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seccomp: add tests for ptrace hole
[mirror_ubuntu-zesty-kernel.git] / tools / testing / selftests / seccomp / seccomp_bpf.c
CommitLineData
c99ee51a
KC		 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
0ce105bf 8#include <sys/types.h>
c99ee51a
KC		 9#include <asm/siginfo.h>
10#define __have_siginfo_t 1
11#define __have_sigval_t 1
12#define __have_sigevent_t 1
13
14#include <errno.h>
15#include <linux/filter.h>
16#include <sys/prctl.h>
17#include <sys/ptrace.h>
18#include <sys/user.h>
19#include <linux/prctl.h>
20#include <linux/ptrace.h>
21#include <linux/seccomp.h>
c99ee51a
KC		 22#include <pthread.h>
23#include <semaphore.h>
24#include <signal.h>
25#include <stddef.h>
26#include <stdbool.h>
27#include <string.h>
256d0afb 28#include <time.h>
c99ee51a
KC		 29#include <linux/elf.h>
30#include <sys/uio.h>
256d0afb 31#include <sys/utsname.h>
fd88d16c
RS		 32#include <sys/fcntl.h>
33#include <sys/mman.h>
34#include <sys/times.h>
c99ee51a
KC		 35
36#define _GNU_SOURCE
37#include <unistd.h>
38#include <sys/syscall.h>
39
40#include "test_harness.h"
41
42#ifndef PR_SET_PTRACER
43# define PR_SET_PTRACER 0x59616d61
44#endif
45
46#ifndef PR_SET_NO_NEW_PRIVS
47#define PR_SET_NO_NEW_PRIVS 38
48#define PR_GET_NO_NEW_PRIVS 39
49#endif
50
51#ifndef PR_SECCOMP_EXT
52#define PR_SECCOMP_EXT 43
53#endif
54
55#ifndef SECCOMP_EXT_ACT
56#define SECCOMP_EXT_ACT 1
57#endif
58
59#ifndef SECCOMP_EXT_ACT_TSYNC
60#define SECCOMP_EXT_ACT_TSYNC 1
61#endif
62
63#ifndef SECCOMP_MODE_STRICT
64#define SECCOMP_MODE_STRICT 1
65#endif
66
67#ifndef SECCOMP_MODE_FILTER
68#define SECCOMP_MODE_FILTER 2
69#endif
70
71#ifndef SECCOMP_RET_KILL
72#define SECCOMP_RET_KILL 0x00000000U /* kill the task immediately */
73#define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
74#define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
75#define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
76#define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
77
78/* Masks for the return value sections. */
79#define SECCOMP_RET_ACTION 0x7fff0000U
80#define SECCOMP_RET_DATA 0x0000ffffU
81
82struct seccomp_data {
83 int nr;
84 __u32 arch;
85 __u64 instruction_pointer;
86 __u64 args[6];
87};
88#endif
89
c385d0db 90#if __BYTE_ORDER == __LITTLE_ENDIAN
c99ee51a 91#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
c385d0db
ME		 92#elif __BYTE_ORDER == __BIG_ENDIAN
93#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
94#else
95#error "wut? Unknown __BYTE_ORDER?!"
96#endif
c99ee51a
KC		 97
98#define SIBLING_EXIT_UNKILLED 0xbadbeef
99#define SIBLING_EXIT_FAILURE 0xbadface
100#define SIBLING_EXIT_NEWPRIVS 0xbadfeed
101
102TEST(mode_strict_support)
103{
104 long ret;
105
106 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
107 ASSERT_EQ(0, ret) {
108 TH_LOG("Kernel does not support CONFIG_SECCOMP");
109 }
110 syscall(__NR_exit, 1);
111}
112
113TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
114{
115 long ret;
116
117 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
118 ASSERT_EQ(0, ret) {
119 TH_LOG("Kernel does not support CONFIG_SECCOMP");
120 }
121 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
122 NULL, NULL, NULL);
123 EXPECT_FALSE(true) {
124 TH_LOG("Unreachable!");
125 }
126}
127
128/* Note! This doesn't test no new privs behavior */
129TEST(no_new_privs_support)
130{
131 long ret;
132
133 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
134 EXPECT_EQ(0, ret) {
135 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
136 }
137}
138
139/* Tests kernel support by checking for a copy_from_user() fault on * NULL. */
140TEST(mode_filter_support)
141{
142 long ret;
143
144 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
145 ASSERT_EQ(0, ret) {
146 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
147 }
148 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
149 EXPECT_EQ(-1, ret);
150 EXPECT_EQ(EFAULT, errno) {
151 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
152 }
153}
154
155TEST(mode_filter_without_nnp)
156{
157 struct sock_filter filter[] = {
158 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
159 };
160 struct sock_fprog prog = {
161 .len = (unsigned short)ARRAY_SIZE(filter),
162 .filter = filter,
163 };
164 long ret;
165
166 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
167 ASSERT_LE(0, ret) {
168 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
169 }
170 errno = 0;
171 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
172 /* Succeeds with CAP_SYS_ADMIN, fails without */
173 /* TODO(wad) check caps not euid */
174 if (geteuid()) {
175 EXPECT_EQ(-1, ret);
176 EXPECT_EQ(EACCES, errno);
177 } else {
178 EXPECT_EQ(0, ret);
179 }
180}
181
182#define MAX_INSNS_PER_PATH 32768
183
184TEST(filter_size_limits)
185{
186 int i;
187 int count = BPF_MAXINSNS + 1;
188 struct sock_filter allow[] = {
189 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
190 };
191 struct sock_filter *filter;
192 struct sock_fprog prog = { };
193 long ret;
194
195 filter = calloc(count, sizeof(*filter));
196 ASSERT_NE(NULL, filter);
197
198 for (i = 0; i < count; i++)
199 filter[i] = allow[0];
200
201 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
202 ASSERT_EQ(0, ret);
203
204 prog.filter = filter;
205 prog.len = count;
206
207 /* Too many filter instructions in a single filter. */
208 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
209 ASSERT_NE(0, ret) {
210 TH_LOG("Installing %d insn filter was allowed", prog.len);
211 }
212
213 /* One less is okay, though. */
214 prog.len -= 1;
215 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
216 ASSERT_EQ(0, ret) {
217 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
218 }
219}
220
221TEST(filter_chain_limits)
222{
223 int i;
224 int count = BPF_MAXINSNS;
225 struct sock_filter allow[] = {
226 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
227 };
228 struct sock_filter *filter;
229 struct sock_fprog prog = { };
230 long ret;
231
232 filter = calloc(count, sizeof(*filter));
233 ASSERT_NE(NULL, filter);
234
235 for (i = 0; i < count; i++)
236 filter[i] = allow[0];
237
238 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
239 ASSERT_EQ(0, ret);
240
241 prog.filter = filter;
242 prog.len = 1;
243
244 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
245 ASSERT_EQ(0, ret);
246
247 prog.len = count;
248
249 /* Too many total filter instructions. */
250 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
251 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
252 if (ret != 0)
253 break;
254 }
255 ASSERT_NE(0, ret) {
256 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
257 i, count, i * (count + 4));
258 }
259}
260
261TEST(mode_filter_cannot_move_to_strict)
262{
263 struct sock_filter filter[] = {
264 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
265 };
266 struct sock_fprog prog = {
267 .len = (unsigned short)ARRAY_SIZE(filter),
268 .filter = filter,
269 };
270 long ret;
271
272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
273 ASSERT_EQ(0, ret);
274
275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
276 ASSERT_EQ(0, ret);
277
278 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
279 EXPECT_EQ(-1, ret);
280 EXPECT_EQ(EINVAL, errno);
281}
282
283
284TEST(mode_filter_get_seccomp)
285{
286 struct sock_filter filter[] = {
287 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
288 };
289 struct sock_fprog prog = {
290 .len = (unsigned short)ARRAY_SIZE(filter),
291 .filter = filter,
292 };
293 long ret;
294
295 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
296 ASSERT_EQ(0, ret);
297
298 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
299 EXPECT_EQ(0, ret);
300
301 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
302 ASSERT_EQ(0, ret);
303
304 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
305 EXPECT_EQ(2, ret);
306}
307
308
309TEST(ALLOW_all)
310{
311 struct sock_filter filter[] = {
312 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
313 };
314 struct sock_fprog prog = {
315 .len = (unsigned short)ARRAY_SIZE(filter),
316 .filter = filter,
317 };
318 long ret;
319
320 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
321 ASSERT_EQ(0, ret);
322
323 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
324 ASSERT_EQ(0, ret);
325}
326
327TEST(empty_prog)
328{
329 struct sock_filter filter[] = {
330 };
331 struct sock_fprog prog = {
332 .len = (unsigned short)ARRAY_SIZE(filter),
333 .filter = filter,
334 };
335 long ret;
336
337 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
338 ASSERT_EQ(0, ret);
339
340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
341 EXPECT_EQ(-1, ret);
342 EXPECT_EQ(EINVAL, errno);
343}
344
345TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
346{
347 struct sock_filter filter[] = {
348 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
349 };
350 struct sock_fprog prog = {
351 .len = (unsigned short)ARRAY_SIZE(filter),
352 .filter = filter,
353 };
354 long ret;
355
356 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
357 ASSERT_EQ(0, ret);
358
359 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
360 ASSERT_EQ(0, ret);
361 EXPECT_EQ(0, syscall(__NR_getpid)) {
362 TH_LOG("getpid() shouldn't ever return");
363 }
364}
365
366/* return code >= 0x80000000 is unused. */
367TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
368{
369 struct sock_filter filter[] = {
370 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
371 };
372 struct sock_fprog prog = {
373 .len = (unsigned short)ARRAY_SIZE(filter),
374 .filter = filter,
375 };
376 long ret;
377
378 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
379 ASSERT_EQ(0, ret);
380
381 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
382 ASSERT_EQ(0, ret);
383 EXPECT_EQ(0, syscall(__NR_getpid)) {
384 TH_LOG("getpid() shouldn't ever return");
385 }
386}
387
388TEST_SIGNAL(KILL_all, SIGSYS)
389{
390 struct sock_filter filter[] = {
391 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
392 };
393 struct sock_fprog prog = {
394 .len = (unsigned short)ARRAY_SIZE(filter),
395 .filter = filter,
396 };
397 long ret;
398
399 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
400 ASSERT_EQ(0, ret);
401
402 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
403 ASSERT_EQ(0, ret);
404}
405
406TEST_SIGNAL(KILL_one, SIGSYS)
407{
408 struct sock_filter filter[] = {
409 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
410 offsetof(struct seccomp_data, nr)),
411 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
412 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
413 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
414 };
415 struct sock_fprog prog = {
416 .len = (unsigned short)ARRAY_SIZE(filter),
417 .filter = filter,
418 };
419 long ret;
420 pid_t parent = getppid();
421
422 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
423 ASSERT_EQ(0, ret);
424
425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
426 ASSERT_EQ(0, ret);
427
428 EXPECT_EQ(parent, syscall(__NR_getppid));
429 /* getpid() should never return. */
430 EXPECT_EQ(0, syscall(__NR_getpid));
431}
432
433TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
434{
fd88d16c 435 void *fatal_address;
c99ee51a
KC		 436 struct sock_filter filter[] = {
437 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
438 offsetof(struct seccomp_data, nr)),
fd88d16c 439 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
c99ee51a
KC		 440 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
441 /* Only both with lower 32-bit for now. */
442 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
fd88d16c
RS		 443 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
444 (unsigned long)&fatal_address, 0, 1),
c99ee51a
KC		 445 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
446 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
447 };
448 struct sock_fprog prog = {
449 .len = (unsigned short)ARRAY_SIZE(filter),
450 .filter = filter,
451 };
452 long ret;
453 pid_t parent = getppid();
fd88d16c
RS		 454 struct tms timebuf;
455 clock_t clock = times(&timebuf);
c99ee51a
KC		 456
457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
458 ASSERT_EQ(0, ret);
459
460 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
461 ASSERT_EQ(0, ret);
462
463 EXPECT_EQ(parent, syscall(__NR_getppid));
fd88d16c
RS		 464 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
465 /* times() should never return. */
466 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
c99ee51a
KC		 467}
468
469TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
470{
fd88d16c
RS		 471#ifndef __NR_mmap2
472 int sysno = __NR_mmap;
473#else
474 int sysno = __NR_mmap2;
475#endif
c99ee51a
KC		 476 struct sock_filter filter[] = {
477 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
478 offsetof(struct seccomp_data, nr)),
fd88d16c 479 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
c99ee51a
KC		 480 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
481 /* Only both with lower 32-bit for now. */
482 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
483 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
484 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
485 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
486 };
487 struct sock_fprog prog = {
488 .len = (unsigned short)ARRAY_SIZE(filter),
489 .filter = filter,
490 };
491 long ret;
492 pid_t parent = getppid();
fd88d16c
RS		 493 int fd;
494 void *map1, *map2;
2ce47b44
BJZ		 495 int page_size = sysconf(_SC_PAGESIZE);
496
497 ASSERT_LT(0, page_size);
c99ee51a
KC		 498
499 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
500 ASSERT_EQ(0, ret);
501
502 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
503 ASSERT_EQ(0, ret);
504
fd88d16c
RS		 505 fd = open("/dev/zero", O_RDONLY);
506 ASSERT_NE(-1, fd);
507
c99ee51a 508 EXPECT_EQ(parent, syscall(__NR_getppid));
fd88d16c 509 map1 = (void *)syscall(sysno,
2ce47b44 510 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
fd88d16c
RS		 511 EXPECT_NE(MAP_FAILED, map1);
512 /* mmap2() should never return. */
513 map2 = (void *)syscall(sysno,
2ce47b44 514 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
fd88d16c
RS		 515 EXPECT_EQ(MAP_FAILED, map2);
516
517 /* The test failed, so clean up the resources. */
2ce47b44
BJZ		 518 munmap(map1, page_size);
519 munmap(map2, page_size);
fd88d16c 520 close(fd);
c99ee51a
KC		 521}
522
523/* TODO(wad) add 64-bit versus 32-bit arg tests. */
524TEST(arg_out_of_range)
525{
526 struct sock_filter filter[] = {
527 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
528 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
529 };
530 struct sock_fprog prog = {
531 .len = (unsigned short)ARRAY_SIZE(filter),
532 .filter = filter,
533 };
534 long ret;
535
536 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
537 ASSERT_EQ(0, ret);
538
539 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
540 EXPECT_EQ(-1, ret);
541 EXPECT_EQ(EINVAL, errno);
542}
543
544TEST(ERRNO_valid)
545{
546 struct sock_filter filter[] = {
547 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
548 offsetof(struct seccomp_data, nr)),
549 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
550 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | E2BIG),
551 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
552 };
553 struct sock_fprog prog = {
554 .len = (unsigned short)ARRAY_SIZE(filter),
555 .filter = filter,
556 };
557 long ret;
558 pid_t parent = getppid();
559
560 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
561 ASSERT_EQ(0, ret);
562
563 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
564 ASSERT_EQ(0, ret);
565
566 EXPECT_EQ(parent, syscall(__NR_getppid));
567 EXPECT_EQ(-1, read(0, NULL, 0));
568 EXPECT_EQ(E2BIG, errno);
569}
570
571TEST(ERRNO_zero)
572{
573 struct sock_filter filter[] = {
574 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
575 offsetof(struct seccomp_data, nr)),
576 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
577 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 0),
578 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
579 };
580 struct sock_fprog prog = {
581 .len = (unsigned short)ARRAY_SIZE(filter),
582 .filter = filter,
583 };
584 long ret;
585 pid_t parent = getppid();
586
587 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
588 ASSERT_EQ(0, ret);
589
590 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
591 ASSERT_EQ(0, ret);
592
593 EXPECT_EQ(parent, syscall(__NR_getppid));
594 /* "errno" of 0 is ok. */
595 EXPECT_EQ(0, read(0, NULL, 0));
596}
597
598TEST(ERRNO_capped)
599{
600 struct sock_filter filter[] = {
601 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
602 offsetof(struct seccomp_data, nr)),
603 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
604 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 4096),
605 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
606 };
607 struct sock_fprog prog = {
608 .len = (unsigned short)ARRAY_SIZE(filter),
609 .filter = filter,
610 };
611 long ret;
612 pid_t parent = getppid();
613
614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
615 ASSERT_EQ(0, ret);
616
617 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
618 ASSERT_EQ(0, ret);
619
620 EXPECT_EQ(parent, syscall(__NR_getppid));
621 EXPECT_EQ(-1, read(0, NULL, 0));
622 EXPECT_EQ(4095, errno);
623}
624
625FIXTURE_DATA(TRAP) {
626 struct sock_fprog prog;
627};
628
629FIXTURE_SETUP(TRAP)
630{
631 struct sock_filter filter[] = {
632 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
633 offsetof(struct seccomp_data, nr)),
634 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
635 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
636 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
637 };
638
639 memset(&self->prog, 0, sizeof(self->prog));
640 self->prog.filter = malloc(sizeof(filter));
641 ASSERT_NE(NULL, self->prog.filter);
642 memcpy(self->prog.filter, filter, sizeof(filter));
643 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
644}
645
646FIXTURE_TEARDOWN(TRAP)
647{
648 if (self->prog.filter)
649 free(self->prog.filter);
650}
651
652TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
653{
654 long ret;
655
656 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
657 ASSERT_EQ(0, ret);
658
659 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
660 ASSERT_EQ(0, ret);
661 syscall(__NR_getpid);
662}
663
664/* Ensure that SIGSYS overrides SIG_IGN */
665TEST_F_SIGNAL(TRAP, ign, SIGSYS)
666{
667 long ret;
668
669 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
670 ASSERT_EQ(0, ret);
671
672 signal(SIGSYS, SIG_IGN);
673
674 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
675 ASSERT_EQ(0, ret);
676 syscall(__NR_getpid);
677}
678
679static struct siginfo TRAP_info;
680static volatile int TRAP_nr;
681static void TRAP_action(int nr, siginfo_t *info, void *void_context)
682{
683 memcpy(&TRAP_info, info, sizeof(TRAP_info));
684 TRAP_nr = nr;
685}
686
687TEST_F(TRAP, handler)
688{
689 int ret, test;
690 struct sigaction act;
691 sigset_t mask;
692
693 memset(&act, 0, sizeof(act));
694 sigemptyset(&mask);
695 sigaddset(&mask, SIGSYS);
696
697 act.sa_sigaction = &TRAP_action;
698 act.sa_flags = SA_SIGINFO;
699 ret = sigaction(SIGSYS, &act, NULL);
700 ASSERT_EQ(0, ret) {
701 TH_LOG("sigaction failed");
702 }
703 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
704 ASSERT_EQ(0, ret) {
705 TH_LOG("sigprocmask failed");
706 }
707
708 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
709 ASSERT_EQ(0, ret);
710 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
711 ASSERT_EQ(0, ret);
712 TRAP_nr = 0;
713 memset(&TRAP_info, 0, sizeof(TRAP_info));
714 /* Expect the registers to be rolled back. (nr = error) may vary
715 * based on arch. */
716 ret = syscall(__NR_getpid);
717 /* Silence gcc warning about volatile. */
718 test = TRAP_nr;
719 EXPECT_EQ(SIGSYS, test);
720 struct local_sigsys {
721 void *_call_addr; /* calling user insn */
722 int _syscall; /* triggering system call number */
723 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
724 } *sigsys = (struct local_sigsys *)
725#ifdef si_syscall
726 &(TRAP_info.si_call_addr);
727#else
728 &TRAP_info.si_pid;
729#endif
730 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
731 /* Make sure arch is non-zero. */
732 EXPECT_NE(0, sigsys->_arch);
733 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
734}
735
736FIXTURE_DATA(precedence) {
737 struct sock_fprog allow;
738 struct sock_fprog trace;
739 struct sock_fprog error;
740 struct sock_fprog trap;
741 struct sock_fprog kill;
742};
743
744FIXTURE_SETUP(precedence)
745{
746 struct sock_filter allow_insns[] = {
747 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
748 };
749 struct sock_filter trace_insns[] = {
750 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
751 offsetof(struct seccomp_data, nr)),
752 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
754 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
755 };
756 struct sock_filter error_insns[] = {
757 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
758 offsetof(struct seccomp_data, nr)),
759 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
760 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
761 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
762 };
763 struct sock_filter trap_insns[] = {
764 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
765 offsetof(struct seccomp_data, nr)),
766 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
767 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
768 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
769 };
770 struct sock_filter kill_insns[] = {
771 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
772 offsetof(struct seccomp_data, nr)),
773 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
774 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
775 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
776 };
777
778 memset(self, 0, sizeof(*self));
779#define FILTER_ALLOC(_x) \
780 self->_x.filter = malloc(sizeof(_x##_insns)); \
781 ASSERT_NE(NULL, self->_x.filter); \
782 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
783 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
784 FILTER_ALLOC(allow);
785 FILTER_ALLOC(trace);
786 FILTER_ALLOC(error);
787 FILTER_ALLOC(trap);
788 FILTER_ALLOC(kill);
789}
790
791FIXTURE_TEARDOWN(precedence)
792{
793#define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
794 FILTER_FREE(allow);
795 FILTER_FREE(trace);
796 FILTER_FREE(error);
797 FILTER_FREE(trap);
798 FILTER_FREE(kill);
799}
800
801TEST_F(precedence, allow_ok)
802{
803 pid_t parent, res = 0;
804 long ret;
805
806 parent = getppid();
807 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
808 ASSERT_EQ(0, ret);
809
810 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
811 ASSERT_EQ(0, ret);
812 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
813 ASSERT_EQ(0, ret);
814 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
815 ASSERT_EQ(0, ret);
816 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
817 ASSERT_EQ(0, ret);
818 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
819 ASSERT_EQ(0, ret);
820 /* Should work just fine. */
821 res = syscall(__NR_getppid);
822 EXPECT_EQ(parent, res);
823}
824
825TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
826{
827 pid_t parent, res = 0;
828 long ret;
829
830 parent = getppid();
831 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
832 ASSERT_EQ(0, ret);
833
834 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
835 ASSERT_EQ(0, ret);
836 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
837 ASSERT_EQ(0, ret);
838 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
839 ASSERT_EQ(0, ret);
840 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
841 ASSERT_EQ(0, ret);
842 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
843 ASSERT_EQ(0, ret);
844 /* Should work just fine. */
845 res = syscall(__NR_getppid);
846 EXPECT_EQ(parent, res);
847 /* getpid() should never return. */
848 res = syscall(__NR_getpid);
849 EXPECT_EQ(0, res);
850}
851
852TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
853{
854 pid_t parent;
855 long ret;
856
857 parent = getppid();
858 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
859 ASSERT_EQ(0, ret);
860
861 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
862 ASSERT_EQ(0, ret);
863 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
864 ASSERT_EQ(0, ret);
865 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
866 ASSERT_EQ(0, ret);
867 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
868 ASSERT_EQ(0, ret);
869 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
870 ASSERT_EQ(0, ret);
871 /* Should work just fine. */
872 EXPECT_EQ(parent, syscall(__NR_getppid));
873 /* getpid() should never return. */
874 EXPECT_EQ(0, syscall(__NR_getpid));
875}
876
877TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
878{
879 pid_t parent;
880 long ret;
881
882 parent = getppid();
883 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
884 ASSERT_EQ(0, ret);
885
886 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
887 ASSERT_EQ(0, ret);
888 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
889 ASSERT_EQ(0, ret);
890 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
891 ASSERT_EQ(0, ret);
892 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
893 ASSERT_EQ(0, ret);
894 /* Should work just fine. */
895 EXPECT_EQ(parent, syscall(__NR_getppid));
896 /* getpid() should never return. */
897 EXPECT_EQ(0, syscall(__NR_getpid));
898}
899
900TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
901{
902 pid_t parent;
903 long ret;
904
905 parent = getppid();
906 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
907 ASSERT_EQ(0, ret);
908
909 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
910 ASSERT_EQ(0, ret);
911 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
912 ASSERT_EQ(0, ret);
913 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
914 ASSERT_EQ(0, ret);
915 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
916 ASSERT_EQ(0, ret);
917 /* Should work just fine. */
918 EXPECT_EQ(parent, syscall(__NR_getppid));
919 /* getpid() should never return. */
920 EXPECT_EQ(0, syscall(__NR_getpid));
921}
922
923TEST_F(precedence, errno_is_third)
924{
925 pid_t parent;
926 long ret;
927
928 parent = getppid();
929 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
930 ASSERT_EQ(0, ret);
931
932 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
933 ASSERT_EQ(0, ret);
934 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
935 ASSERT_EQ(0, ret);
936 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
937 ASSERT_EQ(0, ret);
938 /* Should work just fine. */
939 EXPECT_EQ(parent, syscall(__NR_getppid));
940 EXPECT_EQ(0, syscall(__NR_getpid));
941}
942
943TEST_F(precedence, errno_is_third_in_any_order)
944{
945 pid_t parent;
946 long ret;
947
948 parent = getppid();
949 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
950 ASSERT_EQ(0, ret);
951
952 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
953 ASSERT_EQ(0, ret);
954 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
955 ASSERT_EQ(0, ret);
956 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
957 ASSERT_EQ(0, ret);
958 /* Should work just fine. */
959 EXPECT_EQ(parent, syscall(__NR_getppid));
960 EXPECT_EQ(0, syscall(__NR_getpid));
961}
962
963TEST_F(precedence, trace_is_fourth)
964{
965 pid_t parent;
966 long ret;
967
968 parent = getppid();
969 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
970 ASSERT_EQ(0, ret);
971
972 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
973 ASSERT_EQ(0, ret);
974 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
975 ASSERT_EQ(0, ret);
976 /* Should work just fine. */
977 EXPECT_EQ(parent, syscall(__NR_getppid));
978 /* No ptracer */
979 EXPECT_EQ(-1, syscall(__NR_getpid));
980}
981
982TEST_F(precedence, trace_is_fourth_in_any_order)
983{
984 pid_t parent;
985 long ret;
986
987 parent = getppid();
988 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
989 ASSERT_EQ(0, ret);
990
991 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
992 ASSERT_EQ(0, ret);
993 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
994 ASSERT_EQ(0, ret);
995 /* Should work just fine. */
996 EXPECT_EQ(parent, syscall(__NR_getppid));
997 /* No ptracer */
998 EXPECT_EQ(-1, syscall(__NR_getpid));
999}
1000
1001#ifndef PTRACE_O_TRACESECCOMP
1002#define PTRACE_O_TRACESECCOMP 0x00000080
1003#endif
1004
1005/* Catch the Ubuntu 12.04 value error. */
1006#if PTRACE_EVENT_SECCOMP != 7
1007#undef PTRACE_EVENT_SECCOMP
1008#endif
1009
1010#ifndef PTRACE_EVENT_SECCOMP
1011#define PTRACE_EVENT_SECCOMP 7
1012#endif
1013
1014#define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1015bool tracer_running;
1016void tracer_stop(int sig)
1017{
1018 tracer_running = false;
1019}
1020
1021typedef void tracer_func_t(struct __test_metadata *_metadata,
1022 pid_t tracee, int status, void *args);
1023
58d0a862
KC		 1024void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1025 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
c99ee51a
KC		 1026{
1027 int ret = -1;
1028 struct sigaction action = {
1029 .sa_handler = tracer_stop,
1030 };
1031
1032 /* Allow external shutdown. */
1033 tracer_running = true;
1034 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1035
1036 errno = 0;
1037 while (ret == -1 && errno != EINVAL)
1038 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1039 ASSERT_EQ(0, ret) {
1040 kill(tracee, SIGKILL);
1041 }
1042 /* Wait for attach stop */
1043 wait(NULL);
1044
58d0a862
KC		 1045 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1046 PTRACE_O_TRACESYSGOOD :
1047 PTRACE_O_TRACESECCOMP);
c99ee51a
KC		 1048 ASSERT_EQ(0, ret) {
1049 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1050 kill(tracee, SIGKILL);
1051 }
58d0a862
KC		 1052 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1053 tracee, NULL, 0);
1054 ASSERT_EQ(0, ret);
c99ee51a
KC		 1055
1056 /* Unblock the tracee */
1057 ASSERT_EQ(1, write(fd, "A", 1));
1058 ASSERT_EQ(0, close(fd));
1059
1060 /* Run until we're shut down. Must assert to stop execution. */
1061 while (tracer_running) {
1062 int status;
1063
1064 if (wait(&status) != tracee)
1065 continue;
1066 if (WIFSIGNALED(status) || WIFEXITED(status))
1067 /* Child is dead. Time to go. */
1068 return;
1069
58d0a862
KC		 1070 /* Check if this is a seccomp event. */
1071 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
c99ee51a
KC		 1072
1073 tracer_func(_metadata, tracee, status, args);
1074
58d0a862
KC		 1075 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1076 tracee, NULL, 0);
c99ee51a
KC		 1077 ASSERT_EQ(0, ret);
1078 }
1079 /* Directly report the status of our test harness results. */
1080 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1081}
1082
1083/* Common tracer setup/teardown functions. */
1084void cont_handler(int num)
1085{ }
1086pid_t setup_trace_fixture(struct __test_metadata *_metadata,
58d0a862 1087 tracer_func_t func, void *args, bool ptrace_syscall)
c99ee51a
KC		 1088{
1089 char sync;
1090 int pipefd[2];
1091 pid_t tracer_pid;
1092 pid_t tracee = getpid();
1093
1094 /* Setup a pipe for clean synchronization. */
1095 ASSERT_EQ(0, pipe(pipefd));
1096
1097 /* Fork a child which we'll promote to tracer */
1098 tracer_pid = fork();
1099 ASSERT_LE(0, tracer_pid);
1100 signal(SIGALRM, cont_handler);
1101 if (tracer_pid == 0) {
1102 close(pipefd[0]);
58d0a862
KC		 1103 start_tracer(_metadata, pipefd[1], tracee, func, args,
1104 ptrace_syscall);
c99ee51a
KC		 1105 syscall(__NR_exit, 0);
1106 }
1107 close(pipefd[1]);
1108 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1109 read(pipefd[0], &sync, 1);
1110 close(pipefd[0]);
1111
1112 return tracer_pid;
1113}
1114void teardown_trace_fixture(struct __test_metadata *_metadata,
1115 pid_t tracer)
1116{
1117 if (tracer) {
1118 int status;
1119 /*
1120 * Extract the exit code from the other process and
1121 * adopt it for ourselves in case its asserts failed.
1122 */
1123 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1124 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1125 if (WEXITSTATUS(status))
1126 _metadata->passed = 0;
1127 }
1128}
1129
1130/* "poke" tracer arguments and function. */
1131struct tracer_args_poke_t {
1132 unsigned long poke_addr;
1133};
1134
1135void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1136 void *args)
1137{
1138 int ret;
1139 unsigned long msg;
1140 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1141
1142 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1143 EXPECT_EQ(0, ret);
1144 /* If this fails, don't try to recover. */
1145 ASSERT_EQ(0x1001, msg) {
1146 kill(tracee, SIGKILL);
1147 }
1148 /*
1149 * Poke in the message.
1150 * Registers are not touched to try to keep this relatively arch
1151 * agnostic.
1152 */
1153 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1154 EXPECT_EQ(0, ret);
1155}
1156
1157FIXTURE_DATA(TRACE_poke) {
1158 struct sock_fprog prog;
1159 pid_t tracer;
1160 long poked;
1161 struct tracer_args_poke_t tracer_args;
1162};
1163
1164FIXTURE_SETUP(TRACE_poke)
1165{
1166 struct sock_filter filter[] = {
1167 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1168 offsetof(struct seccomp_data, nr)),
1169 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1170 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1171 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1172 };
1173
1174 self->poked = 0;
1175 memset(&self->prog, 0, sizeof(self->prog));
1176 self->prog.filter = malloc(sizeof(filter));
1177 ASSERT_NE(NULL, self->prog.filter);
1178 memcpy(self->prog.filter, filter, sizeof(filter));
1179 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1180
1181 /* Set up tracer args. */
1182 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1183
1184 /* Launch tracer. */
1185 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
58d0a862 1186 &self->tracer_args, false);
c99ee51a
KC		 1187}
1188
1189FIXTURE_TEARDOWN(TRACE_poke)
1190{
1191 teardown_trace_fixture(_metadata, self->tracer);
1192 if (self->prog.filter)
1193 free(self->prog.filter);
1194}
1195
1196TEST_F(TRACE_poke, read_has_side_effects)
1197{
1198 ssize_t ret;
1199
1200 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1201 ASSERT_EQ(0, ret);
1202
1203 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1204 ASSERT_EQ(0, ret);
1205
1206 EXPECT_EQ(0, self->poked);
1207 ret = read(-1, NULL, 0);
1208 EXPECT_EQ(-1, ret);
1209 EXPECT_EQ(0x1001, self->poked);
1210}
1211
1212TEST_F(TRACE_poke, getpid_runs_normally)
1213{
1214 long ret;
1215
1216 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1217 ASSERT_EQ(0, ret);
1218
1219 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1220 ASSERT_EQ(0, ret);
1221
1222 EXPECT_EQ(0, self->poked);
1223 EXPECT_NE(0, syscall(__NR_getpid));
1224 EXPECT_EQ(0, self->poked);
1225}
1226
1227#if defined(__x86_64__)
1228# define ARCH_REGS struct user_regs_struct
1229# define SYSCALL_NUM orig_rax
1230# define SYSCALL_RET rax
1231#elif defined(__i386__)
1232# define ARCH_REGS struct user_regs_struct
1233# define SYSCALL_NUM orig_eax
1234# define SYSCALL_RET eax
1235#elif defined(__arm__)
1236# define ARCH_REGS struct pt_regs
1237# define SYSCALL_NUM ARM_r7
1238# define SYSCALL_RET ARM_r0
1239#elif defined(__aarch64__)
1240# define ARCH_REGS struct user_pt_regs
1241# define SYSCALL_NUM regs[8]
1242# define SYSCALL_RET regs[0]
64e2a42b
HD		 1243#elif defined(__hppa__)
1244# define ARCH_REGS struct user_regs_struct
1245# define SYSCALL_NUM gr[20]
1246# define SYSCALL_RET gr[28]
5d83c2b3
ME		 1247#elif defined(__powerpc__)
1248# define ARCH_REGS struct pt_regs
1249# define SYSCALL_NUM gpr[0]
1250# define SYSCALL_RET gpr[3]
b623c4da
KC		 1251#elif defined(__s390__)
1252# define ARCH_REGS s390_regs
1253# define SYSCALL_NUM gprs[2]
1254# define SYSCALL_RET gprs[2]
0ce105bf
MR		 1255#elif defined(__mips__)
1256# define ARCH_REGS struct pt_regs
1257# define SYSCALL_NUM regs[2]
1258# define SYSCALL_SYSCALL_NUM regs[4]
1259# define SYSCALL_RET regs[2]
1260# define SYSCALL_NUM_RET_SHARE_REG
c99ee51a
KC		 1261#else
1262# error "Do not know how to find your architecture's registers and syscalls"
1263#endif
1264
4a0b8807
MS		 1265/* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1266 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1267 */
0ce105bf 1268#if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
4a0b8807
MS		 1269#define HAVE_GETREGS
1270#endif
1271
c99ee51a
KC		 1272/* Architecture-specific syscall fetching routine. */
1273int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1274{
c99ee51a 1275 ARCH_REGS regs;
4a0b8807
MS		 1276#ifdef HAVE_GETREGS
1277 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
1278 TH_LOG("PTRACE_GETREGS failed");
1279 return -1;
1280 }
1281#else
1282 struct iovec iov;
c99ee51a
KC		 1283
1284 iov.iov_base = &regs;
1285 iov.iov_len = sizeof(regs);
1286 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1287 TH_LOG("PTRACE_GETREGSET failed");
1288 return -1;
1289 }
4a0b8807 1290#endif
c99ee51a 1291
0ce105bf
MR		 1292#if defined(__mips__)
1293 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1294 return regs.SYSCALL_SYSCALL_NUM;
1295#endif
c99ee51a
KC		 1296 return regs.SYSCALL_NUM;
1297}
1298
1299/* Architecture-specific syscall changing routine. */
1300void change_syscall(struct __test_metadata *_metadata,
1301 pid_t tracee, int syscall)
1302{
c99ee51a
KC		 1303 int ret;
1304 ARCH_REGS regs;
4a0b8807
MS		 1305#ifdef HAVE_GETREGS
1306 ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
1307#else
1308 struct iovec iov;
c99ee51a
KC		 1309 iov.iov_base = &regs;
1310 iov.iov_len = sizeof(regs);
1311 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
4a0b8807 1312#endif
c99ee51a
KC		 1313 EXPECT_EQ(0, ret);
1314
256d0afb 1315#if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
64e2a42b 1316 defined(__s390__) || defined(__hppa__)
c99ee51a
KC		 1317 {
1318 regs.SYSCALL_NUM = syscall;
1319 }
0ce105bf
MR		 1320#elif defined(__mips__)
1321 {
1322 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1323 regs.SYSCALL_SYSCALL_NUM = syscall;
1324 else
1325 regs.SYSCALL_NUM = syscall;
1326 }
c99ee51a
KC		 1327
1328#elif defined(__arm__)
1329# ifndef PTRACE_SET_SYSCALL
1330# define PTRACE_SET_SYSCALL 23
1331# endif
1332 {
1333 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1334 EXPECT_EQ(0, ret);
1335 }
1336
256d0afb
KC		 1337#elif defined(__aarch64__)
1338# ifndef NT_ARM_SYSTEM_CALL
1339# define NT_ARM_SYSTEM_CALL 0x404
1340# endif
1341 {
1342 iov.iov_base = &syscall;
1343 iov.iov_len = sizeof(syscall);
1344 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1345 &iov);
1346 EXPECT_EQ(0, ret);
1347 }
1348
c99ee51a
KC		 1349#else
1350 ASSERT_EQ(1, 0) {
1351 TH_LOG("How is the syscall changed on this architecture?");
1352 }
1353#endif
1354
1355 /* If syscall is skipped, change return value. */
1356 if (syscall == -1)
0ce105bf
MR		 1357#ifdef SYSCALL_NUM_RET_SHARE_REG
1358 TH_LOG("Can't modify syscall return on this architecture");
1359#else
c99ee51a 1360 regs.SYSCALL_RET = 1;
0ce105bf 1361#endif
c99ee51a 1362
4a0b8807
MS		 1363#ifdef HAVE_GETREGS
1364 ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
1365#else
256d0afb
KC		 1366 iov.iov_base = &regs;
1367 iov.iov_len = sizeof(regs);
c99ee51a 1368 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
4a0b8807 1369#endif
c99ee51a
KC		 1370 EXPECT_EQ(0, ret);
1371}
1372
1373void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1374 int status, void *args)
1375{
1376 int ret;
1377 unsigned long msg;
1378
1379 /* Make sure we got the right message. */
1380 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1381 EXPECT_EQ(0, ret);
1382
b623c4da 1383 /* Validate and take action on expected syscalls. */
c99ee51a
KC		 1384 switch (msg) {
1385 case 0x1002:
1386 /* change getpid to getppid. */
b623c4da 1387 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
c99ee51a
KC		 1388 change_syscall(_metadata, tracee, __NR_getppid);
1389 break;
1390 case 0x1003:
1391 /* skip gettid. */
b623c4da 1392 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
c99ee51a
KC		 1393 change_syscall(_metadata, tracee, -1);
1394 break;
1395 case 0x1004:
1396 /* do nothing (allow getppid) */
b623c4da 1397 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
c99ee51a
KC		 1398 break;
1399 default:
1400 EXPECT_EQ(0, msg) {
1401 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1402 kill(tracee, SIGKILL);
1403 }
1404 }
1405
1406}
1407
58d0a862
KC		 1408void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1409 int status, void *args)
1410{
1411 int ret, nr;
1412 unsigned long msg;
1413 static bool entry;
1414
1415 /* Make sure we got an empty message. */
1416 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1417 EXPECT_EQ(0, ret);
1418 EXPECT_EQ(0, msg);
1419
1420 /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */
1421 entry = !entry;
1422 if (!entry)
1423 return;
1424
1425 nr = get_syscall(_metadata, tracee);
1426
1427 if (nr == __NR_getpid)
1428 change_syscall(_metadata, tracee, __NR_getppid);
1429}
1430
c99ee51a
KC		 1431FIXTURE_DATA(TRACE_syscall) {
1432 struct sock_fprog prog;
1433 pid_t tracer, mytid, mypid, parent;
1434};
1435
1436FIXTURE_SETUP(TRACE_syscall)
1437{
1438 struct sock_filter filter[] = {
1439 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1440 offsetof(struct seccomp_data, nr)),
1441 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1442 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1443 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1444 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1445 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1446 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1447 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1448 };
1449
1450 memset(&self->prog, 0, sizeof(self->prog));
1451 self->prog.filter = malloc(sizeof(filter));
1452 ASSERT_NE(NULL, self->prog.filter);
1453 memcpy(self->prog.filter, filter, sizeof(filter));
1454 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1455
1456 /* Prepare some testable syscall results. */
1457 self->mytid = syscall(__NR_gettid);
1458 ASSERT_GT(self->mytid, 0);
1459 ASSERT_NE(self->mytid, 1) {
1460 TH_LOG("Running this test as init is not supported. :)");
1461 }
1462
1463 self->mypid = getpid();
1464 ASSERT_GT(self->mypid, 0);
1465 ASSERT_EQ(self->mytid, self->mypid);
1466
1467 self->parent = getppid();
1468 ASSERT_GT(self->parent, 0);
1469 ASSERT_NE(self->parent, self->mypid);
1470
1471 /* Launch tracer. */
58d0a862
KC		 1472 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1473 false);
c99ee51a
KC		 1474}
1475
1476FIXTURE_TEARDOWN(TRACE_syscall)
1477{
1478 teardown_trace_fixture(_metadata, self->tracer);
1479 if (self->prog.filter)
1480 free(self->prog.filter);
1481}
1482
1483TEST_F(TRACE_syscall, syscall_allowed)
1484{
1485 long ret;
1486
1487 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1488 ASSERT_EQ(0, ret);
1489
1490 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1491 ASSERT_EQ(0, ret);
1492
1493 /* getppid works as expected (no changes). */
1494 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1495 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1496}
1497
1498TEST_F(TRACE_syscall, syscall_redirected)
1499{
1500 long ret;
1501
1502 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1503 ASSERT_EQ(0, ret);
1504
1505 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1506 ASSERT_EQ(0, ret);
1507
1508 /* getpid has been redirected to getppid as expected. */
1509 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1510 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1511}
1512
1513TEST_F(TRACE_syscall, syscall_dropped)
1514{
1515 long ret;
1516
1517 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1518 ASSERT_EQ(0, ret);
1519
1520 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1521 ASSERT_EQ(0, ret);
1522
0ce105bf
MR		 1523#ifdef SYSCALL_NUM_RET_SHARE_REG
1524 /* gettid has been skipped */
1525 EXPECT_EQ(-1, syscall(__NR_gettid));
1526#else
c99ee51a
KC		 1527 /* gettid has been skipped and an altered return value stored. */
1528 EXPECT_EQ(1, syscall(__NR_gettid));
0ce105bf 1529#endif
c99ee51a
KC		 1530 EXPECT_NE(self->mytid, syscall(__NR_gettid));
1531}
1532
58d0a862
KC		 1533TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1534{
1535 struct sock_filter filter[] = {
1536 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1537 offsetof(struct seccomp_data, nr)),
1538 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1539 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1540 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1541 };
1542 struct sock_fprog prog = {
1543 .len = (unsigned short)ARRAY_SIZE(filter),
1544 .filter = filter,
1545 };
1546 long ret;
1547
1548 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1549 ASSERT_EQ(0, ret);
1550
1551 /* Install fixture filter. */
1552 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1553 ASSERT_EQ(0, ret);
1554
1555 /* Install "errno on getppid" filter. */
1556 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1557 ASSERT_EQ(0, ret);
1558
1559 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1560 EXPECT_EQ(-1, syscall(__NR_getpid));
1561 EXPECT_EQ(EPERM, errno);
1562}
1563
1564TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1565{
1566 struct sock_filter filter[] = {
1567 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1568 offsetof(struct seccomp_data, nr)),
1569 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1570 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1571 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1572 };
1573 struct sock_fprog prog = {
1574 .len = (unsigned short)ARRAY_SIZE(filter),
1575 .filter = filter,
1576 };
1577 long ret;
1578
1579 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1580 ASSERT_EQ(0, ret);
1581
1582 /* Install fixture filter. */
1583 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1584 ASSERT_EQ(0, ret);
1585
1586 /* Install "death on getppid" filter. */
1587 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1588 ASSERT_EQ(0, ret);
1589
1590 /* Tracer will redirect getpid to getppid, and we should die. */
1591 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1592}
1593
1594TEST_F(TRACE_syscall, skip_after_ptrace)
1595{
1596 struct sock_filter filter[] = {
1597 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1598 offsetof(struct seccomp_data, nr)),
1599 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1600 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1601 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1602 };
1603 struct sock_fprog prog = {
1604 .len = (unsigned short)ARRAY_SIZE(filter),
1605 .filter = filter,
1606 };
1607 long ret;
1608
1609 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1610 teardown_trace_fixture(_metadata, self->tracer);
1611 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1612 true);
1613
1614 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1615 ASSERT_EQ(0, ret);
1616
1617 /* Install "errno on getppid" filter. */
1618 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1619 ASSERT_EQ(0, ret);
1620
1621 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1622 EXPECT_EQ(-1, syscall(__NR_getpid));
1623 EXPECT_EQ(EPERM, errno);
1624}
1625
1626TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
1627{
1628 struct sock_filter filter[] = {
1629 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1630 offsetof(struct seccomp_data, nr)),
1631 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1632 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1633 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1634 };
1635 struct sock_fprog prog = {
1636 .len = (unsigned short)ARRAY_SIZE(filter),
1637 .filter = filter,
1638 };
1639 long ret;
1640
1641 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1642 teardown_trace_fixture(_metadata, self->tracer);
1643 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1644 true);
1645
1646 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1647 ASSERT_EQ(0, ret);
1648
1649 /* Install "death on getppid" filter. */
1650 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1651 ASSERT_EQ(0, ret);
1652
1653 /* Tracer will redirect getpid to getppid, and we should die. */
1654 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1655}
1656
c99ee51a
KC		 1657#ifndef __NR_seccomp
1658# if defined(__i386__)
1659# define __NR_seccomp 354
1660# elif defined(__x86_64__)
1661# define __NR_seccomp 317
1662# elif defined(__arm__)
1663# define __NR_seccomp 383
1664# elif defined(__aarch64__)
1665# define __NR_seccomp 277
64e2a42b
HD		 1666# elif defined(__hppa__)
1667# define __NR_seccomp 338
5d83c2b3
ME		 1668# elif defined(__powerpc__)
1669# define __NR_seccomp 358
b623c4da
KC		 1670# elif defined(__s390__)
1671# define __NR_seccomp 348
c99ee51a
KC		 1672# else
1673# warning "seccomp syscall number unknown for this architecture"
1674# define __NR_seccomp 0xffff
1675# endif
1676#endif
1677
1678#ifndef SECCOMP_SET_MODE_STRICT
1679#define SECCOMP_SET_MODE_STRICT 0
1680#endif
1681
1682#ifndef SECCOMP_SET_MODE_FILTER
1683#define SECCOMP_SET_MODE_FILTER 1
1684#endif
1685
6c045d07
MS		 1686#ifndef SECCOMP_FILTER_FLAG_TSYNC
1687#define SECCOMP_FILTER_FLAG_TSYNC 1
c99ee51a
KC		 1688#endif
1689
1690#ifndef seccomp
505ce68c 1691int seccomp(unsigned int op, unsigned int flags, void *args)
c99ee51a
KC		 1692{
1693 errno = 0;
505ce68c 1694 return syscall(__NR_seccomp, op, flags, args);
c99ee51a
KC		 1695}
1696#endif
1697
1698TEST(seccomp_syscall)
1699{
1700 struct sock_filter filter[] = {
1701 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1702 };
1703 struct sock_fprog prog = {
1704 .len = (unsigned short)ARRAY_SIZE(filter),
1705 .filter = filter,
1706 };
1707 long ret;
1708
1709 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1710 ASSERT_EQ(0, ret) {
1711 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1712 }
1713
1714 /* Reject insane operation. */
1715 ret = seccomp(-1, 0, &prog);
b623c4da
KC		 1716 ASSERT_NE(ENOSYS, errno) {
1717 TH_LOG("Kernel does not support seccomp syscall!");
1718 }
c99ee51a
KC		 1719 EXPECT_EQ(EINVAL, errno) {
1720 TH_LOG("Did not reject crazy op value!");
1721 }
1722
1723 /* Reject strict with flags or pointer. */
1724 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
1725 EXPECT_EQ(EINVAL, errno) {
1726 TH_LOG("Did not reject mode strict with flags!");
1727 }
1728 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
1729 EXPECT_EQ(EINVAL, errno) {
1730 TH_LOG("Did not reject mode strict with uargs!");
1731 }
1732
1733 /* Reject insane args for filter. */
1734 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
1735 EXPECT_EQ(EINVAL, errno) {
1736 TH_LOG("Did not reject crazy filter flags!");
1737 }
1738 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
1739 EXPECT_EQ(EFAULT, errno) {
1740 TH_LOG("Did not reject NULL filter!");
1741 }
1742
1743 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1744 EXPECT_EQ(0, errno) {
1745 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
1746 strerror(errno));
1747 }
1748}
1749
1750TEST(seccomp_syscall_mode_lock)
1751{
1752 struct sock_filter filter[] = {
1753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1754 };
1755 struct sock_fprog prog = {
1756 .len = (unsigned short)ARRAY_SIZE(filter),
1757 .filter = filter,
1758 };
1759 long ret;
1760
1761 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1762 ASSERT_EQ(0, ret) {
1763 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1764 }
1765
1766 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
b623c4da
KC		 1767 ASSERT_NE(ENOSYS, errno) {
1768 TH_LOG("Kernel does not support seccomp syscall!");
1769 }
c99ee51a
KC		 1770 EXPECT_EQ(0, ret) {
1771 TH_LOG("Could not install filter!");
1772 }
1773
1774 /* Make sure neither entry point will switch to strict. */
1775 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
1776 EXPECT_EQ(EINVAL, errno) {
1777 TH_LOG("Switched to mode strict!");
1778 }
1779
1780 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
1781 EXPECT_EQ(EINVAL, errno) {
1782 TH_LOG("Switched to mode strict!");
1783 }
1784}
1785
1786TEST(TSYNC_first)
1787{
1788 struct sock_filter filter[] = {
1789 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1790 };
1791 struct sock_fprog prog = {
1792 .len = (unsigned short)ARRAY_SIZE(filter),
1793 .filter = filter,
1794 };
1795 long ret;
1796
1797 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1798 ASSERT_EQ(0, ret) {
1799 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1800 }
1801
6c045d07 1802 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a 1803 &prog);
b623c4da
KC		 1804 ASSERT_NE(ENOSYS, errno) {
1805 TH_LOG("Kernel does not support seccomp syscall!");
1806 }
c99ee51a
KC		 1807 EXPECT_EQ(0, ret) {
1808 TH_LOG("Could not install initial filter with TSYNC!");
1809 }
1810}
1811
1812#define TSYNC_SIBLINGS 2
1813struct tsync_sibling {
1814 pthread_t tid;
1815 pid_t system_tid;
1816 sem_t *started;
1817 pthread_cond_t *cond;
1818 pthread_mutex_t *mutex;
1819 int diverge;
1820 int num_waits;
1821 struct sock_fprog *prog;
1822 struct __test_metadata *metadata;
1823};
1824
1825FIXTURE_DATA(TSYNC) {
1826 struct sock_fprog root_prog, apply_prog;
1827 struct tsync_sibling sibling[TSYNC_SIBLINGS];
1828 sem_t started;
1829 pthread_cond_t cond;
1830 pthread_mutex_t mutex;
1831 int sibling_count;
1832};
1833
1834FIXTURE_SETUP(TSYNC)
1835{
1836 struct sock_filter root_filter[] = {
1837 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1838 };
1839 struct sock_filter apply_filter[] = {
1840 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1841 offsetof(struct seccomp_data, nr)),
1842 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1843 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1844 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1845 };
1846
1847 memset(&self->root_prog, 0, sizeof(self->root_prog));
1848 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
1849 memset(&self->sibling, 0, sizeof(self->sibling));
1850 self->root_prog.filter = malloc(sizeof(root_filter));
1851 ASSERT_NE(NULL, self->root_prog.filter);
1852 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
1853 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
1854
1855 self->apply_prog.filter = malloc(sizeof(apply_filter));
1856 ASSERT_NE(NULL, self->apply_prog.filter);
1857 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
1858 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
1859
1860 self->sibling_count = 0;
1861 pthread_mutex_init(&self->mutex, NULL);
1862 pthread_cond_init(&self->cond, NULL);
1863 sem_init(&self->started, 0, 0);
1864 self->sibling[0].tid = 0;
1865 self->sibling[0].cond = &self->cond;
1866 self->sibling[0].started = &self->started;
1867 self->sibling[0].mutex = &self->mutex;
1868 self->sibling[0].diverge = 0;
1869 self->sibling[0].num_waits = 1;
1870 self->sibling[0].prog = &self->root_prog;
1871 self->sibling[0].metadata = _metadata;
1872 self->sibling[1].tid = 0;
1873 self->sibling[1].cond = &self->cond;
1874 self->sibling[1].started = &self->started;
1875 self->sibling[1].mutex = &self->mutex;
1876 self->sibling[1].diverge = 0;
1877 self->sibling[1].prog = &self->root_prog;
1878 self->sibling[1].num_waits = 1;
1879 self->sibling[1].metadata = _metadata;
1880}
1881
1882FIXTURE_TEARDOWN(TSYNC)
1883{
1884 int sib = 0;
1885
1886 if (self->root_prog.filter)
1887 free(self->root_prog.filter);
1888 if (self->apply_prog.filter)
1889 free(self->apply_prog.filter);
1890
1891 for ( ; sib < self->sibling_count; ++sib) {
1892 struct tsync_sibling *s = &self->sibling[sib];
1893 void *status;
1894
1895 if (!s->tid)
1896 continue;
1897 if (pthread_kill(s->tid, 0)) {
1898 pthread_cancel(s->tid);
1899 pthread_join(s->tid, &status);
1900 }
1901 }
1902 pthread_mutex_destroy(&self->mutex);
1903 pthread_cond_destroy(&self->cond);
1904 sem_destroy(&self->started);
1905}
1906
1907void *tsync_sibling(void *data)
1908{
1909 long ret = 0;
1910 struct tsync_sibling *me = data;
1911
1912 me->system_tid = syscall(__NR_gettid);
1913
1914 pthread_mutex_lock(me->mutex);
1915 if (me->diverge) {
1916 /* Just re-apply the root prog to fork the tree */
1917 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
1918 me->prog, 0, 0);
1919 }
1920 sem_post(me->started);
1921 /* Return outside of started so parent notices failures. */
1922 if (ret) {
1923 pthread_mutex_unlock(me->mutex);
1924 return (void *)SIBLING_EXIT_FAILURE;
1925 }
1926 do {
1927 pthread_cond_wait(me->cond, me->mutex);
1928 me->num_waits = me->num_waits - 1;
1929 } while (me->num_waits);
1930 pthread_mutex_unlock(me->mutex);
1931
1932 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
1933 if (!ret)
1934 return (void *)SIBLING_EXIT_NEWPRIVS;
1935 read(0, NULL, 0);
1936 return (void *)SIBLING_EXIT_UNKILLED;
1937}
1938
1939void tsync_start_sibling(struct tsync_sibling *sibling)
1940{
1941 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
1942}
1943
1944TEST_F(TSYNC, siblings_fail_prctl)
1945{
1946 long ret;
1947 void *status;
1948 struct sock_filter filter[] = {
1949 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1950 offsetof(struct seccomp_data, nr)),
1951 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
1952 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
1953 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1954 };
1955 struct sock_fprog prog = {
1956 .len = (unsigned short)ARRAY_SIZE(filter),
1957 .filter = filter,
1958 };
1959
1960 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1961 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1962 }
1963
1964 /* Check prctl failure detection by requesting sib 0 diverge. */
1965 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
b623c4da
KC		 1966 ASSERT_NE(ENOSYS, errno) {
1967 TH_LOG("Kernel does not support seccomp syscall!");
1968 }
c99ee51a
KC		 1969 ASSERT_EQ(0, ret) {
1970 TH_LOG("setting filter failed");
1971 }
1972
1973 self->sibling[0].diverge = 1;
1974 tsync_start_sibling(&self->sibling[0]);
1975 tsync_start_sibling(&self->sibling[1]);
1976
1977 while (self->sibling_count < TSYNC_SIBLINGS) {
1978 sem_wait(&self->started);
1979 self->sibling_count++;
1980 }
1981
1982 /* Signal the threads to clean up*/
1983 pthread_mutex_lock(&self->mutex);
1984 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1985 TH_LOG("cond broadcast non-zero");
1986 }
1987 pthread_mutex_unlock(&self->mutex);
1988
1989 /* Ensure diverging sibling failed to call prctl. */
1990 pthread_join(self->sibling[0].tid, &status);
1991 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
1992 pthread_join(self->sibling[1].tid, &status);
1993 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1994}
1995
1996TEST_F(TSYNC, two_siblings_with_ancestor)
1997{
1998 long ret;
1999 void *status;
2000
2001 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2002 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2003 }
2004
2005 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
b623c4da
KC		 2006 ASSERT_NE(ENOSYS, errno) {
2007 TH_LOG("Kernel does not support seccomp syscall!");
2008 }
c99ee51a
KC		 2009 ASSERT_EQ(0, ret) {
2010 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2011 }
2012 tsync_start_sibling(&self->sibling[0]);
2013 tsync_start_sibling(&self->sibling[1]);
2014
2015 while (self->sibling_count < TSYNC_SIBLINGS) {
2016 sem_wait(&self->started);
2017 self->sibling_count++;
2018 }
2019
6c045d07 2020 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a
KC		 2021 &self->apply_prog);
2022 ASSERT_EQ(0, ret) {
2023 TH_LOG("Could install filter on all threads!");
2024 }
2025 /* Tell the siblings to test the policy */
2026 pthread_mutex_lock(&self->mutex);
2027 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2028 TH_LOG("cond broadcast non-zero");
2029 }
2030 pthread_mutex_unlock(&self->mutex);
2031 /* Ensure they are both killed and don't exit cleanly. */
2032 pthread_join(self->sibling[0].tid, &status);
2033 EXPECT_EQ(0x0, (long)status);
2034 pthread_join(self->sibling[1].tid, &status);
2035 EXPECT_EQ(0x0, (long)status);
2036}
2037
2038TEST_F(TSYNC, two_sibling_want_nnp)
2039{
2040 void *status;
2041
2042 /* start siblings before any prctl() operations */
2043 tsync_start_sibling(&self->sibling[0]);
2044 tsync_start_sibling(&self->sibling[1]);
2045 while (self->sibling_count < TSYNC_SIBLINGS) {
2046 sem_wait(&self->started);
2047 self->sibling_count++;
2048 }
2049
2050 /* Tell the siblings to test no policy */
2051 pthread_mutex_lock(&self->mutex);
2052 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2053 TH_LOG("cond broadcast non-zero");
2054 }
2055 pthread_mutex_unlock(&self->mutex);
2056
2057 /* Ensure they are both upset about lacking nnp. */
2058 pthread_join(self->sibling[0].tid, &status);
2059 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2060 pthread_join(self->sibling[1].tid, &status);
2061 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2062}
2063
2064TEST_F(TSYNC, two_siblings_with_no_filter)
2065{
2066 long ret;
2067 void *status;
2068
2069 /* start siblings before any prctl() operations */
2070 tsync_start_sibling(&self->sibling[0]);
2071 tsync_start_sibling(&self->sibling[1]);
2072 while (self->sibling_count < TSYNC_SIBLINGS) {
2073 sem_wait(&self->started);
2074 self->sibling_count++;
2075 }
2076
2077 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2078 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2079 }
2080
6c045d07 2081 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a 2082 &self->apply_prog);
b623c4da
KC		 2083 ASSERT_NE(ENOSYS, errno) {
2084 TH_LOG("Kernel does not support seccomp syscall!");
2085 }
c99ee51a
KC		 2086 ASSERT_EQ(0, ret) {
2087 TH_LOG("Could install filter on all threads!");
2088 }
2089
2090 /* Tell the siblings to test the policy */
2091 pthread_mutex_lock(&self->mutex);
2092 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2093 TH_LOG("cond broadcast non-zero");
2094 }
2095 pthread_mutex_unlock(&self->mutex);
2096
2097 /* Ensure they are both killed and don't exit cleanly. */
2098 pthread_join(self->sibling[0].tid, &status);
2099 EXPECT_EQ(0x0, (long)status);
2100 pthread_join(self->sibling[1].tid, &status);
2101 EXPECT_EQ(0x0, (long)status);
2102}
2103
2104TEST_F(TSYNC, two_siblings_with_one_divergence)
2105{
2106 long ret;
2107 void *status;
2108
2109 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2110 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2111 }
2112
2113 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
b623c4da
KC		 2114 ASSERT_NE(ENOSYS, errno) {
2115 TH_LOG("Kernel does not support seccomp syscall!");
2116 }
c99ee51a
KC		 2117 ASSERT_EQ(0, ret) {
2118 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2119 }
2120 self->sibling[0].diverge = 1;
2121 tsync_start_sibling(&self->sibling[0]);
2122 tsync_start_sibling(&self->sibling[1]);
2123
2124 while (self->sibling_count < TSYNC_SIBLINGS) {
2125 sem_wait(&self->started);
2126 self->sibling_count++;
2127 }
2128
6c045d07 2129 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a
KC		 2130 &self->apply_prog);
2131 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2132 TH_LOG("Did not fail on diverged sibling.");
2133 }
2134
2135 /* Wake the threads */
2136 pthread_mutex_lock(&self->mutex);
2137 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2138 TH_LOG("cond broadcast non-zero");
2139 }
2140 pthread_mutex_unlock(&self->mutex);
2141
2142 /* Ensure they are both unkilled. */
2143 pthread_join(self->sibling[0].tid, &status);
2144 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2145 pthread_join(self->sibling[1].tid, &status);
2146 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2147}
2148
2149TEST_F(TSYNC, two_siblings_not_under_filter)
2150{
2151 long ret, sib;
2152 void *status;
2153
2154 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2155 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2156 }
2157
2158 /*
2159 * Sibling 0 will have its own seccomp policy
2160 * and Sibling 1 will not be under seccomp at
2161 * all. Sibling 1 will enter seccomp and 0
2162 * will cause failure.
2163 */
2164 self->sibling[0].diverge = 1;
2165 tsync_start_sibling(&self->sibling[0]);
2166 tsync_start_sibling(&self->sibling[1]);
2167
2168 while (self->sibling_count < TSYNC_SIBLINGS) {
2169 sem_wait(&self->started);
2170 self->sibling_count++;
2171 }
2172
2173 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
b623c4da
KC		 2174 ASSERT_NE(ENOSYS, errno) {
2175 TH_LOG("Kernel does not support seccomp syscall!");
2176 }
c99ee51a
KC		 2177 ASSERT_EQ(0, ret) {
2178 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2179 }
2180
6c045d07 2181 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a
KC		 2182 &self->apply_prog);
2183 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2184 TH_LOG("Did not fail on diverged sibling.");
2185 }
2186 sib = 1;
2187 if (ret == self->sibling[0].system_tid)
2188 sib = 0;
2189
2190 pthread_mutex_lock(&self->mutex);
2191
2192 /* Increment the other siblings num_waits so we can clean up
2193 * the one we just saw.
2194 */
2195 self->sibling[!sib].num_waits += 1;
2196
2197 /* Signal the thread to clean up*/
2198 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2199 TH_LOG("cond broadcast non-zero");
2200 }
2201 pthread_mutex_unlock(&self->mutex);
2202 pthread_join(self->sibling[sib].tid, &status);
2203 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2204 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2205 while (!kill(self->sibling[sib].system_tid, 0))
2206 sleep(0.1);
2207 /* Switch to the remaining sibling */
2208 sib = !sib;
2209
6c045d07 2210 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a
KC		 2211 &self->apply_prog);
2212 ASSERT_EQ(0, ret) {
2213 TH_LOG("Expected the remaining sibling to sync");
2214 };
2215
2216 pthread_mutex_lock(&self->mutex);
2217
2218 /* If remaining sibling didn't have a chance to wake up during
2219 * the first broadcast, manually reduce the num_waits now.
2220 */
2221 if (self->sibling[sib].num_waits > 1)
2222 self->sibling[sib].num_waits = 1;
2223 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2224 TH_LOG("cond broadcast non-zero");
2225 }
2226 pthread_mutex_unlock(&self->mutex);
2227 pthread_join(self->sibling[sib].tid, &status);
2228 EXPECT_EQ(0, (long)status);
2229 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2230 while (!kill(self->sibling[sib].system_tid, 0))
2231 sleep(0.1);
2232
6c045d07 2233 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
c99ee51a
KC		 2234 &self->apply_prog);
2235 ASSERT_EQ(0, ret); /* just us chickens */
2236}
2237
2238/* Make sure restarted syscalls are seen directly as "restart_syscall". */
2239TEST(syscall_restart)
2240{
2241 long ret;
2242 unsigned long msg;
2243 pid_t child_pid;
2244 int pipefd[2];
2245 int status;
2246 siginfo_t info = { };
2247 struct sock_filter filter[] = {
2248 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2249 offsetof(struct seccomp_data, nr)),
2250
2251#ifdef __NR_sigreturn
2252 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2253#endif
2254 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2255 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2256 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
256d0afb 2257 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
c99ee51a
KC		 2258 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2259
2260 /* Allow __NR_write for easy logging. */
2261 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2262 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2263 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
256d0afb
KC		 2264 /* The nanosleep jump target. */
2265 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2266 /* The restart_syscall jump target. */
2267 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
c99ee51a
KC		 2268 };
2269 struct sock_fprog prog = {
2270 .len = (unsigned short)ARRAY_SIZE(filter),
2271 .filter = filter,
2272 };
256d0afb
KC		 2273#if defined(__arm__)
2274 struct utsname utsbuf;
2275#endif
c99ee51a
KC		 2276
2277 ASSERT_EQ(0, pipe(pipefd));
2278
2279 child_pid = fork();
2280 ASSERT_LE(0, child_pid);
2281 if (child_pid == 0) {
2282 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2283 char buf = ' ';
256d0afb 2284 struct timespec timeout = { };
c99ee51a
KC		 2285
2286 /* Attach parent as tracer and stop. */
2287 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2288 EXPECT_EQ(0, raise(SIGSTOP));
2289
2290 EXPECT_EQ(0, close(pipefd[1]));
2291
2292 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2293 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2294 }
2295
2296 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2297 EXPECT_EQ(0, ret) {
2298 TH_LOG("Failed to install filter!");
2299 }
2300
2301 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2302 TH_LOG("Failed to read() sync from parent");
2303 }
2304 EXPECT_EQ('.', buf) {
2305 TH_LOG("Failed to get sync data from read()");
2306 }
2307
256d0afb
KC		 2308 /* Start nanosleep to be interrupted. */
2309 timeout.tv_sec = 1;
c99ee51a 2310 errno = 0;
256d0afb
KC		 2311 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2312 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
c99ee51a
KC		 2313 }
2314
2315 /* Read final sync from parent. */
2316 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2317 TH_LOG("Failed final read() from parent");
2318 }
2319 EXPECT_EQ('!', buf) {
2320 TH_LOG("Failed to get final data from read()");
2321 }
2322
2323 /* Directly report the status of our test harness results. */
2324 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2325 : EXIT_FAILURE);
2326 }
2327 EXPECT_EQ(0, close(pipefd[0]));
2328
2329 /* Attach to child, setup options, and release. */
2330 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2331 ASSERT_EQ(true, WIFSTOPPED(status));
2332 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2333 PTRACE_O_TRACESECCOMP));
2334 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2335 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2336
256d0afb 2337 /* Wait for nanosleep() to start. */
c99ee51a
KC		 2338 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2339 ASSERT_EQ(true, WIFSTOPPED(status));
2340 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2341 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2342 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2343 ASSERT_EQ(0x100, msg);
256d0afb 2344 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
c99ee51a
KC		 2345
2346 /* Might as well check siginfo for sanity while we're here. */
2347 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2348 ASSERT_EQ(SIGTRAP, info.si_signo);
2349 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2350 EXPECT_EQ(0, info.si_errno);
2351 EXPECT_EQ(getuid(), info.si_uid);
2352 /* Verify signal delivery came from child (seccomp-triggered). */
2353 EXPECT_EQ(child_pid, info.si_pid);
2354
256d0afb 2355 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
c99ee51a
KC		 2356 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2357 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2358 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2359 ASSERT_EQ(true, WIFSTOPPED(status));
2360 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2361 /* Verify signal delivery came from parent now. */
2362 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2363 EXPECT_EQ(getpid(), info.si_pid);
2364
256d0afb 2365 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
c99ee51a
KC		 2366 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2367 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2368 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2369 ASSERT_EQ(true, WIFSTOPPED(status));
2370 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2371 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2372
2373 /* Wait for restart_syscall() to start. */
2374 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2375 ASSERT_EQ(true, WIFSTOPPED(status));
2376 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2377 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2378 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
256d0afb 2379
c99ee51a
KC		 2380 ASSERT_EQ(0x200, msg);
2381 ret = get_syscall(_metadata, child_pid);
2382#if defined(__arm__)
256d0afb
KC		 2383 /*
2384 * FIXME:
2385 * - native ARM registers do NOT expose true syscall.
2386 * - compat ARM registers on ARM64 DO expose true syscall.
2387 */
2388 ASSERT_EQ(0, uname(&utsbuf));
2389 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2390 EXPECT_EQ(__NR_nanosleep, ret);
2391 } else
c99ee51a 2392#endif
256d0afb
KC		 2393 {
2394 EXPECT_EQ(__NR_restart_syscall, ret);
2395 }
c99ee51a 2396
256d0afb 2397 /* Write again to end test. */
c99ee51a
KC		 2398 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2399 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2400 EXPECT_EQ(0, close(pipefd[1]));
2401
2402 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2403 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2404 _metadata->passed = 0;
2405}
2406
2407/*
2408 * TODO:
2409 * - add microbenchmarks
2410 * - expand NNP testing
2411 * - better arch-specific TRACE and TRAP handlers.
2412 * - endianness checking when appropriate
2413 * - 64-bit arg prodding
2414 * - arch value testing (x86 modes especially)
2415 * - ...
2416 */
2417
2418TEST_HARNESS_MAIN
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