppid works as expected (no changes). */
1832 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1833 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1834 }
1835
TEST_F(TRACE_syscall,syscall_redirected)1836 TEST_F(TRACE_syscall, syscall_redirected)
1837 {
1838 long ret;
1839
1840 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1841 ASSERT_EQ(0, ret);
1842
1843 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1844 ASSERT_EQ(0, ret);
1845
1846 /* getpid has been redirected to getppid as expected. */
1847 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1848 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1849 }
1850
TEST_F(TRACE_syscall,syscall_dropped)1851 TEST_F(TRACE_syscall, syscall_dropped)
1852 {
1853 long ret;
1854
1855 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1856 ASSERT_EQ(0, ret);
1857
1858 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1859 ASSERT_EQ(0, ret);
1860
1861 /* gettid has been skipped and an altered return value stored. */
1862 EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_gettid));
1863 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1864 }
1865
1866 /*
1867 * TODO: b/33027081
1868 * These tests do not work on kernels prior to 4.8.
1869 */
1870 #ifndef __ANDROID__
TEST_F(TRACE_syscall,skip_after_RET_TRACE)1871 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1872 {
1873 struct sock_filter filter[] = {
1874 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1875 offsetof(struct seccomp_data, nr)),
1876 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1877 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1878 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1879 };
1880 struct sock_fprog prog = {
1881 .len = (unsigned short)ARRAY_SIZE(filter),
1882 .filter = filter,
1883 };
1884 long ret;
1885
1886 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1887 ASSERT_EQ(0, ret);
1888
1889 /* Install fixture filter. */
1890 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1891 ASSERT_EQ(0, ret);
1892
1893 /* Install "errno on getppid" filter. */
1894 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1895 ASSERT_EQ(0, ret);
1896
1897 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1898 errno = 0;
1899 EXPECT_EQ(-1, syscall(__NR_getpid));
1900 EXPECT_EQ(EPERM, errno);
1901 }
1902
TEST_F_SIGNAL(TRACE_syscall,kill_after_RET_TRACE,SIGSYS)1903 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1904 {
1905 struct sock_filter filter[] = {
1906 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1907 offsetof(struct seccomp_data, nr)),
1908 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1909 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1910 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1911 };
1912 struct sock_fprog prog = {
1913 .len = (unsigned short)ARRAY_SIZE(filter),
1914 .filter = filter,
1915 };
1916 long ret;
1917
1918 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1919 ASSERT_EQ(0, ret);
1920
1921 /* Install fixture filter. */
1922 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1923 ASSERT_EQ(0, ret);
1924
1925 /* Install "death on getppid" filter. */
1926 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1927 ASSERT_EQ(0, ret);
1928
1929 /* Tracer will redirect getpid to getppid, and we should die. */
1930 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1931 }
1932
TEST_F(TRACE_syscall,skip_after_ptrace)1933 TEST_F(TRACE_syscall, skip_after_ptrace)
1934 {
1935 struct sock_filter filter[] = {
1936 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1937 offsetof(struct seccomp_data, nr)),
1938 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1939 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1940 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1941 };
1942 struct sock_fprog prog = {
1943 .len = (unsigned short)ARRAY_SIZE(filter),
1944 .filter = filter,
1945 };
1946 long ret;
1947
1948 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1949 teardown_trace_fixture(_metadata, self->tracer);
1950 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1951 true);
1952
1953 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1954 ASSERT_EQ(0, ret);
1955
1956 /* Install "errno on getppid" filter. */
1957 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1958 ASSERT_EQ(0, ret);
1959
1960 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1961 EXPECT_EQ(-1, syscall(__NR_getpid));
1962 EXPECT_EQ(EPERM, errno);
1963 }
1964
TEST_F_SIGNAL(TRACE_syscall,kill_after_ptrace,SIGSYS)1965 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
1966 {
1967 struct sock_filter filter[] = {
1968 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1969 offsetof(struct seccomp_data, nr)),
1970 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1971 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1972 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1973 };
1974 struct sock_fprog prog = {
1975 .len = (unsigned short)ARRAY_SIZE(filter),
1976 .filter = filter,
1977 };
1978 long ret;
1979
1980 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1981 teardown_trace_fixture(_metadata, self->tracer);
1982 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1983 true);
1984
1985 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1986 ASSERT_EQ(0, ret);
1987
1988 /* Install "death on getppid" filter. */
1989 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1990 ASSERT_EQ(0, ret);
1991
1992 /* Tracer will redirect getpid to getppid, and we should die. */
1993 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1994 }
1995 #endif
1996
TEST(seccomp_syscall)1997 TEST(seccomp_syscall)
1998 {
1999 struct sock_filter filter[] = {
2000 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2001 };
2002 struct sock_fprog prog = {
2003 .len = (unsigned short)ARRAY_SIZE(filter),
2004 .filter = filter,
2005 };
2006 long ret;
2007
2008 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2009 ASSERT_EQ(0, ret) {
2010 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2011 }
2012
2013 /* Reject insane operation. */
2014 ret = seccomp(-1, 0, &prog);
2015 ASSERT_NE(ENOSYS, errno) {
2016 TH_LOG("Kernel does not support seccomp syscall!");
2017 }
2018 EXPECT_EQ(EINVAL, errno) {
2019 TH_LOG("Did not reject crazy op value!");
2020 }
2021
2022 /* Reject strict with flags or pointer. */
2023 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2024 EXPECT_EQ(EINVAL, errno) {
2025 TH_LOG("Did not reject mode strict with flags!");
2026 }
2027 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2028 EXPECT_EQ(EINVAL, errno) {
2029 TH_LOG("Did not reject mode strict with uargs!");
2030 }
2031
2032 /* Reject insane args for filter. */
2033 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2034 EXPECT_EQ(EINVAL, errno) {
2035 TH_LOG("Did not reject crazy filter flags!");
2036 }
2037 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2038 EXPECT_EQ(EFAULT, errno) {
2039 TH_LOG("Did not reject NULL filter!");
2040 }
2041
2042 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2043 EXPECT_EQ(0, errno) {
2044 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2045 strerror(errno));
2046 }
2047 }
2048
TEST(seccomp_syscall_mode_lock)2049 TEST(seccomp_syscall_mode_lock)
2050 {
2051 struct sock_filter filter[] = {
2052 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2053 };
2054 struct sock_fprog prog = {
2055 .len = (unsigned short)ARRAY_SIZE(filter),
2056 .filter = filter,
2057 };
2058 long ret;
2059
2060 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2061 ASSERT_EQ(0, ret) {
2062 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2063 }
2064
2065 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2066 ASSERT_NE(ENOSYS, errno) {
2067 TH_LOG("Kernel does not support seccomp syscall!");
2068 }
2069 EXPECT_EQ(0, ret) {
2070 TH_LOG("Could not install filter!");
2071 }
2072
2073 /* Make sure neither entry point will switch to strict. */
2074 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2075 EXPECT_EQ(EINVAL, errno) {
2076 TH_LOG("Switched to mode strict!");
2077 }
2078
2079 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2080 EXPECT_EQ(EINVAL, errno) {
2081 TH_LOG("Switched to mode strict!");
2082 }
2083 }
2084
2085 #if 0
2086 /*
2087 * Test detection of known and unknown filter flags. Userspace needs to be able
2088 * to check if a filter flag is supported by the current kernel and a good way
2089 * of doing that is by attempting to enter filter mode, with the flag bit in
2090 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2091 * that the flag is valid and EINVAL indicates that the flag is invalid.
2092 */
2093 TEST(detect_seccomp_filter_flags)
2094 {
2095 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2096 SECCOMP_FILTER_FLAG_LOG,
2097 SECCOMP_FILTER_FLAG_SPEC_ALLOW };
2098 unsigned int flag, all_flags;
2099 int i;
2100 long ret;
2101
2102 /* Test detection of known-good filter flags */
2103 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2104 int bits = 0;
2105
2106 flag = flags[i];
2107 /* Make sure the flag is a single bit! */
2108 while (flag) {
2109 if (flag & 0x1)
2110 bits ++;
2111 flag >>= 1;
2112 }
2113 ASSERT_EQ(1, bits);
2114 flag = flags[i];
2115
2116 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2117 ASSERT_NE(ENOSYS, errno) {
2118 TH_LOG("Kernel does not support seccomp syscall!");
2119 }
2120 EXPECT_EQ(-1, ret);
2121 EXPECT_EQ(EFAULT, errno) {
2122 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2123 flag);
2124 }
2125
2126 all_flags |= flag;
2127 }
2128
2129 /* Test detection of all known-good filter flags */
2130 ret = seccomp(SECCOMP_SET_MODE_FILTER, all_flags, NULL);
2131 EXPECT_EQ(-1, ret);
2132 EXPECT_EQ(EFAULT, errno) {
2133 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2134 all_flags);
2135 }
2136
2137 /* Test detection of an unknown filter flag */
2138 flag = -1;
2139 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2140 EXPECT_EQ(-1, ret);
2141 EXPECT_EQ(EINVAL, errno) {
2142 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2143 flag);
2144 }
2145
2146 /*
2147 * Test detection of an unknown filter flag that may simply need to be
2148 * added to this test
2149 */
2150 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2151 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2152 EXPECT_EQ(-1, ret);
2153 EXPECT_EQ(EINVAL, errno) {
2154 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
2155 flag);
2156 }
2157 }
2158 #endif
2159
TEST(TSYNC_first)2160 TEST(TSYNC_first)
2161 {
2162 struct sock_filter filter[] = {
2163 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2164 };
2165 struct sock_fprog prog = {
2166 .len = (unsigned short)ARRAY_SIZE(filter),
2167 .filter = filter,
2168 };
2169 long ret;
2170
2171 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2172 ASSERT_EQ(0, ret) {
2173 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2174 }
2175
2176 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2177 &prog);
2178 ASSERT_NE(ENOSYS, errno) {
2179 TH_LOG("Kernel does not support seccomp syscall!");
2180 }
2181 EXPECT_EQ(0, ret) {
2182 TH_LOG("Could not install initial filter with TSYNC!");
2183 }
2184 }
2185
2186 #define TSYNC_SIBLINGS 2
2187 struct tsync_sibling {
2188 pthread_t tid;
2189 pid_t system_tid;
2190 sem_t *started;
2191 pthread_cond_t *cond;
2192 pthread_mutex_t *mutex;
2193 int diverge;
2194 int num_waits;
2195 struct sock_fprog *prog;
2196 struct __test_metadata *metadata;
2197 };
2198
2199 /*
2200 * To avoid joining joined threads (which is not allowed by Bionic),
2201 * make sure we both successfully join and clear the tid to skip a
2202 * later join attempt during fixture teardown. Any remaining threads
2203 * will be directly killed during teardown.
2204 */
2205 #define PTHREAD_JOIN(tid, status) \
2206 do { \
2207 int _rc = pthread_join(tid, status); \
2208 if (_rc) { \
2209 TH_LOG("pthread_join of tid %u failed: %d\n", \
2210 (unsigned int)tid, _rc); \
2211 } else { \
2212 tid = 0; \
2213 } \
2214 } while (0)
2215
FIXTURE_DATA(TSYNC)2216 FIXTURE_DATA(TSYNC) {
2217 struct sock_fprog root_prog, apply_prog;
2218 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2219 sem_t started;
2220 pthread_cond_t cond;
2221 pthread_mutex_t mutex;
2222 int sibling_count;
2223 };
2224
FIXTURE_SETUP(TSYNC)2225 FIXTURE_SETUP(TSYNC)
2226 {
2227 struct sock_filter root_filter[] = {
2228 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2229 };
2230 struct sock_filter apply_filter[] = {
2231 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2232 offsetof(struct seccomp_data, nr)),
2233 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2234 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2235 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2236 };
2237
2238 memset(&self->root_prog, 0, sizeof(self->root_prog));
2239 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2240 memset(&self->sibling, 0, sizeof(self->sibling));
2241 self->root_prog.filter = malloc(sizeof(root_filter));
2242 ASSERT_NE(NULL, self->root_prog.filter);
2243 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2244 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2245
2246 self->apply_prog.filter = malloc(sizeof(apply_filter));
2247 ASSERT_NE(NULL, self->apply_prog.filter);
2248 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2249 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2250
2251 self->sibling_count = 0;
2252 pthread_mutex_init(&self->mutex, NULL);
2253 pthread_cond_init(&self->cond, NULL);
2254 sem_init(&self->started, 0, 0);
2255 self->sibling[0].tid = 0;
2256 self->sibling[0].cond = &self->cond;
2257 self->sibling[0].started = &self->started;
2258 self->sibling[0].mutex = &self->mutex;
2259 self->sibling[0].diverge = 0;
2260 self->sibling[0].num_waits = 1;
2261 self->sibling[0].prog = &self->root_prog;
2262 self->sibling[0].metadata = _metadata;
2263 self->sibling[1].tid = 0;
2264 self->sibling[1].cond = &self->cond;
2265 self->sibling[1].started = &self->started;
2266 self->sibling[1].mutex = &self->mutex;
2267 self->sibling[1].diverge = 0;
2268 self->sibling[1].prog = &self->root_prog;
2269 self->sibling[1].num_waits = 1;
2270 self->sibling[1].metadata = _metadata;
2271 }
2272
FIXTURE_TEARDOWN(TSYNC)2273 FIXTURE_TEARDOWN(TSYNC)
2274 {
2275 int sib = 0;
2276
2277 if (self->root_prog.filter)
2278 free(self->root_prog.filter);
2279 if (self->apply_prog.filter)
2280 free(self->apply_prog.filter);
2281
2282 for ( ; sib < self->sibling_count; ++sib) {
2283 struct tsync_sibling *s = &self->sibling[sib];
2284
2285 if (!s->tid)
2286 continue;
2287 /*
2288 * If a thread is still running, it may be stuck, so hit
2289 * it over the head really hard.
2290 */
2291 pthread_kill(s->tid, 9);
2292 }
2293 pthread_mutex_destroy(&self->mutex);
2294 pthread_cond_destroy(&self->cond);
2295 sem_destroy(&self->started);
2296 }
2297
tsync_sibling(void * data)2298 void *tsync_sibling(void *data)
2299 {
2300 long ret = 0;
2301 struct tsync_sibling *me = data;
2302
2303 me->system_tid = syscall(__NR_gettid);
2304
2305 pthread_mutex_lock(me->mutex);
2306 if (me->diverge) {
2307 /* Just re-apply the root prog to fork the tree */
2308 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2309 me->prog, 0, 0);
2310 }
2311 sem_post(me->started);
2312 /* Return outside of started so parent notices failures. */
2313 if (ret) {
2314 pthread_mutex_unlock(me->mutex);
2315 return (void *)SIBLING_EXIT_FAILURE;
2316 }
2317 do {
2318 pthread_cond_wait(me->cond, me->mutex);
2319 me->num_waits = me->num_waits - 1;
2320 } while (me->num_waits);
2321 pthread_mutex_unlock(me->mutex);
2322
2323 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2324 if (!ret)
2325 return (void *)SIBLING_EXIT_NEWPRIVS;
2326 read(0, NULL, 0);
2327 return (void *)SIBLING_EXIT_UNKILLED;
2328 }
2329
tsync_start_sibling(struct tsync_sibling * sibling)2330 void tsync_start_sibling(struct tsync_sibling *sibling)
2331 {
2332 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2333 }
2334
TEST_F(TSYNC,siblings_fail_prctl)2335 TEST_F(TSYNC, siblings_fail_prctl)
2336 {
2337 long ret;
2338 void *status;
2339 struct sock_filter filter[] = {
2340 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2341 offsetof(struct seccomp_data, nr)),
2342 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2343 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2344 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2345 };
2346 struct sock_fprog prog = {
2347 .len = (unsigned short)ARRAY_SIZE(filter),
2348 .filter = filter,
2349 };
2350
2351 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2352 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2353 }
2354
2355 /* Check prctl failure detection by requesting sib 0 diverge. */
2356 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2357 ASSERT_NE(ENOSYS, errno) {
2358 TH_LOG("Kernel does not support seccomp syscall!");
2359 }
2360 ASSERT_EQ(0, ret) {
2361 TH_LOG("setting filter failed");
2362 }
2363
2364 self->sibling[0].diverge = 1;
2365 tsync_start_sibling(&self->sibling[0]);
2366 tsync_start_sibling(&self->sibling[1]);
2367
2368 while (self->sibling_count < TSYNC_SIBLINGS) {
2369 sem_wait(&self->started);
2370 self->sibling_count++;
2371 }
2372
2373 /* Signal the threads to clean up*/
2374 pthread_mutex_lock(&self->mutex);
2375 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2376 TH_LOG("cond broadcast non-zero");
2377 }
2378 pthread_mutex_unlock(&self->mutex);
2379
2380 /* Ensure diverging sibling failed to call prctl. */
2381 PTHREAD_JOIN(self->sibling[0].tid, &status);
2382 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2383 PTHREAD_JOIN(self->sibling[1].tid, &status);
2384 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2385 }
2386
TEST_F(TSYNC,two_siblings_with_ancestor)2387 TEST_F(TSYNC, two_siblings_with_ancestor)
2388 {
2389 long ret;
2390 void *status;
2391
2392 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2393 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2394 }
2395
2396 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2397 ASSERT_NE(ENOSYS, errno) {
2398 TH_LOG("Kernel does not support seccomp syscall!");
2399 }
2400 ASSERT_EQ(0, ret) {
2401 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2402 }
2403 tsync_start_sibling(&self->sibling[0]);
2404 tsync_start_sibling(&self->sibling[1]);
2405
2406 while (self->sibling_count < TSYNC_SIBLINGS) {
2407 sem_wait(&self->started);
2408 self->sibling_count++;
2409 }
2410
2411 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2412 &self->apply_prog);
2413 ASSERT_EQ(0, ret) {
2414 TH_LOG("Could install filter on all threads!");
2415 }
2416 /* Tell the siblings to test the policy */
2417 pthread_mutex_lock(&self->mutex);
2418 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2419 TH_LOG("cond broadcast non-zero");
2420 }
2421 pthread_mutex_unlock(&self->mutex);
2422 /* Ensure they are both killed and don't exit cleanly. */
2423 PTHREAD_JOIN(self->sibling[0].tid, &status);
2424 EXPECT_EQ(0x0, (long)status);
2425 PTHREAD_JOIN(self->sibling[1].tid, &status);
2426 EXPECT_EQ(0x0, (long)status);
2427 }
2428
TEST_F(TSYNC,two_sibling_want_nnp)2429 TEST_F(TSYNC, two_sibling_want_nnp)
2430 {
2431 void *status;
2432
2433 /* start siblings before any prctl() operations */
2434 tsync_start_sibling(&self->sibling[0]);
2435 tsync_start_sibling(&self->sibling[1]);
2436 while (self->sibling_count < TSYNC_SIBLINGS) {
2437 sem_wait(&self->started);
2438 self->sibling_count++;
2439 }
2440
2441 /* Tell the siblings to test no policy */
2442 pthread_mutex_lock(&self->mutex);
2443 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2444 TH_LOG("cond broadcast non-zero");
2445 }
2446 pthread_mutex_unlock(&self->mutex);
2447
2448 /* Ensure they are both upset about lacking nnp. */
2449 PTHREAD_JOIN(self->sibling[0].tid, &status);
2450 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2451 PTHREAD_JOIN(self->sibling[1].tid, &status);
2452 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2453 }
2454
TEST_F(TSYNC,two_siblings_with_no_filter)2455 TEST_F(TSYNC, two_siblings_with_no_filter)
2456 {
2457 long ret;
2458 void *status;
2459
2460 /* start siblings before any prctl() operations */
2461 tsync_start_sibling(&self->sibling[0]);
2462 tsync_start_sibling(&self->sibling[1]);
2463 while (self->sibling_count < TSYNC_SIBLINGS) {
2464 sem_wait(&self->started);
2465 self->sibling_count++;
2466 }
2467
2468 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2469 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2470 }
2471
2472 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2473 &self->apply_prog);
2474 ASSERT_NE(ENOSYS, errno) {
2475 TH_LOG("Kernel does not support seccomp syscall!");
2476 }
2477 ASSERT_EQ(0, ret) {
2478 TH_LOG("Could install filter on all threads!");
2479 }
2480
2481 /* Tell the siblings to test the policy */
2482 pthread_mutex_lock(&self->mutex);
2483 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2484 TH_LOG("cond broadcast non-zero");
2485 }
2486 pthread_mutex_unlock(&self->mutex);
2487
2488 /* Ensure they are both killed and don't exit cleanly. */
2489 PTHREAD_JOIN(self->sibling[0].tid, &status);
2490 EXPECT_EQ(0x0, (long)status);
2491 PTHREAD_JOIN(self->sibling[1].tid, &status);
2492 EXPECT_EQ(0x0, (long)status);
2493 }
2494
TEST_F(TSYNC,two_siblings_with_one_divergence)2495 TEST_F(TSYNC, two_siblings_with_one_divergence)
2496 {
2497 long ret;
2498 void *status;
2499
2500 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2501 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2502 }
2503
2504 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2505 ASSERT_NE(ENOSYS, errno) {
2506 TH_LOG("Kernel does not support seccomp syscall!");
2507 }
2508 ASSERT_EQ(0, ret) {
2509 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2510 }
2511 self->sibling[0].diverge = 1;
2512 tsync_start_sibling(&self->sibling[0]);
2513 tsync_start_sibling(&self->sibling[1]);
2514
2515 while (self->sibling_count < TSYNC_SIBLINGS) {
2516 sem_wait(&self->started);
2517 self->sibling_count++;
2518 }
2519
2520 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2521 &self->apply_prog);
2522 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2523 TH_LOG("Did not fail on diverged sibling.");
2524 }
2525
2526 /* Wake the threads */
2527 pthread_mutex_lock(&self->mutex);
2528 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2529 TH_LOG("cond broadcast non-zero");
2530 }
2531 pthread_mutex_unlock(&self->mutex);
2532
2533 /* Ensure they are both unkilled. */
2534 PTHREAD_JOIN(self->sibling[0].tid, &status);
2535 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2536 PTHREAD_JOIN(self->sibling[1].tid, &status);
2537 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2538 }
2539
TEST_F(TSYNC,two_siblings_not_under_filter)2540 TEST_F(TSYNC, two_siblings_not_under_filter)
2541 {
2542 long ret, sib;
2543 void *status;
2544
2545 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2546 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2547 }
2548
2549 /*
2550 * Sibling 0 will have its own seccomp policy
2551 * and Sibling 1 will not be under seccomp at
2552 * all. Sibling 1 will enter seccomp and 0
2553 * will cause failure.
2554 */
2555 self->sibling[0].diverge = 1;
2556 tsync_start_sibling(&self->sibling[0]);
2557 tsync_start_sibling(&self->sibling[1]);
2558
2559 while (self->sibling_count < TSYNC_SIBLINGS) {
2560 sem_wait(&self->started);
2561 self->sibling_count++;
2562 }
2563
2564 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2565 ASSERT_NE(ENOSYS, errno) {
2566 TH_LOG("Kernel does not support seccomp syscall!");
2567 }
2568 ASSERT_EQ(0, ret) {
2569 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2570 }
2571
2572 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2573 &self->apply_prog);
2574 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2575 TH_LOG("Did not fail on diverged sibling.");
2576 }
2577 sib = 1;
2578 if (ret == self->sibling[0].system_tid)
2579 sib = 0;
2580
2581 pthread_mutex_lock(&self->mutex);
2582
2583 /* Increment the other siblings num_waits so we can clean up
2584 * the one we just saw.
2585 */
2586 self->sibling[!sib].num_waits += 1;
2587
2588 /* Signal the thread to clean up*/
2589 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2590 TH_LOG("cond broadcast non-zero");
2591 }
2592 pthread_mutex_unlock(&self->mutex);
2593 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2594 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2595 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2596 while (!kill(self->sibling[sib].system_tid, 0))
2597 sleep(0.1);
2598 /* Switch to the remaining sibling */
2599 sib = !sib;
2600
2601 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2602 &self->apply_prog);
2603 ASSERT_EQ(0, ret) {
2604 TH_LOG("Expected the remaining sibling to sync");
2605 };
2606
2607 pthread_mutex_lock(&self->mutex);
2608
2609 /* If remaining sibling didn't have a chance to wake up during
2610 * the first broadcast, manually reduce the num_waits now.
2611 */
2612 if (self->sibling[sib].num_waits > 1)
2613 self->sibling[sib].num_waits = 1;
2614 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2615 TH_LOG("cond broadcast non-zero");
2616 }
2617 pthread_mutex_unlock(&self->mutex);
2618 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2619 EXPECT_EQ(0, (long)status);
2620 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2621 while (!kill(self->sibling[sib].system_tid, 0))
2622 sleep(0.1);
2623
2624 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2625 &self->apply_prog);
2626 ASSERT_EQ(0, ret); /* just us chickens */
2627 }
2628
2629 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)2630 TEST(syscall_restart)
2631 {
2632 long ret;
2633 unsigned long msg;
2634 pid_t child_pid;
2635 int pipefd[2];
2636 int status;
2637 siginfo_t info = { };
2638 struct sock_filter filter[] = {
2639 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2640 offsetof(struct seccomp_data, nr)),
2641
2642 #ifdef __NR_sigreturn
2643 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2644 #endif
2645 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2646 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2647 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2648 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2649 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2650
2651 /* Allow __NR_write for easy logging. */
2652 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2653 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2654 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2655 /* The nanosleep jump target. */
2656 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2657 /* The restart_syscall jump target. */
2658 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2659 };
2660 struct sock_fprog prog = {
2661 .len = (unsigned short)ARRAY_SIZE(filter),
2662 .filter = filter,
2663 };
2664 #if defined(__arm__)
2665 struct utsname utsbuf;
2666 int arm_version;
2667 #endif
2668
2669 ASSERT_EQ(0, pipe(pipefd));
2670
2671 child_pid = fork();
2672 ASSERT_LE(0, child_pid);
2673 if (child_pid == 0) {
2674 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2675 char buf = ' ';
2676 struct timespec timeout = { };
2677
2678 /* Attach parent as tracer and stop. */
2679 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2680 EXPECT_EQ(0, raise(SIGSTOP));
2681
2682 EXPECT_EQ(0, close(pipefd[1]));
2683
2684 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2685 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2686 }
2687
2688 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2689 EXPECT_EQ(0, ret) {
2690 TH_LOG("Failed to install filter!");
2691 }
2692
2693 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2694 TH_LOG("Failed to read() sync from parent");
2695 }
2696 EXPECT_EQ('.', buf) {
2697 TH_LOG("Failed to get sync data from read()");
2698 }
2699
2700 /* Start nanosleep to be interrupted. */
2701 timeout.tv_sec = 1;
2702 errno = 0;
2703 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2704 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2705 }
2706
2707 /* Read final sync from parent. */
2708 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2709 TH_LOG("Failed final read() from parent");
2710 }
2711 EXPECT_EQ('!', buf) {
2712 TH_LOG("Failed to get final data from read()");
2713 }
2714
2715 /* Directly report the status of our test harness results. */
2716 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2717 : EXIT_FAILURE);
2718 }
2719 EXPECT_EQ(0, close(pipefd[0]));
2720
2721 /* Attach to child, setup options, and release. */
2722 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2723 ASSERT_EQ(true, WIFSTOPPED(status));
2724 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2725 PTRACE_O_TRACESECCOMP));
2726 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2727 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2728
2729 /* Wait for nanosleep() to start. */
2730 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2731 ASSERT_EQ(true, WIFSTOPPED(status));
2732 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2733 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2734 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2735 ASSERT_EQ(0x100, msg);
2736 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2737
2738 /* Might as well check siginfo for sanity while we're here. */
2739 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2740 ASSERT_EQ(SIGTRAP, info.si_signo);
2741 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2742 EXPECT_EQ(0, info.si_errno);
2743 EXPECT_EQ(getuid(), info.si_uid);
2744 /* Verify signal delivery came from child (seccomp-triggered). */
2745 EXPECT_EQ(child_pid, info.si_pid);
2746
2747 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2748 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2749 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2750 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2751 ASSERT_EQ(true, WIFSTOPPED(status));
2752 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2753 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2754 /*
2755 * There is no siginfo on SIGSTOP any more, so we can't verify
2756 * signal delivery came from parent now (getpid() == info.si_pid).
2757 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
2758 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
2759 */
2760 EXPECT_EQ(SIGSTOP, info.si_signo);
2761
2762 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2763 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2764 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2765 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2766 ASSERT_EQ(true, WIFSTOPPED(status));
2767 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2768 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2769
2770 /* Wait for restart_syscall() to start. */
2771 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2772 ASSERT_EQ(true, WIFSTOPPED(status));
2773 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2774 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2775 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2776
2777 ASSERT_EQ(0x200, msg);
2778 ret = get_syscall(_metadata, child_pid);
2779 #if defined(__arm__)
2780 /*
2781 * - native ARM registers do NOT expose true syscall.
2782 * - compat ARM registers on ARM64 DO expose true syscall.
2783 */
2784 ASSERT_EQ(0, uname(&utsbuf));
2785 if (sscanf(utsbuf.machine, "armv%d", &arm_version) == 1 &&
2786 arm_version < 8) {
2787 EXPECT_EQ(__NR_nanosleep, ret);
2788 } else
2789 #endif
2790 {
2791 EXPECT_EQ(__NR_restart_syscall, ret);
2792 }
2793
2794 /* Write again to end test. */
2795 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2796 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2797 EXPECT_EQ(0, close(pipefd[1]));
2798
2799 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2800 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2801 _metadata->passed = 0;
2802 }
2803
2804 #if 0
2805 TEST_SIGNAL(filter_flag_log, SIGSYS)
2806 {
2807 struct sock_filter allow_filter[] = {
2808 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2809 };
2810 struct sock_filter kill_filter[] = {
2811 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2812 offsetof(struct seccomp_data, nr)),
2813 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2814 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2815 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2816 };
2817 struct sock_fprog allow_prog = {
2818 .len = (unsigned short)ARRAY_SIZE(allow_filter),
2819 .filter = allow_filter,
2820 };
2821 struct sock_fprog kill_prog = {
2822 .len = (unsigned short)ARRAY_SIZE(kill_filter),
2823 .filter = kill_filter,
2824 };
2825 long ret;
2826 pid_t parent = getppid();
2827
2828 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2829 ASSERT_EQ(0, ret);
2830
2831 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
2832 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
2833 &allow_prog);
2834 ASSERT_NE(ENOSYS, errno) {
2835 TH_LOG("Kernel does not support seccomp syscall!");
2836 }
2837 EXPECT_NE(0, ret) {
2838 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
2839 }
2840 EXPECT_EQ(EINVAL, errno) {
2841 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
2842 }
2843
2844 /* Verify that a simple, permissive filter can be added with no flags */
2845 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
2846 EXPECT_EQ(0, ret);
2847
2848 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
2849 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2850 &allow_prog);
2851 ASSERT_NE(EINVAL, errno) {
2852 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
2853 }
2854 EXPECT_EQ(0, ret);
2855
2856 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
2857 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2858 &kill_prog);
2859 EXPECT_EQ(0, ret);
2860
2861 EXPECT_EQ(parent, syscall(__NR_getppid));
2862 /* getpid() should never return. */
2863 EXPECT_EQ(0, syscall(__NR_getpid));
2864 }
2865
2866 TEST(get_action_avail)
2867 {
2868 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
2869 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
2870 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
2871 __u32 unknown_action = 0x10000000U;
2872 int i;
2873 long ret;
2874
2875 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
2876 ASSERT_NE(ENOSYS, errno) {
2877 TH_LOG("Kernel does not support seccomp syscall!");
2878 }
2879 ASSERT_NE(EINVAL, errno) {
2880 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
2881 }
2882 EXPECT_EQ(ret, 0);
2883
2884 for (i = 0; i < ARRAY_SIZE(actions); i++) {
2885 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
2886 EXPECT_EQ(ret, 0) {
2887 TH_LOG("Expected action (0x%X) not available!",
2888 actions[i]);
2889 }
2890 }
2891
2892 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
2893 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
2894 EXPECT_EQ(ret, -1);
2895 EXPECT_EQ(errno, EOPNOTSUPP);
2896 }
2897 #endif
2898
2899 #ifndef __ANDROID__ // SECCOMP_FILTER_FLAG_LOG is 4.14 and newer
TEST(get_metadata)2900 TEST(get_metadata)
2901 {
2902 pid_t pid;
2903 int pipefd[2];
2904 char buf;
2905 struct seccomp_metadata md;
2906 long ret;
2907
2908 ASSERT_EQ(0, pipe(pipefd));
2909
2910 pid = fork();
2911 ASSERT_GE(pid, 0);
2912 if (pid == 0) {
2913 struct sock_filter filter[] = {
2914 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2915 };
2916 struct sock_fprog prog = {
2917 .len = (unsigned short)ARRAY_SIZE(filter),
2918 .filter = filter,
2919 };
2920
2921 /* one with log, one without */
2922 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
2923 SECCOMP_FILTER_FLAG_LOG, &prog));
2924 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
2925
2926 ASSERT_EQ(0, close(pipefd[0]));
2927 ASSERT_EQ(1, write(pipefd[1], "1", 1));
2928 ASSERT_EQ(0, close(pipefd[1]));
2929
2930 while (1)
2931 sleep(100);
2932 }
2933
2934 ASSERT_EQ(0, close(pipefd[1]));
2935 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
2936
2937 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
2938 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
2939
2940 /* Past here must not use ASSERT or child process is never killed. */
2941
2942 md.filter_off = 0;
2943 errno = 0;
2944 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
2945 EXPECT_EQ(sizeof(md), ret) {
2946 if (errno == EINVAL)
2947 XFAIL(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
2948 }
2949
2950 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
2951 EXPECT_EQ(md.filter_off, 0);
2952
2953 md.filter_off = 1;
2954 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
2955 EXPECT_EQ(sizeof(md), ret);
2956 EXPECT_EQ(md.flags, 0);
2957 EXPECT_EQ(md.filter_off, 1);
2958
2959 skip:
2960 ASSERT_EQ(0, kill(pid, SIGKILL));
2961 }
2962 #endif
2963
2964 /*
2965 * TODO:
2966 * - add microbenchmarks
2967 * - expand NNP testing
2968 * - better arch-specific TRACE and TRAP handlers.
2969 * - endianness checking when appropriate
2970 * - 64-bit arg prodding
2971 * - arch value testing (x86 modes especially)
2972 * - verify that FILTER_FLAG_LOG filters generate log messages
2973 * - verify that RET_LOG generates log messages
2974 * - ...
2975 */
2976
2977 TEST_HARNESS_MAIN
2978