?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / tools / testing / selftests / seccomp / seccomp_bpf.c
blobee1b727ede045dfd920bf319d3729efd217ef137
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #define _GNU_SOURCE
9 #include <sys/types.h>
10
11 /*
12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
13 * we need to use the kernel's siginfo.h file and trick glibc
14 * into accepting it.
15 */
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
23 #include <errno.h>
24 #include <linux/filter.h>
25 #include <sys/prctl.h>
26 #include <sys/ptrace.h>
27 #include <sys/user.h>
28 #include <linux/prctl.h>
29 #include <linux/ptrace.h>
30 #include <linux/seccomp.h>
31 #include <pthread.h>
32 #include <semaphore.h>
33 #include <signal.h>
34 #include <stddef.h>
35 #include <stdbool.h>
36 #include <string.h>
37 #include <time.h>
38 #include <limits.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 #include <sys/socket.h>
46 #include <sys/ioctl.h>
47 #include <linux/kcmp.h>
48
49 #include <unistd.h>
50 #include <sys/syscall.h>
51 #include <poll.h>
52
53 #include "../kselftest_harness.h"
54
55 #ifndef PR_SET_PTRACER
56 # define PR_SET_PTRACER 0x59616d61
57 #endif
58
59 #ifndef PR_SET_NO_NEW_PRIVS
60 #define PR_SET_NO_NEW_PRIVS 38
61 #define PR_GET_NO_NEW_PRIVS 39
62 #endif
63
64 #ifndef PR_SECCOMP_EXT
65 #define PR_SECCOMP_EXT 43
66 #endif
67
68 #ifndef SECCOMP_EXT_ACT
69 #define SECCOMP_EXT_ACT 1
70 #endif
71
72 #ifndef SECCOMP_EXT_ACT_TSYNC
73 #define SECCOMP_EXT_ACT_TSYNC 1
74 #endif
75
76 #ifndef SECCOMP_MODE_STRICT
77 #define SECCOMP_MODE_STRICT 1
78 #endif
79
80 #ifndef SECCOMP_MODE_FILTER
81 #define SECCOMP_MODE_FILTER 2
82 #endif
83
84 #ifndef SECCOMP_RET_ALLOW
85 struct seccomp_data {
86 int nr;
87 __u32 arch;
88 __u64 instruction_pointer;
89 __u64 args[6];
90 };
91 #endif
92
93 #ifndef SECCOMP_RET_KILL_PROCESS
94 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
95 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
96 #endif
97 #ifndef SECCOMP_RET_KILL
98 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
99 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
100 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
101 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
102 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
103 #endif
104 #ifndef SECCOMP_RET_LOG
105 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
106 #endif
107
108 #ifndef __NR_seccomp
109 # if defined(__i386__)
110 # define __NR_seccomp 354
111 # elif defined(__x86_64__)
112 # define __NR_seccomp 317
113 # elif defined(__arm__)
114 # define __NR_seccomp 383
115 # elif defined(__aarch64__)
116 # define __NR_seccomp 277
117 # elif defined(__riscv)
118 # define __NR_seccomp 277
119 # elif defined(__hppa__)
120 # define __NR_seccomp 338
121 # elif defined(__powerpc__)
122 # define __NR_seccomp 358
123 # elif defined(__s390__)
124 # define __NR_seccomp 348
125 # else
126 # warning "seccomp syscall number unknown for this architecture"
127 # define __NR_seccomp 0xffff
128 # endif
129 #endif
130
131 #ifndef SECCOMP_SET_MODE_STRICT
132 #define SECCOMP_SET_MODE_STRICT 0
133 #endif
134
135 #ifndef SECCOMP_SET_MODE_FILTER
136 #define SECCOMP_SET_MODE_FILTER 1
137 #endif
138
139 #ifndef SECCOMP_GET_ACTION_AVAIL
140 #define SECCOMP_GET_ACTION_AVAIL 2
141 #endif
142
143 #ifndef SECCOMP_GET_NOTIF_SIZES
144 #define SECCOMP_GET_NOTIF_SIZES 3
145 #endif
146
147 #ifndef SECCOMP_FILTER_FLAG_TSYNC
148 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
149 #endif
150
151 #ifndef SECCOMP_FILTER_FLAG_LOG
152 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
153 #endif
154
155 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
156 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
157 #endif
158
159 #ifndef PTRACE_SECCOMP_GET_METADATA
160 #define PTRACE_SECCOMP_GET_METADATA 0x420d
161
162 struct seccomp_metadata {
163 __u64 filter_off; /* Input: which filter */
164 __u64 flags; /* Output: filter's flags */
165 };
166 #endif
167
168 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
169 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
170
171 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
172
173 #define SECCOMP_IOC_MAGIC '!'
174 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
175 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
176 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
177 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
178
179 /* Flags for seccomp notification fd ioctl. */
180 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
181 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
182 struct seccomp_notif_resp)
183 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOR(2, __u64)
184
185 struct seccomp_notif {
186 __u64 id;
187 __u32 pid;
188 __u32 flags;
189 struct seccomp_data data;
190 };
191
192 struct seccomp_notif_resp {
193 __u64 id;
194 __s64 val;
195 __s32 error;
196 __u32 flags;
197 };
198
199 struct seccomp_notif_sizes {
200 __u16 seccomp_notif;
201 __u16 seccomp_notif_resp;
202 __u16 seccomp_data;
203 };
204 #endif
205
206 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
207 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
208 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
209 #endif
210
211 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
212 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
213 #endif
214
215 #ifndef seccomp
216 int seccomp(unsigned int op, unsigned int flags, void *args)
217 {
218 errno = 0;
219 return syscall(__NR_seccomp, op, flags, args);
220 }
221 #endif
222
223 #if __BYTE_ORDER == __LITTLE_ENDIAN
224 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
225 #elif __BYTE_ORDER == __BIG_ENDIAN
226 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
227 #else
228 #error "wut? Unknown __BYTE_ORDER?!"
229 #endif
230
231 #define SIBLING_EXIT_UNKILLED 0xbadbeef
232 #define SIBLING_EXIT_FAILURE 0xbadface
233 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
234
235 TEST(mode_strict_support)
236 {
237 long ret;
238
239 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
240 ASSERT_EQ(0, ret) {
241 TH_LOG("Kernel does not support CONFIG_SECCOMP");
242 }
243 syscall(__NR_exit, 0);
244 }
245
246 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
247 {
248 long ret;
249
250 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
251 ASSERT_EQ(0, ret) {
252 TH_LOG("Kernel does not support CONFIG_SECCOMP");
253 }
254 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
255 NULL, NULL, NULL);
256 EXPECT_FALSE(true) {
257 TH_LOG("Unreachable!");
258 }
259 }
260
261 /* Note! This doesn't test no new privs behavior */
262 TEST(no_new_privs_support)
263 {
264 long ret;
265
266 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
267 EXPECT_EQ(0, ret) {
268 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
269 }
270 }
271
272 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
273 TEST(mode_filter_support)
274 {
275 long ret;
276
277 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
278 ASSERT_EQ(0, ret) {
279 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
280 }
281 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
282 EXPECT_EQ(-1, ret);
283 EXPECT_EQ(EFAULT, errno) {
284 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
285 }
286 }
287
288 TEST(mode_filter_without_nnp)
289 {
290 struct sock_filter filter[] = {
291 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
292 };
293 struct sock_fprog prog = {
294 .len = (unsigned short)ARRAY_SIZE(filter),
295 .filter = filter,
296 };
297 long ret;
298
299 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
300 ASSERT_LE(0, ret) {
301 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
302 }
303 errno = 0;
304 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
305 /* Succeeds with CAP_SYS_ADMIN, fails without */
306 /* TODO(wad) check caps not euid */
307 if (geteuid()) {
308 EXPECT_EQ(-1, ret);
309 EXPECT_EQ(EACCES, errno);
310 } else {
311 EXPECT_EQ(0, ret);
312 }
313 }
314
315 #define MAX_INSNS_PER_PATH 32768
316
317 TEST(filter_size_limits)
318 {
319 int i;
320 int count = BPF_MAXINSNS + 1;
321 struct sock_filter allow[] = {
322 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
323 };
324 struct sock_filter *filter;
325 struct sock_fprog prog = { };
326 long ret;
327
328 filter = calloc(count, sizeof(*filter));
329 ASSERT_NE(NULL, filter);
330
331 for (i = 0; i < count; i++)
332 filter[i] = allow[0];
333
334 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
335 ASSERT_EQ(0, ret);
336
337 prog.filter = filter;
338 prog.len = count;
339
340 /* Too many filter instructions in a single filter. */
341 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
342 ASSERT_NE(0, ret) {
343 TH_LOG("Installing %d insn filter was allowed", prog.len);
344 }
345
346 /* One less is okay, though. */
347 prog.len -= 1;
348 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
349 ASSERT_EQ(0, ret) {
350 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
351 }
352 }
353
354 TEST(filter_chain_limits)
355 {
356 int i;
357 int count = BPF_MAXINSNS;
358 struct sock_filter allow[] = {
359 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
360 };
361 struct sock_filter *filter;
362 struct sock_fprog prog = { };
363 long ret;
364
365 filter = calloc(count, sizeof(*filter));
366 ASSERT_NE(NULL, filter);
367
368 for (i = 0; i < count; i++)
369 filter[i] = allow[0];
370
371 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
372 ASSERT_EQ(0, ret);
373
374 prog.filter = filter;
375 prog.len = 1;
376
377 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
378 ASSERT_EQ(0, ret);
379
380 prog.len = count;
381
382 /* Too many total filter instructions. */
383 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
384 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
385 if (ret != 0)
386 break;
387 }
388 ASSERT_NE(0, ret) {
389 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
390 i, count, i * (count + 4));
391 }
392 }
393
394 TEST(mode_filter_cannot_move_to_strict)
395 {
396 struct sock_filter filter[] = {
397 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
398 };
399 struct sock_fprog prog = {
400 .len = (unsigned short)ARRAY_SIZE(filter),
401 .filter = filter,
402 };
403 long ret;
404
405 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
406 ASSERT_EQ(0, ret);
407
408 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
409 ASSERT_EQ(0, ret);
410
411 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
412 EXPECT_EQ(-1, ret);
413 EXPECT_EQ(EINVAL, errno);
414 }
415
416
417 TEST(mode_filter_get_seccomp)
418 {
419 struct sock_filter filter[] = {
420 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
421 };
422 struct sock_fprog prog = {
423 .len = (unsigned short)ARRAY_SIZE(filter),
424 .filter = filter,
425 };
426 long ret;
427
428 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
429 ASSERT_EQ(0, ret);
430
431 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
432 EXPECT_EQ(0, ret);
433
434 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
435 ASSERT_EQ(0, ret);
436
437 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
438 EXPECT_EQ(2, ret);
439 }
440
441
442 TEST(ALLOW_all)
443 {
444 struct sock_filter filter[] = {
445 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
446 };
447 struct sock_fprog prog = {
448 .len = (unsigned short)ARRAY_SIZE(filter),
449 .filter = filter,
450 };
451 long ret;
452
453 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
454 ASSERT_EQ(0, ret);
455
456 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
457 ASSERT_EQ(0, ret);
458 }
459
460 TEST(empty_prog)
461 {
462 struct sock_filter filter[] = {
463 };
464 struct sock_fprog prog = {
465 .len = (unsigned short)ARRAY_SIZE(filter),
466 .filter = filter,
467 };
468 long ret;
469
470 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
471 ASSERT_EQ(0, ret);
472
473 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
474 EXPECT_EQ(-1, ret);
475 EXPECT_EQ(EINVAL, errno);
476 }
477
478 TEST(log_all)
479 {
480 struct sock_filter filter[] = {
481 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
482 };
483 struct sock_fprog prog = {
484 .len = (unsigned short)ARRAY_SIZE(filter),
485 .filter = filter,
486 };
487 long ret;
488 pid_t parent = getppid();
489
490 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
491 ASSERT_EQ(0, ret);
492
493 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
494 ASSERT_EQ(0, ret);
495
496 /* getppid() should succeed and be logged (no check for logging) */
497 EXPECT_EQ(parent, syscall(__NR_getppid));
498 }
499
500 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
501 {
502 struct sock_filter filter[] = {
503 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
504 };
505 struct sock_fprog prog = {
506 .len = (unsigned short)ARRAY_SIZE(filter),
507 .filter = filter,
508 };
509 long ret;
510
511 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
512 ASSERT_EQ(0, ret);
513
514 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
515 ASSERT_EQ(0, ret);
516 EXPECT_EQ(0, syscall(__NR_getpid)) {
517 TH_LOG("getpid() shouldn't ever return");
518 }
519 }
520
521 /* return code >= 0x80000000 is unused. */
522 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
523 {
524 struct sock_filter filter[] = {
525 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
526 };
527 struct sock_fprog prog = {
528 .len = (unsigned short)ARRAY_SIZE(filter),
529 .filter = filter,
530 };
531 long ret;
532
533 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
534 ASSERT_EQ(0, ret);
535
536 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
537 ASSERT_EQ(0, ret);
538 EXPECT_EQ(0, syscall(__NR_getpid)) {
539 TH_LOG("getpid() shouldn't ever return");
540 }
541 }
542
543 TEST_SIGNAL(KILL_all, SIGSYS)
544 {
545 struct sock_filter filter[] = {
546 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
547 };
548 struct sock_fprog prog = {
549 .len = (unsigned short)ARRAY_SIZE(filter),
550 .filter = filter,
551 };
552 long ret;
553
554 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
555 ASSERT_EQ(0, ret);
556
557 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
558 ASSERT_EQ(0, ret);
559 }
560
561 TEST_SIGNAL(KILL_one, SIGSYS)
562 {
563 struct sock_filter filter[] = {
564 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
565 offsetof(struct seccomp_data, nr)),
566 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
567 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
568 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
569 };
570 struct sock_fprog prog = {
571 .len = (unsigned short)ARRAY_SIZE(filter),
572 .filter = filter,
573 };
574 long ret;
575 pid_t parent = getppid();
576
577 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
578 ASSERT_EQ(0, ret);
579
580 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
581 ASSERT_EQ(0, ret);
582
583 EXPECT_EQ(parent, syscall(__NR_getppid));
584 /* getpid() should never return. */
585 EXPECT_EQ(0, syscall(__NR_getpid));
586 }
587
588 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
589 {
590 void *fatal_address;
591 struct sock_filter filter[] = {
592 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
593 offsetof(struct seccomp_data, nr)),
594 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
595 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
596 /* Only both with lower 32-bit for now. */
597 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
598 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
599 (unsigned long)&fatal_address, 0, 1),
600 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
601 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
602 };
603 struct sock_fprog prog = {
604 .len = (unsigned short)ARRAY_SIZE(filter),
605 .filter = filter,
606 };
607 long ret;
608 pid_t parent = getppid();
609 struct tms timebuf;
610 clock_t clock = times(&timebuf);
611
612 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
613 ASSERT_EQ(0, ret);
614
615 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
616 ASSERT_EQ(0, ret);
617
618 EXPECT_EQ(parent, syscall(__NR_getppid));
619 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
620 /* times() should never return. */
621 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
622 }
623
624 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
625 {
626 #ifndef __NR_mmap2
627 int sysno = __NR_mmap;
628 #else
629 int sysno = __NR_mmap2;
630 #endif
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, sysno, 1, 0),
635 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
636 /* Only both with lower 32-bit for now. */
637 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
638 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
639 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
640 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
641 };
642 struct sock_fprog prog = {
643 .len = (unsigned short)ARRAY_SIZE(filter),
644 .filter = filter,
645 };
646 long ret;
647 pid_t parent = getppid();
648 int fd;
649 void *map1, *map2;
650 int page_size = sysconf(_SC_PAGESIZE);
651
652 ASSERT_LT(0, page_size);
653
654 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
655 ASSERT_EQ(0, ret);
656
657 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
658 ASSERT_EQ(0, ret);
659
660 fd = open("/dev/zero", O_RDONLY);
661 ASSERT_NE(-1, fd);
662
663 EXPECT_EQ(parent, syscall(__NR_getppid));
664 map1 = (void *)syscall(sysno,
665 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
666 EXPECT_NE(MAP_FAILED, map1);
667 /* mmap2() should never return. */
668 map2 = (void *)syscall(sysno,
669 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
670 EXPECT_EQ(MAP_FAILED, map2);
671
672 /* The test failed, so clean up the resources. */
673 munmap(map1, page_size);
674 munmap(map2, page_size);
675 close(fd);
676 }
677
678 /* This is a thread task to die via seccomp filter violation. */
679 void *kill_thread(void *data)
680 {
681 bool die = (bool)data;
682
683 if (die) {
684 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
685 return (void *)SIBLING_EXIT_FAILURE;
686 }
687
688 return (void *)SIBLING_EXIT_UNKILLED;
689 }
690
691 /* Prepare a thread that will kill itself or both of us. */
692 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
693 {
694 pthread_t thread;
695 void *status;
696 /* Kill only when calling __NR_prctl. */
697 struct sock_filter filter_thread[] = {
698 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
699 offsetof(struct seccomp_data, nr)),
700 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
701 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
702 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
703 };
704 struct sock_fprog prog_thread = {
705 .len = (unsigned short)ARRAY_SIZE(filter_thread),
706 .filter = filter_thread,
707 };
708 struct sock_filter filter_process[] = {
709 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
710 offsetof(struct seccomp_data, nr)),
711 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
712 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
713 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
714 };
715 struct sock_fprog prog_process = {
716 .len = (unsigned short)ARRAY_SIZE(filter_process),
717 .filter = filter_process,
718 };
719
720 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
721 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
722 }
723
724 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
725 kill_process ? &prog_process : &prog_thread));
726
727 /*
728 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
729 * flag cannot be downgraded by a new filter.
730 */
731 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
732
733 /* Start a thread that will exit immediately. */
734 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
735 ASSERT_EQ(0, pthread_join(thread, &status));
736 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
737
738 /* Start a thread that will die immediately. */
739 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
740 ASSERT_EQ(0, pthread_join(thread, &status));
741 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
742
743 /*
744 * If we get here, only the spawned thread died. Let the parent know
745 * the whole process didn't die (i.e. this thread, the spawner,
746 * stayed running).
747 */
748 exit(42);
749 }
750
751 TEST(KILL_thread)
752 {
753 int status;
754 pid_t child_pid;
755
756 child_pid = fork();
757 ASSERT_LE(0, child_pid);
758 if (child_pid == 0) {
759 kill_thread_or_group(_metadata, false);
760 _exit(38);
761 }
762
763 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
764
765 /* If only the thread was killed, we'll see exit 42. */
766 ASSERT_TRUE(WIFEXITED(status));
767 ASSERT_EQ(42, WEXITSTATUS(status));
768 }
769
770 TEST(KILL_process)
771 {
772 int status;
773 pid_t child_pid;
774
775 child_pid = fork();
776 ASSERT_LE(0, child_pid);
777 if (child_pid == 0) {
778 kill_thread_or_group(_metadata, true);
779 _exit(38);
780 }
781
782 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
783
784 /* If the entire process was killed, we'll see SIGSYS. */
785 ASSERT_TRUE(WIFSIGNALED(status));
786 ASSERT_EQ(SIGSYS, WTERMSIG(status));
787 }
788
789 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
790 TEST(arg_out_of_range)
791 {
792 struct sock_filter filter[] = {
793 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
794 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
795 };
796 struct sock_fprog prog = {
797 .len = (unsigned short)ARRAY_SIZE(filter),
798 .filter = filter,
799 };
800 long ret;
801
802 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
803 ASSERT_EQ(0, ret);
804
805 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
806 EXPECT_EQ(-1, ret);
807 EXPECT_EQ(EINVAL, errno);
808 }
809
810 #define ERRNO_FILTER(name, errno) \
811 struct sock_filter _read_filter_##name[] = { \
812 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
813 offsetof(struct seccomp_data, nr)), \
814 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
815 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
816 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
817 }; \
818 struct sock_fprog prog_##name = { \
819 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
820 .filter = _read_filter_##name, \
821 }
822
823 /* Make sure basic errno values are correctly passed through a filter. */
824 TEST(ERRNO_valid)
825 {
826 ERRNO_FILTER(valid, E2BIG);
827 long ret;
828 pid_t parent = getppid();
829
830 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
831 ASSERT_EQ(0, ret);
832
833 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
834 ASSERT_EQ(0, ret);
835
836 EXPECT_EQ(parent, syscall(__NR_getppid));
837 EXPECT_EQ(-1, read(0, NULL, 0));
838 EXPECT_EQ(E2BIG, errno);
839 }
840
841 /* Make sure an errno of zero is correctly handled by the arch code. */
842 TEST(ERRNO_zero)
843 {
844 ERRNO_FILTER(zero, 0);
845 long ret;
846 pid_t parent = getppid();
847
848 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
849 ASSERT_EQ(0, ret);
850
851 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
852 ASSERT_EQ(0, ret);
853
854 EXPECT_EQ(parent, syscall(__NR_getppid));
855 /* "errno" of 0 is ok. */
856 EXPECT_EQ(0, read(0, NULL, 0));
857 }
858
859 /*
860 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
861 * This tests that the errno value gets capped correctly, fixed by
862 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
863 */
864 TEST(ERRNO_capped)
865 {
866 ERRNO_FILTER(capped, 4096);
867 long ret;
868 pid_t parent = getppid();
869
870 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
871 ASSERT_EQ(0, ret);
872
873 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
874 ASSERT_EQ(0, ret);
875
876 EXPECT_EQ(parent, syscall(__NR_getppid));
877 EXPECT_EQ(-1, read(0, NULL, 0));
878 EXPECT_EQ(4095, errno);
879 }
880
881 /*
882 * Filters are processed in reverse order: last applied is executed first.
883 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
884 * SECCOMP_RET_DATA mask results will follow the most recently applied
885 * matching filter return (and not the lowest or highest value).
886 */
887 TEST(ERRNO_order)
888 {
889 ERRNO_FILTER(first, 11);
890 ERRNO_FILTER(second, 13);
891 ERRNO_FILTER(third, 12);
892 long ret;
893 pid_t parent = getppid();
894
895 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
896 ASSERT_EQ(0, ret);
897
898 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
899 ASSERT_EQ(0, ret);
900
901 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
902 ASSERT_EQ(0, ret);
903
904 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
905 ASSERT_EQ(0, ret);
906
907 EXPECT_EQ(parent, syscall(__NR_getppid));
908 EXPECT_EQ(-1, read(0, NULL, 0));
909 EXPECT_EQ(12, errno);
910 }
911
912 FIXTURE_DATA(TRAP) {
913 struct sock_fprog prog;
914 };
915
916 FIXTURE_SETUP(TRAP)
917 {
918 struct sock_filter filter[] = {
919 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
920 offsetof(struct seccomp_data, nr)),
921 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
922 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
923 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
924 };
925
926 memset(&self->prog, 0, sizeof(self->prog));
927 self->prog.filter = malloc(sizeof(filter));
928 ASSERT_NE(NULL, self->prog.filter);
929 memcpy(self->prog.filter, filter, sizeof(filter));
930 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
931 }
932
933 FIXTURE_TEARDOWN(TRAP)
934 {
935 if (self->prog.filter)
936 free(self->prog.filter);
937 }
938
939 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
940 {
941 long ret;
942
943 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
944 ASSERT_EQ(0, ret);
945
946 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
947 ASSERT_EQ(0, ret);
948 syscall(__NR_getpid);
949 }
950
951 /* Ensure that SIGSYS overrides SIG_IGN */
952 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
953 {
954 long ret;
955
956 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
957 ASSERT_EQ(0, ret);
958
959 signal(SIGSYS, SIG_IGN);
960
961 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
962 ASSERT_EQ(0, ret);
963 syscall(__NR_getpid);
964 }
965
966 static siginfo_t TRAP_info;
967 static volatile int TRAP_nr;
968 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
969 {
970 memcpy(&TRAP_info, info, sizeof(TRAP_info));
971 TRAP_nr = nr;
972 }
973
974 TEST_F(TRAP, handler)
975 {
976 int ret, test;
977 struct sigaction act;
978 sigset_t mask;
979
980 memset(&act, 0, sizeof(act));
981 sigemptyset(&mask);
982 sigaddset(&mask, SIGSYS);
983
984 act.sa_sigaction = &TRAP_action;
985 act.sa_flags = SA_SIGINFO;
986 ret = sigaction(SIGSYS, &act, NULL);
987 ASSERT_EQ(0, ret) {
988 TH_LOG("sigaction failed");
989 }
990 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
991 ASSERT_EQ(0, ret) {
992 TH_LOG("sigprocmask failed");
993 }
994
995 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
996 ASSERT_EQ(0, ret);
997 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
998 ASSERT_EQ(0, ret);
999 TRAP_nr = 0;
1000 memset(&TRAP_info, 0, sizeof(TRAP_info));
1001 /* Expect the registers to be rolled back. (nr = error) may vary
1002 * based on arch. */
1003 ret = syscall(__NR_getpid);
1004 /* Silence gcc warning about volatile. */
1005 test = TRAP_nr;
1006 EXPECT_EQ(SIGSYS, test);
1007 struct local_sigsys {
1008 void *_call_addr; /* calling user insn */
1009 int _syscall; /* triggering system call number */
1010 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1011 } *sigsys = (struct local_sigsys *)
1012 #ifdef si_syscall
1013 &(TRAP_info.si_call_addr);
1014 #else
1015 &TRAP_info.si_pid;
1016 #endif
1017 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1018 /* Make sure arch is non-zero. */
1019 EXPECT_NE(0, sigsys->_arch);
1020 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1021 }
1022
1023 FIXTURE_DATA(precedence) {
1024 struct sock_fprog allow;
1025 struct sock_fprog log;
1026 struct sock_fprog trace;
1027 struct sock_fprog error;
1028 struct sock_fprog trap;
1029 struct sock_fprog kill;
1030 };
1031
1032 FIXTURE_SETUP(precedence)
1033 {
1034 struct sock_filter allow_insns[] = {
1035 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1036 };
1037 struct sock_filter log_insns[] = {
1038 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1039 offsetof(struct seccomp_data, nr)),
1040 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1041 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1042 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1043 };
1044 struct sock_filter trace_insns[] = {
1045 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1046 offsetof(struct seccomp_data, nr)),
1047 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1048 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1049 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1050 };
1051 struct sock_filter error_insns[] = {
1052 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1053 offsetof(struct seccomp_data, nr)),
1054 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1055 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1056 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1057 };
1058 struct sock_filter trap_insns[] = {
1059 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1060 offsetof(struct seccomp_data, nr)),
1061 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1062 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1063 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1064 };
1065 struct sock_filter kill_insns[] = {
1066 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1067 offsetof(struct seccomp_data, nr)),
1068 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1069 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1070 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1071 };
1072
1073 memset(self, 0, sizeof(*self));
1074 #define FILTER_ALLOC(_x) \
1075 self->_x.filter = malloc(sizeof(_x##_insns)); \
1076 ASSERT_NE(NULL, self->_x.filter); \
1077 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1078 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1079 FILTER_ALLOC(allow);
1080 FILTER_ALLOC(log);
1081 FILTER_ALLOC(trace);
1082 FILTER_ALLOC(error);
1083 FILTER_ALLOC(trap);
1084 FILTER_ALLOC(kill);
1085 }
1086
1087 FIXTURE_TEARDOWN(precedence)
1088 {
1089 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1090 FILTER_FREE(allow);
1091 FILTER_FREE(log);
1092 FILTER_FREE(trace);
1093 FILTER_FREE(error);
1094 FILTER_FREE(trap);
1095 FILTER_FREE(kill);
1096 }
1097
1098 TEST_F(precedence, allow_ok)
1099 {
1100 pid_t parent, res = 0;
1101 long ret;
1102
1103 parent = getppid();
1104 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1105 ASSERT_EQ(0, ret);
1106
1107 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1108 ASSERT_EQ(0, ret);
1109 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1110 ASSERT_EQ(0, ret);
1111 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1112 ASSERT_EQ(0, ret);
1113 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1114 ASSERT_EQ(0, ret);
1115 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1116 ASSERT_EQ(0, ret);
1117 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1118 ASSERT_EQ(0, ret);
1119 /* Should work just fine. */
1120 res = syscall(__NR_getppid);
1121 EXPECT_EQ(parent, res);
1122 }
1123
1124 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1125 {
1126 pid_t parent, res = 0;
1127 long ret;
1128
1129 parent = getppid();
1130 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1131 ASSERT_EQ(0, ret);
1132
1133 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1134 ASSERT_EQ(0, ret);
1135 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1136 ASSERT_EQ(0, ret);
1137 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1138 ASSERT_EQ(0, ret);
1139 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1140 ASSERT_EQ(0, ret);
1141 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1142 ASSERT_EQ(0, ret);
1143 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1144 ASSERT_EQ(0, ret);
1145 /* Should work just fine. */
1146 res = syscall(__NR_getppid);
1147 EXPECT_EQ(parent, res);
1148 /* getpid() should never return. */
1149 res = syscall(__NR_getpid);
1150 EXPECT_EQ(0, res);
1151 }
1152
1153 TEST_F_SIGNAL(precedence, kill_is_highest_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->kill);
1165 ASSERT_EQ(0, ret);
1166 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1167 ASSERT_EQ(0, ret);
1168 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1169 ASSERT_EQ(0, ret);
1170 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1171 ASSERT_EQ(0, ret);
1172 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1173 ASSERT_EQ(0, ret);
1174 /* Should work just fine. */
1175 EXPECT_EQ(parent, syscall(__NR_getppid));
1176 /* getpid() should never return. */
1177 EXPECT_EQ(0, syscall(__NR_getpid));
1178 }
1179
1180 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1181 {
1182 pid_t parent;
1183 long ret;
1184
1185 parent = getppid();
1186 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1187 ASSERT_EQ(0, ret);
1188
1189 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1190 ASSERT_EQ(0, ret);
1191 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1192 ASSERT_EQ(0, ret);
1193 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1194 ASSERT_EQ(0, ret);
1195 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1196 ASSERT_EQ(0, ret);
1197 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1198 ASSERT_EQ(0, ret);
1199 /* Should work just fine. */
1200 EXPECT_EQ(parent, syscall(__NR_getppid));
1201 /* getpid() should never return. */
1202 EXPECT_EQ(0, syscall(__NR_getpid));
1203 }
1204
1205 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1206 {
1207 pid_t parent;
1208 long ret;
1209
1210 parent = getppid();
1211 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1212 ASSERT_EQ(0, ret);
1213
1214 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1215 ASSERT_EQ(0, ret);
1216 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1217 ASSERT_EQ(0, ret);
1218 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1219 ASSERT_EQ(0, ret);
1220 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1221 ASSERT_EQ(0, ret);
1222 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1223 ASSERT_EQ(0, ret);
1224 /* Should work just fine. */
1225 EXPECT_EQ(parent, syscall(__NR_getppid));
1226 /* getpid() should never return. */
1227 EXPECT_EQ(0, syscall(__NR_getpid));
1228 }
1229
1230 TEST_F(precedence, errno_is_third)
1231 {
1232 pid_t parent;
1233 long ret;
1234
1235 parent = getppid();
1236 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1237 ASSERT_EQ(0, ret);
1238
1239 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1240 ASSERT_EQ(0, ret);
1241 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1242 ASSERT_EQ(0, ret);
1243 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1244 ASSERT_EQ(0, ret);
1245 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1246 ASSERT_EQ(0, ret);
1247 /* Should work just fine. */
1248 EXPECT_EQ(parent, syscall(__NR_getppid));
1249 EXPECT_EQ(0, syscall(__NR_getpid));
1250 }
1251
1252 TEST_F(precedence, errno_is_third_in_any_order)
1253 {
1254 pid_t parent;
1255 long ret;
1256
1257 parent = getppid();
1258 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1259 ASSERT_EQ(0, ret);
1260
1261 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1262 ASSERT_EQ(0, ret);
1263 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1264 ASSERT_EQ(0, ret);
1265 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1266 ASSERT_EQ(0, ret);
1267 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1268 ASSERT_EQ(0, ret);
1269 /* Should work just fine. */
1270 EXPECT_EQ(parent, syscall(__NR_getppid));
1271 EXPECT_EQ(0, syscall(__NR_getpid));
1272 }
1273
1274 TEST_F(precedence, trace_is_fourth)
1275 {
1276 pid_t parent;
1277 long ret;
1278
1279 parent = getppid();
1280 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1281 ASSERT_EQ(0, ret);
1282
1283 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1284 ASSERT_EQ(0, ret);
1285 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1286 ASSERT_EQ(0, ret);
1287 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1288 ASSERT_EQ(0, ret);
1289 /* Should work just fine. */
1290 EXPECT_EQ(parent, syscall(__NR_getppid));
1291 /* No ptracer */
1292 EXPECT_EQ(-1, syscall(__NR_getpid));
1293 }
1294
1295 TEST_F(precedence, trace_is_fourth_in_any_order)
1296 {
1297 pid_t parent;
1298 long ret;
1299
1300 parent = getppid();
1301 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1302 ASSERT_EQ(0, ret);
1303
1304 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1305 ASSERT_EQ(0, ret);
1306 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1307 ASSERT_EQ(0, ret);
1308 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1309 ASSERT_EQ(0, ret);
1310 /* Should work just fine. */
1311 EXPECT_EQ(parent, syscall(__NR_getppid));
1312 /* No ptracer */
1313 EXPECT_EQ(-1, syscall(__NR_getpid));
1314 }
1315
1316 TEST_F(precedence, log_is_fifth)
1317 {
1318 pid_t mypid, parent;
1319 long ret;
1320
1321 mypid = getpid();
1322 parent = getppid();
1323 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1324 ASSERT_EQ(0, ret);
1325
1326 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1327 ASSERT_EQ(0, ret);
1328 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1329 ASSERT_EQ(0, ret);
1330 /* Should work just fine. */
1331 EXPECT_EQ(parent, syscall(__NR_getppid));
1332 /* Should also work just fine */
1333 EXPECT_EQ(mypid, syscall(__NR_getpid));
1334 }
1335
1336 TEST_F(precedence, log_is_fifth_in_any_order)
1337 {
1338 pid_t mypid, parent;
1339 long ret;
1340
1341 mypid = getpid();
1342 parent = getppid();
1343 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1344 ASSERT_EQ(0, ret);
1345
1346 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1347 ASSERT_EQ(0, ret);
1348 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1349 ASSERT_EQ(0, ret);
1350 /* Should work just fine. */
1351 EXPECT_EQ(parent, syscall(__NR_getppid));
1352 /* Should also work just fine */
1353 EXPECT_EQ(mypid, syscall(__NR_getpid));
1354 }
1355
1356 #ifndef PTRACE_O_TRACESECCOMP
1357 #define PTRACE_O_TRACESECCOMP 0x00000080
1358 #endif
1359
1360 /* Catch the Ubuntu 12.04 value error. */
1361 #if PTRACE_EVENT_SECCOMP != 7
1362 #undef PTRACE_EVENT_SECCOMP
1363 #endif
1364
1365 #ifndef PTRACE_EVENT_SECCOMP
1366 #define PTRACE_EVENT_SECCOMP 7
1367 #endif
1368
1369 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1370 bool tracer_running;
1371 void tracer_stop(int sig)
1372 {
1373 tracer_running = false;
1374 }
1375
1376 typedef void tracer_func_t(struct __test_metadata *_metadata,
1377 pid_t tracee, int status, void *args);
1378
1379 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1380 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1381 {
1382 int ret = -1;
1383 struct sigaction action = {
1384 .sa_handler = tracer_stop,
1385 };
1386
1387 /* Allow external shutdown. */
1388 tracer_running = true;
1389 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1390
1391 errno = 0;
1392 while (ret == -1 && errno != EINVAL)
1393 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1394 ASSERT_EQ(0, ret) {
1395 kill(tracee, SIGKILL);
1396 }
1397 /* Wait for attach stop */
1398 wait(NULL);
1399
1400 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1401 PTRACE_O_TRACESYSGOOD :
1402 PTRACE_O_TRACESECCOMP);
1403 ASSERT_EQ(0, ret) {
1404 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1405 kill(tracee, SIGKILL);
1406 }
1407 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1408 tracee, NULL, 0);
1409 ASSERT_EQ(0, ret);
1410
1411 /* Unblock the tracee */
1412 ASSERT_EQ(1, write(fd, "A", 1));
1413 ASSERT_EQ(0, close(fd));
1414
1415 /* Run until we're shut down. Must assert to stop execution. */
1416 while (tracer_running) {
1417 int status;
1418
1419 if (wait(&status) != tracee)
1420 continue;
1421 if (WIFSIGNALED(status) || WIFEXITED(status))
1422 /* Child is dead. Time to go. */
1423 return;
1424
1425 /* Check if this is a seccomp event. */
1426 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1427
1428 tracer_func(_metadata, tracee, status, args);
1429
1430 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1431 tracee, NULL, 0);
1432 ASSERT_EQ(0, ret);
1433 }
1434 /* Directly report the status of our test harness results. */
1435 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1436 }
1437
1438 /* Common tracer setup/teardown functions. */
1439 void cont_handler(int num)
1440 { }
1441 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1442 tracer_func_t func, void *args, bool ptrace_syscall)
1443 {
1444 char sync;
1445 int pipefd[2];
1446 pid_t tracer_pid;
1447 pid_t tracee = getpid();
1448
1449 /* Setup a pipe for clean synchronization. */
1450 ASSERT_EQ(0, pipe(pipefd));
1451
1452 /* Fork a child which we'll promote to tracer */
1453 tracer_pid = fork();
1454 ASSERT_LE(0, tracer_pid);
1455 signal(SIGALRM, cont_handler);
1456 if (tracer_pid == 0) {
1457 close(pipefd[0]);
1458 start_tracer(_metadata, pipefd[1], tracee, func, args,
1459 ptrace_syscall);
1460 syscall(__NR_exit, 0);
1461 }
1462 close(pipefd[1]);
1463 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1464 read(pipefd[0], &sync, 1);
1465 close(pipefd[0]);
1466
1467 return tracer_pid;
1468 }
1469 void teardown_trace_fixture(struct __test_metadata *_metadata,
1470 pid_t tracer)
1471 {
1472 if (tracer) {
1473 int status;
1474 /*
1475 * Extract the exit code from the other process and
1476 * adopt it for ourselves in case its asserts failed.
1477 */
1478 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1479 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1480 if (WEXITSTATUS(status))
1481 _metadata->passed = 0;
1482 }
1483 }
1484
1485 /* "poke" tracer arguments and function. */
1486 struct tracer_args_poke_t {
1487 unsigned long poke_addr;
1488 };
1489
1490 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1491 void *args)
1492 {
1493 int ret;
1494 unsigned long msg;
1495 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1496
1497 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1498 EXPECT_EQ(0, ret);
1499 /* If this fails, don't try to recover. */
1500 ASSERT_EQ(0x1001, msg) {
1501 kill(tracee, SIGKILL);
1502 }
1503 /*
1504 * Poke in the message.
1505 * Registers are not touched to try to keep this relatively arch
1506 * agnostic.
1507 */
1508 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1509 EXPECT_EQ(0, ret);
1510 }
1511
1512 FIXTURE_DATA(TRACE_poke) {
1513 struct sock_fprog prog;
1514 pid_t tracer;
1515 long poked;
1516 struct tracer_args_poke_t tracer_args;
1517 };
1518
1519 FIXTURE_SETUP(TRACE_poke)
1520 {
1521 struct sock_filter filter[] = {
1522 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1523 offsetof(struct seccomp_data, nr)),
1524 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1525 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1526 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1527 };
1528
1529 self->poked = 0;
1530 memset(&self->prog, 0, sizeof(self->prog));
1531 self->prog.filter = malloc(sizeof(filter));
1532 ASSERT_NE(NULL, self->prog.filter);
1533 memcpy(self->prog.filter, filter, sizeof(filter));
1534 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1535
1536 /* Set up tracer args. */
1537 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1538
1539 /* Launch tracer. */
1540 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1541 &self->tracer_args, false);
1542 }
1543
1544 FIXTURE_TEARDOWN(TRACE_poke)
1545 {
1546 teardown_trace_fixture(_metadata, self->tracer);
1547 if (self->prog.filter)
1548 free(self->prog.filter);
1549 }
1550
1551 TEST_F(TRACE_poke, read_has_side_effects)
1552 {
1553 ssize_t ret;
1554
1555 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1556 ASSERT_EQ(0, ret);
1557
1558 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1559 ASSERT_EQ(0, ret);
1560
1561 EXPECT_EQ(0, self->poked);
1562 ret = read(-1, NULL, 0);
1563 EXPECT_EQ(-1, ret);
1564 EXPECT_EQ(0x1001, self->poked);
1565 }
1566
1567 TEST_F(TRACE_poke, getpid_runs_normally)
1568 {
1569 long ret;
1570
1571 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1572 ASSERT_EQ(0, ret);
1573
1574 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1575 ASSERT_EQ(0, ret);
1576
1577 EXPECT_EQ(0, self->poked);
1578 EXPECT_NE(0, syscall(__NR_getpid));
1579 EXPECT_EQ(0, self->poked);
1580 }
1581
1582 #if defined(__x86_64__)
1583 # define ARCH_REGS struct user_regs_struct
1584 # define SYSCALL_NUM orig_rax
1585 # define SYSCALL_RET rax
1586 #elif defined(__i386__)
1587 # define ARCH_REGS struct user_regs_struct
1588 # define SYSCALL_NUM orig_eax
1589 # define SYSCALL_RET eax
1590 #elif defined(__arm__)
1591 # define ARCH_REGS struct pt_regs
1592 # define SYSCALL_NUM ARM_r7
1593 # define SYSCALL_RET ARM_r0
1594 #elif defined(__aarch64__)
1595 # define ARCH_REGS struct user_pt_regs
1596 # define SYSCALL_NUM regs[8]
1597 # define SYSCALL_RET regs[0]
1598 #elif defined(__riscv) && __riscv_xlen == 64
1599 # define ARCH_REGS struct user_regs_struct
1600 # define SYSCALL_NUM a7
1601 # define SYSCALL_RET a0
1602 #elif defined(__hppa__)
1603 # define ARCH_REGS struct user_regs_struct
1604 # define SYSCALL_NUM gr[20]
1605 # define SYSCALL_RET gr[28]
1606 #elif defined(__powerpc__)
1607 # define ARCH_REGS struct pt_regs
1608 # define SYSCALL_NUM gpr[0]
1609 # define SYSCALL_RET gpr[3]
1610 #elif defined(__s390__)
1611 # define ARCH_REGS s390_regs
1612 # define SYSCALL_NUM gprs[2]
1613 # define SYSCALL_RET gprs[2]
1614 #elif defined(__mips__)
1615 # define ARCH_REGS struct pt_regs
1616 # define SYSCALL_NUM regs[2]
1617 # define SYSCALL_SYSCALL_NUM regs[4]
1618 # define SYSCALL_RET regs[2]
1619 # define SYSCALL_NUM_RET_SHARE_REG
1620 #else
1621 # error "Do not know how to find your architecture's registers and syscalls"
1622 #endif
1623
1624 /* When the syscall return can't be changed, stub out the tests for it. */
1625 #ifdef SYSCALL_NUM_RET_SHARE_REG
1626 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1627 #else
1628 # define EXPECT_SYSCALL_RETURN(val, action) \
1629 do { \
1630 errno = 0; \
1631 if (val < 0) { \
1632 EXPECT_EQ(-1, action); \
1633 EXPECT_EQ(-(val), errno); \
1634 } else { \
1635 EXPECT_EQ(val, action); \
1636 } \
1637 } while (0)
1638 #endif
1639
1640 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1641 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1642 */
1643 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1644 #define HAVE_GETREGS
1645 #endif
1646
1647 /* Architecture-specific syscall fetching routine. */
1648 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1649 {
1650 ARCH_REGS regs;
1651 #ifdef HAVE_GETREGS
1652 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
1653 TH_LOG("PTRACE_GETREGS failed");
1654 return -1;
1655 }
1656 #else
1657 struct iovec iov;
1658
1659 iov.iov_base = &regs;
1660 iov.iov_len = sizeof(regs);
1661 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1662 TH_LOG("PTRACE_GETREGSET failed");
1663 return -1;
1664 }
1665 #endif
1666
1667 #if defined(__mips__)
1668 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1669 return regs.SYSCALL_SYSCALL_NUM;
1670 #endif
1671 return regs.SYSCALL_NUM;
1672 }
1673
1674 /* Architecture-specific syscall changing routine. */
1675 void change_syscall(struct __test_metadata *_metadata,
1676 pid_t tracee, int syscall, int result)
1677 {
1678 int ret;
1679 ARCH_REGS regs;
1680 #ifdef HAVE_GETREGS
1681 ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
1682 #else
1683 struct iovec iov;
1684 iov.iov_base = &regs;
1685 iov.iov_len = sizeof(regs);
1686 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1687 #endif
1688 EXPECT_EQ(0, ret) {}
1689
1690 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1691 defined(__s390__) || defined(__hppa__) || defined(__riscv)
1692 {
1693 regs.SYSCALL_NUM = syscall;
1694 }
1695 #elif defined(__mips__)
1696 {
1697 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1698 regs.SYSCALL_SYSCALL_NUM = syscall;
1699 else
1700 regs.SYSCALL_NUM = syscall;
1701 }
1702
1703 #elif defined(__arm__)
1704 # ifndef PTRACE_SET_SYSCALL
1705 # define PTRACE_SET_SYSCALL 23
1706 # endif
1707 {
1708 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1709 EXPECT_EQ(0, ret);
1710 }
1711
1712 #elif defined(__aarch64__)
1713 # ifndef NT_ARM_SYSTEM_CALL
1714 # define NT_ARM_SYSTEM_CALL 0x404
1715 # endif
1716 {
1717 iov.iov_base = &syscall;
1718 iov.iov_len = sizeof(syscall);
1719 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1720 &iov);
1721 EXPECT_EQ(0, ret);
1722 }
1723
1724 #else
1725 ASSERT_EQ(1, 0) {
1726 TH_LOG("How is the syscall changed on this architecture?");
1727 }
1728 #endif
1729
1730 /* If syscall is skipped, change return value. */
1731 if (syscall == -1)
1732 #ifdef SYSCALL_NUM_RET_SHARE_REG
1733 TH_LOG("Can't modify syscall return on this architecture");
1734 #else
1735 regs.SYSCALL_RET = result;
1736 #endif
1737
1738 #ifdef HAVE_GETREGS
1739 ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
1740 #else
1741 iov.iov_base = &regs;
1742 iov.iov_len = sizeof(regs);
1743 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1744 #endif
1745 EXPECT_EQ(0, ret);
1746 }
1747
1748 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1749 int status, void *args)
1750 {
1751 int ret;
1752 unsigned long msg;
1753
1754 /* Make sure we got the right message. */
1755 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1756 EXPECT_EQ(0, ret);
1757
1758 /* Validate and take action on expected syscalls. */
1759 switch (msg) {
1760 case 0x1002:
1761 /* change getpid to getppid. */
1762 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1763 change_syscall(_metadata, tracee, __NR_getppid, 0);
1764 break;
1765 case 0x1003:
1766 /* skip gettid with valid return code. */
1767 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1768 change_syscall(_metadata, tracee, -1, 45000);
1769 break;
1770 case 0x1004:
1771 /* skip openat with error. */
1772 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
1773 change_syscall(_metadata, tracee, -1, -ESRCH);
1774 break;
1775 case 0x1005:
1776 /* do nothing (allow getppid) */
1777 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1778 break;
1779 default:
1780 EXPECT_EQ(0, msg) {
1781 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1782 kill(tracee, SIGKILL);
1783 }
1784 }
1785
1786 }
1787
1788 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1789 int status, void *args)
1790 {
1791 int ret, nr;
1792 unsigned long msg;
1793 static bool entry;
1794
1795 /*
1796 * The traditional way to tell PTRACE_SYSCALL entry/exit
1797 * is by counting.
1798 */
1799 entry = !entry;
1800
1801 /* Make sure we got an appropriate message. */
1802 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1803 EXPECT_EQ(0, ret);
1804 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
1805 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
1806
1807 if (!entry)
1808 return;
1809
1810 nr = get_syscall(_metadata, tracee);
1811
1812 if (nr == __NR_getpid)
1813 change_syscall(_metadata, tracee, __NR_getppid, 0);
1814 if (nr == __NR_gettid)
1815 change_syscall(_metadata, tracee, -1, 45000);
1816 if (nr == __NR_openat)
1817 change_syscall(_metadata, tracee, -1, -ESRCH);
1818 }
1819
1820 FIXTURE_DATA(TRACE_syscall) {
1821 struct sock_fprog prog;
1822 pid_t tracer, mytid, mypid, parent;
1823 };
1824
1825 FIXTURE_SETUP(TRACE_syscall)
1826 {
1827 struct sock_filter filter[] = {
1828 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1829 offsetof(struct seccomp_data, nr)),
1830 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1831 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1832 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1833 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1834 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
1835 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1836 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1837 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
1838 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1839 };
1840
1841 memset(&self->prog, 0, sizeof(self->prog));
1842 self->prog.filter = malloc(sizeof(filter));
1843 ASSERT_NE(NULL, self->prog.filter);
1844 memcpy(self->prog.filter, filter, sizeof(filter));
1845 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1846
1847 /* Prepare some testable syscall results. */
1848 self->mytid = syscall(__NR_gettid);
1849 ASSERT_GT(self->mytid, 0);
1850 ASSERT_NE(self->mytid, 1) {
1851 TH_LOG("Running this test as init is not supported. :)");
1852 }
1853
1854 self->mypid = getpid();
1855 ASSERT_GT(self->mypid, 0);
1856 ASSERT_EQ(self->mytid, self->mypid);
1857
1858 self->parent = getppid();
1859 ASSERT_GT(self->parent, 0);
1860 ASSERT_NE(self->parent, self->mypid);
1861
1862 /* Launch tracer. */
1863 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1864 false);
1865 }
1866
1867 FIXTURE_TEARDOWN(TRACE_syscall)
1868 {
1869 teardown_trace_fixture(_metadata, self->tracer);
1870 if (self->prog.filter)
1871 free(self->prog.filter);
1872 }
1873
1874 TEST_F(TRACE_syscall, ptrace_syscall_redirected)
1875 {
1876 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1877 teardown_trace_fixture(_metadata, self->tracer);
1878 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1879 true);
1880
1881 /* Tracer will redirect getpid to getppid. */
1882 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1883 }
1884
1885 TEST_F(TRACE_syscall, ptrace_syscall_errno)
1886 {
1887 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1888 teardown_trace_fixture(_metadata, self->tracer);
1889 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1890 true);
1891
1892 /* Tracer should skip the open syscall, resulting in ESRCH. */
1893 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
1894 }
1895
1896 TEST_F(TRACE_syscall, ptrace_syscall_faked)
1897 {
1898 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1899 teardown_trace_fixture(_metadata, self->tracer);
1900 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1901 true);
1902
1903 /* Tracer should skip the gettid syscall, resulting fake pid. */
1904 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
1905 }
1906
1907 TEST_F(TRACE_syscall, syscall_allowed)
1908 {
1909 long ret;
1910
1911 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1912 ASSERT_EQ(0, ret);
1913
1914 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1915 ASSERT_EQ(0, ret);
1916
1917 /* getppid works as expected (no changes). */
1918 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1919 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1920 }
1921
1922 TEST_F(TRACE_syscall, syscall_redirected)
1923 {
1924 long ret;
1925
1926 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1927 ASSERT_EQ(0, ret);
1928
1929 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1930 ASSERT_EQ(0, ret);
1931
1932 /* getpid has been redirected to getppid as expected. */
1933 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1934 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1935 }
1936
1937 TEST_F(TRACE_syscall, syscall_errno)
1938 {
1939 long ret;
1940
1941 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1942 ASSERT_EQ(0, ret);
1943
1944 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1945 ASSERT_EQ(0, ret);
1946
1947 /* openat has been skipped and an errno return. */
1948 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
1949 }
1950
1951 TEST_F(TRACE_syscall, syscall_faked)
1952 {
1953 long ret;
1954
1955 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1956 ASSERT_EQ(0, ret);
1957
1958 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1959 ASSERT_EQ(0, ret);
1960
1961 /* gettid has been skipped and an altered return value stored. */
1962 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
1963 }
1964
1965 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
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_ERRNO | EPERM),
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 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1981 ASSERT_EQ(0, ret);
1982
1983 /* Install fixture filter. */
1984 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1985 ASSERT_EQ(0, ret);
1986
1987 /* Install "errno on getppid" filter. */
1988 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1989 ASSERT_EQ(0, ret);
1990
1991 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1992 errno = 0;
1993 EXPECT_EQ(-1, syscall(__NR_getpid));
1994 EXPECT_EQ(EPERM, errno);
1995 }
1996
1997 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1998 {
1999 struct sock_filter filter[] = {
2000 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2001 offsetof(struct seccomp_data, nr)),
2002 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2003 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2004 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2005 };
2006 struct sock_fprog prog = {
2007 .len = (unsigned short)ARRAY_SIZE(filter),
2008 .filter = filter,
2009 };
2010 long ret;
2011
2012 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2013 ASSERT_EQ(0, ret);
2014
2015 /* Install fixture filter. */
2016 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
2017 ASSERT_EQ(0, ret);
2018
2019 /* Install "death on getppid" filter. */
2020 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2021 ASSERT_EQ(0, ret);
2022
2023 /* Tracer will redirect getpid to getppid, and we should die. */
2024 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2025 }
2026
2027 TEST_F(TRACE_syscall, skip_after_ptrace)
2028 {
2029 struct sock_filter filter[] = {
2030 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2031 offsetof(struct seccomp_data, nr)),
2032 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2033 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2034 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2035 };
2036 struct sock_fprog prog = {
2037 .len = (unsigned short)ARRAY_SIZE(filter),
2038 .filter = filter,
2039 };
2040 long ret;
2041
2042 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
2043 teardown_trace_fixture(_metadata, self->tracer);
2044 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
2045 true);
2046
2047 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2048 ASSERT_EQ(0, ret);
2049
2050 /* Install "errno on getppid" filter. */
2051 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2052 ASSERT_EQ(0, ret);
2053
2054 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2055 EXPECT_EQ(-1, syscall(__NR_getpid));
2056 EXPECT_EQ(EPERM, errno);
2057 }
2058
2059 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
2060 {
2061 struct sock_filter filter[] = {
2062 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2063 offsetof(struct seccomp_data, nr)),
2064 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2065 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2066 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2067 };
2068 struct sock_fprog prog = {
2069 .len = (unsigned short)ARRAY_SIZE(filter),
2070 .filter = filter,
2071 };
2072 long ret;
2073
2074 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
2075 teardown_trace_fixture(_metadata, self->tracer);
2076 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
2077 true);
2078
2079 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2080 ASSERT_EQ(0, ret);
2081
2082 /* Install "death on getppid" filter. */
2083 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2084 ASSERT_EQ(0, ret);
2085
2086 /* Tracer will redirect getpid to getppid, and we should die. */
2087 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2088 }
2089
2090 TEST(seccomp_syscall)
2091 {
2092 struct sock_filter filter[] = {
2093 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2094 };
2095 struct sock_fprog prog = {
2096 .len = (unsigned short)ARRAY_SIZE(filter),
2097 .filter = filter,
2098 };
2099 long ret;
2100
2101 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2102 ASSERT_EQ(0, ret) {
2103 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2104 }
2105
2106 /* Reject insane operation. */
2107 ret = seccomp(-1, 0, &prog);
2108 ASSERT_NE(ENOSYS, errno) {
2109 TH_LOG("Kernel does not support seccomp syscall!");
2110 }
2111 EXPECT_EQ(EINVAL, errno) {
2112 TH_LOG("Did not reject crazy op value!");
2113 }
2114
2115 /* Reject strict with flags or pointer. */
2116 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2117 EXPECT_EQ(EINVAL, errno) {
2118 TH_LOG("Did not reject mode strict with flags!");
2119 }
2120 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2121 EXPECT_EQ(EINVAL, errno) {
2122 TH_LOG("Did not reject mode strict with uargs!");
2123 }
2124
2125 /* Reject insane args for filter. */
2126 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2127 EXPECT_EQ(EINVAL, errno) {
2128 TH_LOG("Did not reject crazy filter flags!");
2129 }
2130 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2131 EXPECT_EQ(EFAULT, errno) {
2132 TH_LOG("Did not reject NULL filter!");
2133 }
2134
2135 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2136 EXPECT_EQ(0, errno) {
2137 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2138 strerror(errno));
2139 }
2140 }
2141
2142 TEST(seccomp_syscall_mode_lock)
2143 {
2144 struct sock_filter filter[] = {
2145 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2146 };
2147 struct sock_fprog prog = {
2148 .len = (unsigned short)ARRAY_SIZE(filter),
2149 .filter = filter,
2150 };
2151 long ret;
2152
2153 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2154 ASSERT_EQ(0, ret) {
2155 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2156 }
2157
2158 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2159 ASSERT_NE(ENOSYS, errno) {
2160 TH_LOG("Kernel does not support seccomp syscall!");
2161 }
2162 EXPECT_EQ(0, ret) {
2163 TH_LOG("Could not install filter!");
2164 }
2165
2166 /* Make sure neither entry point will switch to strict. */
2167 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2168 EXPECT_EQ(EINVAL, errno) {
2169 TH_LOG("Switched to mode strict!");
2170 }
2171
2172 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2173 EXPECT_EQ(EINVAL, errno) {
2174 TH_LOG("Switched to mode strict!");
2175 }
2176 }
2177
2178 /*
2179 * Test detection of known and unknown filter flags. Userspace needs to be able
2180 * to check if a filter flag is supported by the current kernel and a good way
2181 * of doing that is by attempting to enter filter mode, with the flag bit in
2182 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2183 * that the flag is valid and EINVAL indicates that the flag is invalid.
2184 */
2185 TEST(detect_seccomp_filter_flags)
2186 {
2187 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2188 SECCOMP_FILTER_FLAG_LOG,
2189 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2190 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2191 unsigned int exclusive[] = {
2192 SECCOMP_FILTER_FLAG_TSYNC,
2193 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2194 unsigned int flag, all_flags, exclusive_mask;
2195 int i;
2196 long ret;
2197
2198 /* Test detection of individual known-good filter flags */
2199 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2200 int bits = 0;
2201
2202 flag = flags[i];
2203 /* Make sure the flag is a single bit! */
2204 while (flag) {
2205 if (flag & 0x1)
2206 bits ++;
2207 flag >>= 1;
2208 }
2209 ASSERT_EQ(1, bits);
2210 flag = flags[i];
2211
2212 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2213 ASSERT_NE(ENOSYS, errno) {
2214 TH_LOG("Kernel does not support seccomp syscall!");
2215 }
2216 EXPECT_EQ(-1, ret);
2217 EXPECT_EQ(EFAULT, errno) {
2218 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2219 flag);
2220 }
2221
2222 all_flags |= flag;
2223 }
2224
2225 /*
2226 * Test detection of all known-good filter flags combined. But
2227 * for the exclusive flags we need to mask them out and try them
2228 * individually for the "all flags" testing.
2229 */
2230 exclusive_mask = 0;
2231 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2232 exclusive_mask |= exclusive[i];
2233 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2234 flag = all_flags & ~exclusive_mask;
2235 flag |= exclusive[i];
2236
2237 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2238 EXPECT_EQ(-1, ret);
2239 EXPECT_EQ(EFAULT, errno) {
2240 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2241 flag);
2242 }
2243 }
2244
2245 /* Test detection of an unknown filter flags, without exclusives. */
2246 flag = -1;
2247 flag &= ~exclusive_mask;
2248 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2249 EXPECT_EQ(-1, ret);
2250 EXPECT_EQ(EINVAL, errno) {
2251 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2252 flag);
2253 }
2254
2255 /*
2256 * Test detection of an unknown filter flag that may simply need to be
2257 * added to this test
2258 */
2259 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2260 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2261 EXPECT_EQ(-1, ret);
2262 EXPECT_EQ(EINVAL, errno) {
2263 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?",
2264 flag);
2265 }
2266 }
2267
2268 TEST(TSYNC_first)
2269 {
2270 struct sock_filter filter[] = {
2271 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2272 };
2273 struct sock_fprog prog = {
2274 .len = (unsigned short)ARRAY_SIZE(filter),
2275 .filter = filter,
2276 };
2277 long ret;
2278
2279 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2280 ASSERT_EQ(0, ret) {
2281 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2282 }
2283
2284 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2285 &prog);
2286 ASSERT_NE(ENOSYS, errno) {
2287 TH_LOG("Kernel does not support seccomp syscall!");
2288 }
2289 EXPECT_EQ(0, ret) {
2290 TH_LOG("Could not install initial filter with TSYNC!");
2291 }
2292 }
2293
2294 #define TSYNC_SIBLINGS 2
2295 struct tsync_sibling {
2296 pthread_t tid;
2297 pid_t system_tid;
2298 sem_t *started;
2299 pthread_cond_t *cond;
2300 pthread_mutex_t *mutex;
2301 int diverge;
2302 int num_waits;
2303 struct sock_fprog *prog;
2304 struct __test_metadata *metadata;
2305 };
2306
2307 /*
2308 * To avoid joining joined threads (which is not allowed by Bionic),
2309 * make sure we both successfully join and clear the tid to skip a
2310 * later join attempt during fixture teardown. Any remaining threads
2311 * will be directly killed during teardown.
2312 */
2313 #define PTHREAD_JOIN(tid, status) \
2314 do { \
2315 int _rc = pthread_join(tid, status); \
2316 if (_rc) { \
2317 TH_LOG("pthread_join of tid %u failed: %d\n", \
2318 (unsigned int)tid, _rc); \
2319 } else { \
2320 tid = 0; \
2321 } \
2322 } while (0)
2323
2324 FIXTURE_DATA(TSYNC) {
2325 struct sock_fprog root_prog, apply_prog;
2326 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2327 sem_t started;
2328 pthread_cond_t cond;
2329 pthread_mutex_t mutex;
2330 int sibling_count;
2331 };
2332
2333 FIXTURE_SETUP(TSYNC)
2334 {
2335 struct sock_filter root_filter[] = {
2336 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2337 };
2338 struct sock_filter apply_filter[] = {
2339 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2340 offsetof(struct seccomp_data, nr)),
2341 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2342 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2343 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2344 };
2345
2346 memset(&self->root_prog, 0, sizeof(self->root_prog));
2347 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2348 memset(&self->sibling, 0, sizeof(self->sibling));
2349 self->root_prog.filter = malloc(sizeof(root_filter));
2350 ASSERT_NE(NULL, self->root_prog.filter);
2351 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2352 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2353
2354 self->apply_prog.filter = malloc(sizeof(apply_filter));
2355 ASSERT_NE(NULL, self->apply_prog.filter);
2356 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2357 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2358
2359 self->sibling_count = 0;
2360 pthread_mutex_init(&self->mutex, NULL);
2361 pthread_cond_init(&self->cond, NULL);
2362 sem_init(&self->started, 0, 0);
2363 self->sibling[0].tid = 0;
2364 self->sibling[0].cond = &self->cond;
2365 self->sibling[0].started = &self->started;
2366 self->sibling[0].mutex = &self->mutex;
2367 self->sibling[0].diverge = 0;
2368 self->sibling[0].num_waits = 1;
2369 self->sibling[0].prog = &self->root_prog;
2370 self->sibling[0].metadata = _metadata;
2371 self->sibling[1].tid = 0;
2372 self->sibling[1].cond = &self->cond;
2373 self->sibling[1].started = &self->started;
2374 self->sibling[1].mutex = &self->mutex;
2375 self->sibling[1].diverge = 0;
2376 self->sibling[1].prog = &self->root_prog;
2377 self->sibling[1].num_waits = 1;
2378 self->sibling[1].metadata = _metadata;
2379 }
2380
2381 FIXTURE_TEARDOWN(TSYNC)
2382 {
2383 int sib = 0;
2384
2385 if (self->root_prog.filter)
2386 free(self->root_prog.filter);
2387 if (self->apply_prog.filter)
2388 free(self->apply_prog.filter);
2389
2390 for ( ; sib < self->sibling_count; ++sib) {
2391 struct tsync_sibling *s = &self->sibling[sib];
2392
2393 if (!s->tid)
2394 continue;
2395 /*
2396 * If a thread is still running, it may be stuck, so hit
2397 * it over the head really hard.
2398 */
2399 pthread_kill(s->tid, 9);
2400 }
2401 pthread_mutex_destroy(&self->mutex);
2402 pthread_cond_destroy(&self->cond);
2403 sem_destroy(&self->started);
2404 }
2405
2406 void *tsync_sibling(void *data)
2407 {
2408 long ret = 0;
2409 struct tsync_sibling *me = data;
2410
2411 me->system_tid = syscall(__NR_gettid);
2412
2413 pthread_mutex_lock(me->mutex);
2414 if (me->diverge) {
2415 /* Just re-apply the root prog to fork the tree */
2416 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2417 me->prog, 0, 0);
2418 }
2419 sem_post(me->started);
2420 /* Return outside of started so parent notices failures. */
2421 if (ret) {
2422 pthread_mutex_unlock(me->mutex);
2423 return (void *)SIBLING_EXIT_FAILURE;
2424 }
2425 do {
2426 pthread_cond_wait(me->cond, me->mutex);
2427 me->num_waits = me->num_waits - 1;
2428 } while (me->num_waits);
2429 pthread_mutex_unlock(me->mutex);
2430
2431 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2432 if (!ret)
2433 return (void *)SIBLING_EXIT_NEWPRIVS;
2434 read(0, NULL, 0);
2435 return (void *)SIBLING_EXIT_UNKILLED;
2436 }
2437
2438 void tsync_start_sibling(struct tsync_sibling *sibling)
2439 {
2440 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2441 }
2442
2443 TEST_F(TSYNC, siblings_fail_prctl)
2444 {
2445 long ret;
2446 void *status;
2447 struct sock_filter filter[] = {
2448 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2449 offsetof(struct seccomp_data, nr)),
2450 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2451 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2452 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2453 };
2454 struct sock_fprog prog = {
2455 .len = (unsigned short)ARRAY_SIZE(filter),
2456 .filter = filter,
2457 };
2458
2459 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2460 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2461 }
2462
2463 /* Check prctl failure detection by requesting sib 0 diverge. */
2464 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2465 ASSERT_NE(ENOSYS, errno) {
2466 TH_LOG("Kernel does not support seccomp syscall!");
2467 }
2468 ASSERT_EQ(0, ret) {
2469 TH_LOG("setting filter failed");
2470 }
2471
2472 self->sibling[0].diverge = 1;
2473 tsync_start_sibling(&self->sibling[0]);
2474 tsync_start_sibling(&self->sibling[1]);
2475
2476 while (self->sibling_count < TSYNC_SIBLINGS) {
2477 sem_wait(&self->started);
2478 self->sibling_count++;
2479 }
2480
2481 /* Signal the threads to clean up*/
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 diverging sibling failed to call prctl. */
2489 PTHREAD_JOIN(self->sibling[0].tid, &status);
2490 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2491 PTHREAD_JOIN(self->sibling[1].tid, &status);
2492 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2493 }
2494
2495 TEST_F(TSYNC, two_siblings_with_ancestor)
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 tsync_start_sibling(&self->sibling[0]);
2512 tsync_start_sibling(&self->sibling[1]);
2513
2514 while (self->sibling_count < TSYNC_SIBLINGS) {
2515 sem_wait(&self->started);
2516 self->sibling_count++;
2517 }
2518
2519 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2520 &self->apply_prog);
2521 ASSERT_EQ(0, ret) {
2522 TH_LOG("Could install filter on all threads!");
2523 }
2524 /* Tell the siblings to test the policy */
2525 pthread_mutex_lock(&self->mutex);
2526 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2527 TH_LOG("cond broadcast non-zero");
2528 }
2529 pthread_mutex_unlock(&self->mutex);
2530 /* Ensure they are both killed and don't exit cleanly. */
2531 PTHREAD_JOIN(self->sibling[0].tid, &status);
2532 EXPECT_EQ(0x0, (long)status);
2533 PTHREAD_JOIN(self->sibling[1].tid, &status);
2534 EXPECT_EQ(0x0, (long)status);
2535 }
2536
2537 TEST_F(TSYNC, two_sibling_want_nnp)
2538 {
2539 void *status;
2540
2541 /* start siblings before any prctl() operations */
2542 tsync_start_sibling(&self->sibling[0]);
2543 tsync_start_sibling(&self->sibling[1]);
2544 while (self->sibling_count < TSYNC_SIBLINGS) {
2545 sem_wait(&self->started);
2546 self->sibling_count++;
2547 }
2548
2549 /* Tell the siblings to test no policy */
2550 pthread_mutex_lock(&self->mutex);
2551 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2552 TH_LOG("cond broadcast non-zero");
2553 }
2554 pthread_mutex_unlock(&self->mutex);
2555
2556 /* Ensure they are both upset about lacking nnp. */
2557 PTHREAD_JOIN(self->sibling[0].tid, &status);
2558 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2559 PTHREAD_JOIN(self->sibling[1].tid, &status);
2560 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2561 }
2562
2563 TEST_F(TSYNC, two_siblings_with_no_filter)
2564 {
2565 long ret;
2566 void *status;
2567
2568 /* start siblings before any prctl() operations */
2569 tsync_start_sibling(&self->sibling[0]);
2570 tsync_start_sibling(&self->sibling[1]);
2571 while (self->sibling_count < TSYNC_SIBLINGS) {
2572 sem_wait(&self->started);
2573 self->sibling_count++;
2574 }
2575
2576 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2577 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2578 }
2579
2580 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2581 &self->apply_prog);
2582 ASSERT_NE(ENOSYS, errno) {
2583 TH_LOG("Kernel does not support seccomp syscall!");
2584 }
2585 ASSERT_EQ(0, ret) {
2586 TH_LOG("Could install filter on all threads!");
2587 }
2588
2589 /* Tell the siblings to test the policy */
2590 pthread_mutex_lock(&self->mutex);
2591 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2592 TH_LOG("cond broadcast non-zero");
2593 }
2594 pthread_mutex_unlock(&self->mutex);
2595
2596 /* Ensure they are both killed and don't exit cleanly. */
2597 PTHREAD_JOIN(self->sibling[0].tid, &status);
2598 EXPECT_EQ(0x0, (long)status);
2599 PTHREAD_JOIN(self->sibling[1].tid, &status);
2600 EXPECT_EQ(0x0, (long)status);
2601 }
2602
2603 TEST_F(TSYNC, two_siblings_with_one_divergence)
2604 {
2605 long ret;
2606 void *status;
2607
2608 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2609 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2610 }
2611
2612 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2613 ASSERT_NE(ENOSYS, errno) {
2614 TH_LOG("Kernel does not support seccomp syscall!");
2615 }
2616 ASSERT_EQ(0, ret) {
2617 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2618 }
2619 self->sibling[0].diverge = 1;
2620 tsync_start_sibling(&self->sibling[0]);
2621 tsync_start_sibling(&self->sibling[1]);
2622
2623 while (self->sibling_count < TSYNC_SIBLINGS) {
2624 sem_wait(&self->started);
2625 self->sibling_count++;
2626 }
2627
2628 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2629 &self->apply_prog);
2630 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2631 TH_LOG("Did not fail on diverged sibling.");
2632 }
2633
2634 /* Wake the threads */
2635 pthread_mutex_lock(&self->mutex);
2636 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2637 TH_LOG("cond broadcast non-zero");
2638 }
2639 pthread_mutex_unlock(&self->mutex);
2640
2641 /* Ensure they are both unkilled. */
2642 PTHREAD_JOIN(self->sibling[0].tid, &status);
2643 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2644 PTHREAD_JOIN(self->sibling[1].tid, &status);
2645 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2646 }
2647
2648 TEST_F(TSYNC, two_siblings_not_under_filter)
2649 {
2650 long ret, sib;
2651 void *status;
2652 struct timespec delay = { .tv_nsec = 100000000 };
2653
2654 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2655 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2656 }
2657
2658 /*
2659 * Sibling 0 will have its own seccomp policy
2660 * and Sibling 1 will not be under seccomp at
2661 * all. Sibling 1 will enter seccomp and 0
2662 * will cause failure.
2663 */
2664 self->sibling[0].diverge = 1;
2665 tsync_start_sibling(&self->sibling[0]);
2666 tsync_start_sibling(&self->sibling[1]);
2667
2668 while (self->sibling_count < TSYNC_SIBLINGS) {
2669 sem_wait(&self->started);
2670 self->sibling_count++;
2671 }
2672
2673 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2674 ASSERT_NE(ENOSYS, errno) {
2675 TH_LOG("Kernel does not support seccomp syscall!");
2676 }
2677 ASSERT_EQ(0, ret) {
2678 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2679 }
2680
2681 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2682 &self->apply_prog);
2683 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2684 TH_LOG("Did not fail on diverged sibling.");
2685 }
2686 sib = 1;
2687 if (ret == self->sibling[0].system_tid)
2688 sib = 0;
2689
2690 pthread_mutex_lock(&self->mutex);
2691
2692 /* Increment the other siblings num_waits so we can clean up
2693 * the one we just saw.
2694 */
2695 self->sibling[!sib].num_waits += 1;
2696
2697 /* Signal the thread to clean up*/
2698 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2699 TH_LOG("cond broadcast non-zero");
2700 }
2701 pthread_mutex_unlock(&self->mutex);
2702 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2703 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2704 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2705 while (!kill(self->sibling[sib].system_tid, 0))
2706 nanosleep(&delay, NULL);
2707 /* Switch to the remaining sibling */
2708 sib = !sib;
2709
2710 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2711 &self->apply_prog);
2712 ASSERT_EQ(0, ret) {
2713 TH_LOG("Expected the remaining sibling to sync");
2714 };
2715
2716 pthread_mutex_lock(&self->mutex);
2717
2718 /* If remaining sibling didn't have a chance to wake up during
2719 * the first broadcast, manually reduce the num_waits now.
2720 */
2721 if (self->sibling[sib].num_waits > 1)
2722 self->sibling[sib].num_waits = 1;
2723 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2724 TH_LOG("cond broadcast non-zero");
2725 }
2726 pthread_mutex_unlock(&self->mutex);
2727 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2728 EXPECT_EQ(0, (long)status);
2729 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2730 while (!kill(self->sibling[sib].system_tid, 0))
2731 nanosleep(&delay, NULL);
2732
2733 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2734 &self->apply_prog);
2735 ASSERT_EQ(0, ret); /* just us chickens */
2736 }
2737
2738 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2739 TEST(syscall_restart)
2740 {
2741 long ret;
2742 unsigned long msg;
2743 pid_t child_pid;
2744 int pipefd[2];
2745 int status;
2746 siginfo_t info = { };
2747 struct sock_filter filter[] = {
2748 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2749 offsetof(struct seccomp_data, nr)),
2750
2751 #ifdef __NR_sigreturn
2752 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2753 #endif
2754 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2755 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2756 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2757 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2758 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2759
2760 /* Allow __NR_write for easy logging. */
2761 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2762 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2763 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2764 /* The nanosleep jump target. */
2765 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2766 /* The restart_syscall jump target. */
2767 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2768 };
2769 struct sock_fprog prog = {
2770 .len = (unsigned short)ARRAY_SIZE(filter),
2771 .filter = filter,
2772 };
2773 #if defined(__arm__)
2774 struct utsname utsbuf;
2775 #endif
2776
2777 ASSERT_EQ(0, pipe(pipefd));
2778
2779 child_pid = fork();
2780 ASSERT_LE(0, child_pid);
2781 if (child_pid == 0) {
2782 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2783 char buf = ' ';
2784 struct timespec timeout = { };
2785
2786 /* Attach parent as tracer and stop. */
2787 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2788 EXPECT_EQ(0, raise(SIGSTOP));
2789
2790 EXPECT_EQ(0, close(pipefd[1]));
2791
2792 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2793 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2794 }
2795
2796 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2797 EXPECT_EQ(0, ret) {
2798 TH_LOG("Failed to install filter!");
2799 }
2800
2801 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2802 TH_LOG("Failed to read() sync from parent");
2803 }
2804 EXPECT_EQ('.', buf) {
2805 TH_LOG("Failed to get sync data from read()");
2806 }
2807
2808 /* Start nanosleep to be interrupted. */
2809 timeout.tv_sec = 1;
2810 errno = 0;
2811 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2812 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2813 }
2814
2815 /* Read final sync from parent. */
2816 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2817 TH_LOG("Failed final read() from parent");
2818 }
2819 EXPECT_EQ('!', buf) {
2820 TH_LOG("Failed to get final data from read()");
2821 }
2822
2823 /* Directly report the status of our test harness results. */
2824 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2825 : EXIT_FAILURE);
2826 }
2827 EXPECT_EQ(0, close(pipefd[0]));
2828
2829 /* Attach to child, setup options, and release. */
2830 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2831 ASSERT_EQ(true, WIFSTOPPED(status));
2832 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2833 PTRACE_O_TRACESECCOMP));
2834 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2835 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2836
2837 /* Wait for nanosleep() to start. */
2838 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2839 ASSERT_EQ(true, WIFSTOPPED(status));
2840 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2841 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2842 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2843 ASSERT_EQ(0x100, msg);
2844 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2845
2846 /* Might as well check siginfo for sanity while we're here. */
2847 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2848 ASSERT_EQ(SIGTRAP, info.si_signo);
2849 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2850 EXPECT_EQ(0, info.si_errno);
2851 EXPECT_EQ(getuid(), info.si_uid);
2852 /* Verify signal delivery came from child (seccomp-triggered). */
2853 EXPECT_EQ(child_pid, info.si_pid);
2854
2855 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2856 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2857 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2858 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2859 ASSERT_EQ(true, WIFSTOPPED(status));
2860 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2861 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2862 /*
2863 * There is no siginfo on SIGSTOP any more, so we can't verify
2864 * signal delivery came from parent now (getpid() == info.si_pid).
2865 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
2866 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
2867 */
2868 EXPECT_EQ(SIGSTOP, info.si_signo);
2869
2870 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2871 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2872 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2873 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2874 ASSERT_EQ(true, WIFSTOPPED(status));
2875 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2876 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2877
2878 /* Wait for restart_syscall() to start. */
2879 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2880 ASSERT_EQ(true, WIFSTOPPED(status));
2881 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2882 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2883 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2884
2885 ASSERT_EQ(0x200, msg);
2886 ret = get_syscall(_metadata, child_pid);
2887 #if defined(__arm__)
2888 /*
2889 * FIXME:
2890 * - native ARM registers do NOT expose true syscall.
2891 * - compat ARM registers on ARM64 DO expose true syscall.
2892 */
2893 ASSERT_EQ(0, uname(&utsbuf));
2894 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2895 EXPECT_EQ(__NR_nanosleep, ret);
2896 } else
2897 #endif
2898 {
2899 EXPECT_EQ(__NR_restart_syscall, ret);
2900 }
2901
2902 /* Write again to end test. */
2903 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2904 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2905 EXPECT_EQ(0, close(pipefd[1]));
2906
2907 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2908 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2909 _metadata->passed = 0;
2910 }
2911
2912 TEST_SIGNAL(filter_flag_log, SIGSYS)
2913 {
2914 struct sock_filter allow_filter[] = {
2915 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2916 };
2917 struct sock_filter kill_filter[] = {
2918 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2919 offsetof(struct seccomp_data, nr)),
2920 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2921 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2922 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2923 };
2924 struct sock_fprog allow_prog = {
2925 .len = (unsigned short)ARRAY_SIZE(allow_filter),
2926 .filter = allow_filter,
2927 };
2928 struct sock_fprog kill_prog = {
2929 .len = (unsigned short)ARRAY_SIZE(kill_filter),
2930 .filter = kill_filter,
2931 };
2932 long ret;
2933 pid_t parent = getppid();
2934
2935 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2936 ASSERT_EQ(0, ret);
2937
2938 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
2939 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
2940 &allow_prog);
2941 ASSERT_NE(ENOSYS, errno) {
2942 TH_LOG("Kernel does not support seccomp syscall!");
2943 }
2944 EXPECT_NE(0, ret) {
2945 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
2946 }
2947 EXPECT_EQ(EINVAL, errno) {
2948 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
2949 }
2950
2951 /* Verify that a simple, permissive filter can be added with no flags */
2952 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
2953 EXPECT_EQ(0, ret);
2954
2955 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
2956 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2957 &allow_prog);
2958 ASSERT_NE(EINVAL, errno) {
2959 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
2960 }
2961 EXPECT_EQ(0, ret);
2962
2963 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
2964 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2965 &kill_prog);
2966 EXPECT_EQ(0, ret);
2967
2968 EXPECT_EQ(parent, syscall(__NR_getppid));
2969 /* getpid() should never return. */
2970 EXPECT_EQ(0, syscall(__NR_getpid));
2971 }
2972
2973 TEST(get_action_avail)
2974 {
2975 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
2976 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
2977 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
2978 __u32 unknown_action = 0x10000000U;
2979 int i;
2980 long ret;
2981
2982 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
2983 ASSERT_NE(ENOSYS, errno) {
2984 TH_LOG("Kernel does not support seccomp syscall!");
2985 }
2986 ASSERT_NE(EINVAL, errno) {
2987 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
2988 }
2989 EXPECT_EQ(ret, 0);
2990
2991 for (i = 0; i < ARRAY_SIZE(actions); i++) {
2992 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
2993 EXPECT_EQ(ret, 0) {
2994 TH_LOG("Expected action (0x%X) not available!",
2995 actions[i]);
2996 }
2997 }
2998
2999 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
3000 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
3001 EXPECT_EQ(ret, -1);
3002 EXPECT_EQ(errno, EOPNOTSUPP);
3003 }
3004
3005 TEST(get_metadata)
3006 {
3007 pid_t pid;
3008 int pipefd[2];
3009 char buf;
3010 struct seccomp_metadata md;
3011 long ret;
3012
3013 /* Only real root can get metadata. */
3014 if (geteuid()) {
3015 XFAIL(return, "get_metadata requires real root");
3016 return;
3017 }
3018
3019 ASSERT_EQ(0, pipe(pipefd));
3020
3021 pid = fork();
3022 ASSERT_GE(pid, 0);
3023 if (pid == 0) {
3024 struct sock_filter filter[] = {
3025 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3026 };
3027 struct sock_fprog prog = {
3028 .len = (unsigned short)ARRAY_SIZE(filter),
3029 .filter = filter,
3030 };
3031
3032 /* one with log, one without */
3033 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3034 SECCOMP_FILTER_FLAG_LOG, &prog));
3035 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3036
3037 EXPECT_EQ(0, close(pipefd[0]));
3038 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3039 ASSERT_EQ(0, close(pipefd[1]));
3040
3041 while (1)
3042 sleep(100);
3043 }
3044
3045 ASSERT_EQ(0, close(pipefd[1]));
3046 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3047
3048 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3049 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3050
3051 /* Past here must not use ASSERT or child process is never killed. */
3052
3053 md.filter_off = 0;
3054 errno = 0;
3055 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3056 EXPECT_EQ(sizeof(md), ret) {
3057 if (errno == EINVAL)
3058 XFAIL(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3059 }
3060
3061 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3062 EXPECT_EQ(md.filter_off, 0);
3063
3064 md.filter_off = 1;
3065 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3066 EXPECT_EQ(sizeof(md), ret);
3067 EXPECT_EQ(md.flags, 0);
3068 EXPECT_EQ(md.filter_off, 1);
3069
3070 skip:
3071 ASSERT_EQ(0, kill(pid, SIGKILL));
3072 }
3073
3074 static int user_trap_syscall(int nr, unsigned int flags)
3075 {
3076 struct sock_filter filter[] = {
3077 BPF_STMT(BPF_LD+BPF_W+BPF_ABS,
3078 offsetof(struct seccomp_data, nr)),
3079 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, nr, 0, 1),
3080 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_USER_NOTIF),
3081 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
3082 };
3083
3084 struct sock_fprog prog = {
3085 .len = (unsigned short)ARRAY_SIZE(filter),
3086 .filter = filter,
3087 };
3088
3089 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3090 }
3091
3092 #define USER_NOTIF_MAGIC INT_MAX
3093 TEST(user_notification_basic)
3094 {
3095 pid_t pid;
3096 long ret;
3097 int status, listener;
3098 struct seccomp_notif req = {};
3099 struct seccomp_notif_resp resp = {};
3100 struct pollfd pollfd;
3101
3102 struct sock_filter filter[] = {
3103 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3104 };
3105 struct sock_fprog prog = {
3106 .len = (unsigned short)ARRAY_SIZE(filter),
3107 .filter = filter,
3108 };
3109
3110 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3111 ASSERT_EQ(0, ret) {
3112 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3113 }
3114
3115 pid = fork();
3116 ASSERT_GE(pid, 0);
3117
3118 /* Check that we get -ENOSYS with no listener attached */
3119 if (pid == 0) {
3120 if (user_trap_syscall(__NR_getppid, 0) < 0)
3121 exit(1);
3122 ret = syscall(__NR_getppid);
3123 exit(ret >= 0 || errno != ENOSYS);
3124 }
3125
3126 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3127 EXPECT_EQ(true, WIFEXITED(status));
3128 EXPECT_EQ(0, WEXITSTATUS(status));
3129
3130 /* Add some no-op filters for grins. */
3131 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3132 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3133 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3134 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3135
3136 /* Check that the basic notification machinery works */
3137 listener = user_trap_syscall(__NR_getppid,
3138 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3139 ASSERT_GE(listener, 0);
3140
3141 /* Installing a second listener in the chain should EBUSY */
3142 EXPECT_EQ(user_trap_syscall(__NR_getppid,
3143 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3144 -1);
3145 EXPECT_EQ(errno, EBUSY);
3146
3147 pid = fork();
3148 ASSERT_GE(pid, 0);
3149
3150 if (pid == 0) {
3151 ret = syscall(__NR_getppid);
3152 exit(ret != USER_NOTIF_MAGIC);
3153 }
3154
3155 pollfd.fd = listener;
3156 pollfd.events = POLLIN | POLLOUT;
3157
3158 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3159 EXPECT_EQ(pollfd.revents, POLLIN);
3160
3161 /* Test that we can't pass garbage to the kernel. */
3162 memset(&req, 0, sizeof(req));
3163 req.pid = -1;
3164 errno = 0;
3165 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
3166 EXPECT_EQ(-1, ret);
3167 EXPECT_EQ(EINVAL, errno);
3168
3169 if (ret) {
3170 req.pid = 0;
3171 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3172 }
3173
3174 pollfd.fd = listener;
3175 pollfd.events = POLLIN | POLLOUT;
3176
3177 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3178 EXPECT_EQ(pollfd.revents, POLLOUT);
3179
3180 EXPECT_EQ(req.data.nr, __NR_getppid);
3181
3182 resp.id = req.id;
3183 resp.error = 0;
3184 resp.val = USER_NOTIF_MAGIC;
3185
3186 /* check that we make sure flags == 0 */
3187 resp.flags = 1;
3188 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3189 EXPECT_EQ(errno, EINVAL);
3190
3191 resp.flags = 0;
3192 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3193
3194 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3195 EXPECT_EQ(true, WIFEXITED(status));
3196 EXPECT_EQ(0, WEXITSTATUS(status));
3197 }
3198
3199 TEST(user_notification_kill_in_middle)
3200 {
3201 pid_t pid;
3202 long ret;
3203 int listener;
3204 struct seccomp_notif req = {};
3205 struct seccomp_notif_resp resp = {};
3206
3207 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3208 ASSERT_EQ(0, ret) {
3209 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3210 }
3211
3212 listener = user_trap_syscall(__NR_getppid,
3213 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3214 ASSERT_GE(listener, 0);
3215
3216 /*
3217 * Check that nothing bad happens when we kill the task in the middle
3218 * of a syscall.
3219 */
3220 pid = fork();
3221 ASSERT_GE(pid, 0);
3222
3223 if (pid == 0) {
3224 ret = syscall(__NR_getppid);
3225 exit(ret != USER_NOTIF_MAGIC);
3226 }
3227
3228 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3229 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3230
3231 EXPECT_EQ(kill(pid, SIGKILL), 0);
3232 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3233
3234 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3235
3236 resp.id = req.id;
3237 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3238 EXPECT_EQ(ret, -1);
3239 EXPECT_EQ(errno, ENOENT);
3240 }
3241
3242 static int handled = -1;
3243
3244 static void signal_handler(int signal)
3245 {
3246 if (write(handled, "c", 1) != 1)
3247 perror("write from signal");
3248 }
3249
3250 TEST(user_notification_signal)
3251 {
3252 pid_t pid;
3253 long ret;
3254 int status, listener, sk_pair[2];
3255 struct seccomp_notif req = {};
3256 struct seccomp_notif_resp resp = {};
3257 char c;
3258
3259 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3260 ASSERT_EQ(0, ret) {
3261 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3262 }
3263
3264 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3265
3266 listener = user_trap_syscall(__NR_gettid,
3267 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3268 ASSERT_GE(listener, 0);
3269
3270 pid = fork();
3271 ASSERT_GE(pid, 0);
3272
3273 if (pid == 0) {
3274 close(sk_pair[0]);
3275 handled = sk_pair[1];
3276 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3277 perror("signal");
3278 exit(1);
3279 }
3280 /*
3281 * ERESTARTSYS behavior is a bit hard to test, because we need
3282 * to rely on a signal that has not yet been handled. Let's at
3283 * least check that the error code gets propagated through, and
3284 * hope that it doesn't break when there is actually a signal :)
3285 */
3286 ret = syscall(__NR_gettid);
3287 exit(!(ret == -1 && errno == 512));
3288 }
3289
3290 close(sk_pair[1]);
3291
3292 memset(&req, 0, sizeof(req));
3293 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3294
3295 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3296
3297 /*
3298 * Make sure the signal really is delivered, which means we're not
3299 * stuck in the user notification code any more and the notification
3300 * should be dead.
3301 */
3302 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3303
3304 resp.id = req.id;
3305 resp.error = -EPERM;
3306 resp.val = 0;
3307
3308 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3309 EXPECT_EQ(errno, ENOENT);
3310
3311 memset(&req, 0, sizeof(req));
3312 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3313
3314 resp.id = req.id;
3315 resp.error = -512; /* -ERESTARTSYS */
3316 resp.val = 0;
3317
3318 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3319
3320 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3321 EXPECT_EQ(true, WIFEXITED(status));
3322 EXPECT_EQ(0, WEXITSTATUS(status));
3323 }
3324
3325 TEST(user_notification_closed_listener)
3326 {
3327 pid_t pid;
3328 long ret;
3329 int status, listener;
3330
3331 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3332 ASSERT_EQ(0, ret) {
3333 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3334 }
3335
3336 listener = user_trap_syscall(__NR_getppid,
3337 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3338 ASSERT_GE(listener, 0);
3339
3340 /*
3341 * Check that we get an ENOSYS when the listener is closed.
3342 */
3343 pid = fork();
3344 ASSERT_GE(pid, 0);
3345 if (pid == 0) {
3346 close(listener);
3347 ret = syscall(__NR_getppid);
3348 exit(ret != -1 && errno != ENOSYS);
3349 }
3350
3351 close(listener);
3352
3353 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3354 EXPECT_EQ(true, WIFEXITED(status));
3355 EXPECT_EQ(0, WEXITSTATUS(status));
3356 }
3357
3358 /*
3359 * Check that a pid in a child namespace still shows up as valid in ours.
3360 */
3361 TEST(user_notification_child_pid_ns)
3362 {
3363 pid_t pid;
3364 int status, listener;
3365 struct seccomp_notif req = {};
3366 struct seccomp_notif_resp resp = {};
3367
3368 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0);
3369
3370 listener = user_trap_syscall(__NR_getppid,
3371 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3372 ASSERT_GE(listener, 0);
3373
3374 pid = fork();
3375 ASSERT_GE(pid, 0);
3376
3377 if (pid == 0)
3378 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3379
3380 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3381 EXPECT_EQ(req.pid, pid);
3382
3383 resp.id = req.id;
3384 resp.error = 0;
3385 resp.val = USER_NOTIF_MAGIC;
3386
3387 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3388
3389 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3390 EXPECT_EQ(true, WIFEXITED(status));
3391 EXPECT_EQ(0, WEXITSTATUS(status));
3392 close(listener);
3393 }
3394
3395 /*
3396 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3397 * invalid.
3398 */
3399 TEST(user_notification_sibling_pid_ns)
3400 {
3401 pid_t pid, pid2;
3402 int status, listener;
3403 struct seccomp_notif req = {};
3404 struct seccomp_notif_resp resp = {};
3405
3406 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3407 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3408 }
3409
3410 listener = user_trap_syscall(__NR_getppid,
3411 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3412 ASSERT_GE(listener, 0);
3413
3414 pid = fork();
3415 ASSERT_GE(pid, 0);
3416
3417 if (pid == 0) {
3418 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3419
3420 pid2 = fork();
3421 ASSERT_GE(pid2, 0);
3422
3423 if (pid2 == 0)
3424 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3425
3426 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3427 EXPECT_EQ(true, WIFEXITED(status));
3428 EXPECT_EQ(0, WEXITSTATUS(status));
3429 exit(WEXITSTATUS(status));
3430 }
3431
3432 /* Create the sibling ns, and sibling in it. */
3433 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3434 ASSERT_EQ(errno, 0);
3435
3436 pid2 = fork();
3437 ASSERT_GE(pid2, 0);
3438
3439 if (pid2 == 0) {
3440 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3441 /*
3442 * The pid should be 0, i.e. the task is in some namespace that
3443 * we can't "see".
3444 */
3445 EXPECT_EQ(req.pid, 0);
3446
3447 resp.id = req.id;
3448 resp.error = 0;
3449 resp.val = USER_NOTIF_MAGIC;
3450
3451 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3452 exit(0);
3453 }
3454
3455 close(listener);
3456
3457 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3458 EXPECT_EQ(true, WIFEXITED(status));
3459 EXPECT_EQ(0, WEXITSTATUS(status));
3460
3461 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3462 EXPECT_EQ(true, WIFEXITED(status));
3463 EXPECT_EQ(0, WEXITSTATUS(status));
3464 }
3465
3466 TEST(user_notification_fault_recv)
3467 {
3468 pid_t pid;
3469 int status, listener;
3470 struct seccomp_notif req = {};
3471 struct seccomp_notif_resp resp = {};
3472
3473 ASSERT_EQ(unshare(CLONE_NEWUSER), 0);
3474
3475 listener = user_trap_syscall(__NR_getppid,
3476 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3477 ASSERT_GE(listener, 0);
3478
3479 pid = fork();
3480 ASSERT_GE(pid, 0);
3481
3482 if (pid == 0)
3483 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3484
3485 /* Do a bad recv() */
3486 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3487 EXPECT_EQ(errno, EFAULT);
3488
3489 /* We should still be able to receive this notification, though. */
3490 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3491 EXPECT_EQ(req.pid, pid);
3492
3493 resp.id = req.id;
3494 resp.error = 0;
3495 resp.val = USER_NOTIF_MAGIC;
3496
3497 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3498
3499 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3500 EXPECT_EQ(true, WIFEXITED(status));
3501 EXPECT_EQ(0, WEXITSTATUS(status));
3502 }
3503
3504 TEST(seccomp_get_notif_sizes)
3505 {
3506 struct seccomp_notif_sizes sizes;
3507
3508 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3509 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3510 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3511 }
3512
3513 static int filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
3514 {
3515 #ifdef __NR_kcmp
3516 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
3517 #else
3518 errno = ENOSYS;
3519 return -1;
3520 #endif
3521 }
3522
3523 TEST(user_notification_continue)
3524 {
3525 pid_t pid;
3526 long ret;
3527 int status, listener;
3528 struct seccomp_notif req = {};
3529 struct seccomp_notif_resp resp = {};
3530 struct pollfd pollfd;
3531
3532 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3533 ASSERT_EQ(0, ret) {
3534 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3535 }
3536
3537 listener = user_trap_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3538 ASSERT_GE(listener, 0);
3539
3540 pid = fork();
3541 ASSERT_GE(pid, 0);
3542
3543 if (pid == 0) {
3544 int dup_fd, pipe_fds[2];
3545 pid_t self;
3546
3547 ret = pipe(pipe_fds);
3548 if (ret < 0)
3549 exit(1);
3550
3551 dup_fd = dup(pipe_fds[0]);
3552 if (dup_fd < 0)
3553 exit(1);
3554
3555 self = getpid();
3556
3557 ret = filecmp(self, self, pipe_fds[0], dup_fd);
3558 if (ret)
3559 exit(2);
3560
3561 exit(0);
3562 }
3563
3564 pollfd.fd = listener;
3565 pollfd.events = POLLIN | POLLOUT;
3566
3567 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3568 EXPECT_EQ(pollfd.revents, POLLIN);
3569
3570 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3571
3572 pollfd.fd = listener;
3573 pollfd.events = POLLIN | POLLOUT;
3574
3575 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3576 EXPECT_EQ(pollfd.revents, POLLOUT);
3577
3578 EXPECT_EQ(req.data.nr, __NR_dup);
3579
3580 resp.id = req.id;
3581 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
3582
3583 /*
3584 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
3585 * args be set to 0.
3586 */
3587 resp.error = 0;
3588 resp.val = USER_NOTIF_MAGIC;
3589 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3590 EXPECT_EQ(errno, EINVAL);
3591
3592 resp.error = USER_NOTIF_MAGIC;
3593 resp.val = 0;
3594 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3595 EXPECT_EQ(errno, EINVAL);
3596
3597 resp.error = 0;
3598 resp.val = 0;
3599 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
3600 if (errno == EINVAL)
3601 XFAIL(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
3602 }
3603
3604 skip:
3605 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3606 EXPECT_EQ(true, WIFEXITED(status));
3607 EXPECT_EQ(0, WEXITSTATUS(status)) {
3608 if (WEXITSTATUS(status) == 2) {
3609 XFAIL(return, "Kernel does not support kcmp() syscall");
3610 return;
3611 }
3612 }
3613 }
3614
3615 /*
3616 * TODO:
3617 * - add microbenchmarks
3618 * - expand NNP testing
3619 * - better arch-specific TRACE and TRAP handlers.
3620 * - endianness checking when appropriate
3621 * - 64-bit arg prodding
3622 * - arch value testing (x86 modes especially)
3623 * - verify that FILTER_FLAG_LOG filters generate log messages
3624 * - verify that RET_LOG generates log messages
3625 * - ...
3626 */
3627
3628 TEST_HARNESS_MAIN
Linux with added FPC-III support