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 #include <sys/resource.h>
49 #include <sys/capability.h>
50
51 #include <unistd.h>
52 #include <sys/syscall.h>
53 #include <poll.h>
54
55 #include "../kselftest_harness.h"
56 #include "../clone3/clone3_selftests.h"
57
58 /* Attempt to de-conflict with the selftests tree. */
59 #ifndef SKIP
60 #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
61 #endif
62
63 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
64
65 #ifndef PR_SET_PTRACER
66 # define PR_SET_PTRACER 0x59616d61
67 #endif
68
69 #ifndef PR_SET_NO_NEW_PRIVS
70 #define PR_SET_NO_NEW_PRIVS 38
71 #define PR_GET_NO_NEW_PRIVS 39
72 #endif
73
74 #ifndef PR_SECCOMP_EXT
75 #define PR_SECCOMP_EXT 43
76 #endif
77
78 #ifndef SECCOMP_EXT_ACT
79 #define SECCOMP_EXT_ACT 1
80 #endif
81
82 #ifndef SECCOMP_EXT_ACT_TSYNC
83 #define SECCOMP_EXT_ACT_TSYNC 1
84 #endif
85
86 #ifndef SECCOMP_MODE_STRICT
87 #define SECCOMP_MODE_STRICT 1
88 #endif
89
90 #ifndef SECCOMP_MODE_FILTER
91 #define SECCOMP_MODE_FILTER 2
92 #endif
93
94 #ifndef SECCOMP_RET_ALLOW
95 struct seccomp_data {
96 int nr;
97 __u32 arch;
98 __u64 instruction_pointer;
99 __u64 args[6];
100 };
101 #endif
102
103 #ifndef SECCOMP_RET_KILL_PROCESS
104 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
105 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
106 #endif
107 #ifndef SECCOMP_RET_KILL
108 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
109 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
110 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
111 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
112 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
113 #endif
114 #ifndef SECCOMP_RET_LOG
115 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
116 #endif
117
118 #ifndef __NR_seccomp
119 # if defined(__i386__)
120 # define __NR_seccomp 354
121 # elif defined(__x86_64__)
122 # define __NR_seccomp 317
123 # elif defined(__arm__)
124 # define __NR_seccomp 383
125 # elif defined(__aarch64__)
126 # define __NR_seccomp 277
127 # elif defined(__riscv)
128 # define __NR_seccomp 277
129 # elif defined(__csky__)
130 # define __NR_seccomp 277
131 # elif defined(__hppa__)
132 # define __NR_seccomp 338
133 # elif defined(__powerpc__)
134 # define __NR_seccomp 358
135 # elif defined(__s390__)
136 # define __NR_seccomp 348
137 # elif defined(__xtensa__)
138 # define __NR_seccomp 337
139 # elif defined(__sh__)
140 # define __NR_seccomp 372
141 # else
142 # warning "seccomp syscall number unknown for this architecture"
143 # define __NR_seccomp 0xffff
144 # endif
145 #endif
146
147 #ifndef SECCOMP_SET_MODE_STRICT
148 #define SECCOMP_SET_MODE_STRICT 0
149 #endif
150
151 #ifndef SECCOMP_SET_MODE_FILTER
152 #define SECCOMP_SET_MODE_FILTER 1
153 #endif
154
155 #ifndef SECCOMP_GET_ACTION_AVAIL
156 #define SECCOMP_GET_ACTION_AVAIL 2
157 #endif
158
159 #ifndef SECCOMP_GET_NOTIF_SIZES
160 #define SECCOMP_GET_NOTIF_SIZES 3
161 #endif
162
163 #ifndef SECCOMP_FILTER_FLAG_TSYNC
164 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
165 #endif
166
167 #ifndef SECCOMP_FILTER_FLAG_LOG
168 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
169 #endif
170
171 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
172 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
173 #endif
174
175 #ifndef PTRACE_SECCOMP_GET_METADATA
176 #define PTRACE_SECCOMP_GET_METADATA 0x420d
177
178 struct seccomp_metadata {
179 __u64 filter_off; /* Input: which filter */
180 __u64 flags; /* Output: filter's flags */
181 };
182 #endif
183
184 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
185 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
186 #endif
187
188 #ifndef SECCOMP_RET_USER_NOTIF
189 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
190
191 #define SECCOMP_IOC_MAGIC '!'
192 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
193 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
194 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
195 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
196
197 /* Flags for seccomp notification fd ioctl. */
198 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
199 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
200 struct seccomp_notif_resp)
201 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)
202
203 struct seccomp_notif {
204 __u64 id;
205 __u32 pid;
206 __u32 flags;
207 struct seccomp_data data;
208 };
209
210 struct seccomp_notif_resp {
211 __u64 id;
212 __s64 val;
213 __s32 error;
214 __u32 flags;
215 };
216
217 struct seccomp_notif_sizes {
218 __u16 seccomp_notif;
219 __u16 seccomp_notif_resp;
220 __u16 seccomp_data;
221 };
222 #endif
223
224 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD
225 /* On success, the return value is the remote process's added fd number */
226 #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \
227 struct seccomp_notif_addfd)
228
229 /* valid flags for seccomp_notif_addfd */
230 #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */
231
232 struct seccomp_notif_addfd {
233 __u64 id;
234 __u32 flags;
235 __u32 srcfd;
236 __u32 newfd;
237 __u32 newfd_flags;
238 };
239 #endif
240
241 #ifndef SECCOMP_ADDFD_FLAG_SEND
242 #define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */
243 #endif
244
245 struct seccomp_notif_addfd_small {
246 __u64 id;
247 char weird[4];
248 };
249 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \
250 SECCOMP_IOW(3, struct seccomp_notif_addfd_small)
251
252 struct seccomp_notif_addfd_big {
253 union {
254 struct seccomp_notif_addfd addfd;
255 char buf[sizeof(struct seccomp_notif_addfd) + 8];
256 };
257 };
258 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \
259 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big)
260
261 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
262 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
263 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
264 #endif
265
266 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
267 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
268 #endif
269
270 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
271 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
272 #endif
273
274 #ifndef SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
275 #define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5)
276 #endif
277
278 #ifndef seccomp
seccomp(unsigned int op,unsigned int flags,void * args)279 int seccomp(unsigned int op, unsigned int flags, void *args)
280 {
281 errno = 0;
282 return syscall(__NR_seccomp, op, flags, args);
283 }
284 #endif
285
286 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
287 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
288 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
289 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
290 #else
291 #error "wut? Unknown __BYTE_ORDER__?!"
292 #endif
293
294 #define SIBLING_EXIT_UNKILLED 0xbadbeef
295 #define SIBLING_EXIT_FAILURE 0xbadface
296 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
297
__filecmp(pid_t pid1,pid_t pid2,int fd1,int fd2)298 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
299 {
300 #ifdef __NR_kcmp
301 errno = 0;
302 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
303 #else
304 errno = ENOSYS;
305 return -1;
306 #endif
307 }
308
309 /* Have TH_LOG report actual location filecmp() is used. */
310 #define filecmp(pid1, pid2, fd1, fd2) ({ \
311 int _ret; \
312 \
313 _ret = __filecmp(pid1, pid2, fd1, fd2); \
314 if (_ret != 0) { \
315 if (_ret < 0 && errno == ENOSYS) { \
316 TH_LOG("kcmp() syscall missing (test is less accurate)");\
317 _ret = 0; \
318 } \
319 } \
320 _ret; })
321
TEST(kcmp)322 TEST(kcmp)
323 {
324 int ret;
325
326 ret = __filecmp(getpid(), getpid(), 1, 1);
327 EXPECT_EQ(ret, 0);
328 if (ret != 0 && errno == ENOSYS)
329 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)");
330 }
331
TEST(mode_strict_support)332 TEST(mode_strict_support)
333 {
334 long ret;
335
336 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
337 ASSERT_EQ(0, ret) {
338 TH_LOG("Kernel does not support CONFIG_SECCOMP");
339 }
340 syscall(__NR_exit, 0);
341 }
342
TEST_SIGNAL(mode_strict_cannot_call_prctl,SIGKILL)343 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
344 {
345 long ret;
346
347 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
348 ASSERT_EQ(0, ret) {
349 TH_LOG("Kernel does not support CONFIG_SECCOMP");
350 }
351 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
352 NULL, NULL, NULL);
353 EXPECT_FALSE(true) {
354 TH_LOG("Unreachable!");
355 }
356 }
357
358 /* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)359 TEST(no_new_privs_support)
360 {
361 long ret;
362
363 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
364 EXPECT_EQ(0, ret) {
365 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
366 }
367 }
368
369 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)370 TEST(mode_filter_support)
371 {
372 long ret;
373
374 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
375 ASSERT_EQ(0, ret) {
376 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
377 }
378 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
379 EXPECT_EQ(-1, ret);
380 EXPECT_EQ(EFAULT, errno) {
381 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
382 }
383 }
384
TEST(mode_filter_without_nnp)385 TEST(mode_filter_without_nnp)
386 {
387 struct sock_filter filter[] = {
388 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
389 };
390 struct sock_fprog prog = {
391 .len = (unsigned short)ARRAY_SIZE(filter),
392 .filter = filter,
393 };
394 long ret;
395
396 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
397 ASSERT_LE(0, ret) {
398 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
399 }
400 errno = 0;
401 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
402 /* Succeeds with CAP_SYS_ADMIN, fails without */
403 /* TODO(wad) check caps not euid */
404 if (geteuid()) {
405 EXPECT_EQ(-1, ret);
406 EXPECT_EQ(EACCES, errno);
407 } else {
408 EXPECT_EQ(0, ret);
409 }
410 }
411
412 #define MAX_INSNS_PER_PATH 32768
413
TEST(filter_size_limits)414 TEST(filter_size_limits)
415 {
416 int i;
417 int count = BPF_MAXINSNS + 1;
418 struct sock_filter allow[] = {
419 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
420 };
421 struct sock_filter *filter;
422 struct sock_fprog prog = { };
423 long ret;
424
425 filter = calloc(count, sizeof(*filter));
426 ASSERT_NE(NULL, filter);
427
428 for (i = 0; i < count; i++)
429 filter[i] = allow[0];
430
431 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
432 ASSERT_EQ(0, ret);
433
434 prog.filter = filter;
435 prog.len = count;
436
437 /* Too many filter instructions in a single filter. */
438 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
439 ASSERT_NE(0, ret) {
440 TH_LOG("Installing %d insn filter was allowed", prog.len);
441 }
442
443 /* One less is okay, though. */
444 prog.len -= 1;
445 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
446 ASSERT_EQ(0, ret) {
447 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
448 }
449 }
450
TEST(filter_chain_limits)451 TEST(filter_chain_limits)
452 {
453 int i;
454 int count = BPF_MAXINSNS;
455 struct sock_filter allow[] = {
456 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
457 };
458 struct sock_filter *filter;
459 struct sock_fprog prog = { };
460 long ret;
461
462 filter = calloc(count, sizeof(*filter));
463 ASSERT_NE(NULL, filter);
464
465 for (i = 0; i < count; i++)
466 filter[i] = allow[0];
467
468 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
469 ASSERT_EQ(0, ret);
470
471 prog.filter = filter;
472 prog.len = 1;
473
474 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
475 ASSERT_EQ(0, ret);
476
477 prog.len = count;
478
479 /* Too many total filter instructions. */
480 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
481 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
482 if (ret != 0)
483 break;
484 }
485 ASSERT_NE(0, ret) {
486 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
487 i, count, i * (count + 4));
488 }
489 }
490
TEST(mode_filter_cannot_move_to_strict)491 TEST(mode_filter_cannot_move_to_strict)
492 {
493 struct sock_filter filter[] = {
494 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
495 };
496 struct sock_fprog prog = {
497 .len = (unsigned short)ARRAY_SIZE(filter),
498 .filter = filter,
499 };
500 long ret;
501
502 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
503 ASSERT_EQ(0, ret);
504
505 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
506 ASSERT_EQ(0, ret);
507
508 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
509 EXPECT_EQ(-1, ret);
510 EXPECT_EQ(EINVAL, errno);
511 }
512
513
TEST(mode_filter_get_seccomp)514 TEST(mode_filter_get_seccomp)
515 {
516 struct sock_filter filter[] = {
517 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
518 };
519 struct sock_fprog prog = {
520 .len = (unsigned short)ARRAY_SIZE(filter),
521 .filter = filter,
522 };
523 long ret;
524
525 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
526 ASSERT_EQ(0, ret);
527
528 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
529 EXPECT_EQ(0, ret);
530
531 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
532 ASSERT_EQ(0, ret);
533
534 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
535 EXPECT_EQ(2, ret);
536 }
537
538
TEST(ALLOW_all)539 TEST(ALLOW_all)
540 {
541 struct sock_filter filter[] = {
542 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
543 };
544 struct sock_fprog prog = {
545 .len = (unsigned short)ARRAY_SIZE(filter),
546 .filter = filter,
547 };
548 long ret;
549
550 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
551 ASSERT_EQ(0, ret);
552
553 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
554 ASSERT_EQ(0, ret);
555 }
556
TEST(empty_prog)557 TEST(empty_prog)
558 {
559 struct sock_filter filter[] = {
560 };
561 struct sock_fprog prog = {
562 .len = (unsigned short)ARRAY_SIZE(filter),
563 .filter = filter,
564 };
565 long ret;
566
567 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
568 ASSERT_EQ(0, ret);
569
570 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
571 EXPECT_EQ(-1, ret);
572 EXPECT_EQ(EINVAL, errno);
573 }
574
TEST(log_all)575 TEST(log_all)
576 {
577 struct sock_filter filter[] = {
578 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
579 };
580 struct sock_fprog prog = {
581 .len = (unsigned short)ARRAY_SIZE(filter),
582 .filter = filter,
583 };
584 long ret;
585 pid_t parent = getppid();
586
587 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
588 ASSERT_EQ(0, ret);
589
590 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
591 ASSERT_EQ(0, ret);
592
593 /* getppid() should succeed and be logged (no check for logging) */
594 EXPECT_EQ(parent, syscall(__NR_getppid));
595 }
596
TEST_SIGNAL(unknown_ret_is_kill_inside,SIGSYS)597 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
598 {
599 struct sock_filter filter[] = {
600 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
601 };
602 struct sock_fprog prog = {
603 .len = (unsigned short)ARRAY_SIZE(filter),
604 .filter = filter,
605 };
606 long ret;
607
608 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
609 ASSERT_EQ(0, ret);
610
611 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
612 ASSERT_EQ(0, ret);
613 EXPECT_EQ(0, syscall(__NR_getpid)) {
614 TH_LOG("getpid() shouldn't ever return");
615 }
616 }
617
618 /* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow,SIGSYS)619 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
620 {
621 struct sock_filter filter[] = {
622 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
623 };
624 struct sock_fprog prog = {
625 .len = (unsigned short)ARRAY_SIZE(filter),
626 .filter = filter,
627 };
628 long ret;
629
630 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
631 ASSERT_EQ(0, ret);
632
633 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
634 ASSERT_EQ(0, ret);
635 EXPECT_EQ(0, syscall(__NR_getpid)) {
636 TH_LOG("getpid() shouldn't ever return");
637 }
638 }
639
TEST_SIGNAL(KILL_all,SIGSYS)640 TEST_SIGNAL(KILL_all, SIGSYS)
641 {
642 struct sock_filter filter[] = {
643 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
644 };
645 struct sock_fprog prog = {
646 .len = (unsigned short)ARRAY_SIZE(filter),
647 .filter = filter,
648 };
649 long ret;
650
651 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
652 ASSERT_EQ(0, ret);
653
654 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
655 ASSERT_EQ(0, ret);
656 }
657
TEST_SIGNAL(KILL_one,SIGSYS)658 TEST_SIGNAL(KILL_one, SIGSYS)
659 {
660 struct sock_filter filter[] = {
661 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
662 offsetof(struct seccomp_data, nr)),
663 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
664 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
665 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
666 };
667 struct sock_fprog prog = {
668 .len = (unsigned short)ARRAY_SIZE(filter),
669 .filter = filter,
670 };
671 long ret;
672 pid_t parent = getppid();
673
674 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
675 ASSERT_EQ(0, ret);
676
677 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
678 ASSERT_EQ(0, ret);
679
680 EXPECT_EQ(parent, syscall(__NR_getppid));
681 /* getpid() should never return. */
682 EXPECT_EQ(0, syscall(__NR_getpid));
683 }
684
TEST_SIGNAL(KILL_one_arg_one,SIGSYS)685 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
686 {
687 void *fatal_address;
688 struct sock_filter filter[] = {
689 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
690 offsetof(struct seccomp_data, nr)),
691 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
692 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
693 /* Only both with lower 32-bit for now. */
694 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
695 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
696 (unsigned long)&fatal_address, 0, 1),
697 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
698 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
699 };
700 struct sock_fprog prog = {
701 .len = (unsigned short)ARRAY_SIZE(filter),
702 .filter = filter,
703 };
704 long ret;
705 pid_t parent = getppid();
706 struct tms timebuf;
707 clock_t clock = times(&timebuf);
708
709 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
710 ASSERT_EQ(0, ret);
711
712 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
713 ASSERT_EQ(0, ret);
714
715 EXPECT_EQ(parent, syscall(__NR_getppid));
716 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
717 /* times() should never return. */
718 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
719 }
720
TEST_SIGNAL(KILL_one_arg_six,SIGSYS)721 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
722 {
723 #ifndef __NR_mmap2
724 int sysno = __NR_mmap;
725 #else
726 int sysno = __NR_mmap2;
727 #endif
728 struct sock_filter filter[] = {
729 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
730 offsetof(struct seccomp_data, nr)),
731 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
732 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
733 /* Only both with lower 32-bit for now. */
734 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
735 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
736 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
737 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
738 };
739 struct sock_fprog prog = {
740 .len = (unsigned short)ARRAY_SIZE(filter),
741 .filter = filter,
742 };
743 long ret;
744 pid_t parent = getppid();
745 int fd;
746 void *map1, *map2;
747 int page_size = sysconf(_SC_PAGESIZE);
748
749 ASSERT_LT(0, page_size);
750
751 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
752 ASSERT_EQ(0, ret);
753
754 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
755 ASSERT_EQ(0, ret);
756
757 fd = open("/dev/zero", O_RDONLY);
758 ASSERT_NE(-1, fd);
759
760 EXPECT_EQ(parent, syscall(__NR_getppid));
761 map1 = (void *)syscall(sysno,
762 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
763 EXPECT_NE(MAP_FAILED, map1);
764 /* mmap2() should never return. */
765 map2 = (void *)syscall(sysno,
766 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
767 EXPECT_EQ(MAP_FAILED, map2);
768
769 /* The test failed, so clean up the resources. */
770 munmap(map1, page_size);
771 munmap(map2, page_size);
772 close(fd);
773 }
774
775 /* This is a thread task to die via seccomp filter violation. */
kill_thread(void * data)776 void *kill_thread(void *data)
777 {
778 bool die = (bool)data;
779
780 if (die) {
781 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
782 return (void *)SIBLING_EXIT_FAILURE;
783 }
784
785 return (void *)SIBLING_EXIT_UNKILLED;
786 }
787
788 enum kill_t {
789 KILL_THREAD,
790 KILL_PROCESS,
791 RET_UNKNOWN
792 };
793
794 /* Prepare a thread that will kill itself or both of us. */
kill_thread_or_group(struct __test_metadata * _metadata,enum kill_t kill_how)795 void kill_thread_or_group(struct __test_metadata *_metadata,
796 enum kill_t kill_how)
797 {
798 pthread_t thread;
799 void *status;
800 /* Kill only when calling __NR_prctl. */
801 struct sock_filter filter_thread[] = {
802 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
803 offsetof(struct seccomp_data, nr)),
804 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
805 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
806 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
807 };
808 struct sock_fprog prog_thread = {
809 .len = (unsigned short)ARRAY_SIZE(filter_thread),
810 .filter = filter_thread,
811 };
812 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAA;
813 struct sock_filter filter_process[] = {
814 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
815 offsetof(struct seccomp_data, nr)),
816 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
817 BPF_STMT(BPF_RET|BPF_K, kill),
818 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
819 };
820 struct sock_fprog prog_process = {
821 .len = (unsigned short)ARRAY_SIZE(filter_process),
822 .filter = filter_process,
823 };
824
825 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
826 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
827 }
828
829 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
830 kill_how == KILL_THREAD ? &prog_thread
831 : &prog_process));
832
833 /*
834 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
835 * flag cannot be downgraded by a new filter.
836 */
837 if (kill_how == KILL_PROCESS)
838 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
839
840 /* Start a thread that will exit immediately. */
841 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
842 ASSERT_EQ(0, pthread_join(thread, &status));
843 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
844
845 /* Start a thread that will die immediately. */
846 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
847 ASSERT_EQ(0, pthread_join(thread, &status));
848 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
849
850 /*
851 * If we get here, only the spawned thread died. Let the parent know
852 * the whole process didn't die (i.e. this thread, the spawner,
853 * stayed running).
854 */
855 exit(42);
856 }
857
TEST(KILL_thread)858 TEST(KILL_thread)
859 {
860 int status;
861 pid_t child_pid;
862
863 child_pid = fork();
864 ASSERT_LE(0, child_pid);
865 if (child_pid == 0) {
866 kill_thread_or_group(_metadata, KILL_THREAD);
867 _exit(38);
868 }
869
870 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
871
872 /* If only the thread was killed, we'll see exit 42. */
873 ASSERT_TRUE(WIFEXITED(status));
874 ASSERT_EQ(42, WEXITSTATUS(status));
875 }
876
TEST(KILL_process)877 TEST(KILL_process)
878 {
879 int status;
880 pid_t child_pid;
881
882 child_pid = fork();
883 ASSERT_LE(0, child_pid);
884 if (child_pid == 0) {
885 kill_thread_or_group(_metadata, KILL_PROCESS);
886 _exit(38);
887 }
888
889 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
890
891 /* If the entire process was killed, we'll see SIGSYS. */
892 ASSERT_TRUE(WIFSIGNALED(status));
893 ASSERT_EQ(SIGSYS, WTERMSIG(status));
894 }
895
TEST(KILL_unknown)896 TEST(KILL_unknown)
897 {
898 int status;
899 pid_t child_pid;
900
901 child_pid = fork();
902 ASSERT_LE(0, child_pid);
903 if (child_pid == 0) {
904 kill_thread_or_group(_metadata, RET_UNKNOWN);
905 _exit(38);
906 }
907
908 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
909
910 /* If the entire process was killed, we'll see SIGSYS. */
911 EXPECT_TRUE(WIFSIGNALED(status)) {
912 TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
913 }
914 ASSERT_EQ(SIGSYS, WTERMSIG(status));
915 }
916
917 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)918 TEST(arg_out_of_range)
919 {
920 struct sock_filter filter[] = {
921 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
922 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
923 };
924 struct sock_fprog prog = {
925 .len = (unsigned short)ARRAY_SIZE(filter),
926 .filter = filter,
927 };
928 long ret;
929
930 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
931 ASSERT_EQ(0, ret);
932
933 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
934 EXPECT_EQ(-1, ret);
935 EXPECT_EQ(EINVAL, errno);
936 }
937
938 #define ERRNO_FILTER(name, errno) \
939 struct sock_filter _read_filter_##name[] = { \
940 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
941 offsetof(struct seccomp_data, nr)), \
942 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
943 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
944 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
945 }; \
946 struct sock_fprog prog_##name = { \
947 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
948 .filter = _read_filter_##name, \
949 }
950
951 /* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)952 TEST(ERRNO_valid)
953 {
954 ERRNO_FILTER(valid, E2BIG);
955 long ret;
956 pid_t parent = getppid();
957
958 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
959 ASSERT_EQ(0, ret);
960
961 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
962 ASSERT_EQ(0, ret);
963
964 EXPECT_EQ(parent, syscall(__NR_getppid));
965 EXPECT_EQ(-1, read(-1, NULL, 0));
966 EXPECT_EQ(E2BIG, errno);
967 }
968
969 /* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)970 TEST(ERRNO_zero)
971 {
972 ERRNO_FILTER(zero, 0);
973 long ret;
974 pid_t parent = getppid();
975
976 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
977 ASSERT_EQ(0, ret);
978
979 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
980 ASSERT_EQ(0, ret);
981
982 EXPECT_EQ(parent, syscall(__NR_getppid));
983 /* "errno" of 0 is ok. */
984 EXPECT_EQ(0, read(-1, NULL, 0));
985 }
986
987 /*
988 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
989 * This tests that the errno value gets capped correctly, fixed by
990 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
991 */
TEST(ERRNO_capped)992 TEST(ERRNO_capped)
993 {
994 ERRNO_FILTER(capped, 4096);
995 long ret;
996 pid_t parent = getppid();
997
998 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
999 ASSERT_EQ(0, ret);
1000
1001 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
1002 ASSERT_EQ(0, ret);
1003
1004 EXPECT_EQ(parent, syscall(__NR_getppid));
1005 EXPECT_EQ(-1, read(-1, NULL, 0));
1006 EXPECT_EQ(4095, errno);
1007 }
1008
1009 /*
1010 * Filters are processed in reverse order: last applied is executed first.
1011 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
1012 * SECCOMP_RET_DATA mask results will follow the most recently applied
1013 * matching filter return (and not the lowest or highest value).
1014 */
TEST(ERRNO_order)1015 TEST(ERRNO_order)
1016 {
1017 ERRNO_FILTER(first, 11);
1018 ERRNO_FILTER(second, 13);
1019 ERRNO_FILTER(third, 12);
1020 long ret;
1021 pid_t parent = getppid();
1022
1023 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1024 ASSERT_EQ(0, ret);
1025
1026 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
1027 ASSERT_EQ(0, ret);
1028
1029 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
1030 ASSERT_EQ(0, ret);
1031
1032 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
1033 ASSERT_EQ(0, ret);
1034
1035 EXPECT_EQ(parent, syscall(__NR_getppid));
1036 EXPECT_EQ(-1, read(-1, NULL, 0));
1037 EXPECT_EQ(12, errno);
1038 }
1039
FIXTURE(TRAP)1040 FIXTURE(TRAP) {
1041 struct sock_fprog prog;
1042 };
1043
FIXTURE_SETUP(TRAP)1044 FIXTURE_SETUP(TRAP)
1045 {
1046 struct sock_filter filter[] = {
1047 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1048 offsetof(struct seccomp_data, nr)),
1049 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1050 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1051 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1052 };
1053
1054 memset(&self->prog, 0, sizeof(self->prog));
1055 self->prog.filter = malloc(sizeof(filter));
1056 ASSERT_NE(NULL, self->prog.filter);
1057 memcpy(self->prog.filter, filter, sizeof(filter));
1058 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1059 }
1060
FIXTURE_TEARDOWN(TRAP)1061 FIXTURE_TEARDOWN(TRAP)
1062 {
1063 if (self->prog.filter)
1064 free(self->prog.filter);
1065 }
1066
TEST_F_SIGNAL(TRAP,dfl,SIGSYS)1067 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
1068 {
1069 long ret;
1070
1071 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1072 ASSERT_EQ(0, ret);
1073
1074 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1075 ASSERT_EQ(0, ret);
1076 syscall(__NR_getpid);
1077 }
1078
1079 /* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP,ign,SIGSYS)1080 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
1081 {
1082 long ret;
1083
1084 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1085 ASSERT_EQ(0, ret);
1086
1087 signal(SIGSYS, SIG_IGN);
1088
1089 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1090 ASSERT_EQ(0, ret);
1091 syscall(__NR_getpid);
1092 }
1093
1094 static siginfo_t TRAP_info;
1095 static volatile int TRAP_nr;
TRAP_action(int nr,siginfo_t * info,void * void_context)1096 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
1097 {
1098 memcpy(&TRAP_info, info, sizeof(TRAP_info));
1099 TRAP_nr = nr;
1100 }
1101
TEST_F(TRAP,handler)1102 TEST_F(TRAP, handler)
1103 {
1104 int ret, test;
1105 struct sigaction act;
1106 sigset_t mask;
1107
1108 memset(&act, 0, sizeof(act));
1109 sigemptyset(&mask);
1110 sigaddset(&mask, SIGSYS);
1111
1112 act.sa_sigaction = &TRAP_action;
1113 act.sa_flags = SA_SIGINFO;
1114 ret = sigaction(SIGSYS, &act, NULL);
1115 ASSERT_EQ(0, ret) {
1116 TH_LOG("sigaction failed");
1117 }
1118 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
1119 ASSERT_EQ(0, ret) {
1120 TH_LOG("sigprocmask failed");
1121 }
1122
1123 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1124 ASSERT_EQ(0, ret);
1125 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1126 ASSERT_EQ(0, ret);
1127 TRAP_nr = 0;
1128 memset(&TRAP_info, 0, sizeof(TRAP_info));
1129 /* Expect the registers to be rolled back. (nr = error) may vary
1130 * based on arch. */
1131 ret = syscall(__NR_getpid);
1132 /* Silence gcc warning about volatile. */
1133 test = TRAP_nr;
1134 EXPECT_EQ(SIGSYS, test);
1135 struct local_sigsys {
1136 void *_call_addr; /* calling user insn */
1137 int _syscall; /* triggering system call number */
1138 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1139 } *sigsys = (struct local_sigsys *)
1140 #ifdef si_syscall
1141 &(TRAP_info.si_call_addr);
1142 #else
1143 &TRAP_info.si_pid;
1144 #endif
1145 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1146 /* Make sure arch is non-zero. */
1147 EXPECT_NE(0, sigsys->_arch);
1148 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1149 }
1150
FIXTURE(precedence)1151 FIXTURE(precedence) {
1152 struct sock_fprog allow;
1153 struct sock_fprog log;
1154 struct sock_fprog trace;
1155 struct sock_fprog error;
1156 struct sock_fprog trap;
1157 struct sock_fprog kill;
1158 };
1159
FIXTURE_SETUP(precedence)1160 FIXTURE_SETUP(precedence)
1161 {
1162 struct sock_filter allow_insns[] = {
1163 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1164 };
1165 struct sock_filter log_insns[] = {
1166 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1167 offsetof(struct seccomp_data, nr)),
1168 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1169 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1170 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1171 };
1172 struct sock_filter trace_insns[] = {
1173 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1174 offsetof(struct seccomp_data, nr)),
1175 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1176 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1177 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1178 };
1179 struct sock_filter error_insns[] = {
1180 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1181 offsetof(struct seccomp_data, nr)),
1182 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1183 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1184 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1185 };
1186 struct sock_filter trap_insns[] = {
1187 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1188 offsetof(struct seccomp_data, nr)),
1189 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1190 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1191 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1192 };
1193 struct sock_filter kill_insns[] = {
1194 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1195 offsetof(struct seccomp_data, nr)),
1196 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1197 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1198 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1199 };
1200
1201 memset(self, 0, sizeof(*self));
1202 #define FILTER_ALLOC(_x) \
1203 self->_x.filter = malloc(sizeof(_x##_insns)); \
1204 ASSERT_NE(NULL, self->_x.filter); \
1205 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1206 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1207 FILTER_ALLOC(allow);
1208 FILTER_ALLOC(log);
1209 FILTER_ALLOC(trace);
1210 FILTER_ALLOC(error);
1211 FILTER_ALLOC(trap);
1212 FILTER_ALLOC(kill);
1213 }
1214
FIXTURE_TEARDOWN(precedence)1215 FIXTURE_TEARDOWN(precedence)
1216 {
1217 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1218 FILTER_FREE(allow);
1219 FILTER_FREE(log);
1220 FILTER_FREE(trace);
1221 FILTER_FREE(error);
1222 FILTER_FREE(trap);
1223 FILTER_FREE(kill);
1224 }
1225
TEST_F(precedence,allow_ok)1226 TEST_F(precedence, allow_ok)
1227 {
1228 pid_t parent, res = 0;
1229 long ret;
1230
1231 parent = getppid();
1232 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1233 ASSERT_EQ(0, ret);
1234
1235 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1236 ASSERT_EQ(0, ret);
1237 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1238 ASSERT_EQ(0, ret);
1239 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1240 ASSERT_EQ(0, ret);
1241 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1242 ASSERT_EQ(0, ret);
1243 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1244 ASSERT_EQ(0, ret);
1245 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1246 ASSERT_EQ(0, ret);
1247 /* Should work just fine. */
1248 res = syscall(__NR_getppid);
1249 EXPECT_EQ(parent, res);
1250 }
1251
TEST_F_SIGNAL(precedence,kill_is_highest,SIGSYS)1252 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1253 {
1254 pid_t parent, res = 0;
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->allow);
1262 ASSERT_EQ(0, ret);
1263 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
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->error);
1268 ASSERT_EQ(0, ret);
1269 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1270 ASSERT_EQ(0, ret);
1271 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1272 ASSERT_EQ(0, ret);
1273 /* Should work just fine. */
1274 res = syscall(__NR_getppid);
1275 EXPECT_EQ(parent, res);
1276 /* getpid() should never return. */
1277 res = syscall(__NR_getpid);
1278 EXPECT_EQ(0, res);
1279 }
1280
TEST_F_SIGNAL(precedence,kill_is_highest_in_any_order,SIGSYS)1281 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1282 {
1283 pid_t parent;
1284 long ret;
1285
1286 parent = getppid();
1287 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1288 ASSERT_EQ(0, ret);
1289
1290 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1291 ASSERT_EQ(0, ret);
1292 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1293 ASSERT_EQ(0, ret);
1294 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1295 ASSERT_EQ(0, ret);
1296 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1297 ASSERT_EQ(0, ret);
1298 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1299 ASSERT_EQ(0, ret);
1300 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1301 ASSERT_EQ(0, ret);
1302 /* Should work just fine. */
1303 EXPECT_EQ(parent, syscall(__NR_getppid));
1304 /* getpid() should never return. */
1305 EXPECT_EQ(0, syscall(__NR_getpid));
1306 }
1307
TEST_F_SIGNAL(precedence,trap_is_second,SIGSYS)1308 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1309 {
1310 pid_t parent;
1311 long ret;
1312
1313 parent = getppid();
1314 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1315 ASSERT_EQ(0, ret);
1316
1317 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1318 ASSERT_EQ(0, ret);
1319 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1320 ASSERT_EQ(0, ret);
1321 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1322 ASSERT_EQ(0, ret);
1323 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1324 ASSERT_EQ(0, ret);
1325 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1326 ASSERT_EQ(0, ret);
1327 /* Should work just fine. */
1328 EXPECT_EQ(parent, syscall(__NR_getppid));
1329 /* getpid() should never return. */
1330 EXPECT_EQ(0, syscall(__NR_getpid));
1331 }
1332
TEST_F_SIGNAL(precedence,trap_is_second_in_any_order,SIGSYS)1333 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1334 {
1335 pid_t parent;
1336 long ret;
1337
1338 parent = getppid();
1339 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1340 ASSERT_EQ(0, ret);
1341
1342 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1343 ASSERT_EQ(0, ret);
1344 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1345 ASSERT_EQ(0, ret);
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->trace);
1349 ASSERT_EQ(0, ret);
1350 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1351 ASSERT_EQ(0, ret);
1352 /* Should work just fine. */
1353 EXPECT_EQ(parent, syscall(__NR_getppid));
1354 /* getpid() should never return. */
1355 EXPECT_EQ(0, syscall(__NR_getpid));
1356 }
1357
TEST_F(precedence,errno_is_third)1358 TEST_F(precedence, errno_is_third)
1359 {
1360 pid_t parent;
1361 long ret;
1362
1363 parent = getppid();
1364 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1365 ASSERT_EQ(0, ret);
1366
1367 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1368 ASSERT_EQ(0, ret);
1369 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1370 ASSERT_EQ(0, ret);
1371 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1372 ASSERT_EQ(0, ret);
1373 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1374 ASSERT_EQ(0, ret);
1375 /* Should work just fine. */
1376 EXPECT_EQ(parent, syscall(__NR_getppid));
1377 EXPECT_EQ(0, syscall(__NR_getpid));
1378 }
1379
TEST_F(precedence,errno_is_third_in_any_order)1380 TEST_F(precedence, errno_is_third_in_any_order)
1381 {
1382 pid_t parent;
1383 long ret;
1384
1385 parent = getppid();
1386 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1387 ASSERT_EQ(0, ret);
1388
1389 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1390 ASSERT_EQ(0, ret);
1391 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1392 ASSERT_EQ(0, ret);
1393 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1394 ASSERT_EQ(0, ret);
1395 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1396 ASSERT_EQ(0, ret);
1397 /* Should work just fine. */
1398 EXPECT_EQ(parent, syscall(__NR_getppid));
1399 EXPECT_EQ(0, syscall(__NR_getpid));
1400 }
1401
TEST_F(precedence,trace_is_fourth)1402 TEST_F(precedence, trace_is_fourth)
1403 {
1404 pid_t parent;
1405 long ret;
1406
1407 parent = getppid();
1408 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1409 ASSERT_EQ(0, ret);
1410
1411 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1412 ASSERT_EQ(0, ret);
1413 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1414 ASSERT_EQ(0, ret);
1415 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1416 ASSERT_EQ(0, ret);
1417 /* Should work just fine. */
1418 EXPECT_EQ(parent, syscall(__NR_getppid));
1419 /* No ptracer */
1420 EXPECT_EQ(-1, syscall(__NR_getpid));
1421 }
1422
TEST_F(precedence,trace_is_fourth_in_any_order)1423 TEST_F(precedence, trace_is_fourth_in_any_order)
1424 {
1425 pid_t parent;
1426 long ret;
1427
1428 parent = getppid();
1429 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1430 ASSERT_EQ(0, ret);
1431
1432 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1433 ASSERT_EQ(0, ret);
1434 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1435 ASSERT_EQ(0, ret);
1436 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1437 ASSERT_EQ(0, ret);
1438 /* Should work just fine. */
1439 EXPECT_EQ(parent, syscall(__NR_getppid));
1440 /* No ptracer */
1441 EXPECT_EQ(-1, syscall(__NR_getpid));
1442 }
1443
TEST_F(precedence,log_is_fifth)1444 TEST_F(precedence, log_is_fifth)
1445 {
1446 pid_t mypid, parent;
1447 long ret;
1448
1449 mypid = getpid();
1450 parent = getppid();
1451 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1452 ASSERT_EQ(0, ret);
1453
1454 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1455 ASSERT_EQ(0, ret);
1456 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1457 ASSERT_EQ(0, ret);
1458 /* Should work just fine. */
1459 EXPECT_EQ(parent, syscall(__NR_getppid));
1460 /* Should also work just fine */
1461 EXPECT_EQ(mypid, syscall(__NR_getpid));
1462 }
1463
TEST_F(precedence,log_is_fifth_in_any_order)1464 TEST_F(precedence, log_is_fifth_in_any_order)
1465 {
1466 pid_t mypid, parent;
1467 long ret;
1468
1469 mypid = getpid();
1470 parent = getppid();
1471 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1472 ASSERT_EQ(0, ret);
1473
1474 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1475 ASSERT_EQ(0, ret);
1476 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1477 ASSERT_EQ(0, ret);
1478 /* Should work just fine. */
1479 EXPECT_EQ(parent, syscall(__NR_getppid));
1480 /* Should also work just fine */
1481 EXPECT_EQ(mypid, syscall(__NR_getpid));
1482 }
1483
1484 #ifndef PTRACE_O_TRACESECCOMP
1485 #define PTRACE_O_TRACESECCOMP 0x00000080
1486 #endif
1487
1488 /* Catch the Ubuntu 12.04 value error. */
1489 #if PTRACE_EVENT_SECCOMP != 7
1490 #undef PTRACE_EVENT_SECCOMP
1491 #endif
1492
1493 #ifndef PTRACE_EVENT_SECCOMP
1494 #define PTRACE_EVENT_SECCOMP 7
1495 #endif
1496
1497 #define PTRACE_EVENT_MASK(status) ((status) >> 16)
1498 bool tracer_running;
tracer_stop(int sig)1499 void tracer_stop(int sig)
1500 {
1501 tracer_running = false;
1502 }
1503
1504 typedef void tracer_func_t(struct __test_metadata *_metadata,
1505 pid_t tracee, int status, void *args);
1506
start_tracer(struct __test_metadata * _metadata,int fd,pid_t tracee,tracer_func_t tracer_func,void * args,bool ptrace_syscall)1507 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1508 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1509 {
1510 int ret = -1;
1511 struct sigaction action = {
1512 .sa_handler = tracer_stop,
1513 };
1514
1515 /* Allow external shutdown. */
1516 tracer_running = true;
1517 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1518
1519 errno = 0;
1520 while (ret == -1 && errno != EINVAL)
1521 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1522 ASSERT_EQ(0, ret) {
1523 kill(tracee, SIGKILL);
1524 }
1525 /* Wait for attach stop */
1526 wait(NULL);
1527
1528 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1529 PTRACE_O_TRACESYSGOOD :
1530 PTRACE_O_TRACESECCOMP);
1531 ASSERT_EQ(0, ret) {
1532 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1533 kill(tracee, SIGKILL);
1534 }
1535 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1536 tracee, NULL, 0);
1537 ASSERT_EQ(0, ret);
1538
1539 /* Unblock the tracee */
1540 ASSERT_EQ(1, write(fd, "A", 1));
1541 ASSERT_EQ(0, close(fd));
1542
1543 /* Run until we're shut down. Must assert to stop execution. */
1544 while (tracer_running) {
1545 int status;
1546
1547 if (wait(&status) != tracee)
1548 continue;
1549
1550 if (WIFSIGNALED(status)) {
1551 /* Child caught a fatal signal. */
1552 return;
1553 }
1554 if (WIFEXITED(status)) {
1555 /* Child exited with code. */
1556 return;
1557 }
1558
1559 /* Check if we got an expected event. */
1560 ASSERT_EQ(WIFCONTINUED(status), false);
1561 ASSERT_EQ(WIFSTOPPED(status), true);
1562 ASSERT_EQ(WSTOPSIG(status) & SIGTRAP, SIGTRAP) {
1563 TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
1564 }
1565
1566 tracer_func(_metadata, tracee, status, args);
1567
1568 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1569 tracee, NULL, 0);
1570 ASSERT_EQ(0, ret);
1571 }
1572 /* Directly report the status of our test harness results. */
1573 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1574 }
1575
1576 /* Common tracer setup/teardown functions. */
cont_handler(int num)1577 void cont_handler(int num)
1578 { }
setup_trace_fixture(struct __test_metadata * _metadata,tracer_func_t func,void * args,bool ptrace_syscall)1579 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1580 tracer_func_t func, void *args, bool ptrace_syscall)
1581 {
1582 char sync;
1583 int pipefd[2];
1584 pid_t tracer_pid;
1585 pid_t tracee = getpid();
1586
1587 /* Setup a pipe for clean synchronization. */
1588 ASSERT_EQ(0, pipe(pipefd));
1589
1590 /* Fork a child which we'll promote to tracer */
1591 tracer_pid = fork();
1592 ASSERT_LE(0, tracer_pid);
1593 signal(SIGALRM, cont_handler);
1594 if (tracer_pid == 0) {
1595 close(pipefd[0]);
1596 start_tracer(_metadata, pipefd[1], tracee, func, args,
1597 ptrace_syscall);
1598 syscall(__NR_exit, 0);
1599 }
1600 close(pipefd[1]);
1601 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1602 read(pipefd[0], &sync, 1);
1603 close(pipefd[0]);
1604
1605 return tracer_pid;
1606 }
1607
teardown_trace_fixture(struct __test_metadata * _metadata,pid_t tracer)1608 void teardown_trace_fixture(struct __test_metadata *_metadata,
1609 pid_t tracer)
1610 {
1611 if (tracer) {
1612 int status;
1613 /*
1614 * Extract the exit code from the other process and
1615 * adopt it for ourselves in case its asserts failed.
1616 */
1617 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1618 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1619 if (WEXITSTATUS(status))
1620 _metadata->passed = 0;
1621 }
1622 }
1623
1624 /* "poke" tracer arguments and function. */
1625 struct tracer_args_poke_t {
1626 unsigned long poke_addr;
1627 };
1628
tracer_poke(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1629 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1630 void *args)
1631 {
1632 int ret;
1633 unsigned long msg;
1634 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1635
1636 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1637 EXPECT_EQ(0, ret);
1638 /* If this fails, don't try to recover. */
1639 ASSERT_EQ(0x1001, msg) {
1640 kill(tracee, SIGKILL);
1641 }
1642 /*
1643 * Poke in the message.
1644 * Registers are not touched to try to keep this relatively arch
1645 * agnostic.
1646 */
1647 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1648 EXPECT_EQ(0, ret);
1649 }
1650
FIXTURE(TRACE_poke)1651 FIXTURE(TRACE_poke) {
1652 struct sock_fprog prog;
1653 pid_t tracer;
1654 long poked;
1655 struct tracer_args_poke_t tracer_args;
1656 };
1657
FIXTURE_SETUP(TRACE_poke)1658 FIXTURE_SETUP(TRACE_poke)
1659 {
1660 struct sock_filter filter[] = {
1661 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1662 offsetof(struct seccomp_data, nr)),
1663 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1664 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1665 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1666 };
1667
1668 self->poked = 0;
1669 memset(&self->prog, 0, sizeof(self->prog));
1670 self->prog.filter = malloc(sizeof(filter));
1671 ASSERT_NE(NULL, self->prog.filter);
1672 memcpy(self->prog.filter, filter, sizeof(filter));
1673 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1674
1675 /* Set up tracer args. */
1676 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1677
1678 /* Launch tracer. */
1679 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1680 &self->tracer_args, false);
1681 }
1682
FIXTURE_TEARDOWN(TRACE_poke)1683 FIXTURE_TEARDOWN(TRACE_poke)
1684 {
1685 teardown_trace_fixture(_metadata, self->tracer);
1686 if (self->prog.filter)
1687 free(self->prog.filter);
1688 }
1689
TEST_F(TRACE_poke,read_has_side_effects)1690 TEST_F(TRACE_poke, read_has_side_effects)
1691 {
1692 ssize_t ret;
1693
1694 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1695 ASSERT_EQ(0, ret);
1696
1697 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1698 ASSERT_EQ(0, ret);
1699
1700 EXPECT_EQ(0, self->poked);
1701 ret = read(-1, NULL, 0);
1702 EXPECT_EQ(-1, ret);
1703 EXPECT_EQ(0x1001, self->poked);
1704 }
1705
TEST_F(TRACE_poke,getpid_runs_normally)1706 TEST_F(TRACE_poke, getpid_runs_normally)
1707 {
1708 long ret;
1709
1710 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1711 ASSERT_EQ(0, ret);
1712
1713 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1714 ASSERT_EQ(0, ret);
1715
1716 EXPECT_EQ(0, self->poked);
1717 EXPECT_NE(0, syscall(__NR_getpid));
1718 EXPECT_EQ(0, self->poked);
1719 }
1720
1721 #if defined(__x86_64__)
1722 # define ARCH_REGS struct user_regs_struct
1723 # define SYSCALL_NUM(_regs) (_regs).orig_rax
1724 # define SYSCALL_RET(_regs) (_regs).rax
1725 #elif defined(__i386__)
1726 # define ARCH_REGS struct user_regs_struct
1727 # define SYSCALL_NUM(_regs) (_regs).orig_eax
1728 # define SYSCALL_RET(_regs) (_regs).eax
1729 #elif defined(__arm__)
1730 # define ARCH_REGS struct pt_regs
1731 # define SYSCALL_NUM(_regs) (_regs).ARM_r7
1732 # ifndef PTRACE_SET_SYSCALL
1733 # define PTRACE_SET_SYSCALL 23
1734 # endif
1735 # define SYSCALL_NUM_SET(_regs, _nr) \
1736 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
1737 # define SYSCALL_RET(_regs) (_regs).ARM_r0
1738 #elif defined(__aarch64__)
1739 # define ARCH_REGS struct user_pt_regs
1740 # define SYSCALL_NUM(_regs) (_regs).regs[8]
1741 # ifndef NT_ARM_SYSTEM_CALL
1742 # define NT_ARM_SYSTEM_CALL 0x404
1743 # endif
1744 # define SYSCALL_NUM_SET(_regs, _nr) \
1745 do { \
1746 struct iovec __v; \
1747 typeof(_nr) __nr = (_nr); \
1748 __v.iov_base = &__nr; \
1749 __v.iov_len = sizeof(__nr); \
1750 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \
1751 NT_ARM_SYSTEM_CALL, &__v)); \
1752 } while (0)
1753 # define SYSCALL_RET(_regs) (_regs).regs[0]
1754 #elif defined(__riscv) && __riscv_xlen == 64
1755 # define ARCH_REGS struct user_regs_struct
1756 # define SYSCALL_NUM(_regs) (_regs).a7
1757 # define SYSCALL_RET(_regs) (_regs).a0
1758 #elif defined(__csky__)
1759 # define ARCH_REGS struct pt_regs
1760 # if defined(__CSKYABIV2__)
1761 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1762 # else
1763 # define SYSCALL_NUM(_regs) (_regs).regs[9]
1764 # endif
1765 # define SYSCALL_RET(_regs) (_regs).a0
1766 #elif defined(__hppa__)
1767 # define ARCH_REGS struct user_regs_struct
1768 # define SYSCALL_NUM(_regs) (_regs).gr[20]
1769 # define SYSCALL_RET(_regs) (_regs).gr[28]
1770 #elif defined(__powerpc__)
1771 # define ARCH_REGS struct pt_regs
1772 # define SYSCALL_NUM(_regs) (_regs).gpr[0]
1773 # define SYSCALL_RET(_regs) (_regs).gpr[3]
1774 # define SYSCALL_RET_SET(_regs, _val) \
1775 do { \
1776 typeof(_val) _result = (_val); \
1777 if ((_regs.trap & 0xfff0) == 0x3000) { \
1778 /* \
1779 * scv 0 system call uses -ve result \
1780 * for error, so no need to adjust. \
1781 */ \
1782 SYSCALL_RET(_regs) = _result; \
1783 } else { \
1784 /* \
1785 * A syscall error is signaled by the \
1786 * CR0 SO bit and the code is stored as \
1787 * a positive value. \
1788 */ \
1789 if (_result < 0) { \
1790 SYSCALL_RET(_regs) = -_result; \
1791 (_regs).ccr |= 0x10000000; \
1792 } else { \
1793 SYSCALL_RET(_regs) = _result; \
1794 (_regs).ccr &= ~0x10000000; \
1795 } \
1796 } \
1797 } while (0)
1798 # define SYSCALL_RET_SET_ON_PTRACE_EXIT
1799 #elif defined(__s390__)
1800 # define ARCH_REGS s390_regs
1801 # define SYSCALL_NUM(_regs) (_regs).gprs[2]
1802 # define SYSCALL_RET_SET(_regs, _val) \
1803 TH_LOG("Can't modify syscall return on this architecture")
1804 #elif defined(__mips__)
1805 # include <asm/unistd_nr_n32.h>
1806 # include <asm/unistd_nr_n64.h>
1807 # include <asm/unistd_nr_o32.h>
1808 # define ARCH_REGS struct pt_regs
1809 # define SYSCALL_NUM(_regs) \
1810 ({ \
1811 typeof((_regs).regs[2]) _nr; \
1812 if ((_regs).regs[2] == __NR_O32_Linux) \
1813 _nr = (_regs).regs[4]; \
1814 else \
1815 _nr = (_regs).regs[2]; \
1816 _nr; \
1817 })
1818 # define SYSCALL_NUM_SET(_regs, _nr) \
1819 do { \
1820 if ((_regs).regs[2] == __NR_O32_Linux) \
1821 (_regs).regs[4] = _nr; \
1822 else \
1823 (_regs).regs[2] = _nr; \
1824 } while (0)
1825 # define SYSCALL_RET_SET(_regs, _val) \
1826 TH_LOG("Can't modify syscall return on this architecture")
1827 #elif defined(__xtensa__)
1828 # define ARCH_REGS struct user_pt_regs
1829 # define SYSCALL_NUM(_regs) (_regs).syscall
1830 /*
1831 * On xtensa syscall return value is in the register
1832 * a2 of the current window which is not fixed.
1833 */
1834 #define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2]
1835 #elif defined(__sh__)
1836 # define ARCH_REGS struct pt_regs
1837 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1838 # define SYSCALL_RET(_regs) (_regs).regs[0]
1839 #else
1840 # error "Do not know how to find your architecture's registers and syscalls"
1841 #endif
1842
1843 /*
1844 * Most architectures can change the syscall by just updating the
1845 * associated register. This is the default if not defined above.
1846 */
1847 #ifndef SYSCALL_NUM_SET
1848 # define SYSCALL_NUM_SET(_regs, _nr) \
1849 do { \
1850 SYSCALL_NUM(_regs) = (_nr); \
1851 } while (0)
1852 #endif
1853 /*
1854 * Most architectures can change the syscall return value by just
1855 * writing to the SYSCALL_RET register. This is the default if not
1856 * defined above. If an architecture cannot set the return value
1857 * (for example when the syscall and return value register is
1858 * shared), report it with TH_LOG() in an arch-specific definition
1859 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
1860 */
1861 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
1862 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
1863 #endif
1864 #ifndef SYSCALL_RET_SET
1865 # define SYSCALL_RET_SET(_regs, _val) \
1866 do { \
1867 SYSCALL_RET(_regs) = (_val); \
1868 } while (0)
1869 #endif
1870
1871 /* When the syscall return can't be changed, stub out the tests for it. */
1872 #ifndef SYSCALL_RET
1873 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1874 #else
1875 # define EXPECT_SYSCALL_RETURN(val, action) \
1876 do { \
1877 errno = 0; \
1878 if (val < 0) { \
1879 EXPECT_EQ(-1, action); \
1880 EXPECT_EQ(-(val), errno); \
1881 } else { \
1882 EXPECT_EQ(val, action); \
1883 } \
1884 } while (0)
1885 #endif
1886
1887 /*
1888 * Some architectures (e.g. powerpc) can only set syscall
1889 * return values on syscall exit during ptrace.
1890 */
1891 const bool ptrace_entry_set_syscall_nr = true;
1892 const bool ptrace_entry_set_syscall_ret =
1893 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
1894 true;
1895 #else
1896 false;
1897 #endif
1898
1899 /*
1900 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1901 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1902 */
1903 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1904 # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
1905 # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
1906 #else
1907 # define ARCH_GETREGS(_regs) ({ \
1908 struct iovec __v; \
1909 __v.iov_base = &(_regs); \
1910 __v.iov_len = sizeof(_regs); \
1911 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \
1912 })
1913 # define ARCH_SETREGS(_regs) ({ \
1914 struct iovec __v; \
1915 __v.iov_base = &(_regs); \
1916 __v.iov_len = sizeof(_regs); \
1917 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \
1918 })
1919 #endif
1920
1921 /* Architecture-specific syscall fetching routine. */
get_syscall(struct __test_metadata * _metadata,pid_t tracee)1922 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1923 {
1924 ARCH_REGS regs;
1925
1926 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1927 return -1;
1928 }
1929
1930 return SYSCALL_NUM(regs);
1931 }
1932
1933 /* Architecture-specific syscall changing routine. */
__change_syscall(struct __test_metadata * _metadata,pid_t tracee,long * syscall,long * ret)1934 void __change_syscall(struct __test_metadata *_metadata,
1935 pid_t tracee, long *syscall, long *ret)
1936 {
1937 ARCH_REGS orig, regs;
1938
1939 /* Do not get/set registers if we have nothing to do. */
1940 if (!syscall && !ret)
1941 return;
1942
1943 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1944 return;
1945 }
1946 orig = regs;
1947
1948 if (syscall)
1949 SYSCALL_NUM_SET(regs, *syscall);
1950
1951 if (ret)
1952 SYSCALL_RET_SET(regs, *ret);
1953
1954 /* Flush any register changes made. */
1955 if (memcmp(&orig, ®s, sizeof(orig)) != 0)
1956 EXPECT_EQ(0, ARCH_SETREGS(regs));
1957 }
1958
1959 /* Change only syscall number. */
change_syscall_nr(struct __test_metadata * _metadata,pid_t tracee,long syscall)1960 void change_syscall_nr(struct __test_metadata *_metadata,
1961 pid_t tracee, long syscall)
1962 {
1963 __change_syscall(_metadata, tracee, &syscall, NULL);
1964 }
1965
1966 /* Change syscall return value (and set syscall number to -1). */
change_syscall_ret(struct __test_metadata * _metadata,pid_t tracee,long ret)1967 void change_syscall_ret(struct __test_metadata *_metadata,
1968 pid_t tracee, long ret)
1969 {
1970 long syscall = -1;
1971
1972 __change_syscall(_metadata, tracee, &syscall, &ret);
1973 }
1974
tracer_seccomp(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1975 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
1976 int status, void *args)
1977 {
1978 int ret;
1979 unsigned long msg;
1980
1981 EXPECT_EQ(PTRACE_EVENT_MASK(status), PTRACE_EVENT_SECCOMP) {
1982 TH_LOG("Unexpected ptrace event: %d", PTRACE_EVENT_MASK(status));
1983 return;
1984 }
1985
1986 /* Make sure we got the right message. */
1987 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1988 EXPECT_EQ(0, ret);
1989
1990 /* Validate and take action on expected syscalls. */
1991 switch (msg) {
1992 case 0x1002:
1993 /* change getpid to getppid. */
1994 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1995 change_syscall_nr(_metadata, tracee, __NR_getppid);
1996 break;
1997 case 0x1003:
1998 /* skip gettid with valid return code. */
1999 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
2000 change_syscall_ret(_metadata, tracee, 45000);
2001 break;
2002 case 0x1004:
2003 /* skip openat with error. */
2004 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
2005 change_syscall_ret(_metadata, tracee, -ESRCH);
2006 break;
2007 case 0x1005:
2008 /* do nothing (allow getppid) */
2009 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
2010 break;
2011 default:
2012 EXPECT_EQ(0, msg) {
2013 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
2014 kill(tracee, SIGKILL);
2015 }
2016 }
2017
2018 }
2019
FIXTURE(TRACE_syscall)2020 FIXTURE(TRACE_syscall) {
2021 struct sock_fprog prog;
2022 pid_t tracer, mytid, mypid, parent;
2023 long syscall_nr;
2024 };
2025
tracer_ptrace(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)2026 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
2027 int status, void *args)
2028 {
2029 int ret;
2030 unsigned long msg;
2031 static bool entry;
2032 long syscall_nr_val, syscall_ret_val;
2033 long *syscall_nr = NULL, *syscall_ret = NULL;
2034 FIXTURE_DATA(TRACE_syscall) *self = args;
2035
2036 EXPECT_EQ(WSTOPSIG(status) & 0x80, 0x80) {
2037 TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
2038 return;
2039 }
2040
2041 /*
2042 * The traditional way to tell PTRACE_SYSCALL entry/exit
2043 * is by counting.
2044 */
2045 entry = !entry;
2046
2047 /* Make sure we got an appropriate message. */
2048 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
2049 EXPECT_EQ(0, ret);
2050 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
2051 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
2052
2053 /*
2054 * Some architectures only support setting return values during
2055 * syscall exit under ptrace, and on exit the syscall number may
2056 * no longer be available. Therefore, save the initial sycall
2057 * number here, so it can be examined during both entry and exit
2058 * phases.
2059 */
2060 if (entry)
2061 self->syscall_nr = get_syscall(_metadata, tracee);
2062
2063 /*
2064 * Depending on the architecture's syscall setting abilities, we
2065 * pick which things to set during this phase (entry or exit).
2066 */
2067 if (entry == ptrace_entry_set_syscall_nr)
2068 syscall_nr = &syscall_nr_val;
2069 if (entry == ptrace_entry_set_syscall_ret)
2070 syscall_ret = &syscall_ret_val;
2071
2072 /* Now handle the actual rewriting cases. */
2073 switch (self->syscall_nr) {
2074 case __NR_getpid:
2075 syscall_nr_val = __NR_getppid;
2076 /* Never change syscall return for this case. */
2077 syscall_ret = NULL;
2078 break;
2079 case __NR_gettid:
2080 syscall_nr_val = -1;
2081 syscall_ret_val = 45000;
2082 break;
2083 case __NR_openat:
2084 syscall_nr_val = -1;
2085 syscall_ret_val = -ESRCH;
2086 break;
2087 default:
2088 /* Unhandled, do nothing. */
2089 return;
2090 }
2091
2092 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
2093 }
2094
FIXTURE_VARIANT(TRACE_syscall)2095 FIXTURE_VARIANT(TRACE_syscall) {
2096 /*
2097 * All of the SECCOMP_RET_TRACE behaviors can be tested with either
2098 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL.
2099 * This indicates if we should use SECCOMP_RET_TRACE (false), or
2100 * ptrace (true).
2101 */
2102 bool use_ptrace;
2103 };
2104
FIXTURE_VARIANT_ADD(TRACE_syscall,ptrace)2105 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) {
2106 .use_ptrace = true,
2107 };
2108
FIXTURE_VARIANT_ADD(TRACE_syscall,seccomp)2109 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) {
2110 .use_ptrace = false,
2111 };
2112
FIXTURE_SETUP(TRACE_syscall)2113 FIXTURE_SETUP(TRACE_syscall)
2114 {
2115 struct sock_filter filter[] = {
2116 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2117 offsetof(struct seccomp_data, nr)),
2118 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2119 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
2120 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
2121 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
2122 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
2123 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
2124 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2125 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
2126 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2127 };
2128 struct sock_fprog prog = {
2129 .len = (unsigned short)ARRAY_SIZE(filter),
2130 .filter = filter,
2131 };
2132 long ret;
2133
2134 /* Prepare some testable syscall results. */
2135 self->mytid = syscall(__NR_gettid);
2136 ASSERT_GT(self->mytid, 0);
2137 ASSERT_NE(self->mytid, 1) {
2138 TH_LOG("Running this test as init is not supported. :)");
2139 }
2140
2141 self->mypid = getpid();
2142 ASSERT_GT(self->mypid, 0);
2143 ASSERT_EQ(self->mytid, self->mypid);
2144
2145 self->parent = getppid();
2146 ASSERT_GT(self->parent, 0);
2147 ASSERT_NE(self->parent, self->mypid);
2148
2149 /* Launch tracer. */
2150 self->tracer = setup_trace_fixture(_metadata,
2151 variant->use_ptrace ? tracer_ptrace
2152 : tracer_seccomp,
2153 self, variant->use_ptrace);
2154
2155 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2156 ASSERT_EQ(0, ret);
2157
2158 /* Do not install seccomp rewrite filters, as we'll use ptrace instead. */
2159 if (variant->use_ptrace)
2160 return;
2161
2162 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2163 ASSERT_EQ(0, ret);
2164 }
2165
FIXTURE_TEARDOWN(TRACE_syscall)2166 FIXTURE_TEARDOWN(TRACE_syscall)
2167 {
2168 teardown_trace_fixture(_metadata, self->tracer);
2169 }
2170
TEST(negative_ENOSYS)2171 TEST(negative_ENOSYS)
2172 {
2173 /*
2174 * There should be no difference between an "internal" skip
2175 * and userspace asking for syscall "-1".
2176 */
2177 errno = 0;
2178 EXPECT_EQ(-1, syscall(-1));
2179 EXPECT_EQ(errno, ENOSYS);
2180 /* And no difference for "still not valid but not -1". */
2181 errno = 0;
2182 EXPECT_EQ(-1, syscall(-101));
2183 EXPECT_EQ(errno, ENOSYS);
2184 }
2185
TEST_F(TRACE_syscall,negative_ENOSYS)2186 TEST_F(TRACE_syscall, negative_ENOSYS)
2187 {
2188 negative_ENOSYS(_metadata);
2189 }
2190
TEST_F(TRACE_syscall,syscall_allowed)2191 TEST_F(TRACE_syscall, syscall_allowed)
2192 {
2193 /* getppid works as expected (no changes). */
2194 EXPECT_EQ(self->parent, syscall(__NR_getppid));
2195 EXPECT_NE(self->mypid, syscall(__NR_getppid));
2196 }
2197
TEST_F(TRACE_syscall,syscall_redirected)2198 TEST_F(TRACE_syscall, syscall_redirected)
2199 {
2200 /* getpid has been redirected to getppid as expected. */
2201 EXPECT_EQ(self->parent, syscall(__NR_getpid));
2202 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2203 }
2204
TEST_F(TRACE_syscall,syscall_errno)2205 TEST_F(TRACE_syscall, syscall_errno)
2206 {
2207 /* Tracer should skip the open syscall, resulting in ESRCH. */
2208 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
2209 }
2210
TEST_F(TRACE_syscall,syscall_faked)2211 TEST_F(TRACE_syscall, syscall_faked)
2212 {
2213 /* Tracer skips the gettid syscall and store altered return value. */
2214 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
2215 }
2216
TEST_F_SIGNAL(TRACE_syscall,kill_immediate,SIGSYS)2217 TEST_F_SIGNAL(TRACE_syscall, kill_immediate, SIGSYS)
2218 {
2219 struct sock_filter filter[] = {
2220 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2221 offsetof(struct seccomp_data, nr)),
2222 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_mknodat, 0, 1),
2223 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
2224 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2225 };
2226 struct sock_fprog prog = {
2227 .len = (unsigned short)ARRAY_SIZE(filter),
2228 .filter = filter,
2229 };
2230 long ret;
2231
2232 /* Install "kill on mknodat" filter. */
2233 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2234 ASSERT_EQ(0, ret);
2235
2236 /* This should immediately die with SIGSYS, regardless of tracer. */
2237 EXPECT_EQ(-1, syscall(__NR_mknodat, -1, NULL, 0, 0));
2238 }
2239
TEST_F(TRACE_syscall,skip_after)2240 TEST_F(TRACE_syscall, skip_after)
2241 {
2242 struct sock_filter filter[] = {
2243 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2244 offsetof(struct seccomp_data, nr)),
2245 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2246 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2247 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2248 };
2249 struct sock_fprog prog = {
2250 .len = (unsigned short)ARRAY_SIZE(filter),
2251 .filter = filter,
2252 };
2253 long ret;
2254
2255 /* Install additional "errno on getppid" filter. */
2256 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2257 ASSERT_EQ(0, ret);
2258
2259 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2260 errno = 0;
2261 EXPECT_EQ(-1, syscall(__NR_getpid));
2262 EXPECT_EQ(EPERM, errno);
2263 }
2264
TEST_F_SIGNAL(TRACE_syscall,kill_after,SIGSYS)2265 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS)
2266 {
2267 struct sock_filter filter[] = {
2268 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2269 offsetof(struct seccomp_data, nr)),
2270 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2271 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2272 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2273 };
2274 struct sock_fprog prog = {
2275 .len = (unsigned short)ARRAY_SIZE(filter),
2276 .filter = filter,
2277 };
2278 long ret;
2279
2280 /* Install additional "death on getppid" filter. */
2281 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2282 ASSERT_EQ(0, ret);
2283
2284 /* Tracer will redirect getpid to getppid, and we should die. */
2285 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2286 }
2287
TEST(seccomp_syscall)2288 TEST(seccomp_syscall)
2289 {
2290 struct sock_filter filter[] = {
2291 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2292 };
2293 struct sock_fprog prog = {
2294 .len = (unsigned short)ARRAY_SIZE(filter),
2295 .filter = filter,
2296 };
2297 long ret;
2298
2299 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2300 ASSERT_EQ(0, ret) {
2301 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2302 }
2303
2304 /* Reject insane operation. */
2305 ret = seccomp(-1, 0, &prog);
2306 ASSERT_NE(ENOSYS, errno) {
2307 TH_LOG("Kernel does not support seccomp syscall!");
2308 }
2309 EXPECT_EQ(EINVAL, errno) {
2310 TH_LOG("Did not reject crazy op value!");
2311 }
2312
2313 /* Reject strict with flags or pointer. */
2314 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2315 EXPECT_EQ(EINVAL, errno) {
2316 TH_LOG("Did not reject mode strict with flags!");
2317 }
2318 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2319 EXPECT_EQ(EINVAL, errno) {
2320 TH_LOG("Did not reject mode strict with uargs!");
2321 }
2322
2323 /* Reject insane args for filter. */
2324 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2325 EXPECT_EQ(EINVAL, errno) {
2326 TH_LOG("Did not reject crazy filter flags!");
2327 }
2328 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2329 EXPECT_EQ(EFAULT, errno) {
2330 TH_LOG("Did not reject NULL filter!");
2331 }
2332
2333 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2334 EXPECT_EQ(0, errno) {
2335 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2336 strerror(errno));
2337 }
2338 }
2339
TEST(seccomp_syscall_mode_lock)2340 TEST(seccomp_syscall_mode_lock)
2341 {
2342 struct sock_filter filter[] = {
2343 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2344 };
2345 struct sock_fprog prog = {
2346 .len = (unsigned short)ARRAY_SIZE(filter),
2347 .filter = filter,
2348 };
2349 long ret;
2350
2351 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2352 ASSERT_EQ(0, ret) {
2353 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2354 }
2355
2356 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2357 ASSERT_NE(ENOSYS, errno) {
2358 TH_LOG("Kernel does not support seccomp syscall!");
2359 }
2360 EXPECT_EQ(0, ret) {
2361 TH_LOG("Could not install filter!");
2362 }
2363
2364 /* Make sure neither entry point will switch to strict. */
2365 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2366 EXPECT_EQ(EINVAL, errno) {
2367 TH_LOG("Switched to mode strict!");
2368 }
2369
2370 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2371 EXPECT_EQ(EINVAL, errno) {
2372 TH_LOG("Switched to mode strict!");
2373 }
2374 }
2375
2376 /*
2377 * Test detection of known and unknown filter flags. Userspace needs to be able
2378 * to check if a filter flag is supported by the current kernel and a good way
2379 * of doing that is by attempting to enter filter mode, with the flag bit in
2380 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2381 * that the flag is valid and EINVAL indicates that the flag is invalid.
2382 */
TEST(detect_seccomp_filter_flags)2383 TEST(detect_seccomp_filter_flags)
2384 {
2385 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2386 SECCOMP_FILTER_FLAG_LOG,
2387 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2388 SECCOMP_FILTER_FLAG_NEW_LISTENER,
2389 SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
2390 unsigned int exclusive[] = {
2391 SECCOMP_FILTER_FLAG_TSYNC,
2392 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2393 unsigned int flag, all_flags, exclusive_mask;
2394 int i;
2395 long ret;
2396
2397 /* Test detection of individual known-good filter flags */
2398 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2399 int bits = 0;
2400
2401 flag = flags[i];
2402 /* Make sure the flag is a single bit! */
2403 while (flag) {
2404 if (flag & 0x1)
2405 bits ++;
2406 flag >>= 1;
2407 }
2408 ASSERT_EQ(1, bits);
2409 flag = flags[i];
2410
2411 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2412 ASSERT_NE(ENOSYS, errno) {
2413 TH_LOG("Kernel does not support seccomp syscall!");
2414 }
2415 EXPECT_EQ(-1, ret);
2416 EXPECT_EQ(EFAULT, errno) {
2417 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2418 flag);
2419 }
2420
2421 all_flags |= flag;
2422 }
2423
2424 /*
2425 * Test detection of all known-good filter flags combined. But
2426 * for the exclusive flags we need to mask them out and try them
2427 * individually for the "all flags" testing.
2428 */
2429 exclusive_mask = 0;
2430 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2431 exclusive_mask |= exclusive[i];
2432 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2433 flag = all_flags & ~exclusive_mask;
2434 flag |= exclusive[i];
2435
2436 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2437 EXPECT_EQ(-1, ret);
2438 EXPECT_EQ(EFAULT, errno) {
2439 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2440 flag);
2441 }
2442 }
2443
2444 /* Test detection of an unknown filter flags, without exclusives. */
2445 flag = -1;
2446 flag &= ~exclusive_mask;
2447 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2448 EXPECT_EQ(-1, ret);
2449 EXPECT_EQ(EINVAL, errno) {
2450 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2451 flag);
2452 }
2453
2454 /*
2455 * Test detection of an unknown filter flag that may simply need to be
2456 * added to this test
2457 */
2458 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2459 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2460 EXPECT_EQ(-1, ret);
2461 EXPECT_EQ(EINVAL, errno) {
2462 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?",
2463 flag);
2464 }
2465 }
2466
TEST(TSYNC_first)2467 TEST(TSYNC_first)
2468 {
2469 struct sock_filter filter[] = {
2470 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2471 };
2472 struct sock_fprog prog = {
2473 .len = (unsigned short)ARRAY_SIZE(filter),
2474 .filter = filter,
2475 };
2476 long ret;
2477
2478 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2479 ASSERT_EQ(0, ret) {
2480 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2481 }
2482
2483 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2484 &prog);
2485 ASSERT_NE(ENOSYS, errno) {
2486 TH_LOG("Kernel does not support seccomp syscall!");
2487 }
2488 EXPECT_EQ(0, ret) {
2489 TH_LOG("Could not install initial filter with TSYNC!");
2490 }
2491 }
2492
2493 #define TSYNC_SIBLINGS 2
2494 struct tsync_sibling {
2495 pthread_t tid;
2496 pid_t system_tid;
2497 sem_t *started;
2498 pthread_cond_t *cond;
2499 pthread_mutex_t *mutex;
2500 int diverge;
2501 int num_waits;
2502 struct sock_fprog *prog;
2503 struct __test_metadata *metadata;
2504 };
2505
2506 /*
2507 * To avoid joining joined threads (which is not allowed by Bionic),
2508 * make sure we both successfully join and clear the tid to skip a
2509 * later join attempt during fixture teardown. Any remaining threads
2510 * will be directly killed during teardown.
2511 */
2512 #define PTHREAD_JOIN(tid, status) \
2513 do { \
2514 int _rc = pthread_join(tid, status); \
2515 if (_rc) { \
2516 TH_LOG("pthread_join of tid %u failed: %d\n", \
2517 (unsigned int)tid, _rc); \
2518 } else { \
2519 tid = 0; \
2520 } \
2521 } while (0)
2522
FIXTURE(TSYNC)2523 FIXTURE(TSYNC) {
2524 struct sock_fprog root_prog, apply_prog;
2525 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2526 sem_t started;
2527 pthread_cond_t cond;
2528 pthread_mutex_t mutex;
2529 int sibling_count;
2530 };
2531
FIXTURE_SETUP(TSYNC)2532 FIXTURE_SETUP(TSYNC)
2533 {
2534 struct sock_filter root_filter[] = {
2535 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2536 };
2537 struct sock_filter apply_filter[] = {
2538 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2539 offsetof(struct seccomp_data, nr)),
2540 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2541 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2542 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2543 };
2544
2545 memset(&self->root_prog, 0, sizeof(self->root_prog));
2546 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2547 memset(&self->sibling, 0, sizeof(self->sibling));
2548 self->root_prog.filter = malloc(sizeof(root_filter));
2549 ASSERT_NE(NULL, self->root_prog.filter);
2550 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2551 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2552
2553 self->apply_prog.filter = malloc(sizeof(apply_filter));
2554 ASSERT_NE(NULL, self->apply_prog.filter);
2555 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2556 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2557
2558 self->sibling_count = 0;
2559 pthread_mutex_init(&self->mutex, NULL);
2560 pthread_cond_init(&self->cond, NULL);
2561 sem_init(&self->started, 0, 0);
2562 self->sibling[0].tid = 0;
2563 self->sibling[0].cond = &self->cond;
2564 self->sibling[0].started = &self->started;
2565 self->sibling[0].mutex = &self->mutex;
2566 self->sibling[0].diverge = 0;
2567 self->sibling[0].num_waits = 1;
2568 self->sibling[0].prog = &self->root_prog;
2569 self->sibling[0].metadata = _metadata;
2570 self->sibling[1].tid = 0;
2571 self->sibling[1].cond = &self->cond;
2572 self->sibling[1].started = &self->started;
2573 self->sibling[1].mutex = &self->mutex;
2574 self->sibling[1].diverge = 0;
2575 self->sibling[1].prog = &self->root_prog;
2576 self->sibling[1].num_waits = 1;
2577 self->sibling[1].metadata = _metadata;
2578 }
2579
FIXTURE_TEARDOWN(TSYNC)2580 FIXTURE_TEARDOWN(TSYNC)
2581 {
2582 int sib = 0;
2583
2584 if (self->root_prog.filter)
2585 free(self->root_prog.filter);
2586 if (self->apply_prog.filter)
2587 free(self->apply_prog.filter);
2588
2589 for ( ; sib < self->sibling_count; ++sib) {
2590 struct tsync_sibling *s = &self->sibling[sib];
2591
2592 if (!s->tid)
2593 continue;
2594 /*
2595 * If a thread is still running, it may be stuck, so hit
2596 * it over the head really hard.
2597 */
2598 pthread_kill(s->tid, 9);
2599 }
2600 pthread_mutex_destroy(&self->mutex);
2601 pthread_cond_destroy(&self->cond);
2602 sem_destroy(&self->started);
2603 }
2604
tsync_sibling(void * data)2605 void *tsync_sibling(void *data)
2606 {
2607 long ret = 0;
2608 struct tsync_sibling *me = data;
2609
2610 me->system_tid = syscall(__NR_gettid);
2611
2612 pthread_mutex_lock(me->mutex);
2613 if (me->diverge) {
2614 /* Just re-apply the root prog to fork the tree */
2615 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2616 me->prog, 0, 0);
2617 }
2618 sem_post(me->started);
2619 /* Return outside of started so parent notices failures. */
2620 if (ret) {
2621 pthread_mutex_unlock(me->mutex);
2622 return (void *)SIBLING_EXIT_FAILURE;
2623 }
2624 do {
2625 pthread_cond_wait(me->cond, me->mutex);
2626 me->num_waits = me->num_waits - 1;
2627 } while (me->num_waits);
2628 pthread_mutex_unlock(me->mutex);
2629
2630 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2631 if (!ret)
2632 return (void *)SIBLING_EXIT_NEWPRIVS;
2633 read(-1, NULL, 0);
2634 return (void *)SIBLING_EXIT_UNKILLED;
2635 }
2636
tsync_start_sibling(struct tsync_sibling * sibling)2637 void tsync_start_sibling(struct tsync_sibling *sibling)
2638 {
2639 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2640 }
2641
TEST_F(TSYNC,siblings_fail_prctl)2642 TEST_F(TSYNC, siblings_fail_prctl)
2643 {
2644 long ret;
2645 void *status;
2646 struct sock_filter filter[] = {
2647 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2648 offsetof(struct seccomp_data, nr)),
2649 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2650 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2651 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2652 };
2653 struct sock_fprog prog = {
2654 .len = (unsigned short)ARRAY_SIZE(filter),
2655 .filter = filter,
2656 };
2657
2658 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2659 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2660 }
2661
2662 /* Check prctl failure detection by requesting sib 0 diverge. */
2663 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2664 ASSERT_NE(ENOSYS, errno) {
2665 TH_LOG("Kernel does not support seccomp syscall!");
2666 }
2667 ASSERT_EQ(0, ret) {
2668 TH_LOG("setting filter failed");
2669 }
2670
2671 self->sibling[0].diverge = 1;
2672 tsync_start_sibling(&self->sibling[0]);
2673 tsync_start_sibling(&self->sibling[1]);
2674
2675 while (self->sibling_count < TSYNC_SIBLINGS) {
2676 sem_wait(&self->started);
2677 self->sibling_count++;
2678 }
2679
2680 /* Signal the threads to clean up*/
2681 pthread_mutex_lock(&self->mutex);
2682 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2683 TH_LOG("cond broadcast non-zero");
2684 }
2685 pthread_mutex_unlock(&self->mutex);
2686
2687 /* Ensure diverging sibling failed to call prctl. */
2688 PTHREAD_JOIN(self->sibling[0].tid, &status);
2689 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2690 PTHREAD_JOIN(self->sibling[1].tid, &status);
2691 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2692 }
2693
TEST_F(TSYNC,two_siblings_with_ancestor)2694 TEST_F(TSYNC, two_siblings_with_ancestor)
2695 {
2696 long ret;
2697 void *status;
2698
2699 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2700 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2701 }
2702
2703 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2704 ASSERT_NE(ENOSYS, errno) {
2705 TH_LOG("Kernel does not support seccomp syscall!");
2706 }
2707 ASSERT_EQ(0, ret) {
2708 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2709 }
2710 tsync_start_sibling(&self->sibling[0]);
2711 tsync_start_sibling(&self->sibling[1]);
2712
2713 while (self->sibling_count < TSYNC_SIBLINGS) {
2714 sem_wait(&self->started);
2715 self->sibling_count++;
2716 }
2717
2718 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2719 &self->apply_prog);
2720 ASSERT_EQ(0, ret) {
2721 TH_LOG("Could install filter on all threads!");
2722 }
2723 /* Tell the siblings to test the policy */
2724 pthread_mutex_lock(&self->mutex);
2725 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2726 TH_LOG("cond broadcast non-zero");
2727 }
2728 pthread_mutex_unlock(&self->mutex);
2729 /* Ensure they are both killed and don't exit cleanly. */
2730 PTHREAD_JOIN(self->sibling[0].tid, &status);
2731 EXPECT_EQ(0x0, (long)status);
2732 PTHREAD_JOIN(self->sibling[1].tid, &status);
2733 EXPECT_EQ(0x0, (long)status);
2734 }
2735
TEST_F(TSYNC,two_sibling_want_nnp)2736 TEST_F(TSYNC, two_sibling_want_nnp)
2737 {
2738 void *status;
2739
2740 /* start siblings before any prctl() operations */
2741 tsync_start_sibling(&self->sibling[0]);
2742 tsync_start_sibling(&self->sibling[1]);
2743 while (self->sibling_count < TSYNC_SIBLINGS) {
2744 sem_wait(&self->started);
2745 self->sibling_count++;
2746 }
2747
2748 /* Tell the siblings to test no policy */
2749 pthread_mutex_lock(&self->mutex);
2750 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2751 TH_LOG("cond broadcast non-zero");
2752 }
2753 pthread_mutex_unlock(&self->mutex);
2754
2755 /* Ensure they are both upset about lacking nnp. */
2756 PTHREAD_JOIN(self->sibling[0].tid, &status);
2757 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2758 PTHREAD_JOIN(self->sibling[1].tid, &status);
2759 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2760 }
2761
TEST_F(TSYNC,two_siblings_with_no_filter)2762 TEST_F(TSYNC, two_siblings_with_no_filter)
2763 {
2764 long ret;
2765 void *status;
2766
2767 /* start siblings before any prctl() operations */
2768 tsync_start_sibling(&self->sibling[0]);
2769 tsync_start_sibling(&self->sibling[1]);
2770 while (self->sibling_count < TSYNC_SIBLINGS) {
2771 sem_wait(&self->started);
2772 self->sibling_count++;
2773 }
2774
2775 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2776 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2777 }
2778
2779 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2780 &self->apply_prog);
2781 ASSERT_NE(ENOSYS, errno) {
2782 TH_LOG("Kernel does not support seccomp syscall!");
2783 }
2784 ASSERT_EQ(0, ret) {
2785 TH_LOG("Could install filter on all threads!");
2786 }
2787
2788 /* Tell the siblings to test the policy */
2789 pthread_mutex_lock(&self->mutex);
2790 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2791 TH_LOG("cond broadcast non-zero");
2792 }
2793 pthread_mutex_unlock(&self->mutex);
2794
2795 /* Ensure they are both killed and don't exit cleanly. */
2796 PTHREAD_JOIN(self->sibling[0].tid, &status);
2797 EXPECT_EQ(0x0, (long)status);
2798 PTHREAD_JOIN(self->sibling[1].tid, &status);
2799 EXPECT_EQ(0x0, (long)status);
2800 }
2801
TEST_F(TSYNC,two_siblings_with_one_divergence)2802 TEST_F(TSYNC, two_siblings_with_one_divergence)
2803 {
2804 long ret;
2805 void *status;
2806
2807 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2808 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2809 }
2810
2811 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2812 ASSERT_NE(ENOSYS, errno) {
2813 TH_LOG("Kernel does not support seccomp syscall!");
2814 }
2815 ASSERT_EQ(0, ret) {
2816 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2817 }
2818 self->sibling[0].diverge = 1;
2819 tsync_start_sibling(&self->sibling[0]);
2820 tsync_start_sibling(&self->sibling[1]);
2821
2822 while (self->sibling_count < TSYNC_SIBLINGS) {
2823 sem_wait(&self->started);
2824 self->sibling_count++;
2825 }
2826
2827 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2828 &self->apply_prog);
2829 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2830 TH_LOG("Did not fail on diverged sibling.");
2831 }
2832
2833 /* Wake the threads */
2834 pthread_mutex_lock(&self->mutex);
2835 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2836 TH_LOG("cond broadcast non-zero");
2837 }
2838 pthread_mutex_unlock(&self->mutex);
2839
2840 /* Ensure they are both unkilled. */
2841 PTHREAD_JOIN(self->sibling[0].tid, &status);
2842 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2843 PTHREAD_JOIN(self->sibling[1].tid, &status);
2844 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2845 }
2846
TEST_F(TSYNC,two_siblings_with_one_divergence_no_tid_in_err)2847 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
2848 {
2849 long ret, flags;
2850 void *status;
2851
2852 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2853 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2854 }
2855
2856 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2857 ASSERT_NE(ENOSYS, errno) {
2858 TH_LOG("Kernel does not support seccomp syscall!");
2859 }
2860 ASSERT_EQ(0, ret) {
2861 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2862 }
2863 self->sibling[0].diverge = 1;
2864 tsync_start_sibling(&self->sibling[0]);
2865 tsync_start_sibling(&self->sibling[1]);
2866
2867 while (self->sibling_count < TSYNC_SIBLINGS) {
2868 sem_wait(&self->started);
2869 self->sibling_count++;
2870 }
2871
2872 flags = SECCOMP_FILTER_FLAG_TSYNC | \
2873 SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
2874 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
2875 ASSERT_EQ(ESRCH, errno) {
2876 TH_LOG("Did not return ESRCH for diverged sibling.");
2877 }
2878 ASSERT_EQ(-1, ret) {
2879 TH_LOG("Did not fail on diverged sibling.");
2880 }
2881
2882 /* Wake the threads */
2883 pthread_mutex_lock(&self->mutex);
2884 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2885 TH_LOG("cond broadcast non-zero");
2886 }
2887 pthread_mutex_unlock(&self->mutex);
2888
2889 /* Ensure they are both unkilled. */
2890 PTHREAD_JOIN(self->sibling[0].tid, &status);
2891 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2892 PTHREAD_JOIN(self->sibling[1].tid, &status);
2893 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2894 }
2895
TEST_F(TSYNC,two_siblings_not_under_filter)2896 TEST_F(TSYNC, two_siblings_not_under_filter)
2897 {
2898 long ret, sib;
2899 void *status;
2900 struct timespec delay = { .tv_nsec = 100000000 };
2901
2902 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2903 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2904 }
2905
2906 /*
2907 * Sibling 0 will have its own seccomp policy
2908 * and Sibling 1 will not be under seccomp at
2909 * all. Sibling 1 will enter seccomp and 0
2910 * will cause failure.
2911 */
2912 self->sibling[0].diverge = 1;
2913 tsync_start_sibling(&self->sibling[0]);
2914 tsync_start_sibling(&self->sibling[1]);
2915
2916 while (self->sibling_count < TSYNC_SIBLINGS) {
2917 sem_wait(&self->started);
2918 self->sibling_count++;
2919 }
2920
2921 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2922 ASSERT_NE(ENOSYS, errno) {
2923 TH_LOG("Kernel does not support seccomp syscall!");
2924 }
2925 ASSERT_EQ(0, ret) {
2926 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2927 }
2928
2929 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2930 &self->apply_prog);
2931 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2932 TH_LOG("Did not fail on diverged sibling.");
2933 }
2934 sib = 1;
2935 if (ret == self->sibling[0].system_tid)
2936 sib = 0;
2937
2938 pthread_mutex_lock(&self->mutex);
2939
2940 /* Increment the other siblings num_waits so we can clean up
2941 * the one we just saw.
2942 */
2943 self->sibling[!sib].num_waits += 1;
2944
2945 /* Signal the thread to clean up*/
2946 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2947 TH_LOG("cond broadcast non-zero");
2948 }
2949 pthread_mutex_unlock(&self->mutex);
2950 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2951 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2952 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2953 while (!kill(self->sibling[sib].system_tid, 0))
2954 nanosleep(&delay, NULL);
2955 /* Switch to the remaining sibling */
2956 sib = !sib;
2957
2958 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2959 &self->apply_prog);
2960 ASSERT_EQ(0, ret) {
2961 TH_LOG("Expected the remaining sibling to sync");
2962 };
2963
2964 pthread_mutex_lock(&self->mutex);
2965
2966 /* If remaining sibling didn't have a chance to wake up during
2967 * the first broadcast, manually reduce the num_waits now.
2968 */
2969 if (self->sibling[sib].num_waits > 1)
2970 self->sibling[sib].num_waits = 1;
2971 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2972 TH_LOG("cond broadcast non-zero");
2973 }
2974 pthread_mutex_unlock(&self->mutex);
2975 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2976 EXPECT_EQ(0, (long)status);
2977 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2978 while (!kill(self->sibling[sib].system_tid, 0))
2979 nanosleep(&delay, NULL);
2980
2981 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2982 &self->apply_prog);
2983 ASSERT_EQ(0, ret); /* just us chickens */
2984 }
2985
2986 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)2987 TEST(syscall_restart)
2988 {
2989 long ret;
2990 unsigned long msg;
2991 pid_t child_pid;
2992 int pipefd[2];
2993 int status;
2994 siginfo_t info = { };
2995 struct sock_filter filter[] = {
2996 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2997 offsetof(struct seccomp_data, nr)),
2998
2999 #ifdef __NR_sigreturn
3000 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0),
3001 #endif
3002 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0),
3003 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0),
3004 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0),
3005 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0),
3006 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0),
3007 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
3008
3009 /* Allow __NR_write for easy logging. */
3010 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
3011 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3012 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
3013 /* The nanosleep jump target. */
3014 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
3015 /* The restart_syscall jump target. */
3016 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
3017 };
3018 struct sock_fprog prog = {
3019 .len = (unsigned short)ARRAY_SIZE(filter),
3020 .filter = filter,
3021 };
3022 #if defined(__arm__)
3023 struct utsname utsbuf;
3024 #endif
3025
3026 ASSERT_EQ(0, pipe(pipefd));
3027
3028 child_pid = fork();
3029 ASSERT_LE(0, child_pid);
3030 if (child_pid == 0) {
3031 /* Child uses EXPECT not ASSERT to deliver status correctly. */
3032 char buf = ' ';
3033 struct timespec timeout = { };
3034
3035 /* Attach parent as tracer and stop. */
3036 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
3037 EXPECT_EQ(0, raise(SIGSTOP));
3038
3039 EXPECT_EQ(0, close(pipefd[1]));
3040
3041 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
3042 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3043 }
3044
3045 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
3046 EXPECT_EQ(0, ret) {
3047 TH_LOG("Failed to install filter!");
3048 }
3049
3050 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3051 TH_LOG("Failed to read() sync from parent");
3052 }
3053 EXPECT_EQ('.', buf) {
3054 TH_LOG("Failed to get sync data from read()");
3055 }
3056
3057 /* Start nanosleep to be interrupted. */
3058 timeout.tv_sec = 1;
3059 errno = 0;
3060 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
3061 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
3062 }
3063
3064 /* Read final sync from parent. */
3065 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3066 TH_LOG("Failed final read() from parent");
3067 }
3068 EXPECT_EQ('!', buf) {
3069 TH_LOG("Failed to get final data from read()");
3070 }
3071
3072 /* Directly report the status of our test harness results. */
3073 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
3074 : EXIT_FAILURE);
3075 }
3076 EXPECT_EQ(0, close(pipefd[0]));
3077
3078 /* Attach to child, setup options, and release. */
3079 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3080 ASSERT_EQ(true, WIFSTOPPED(status));
3081 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
3082 PTRACE_O_TRACESECCOMP));
3083 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3084 ASSERT_EQ(1, write(pipefd[1], ".", 1));
3085
3086 /* Wait for nanosleep() to start. */
3087 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3088 ASSERT_EQ(true, WIFSTOPPED(status));
3089 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3090 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3091 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3092 ASSERT_EQ(0x100, msg);
3093 ret = get_syscall(_metadata, child_pid);
3094 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep);
3095
3096 /* Might as well check siginfo for sanity while we're here. */
3097 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3098 ASSERT_EQ(SIGTRAP, info.si_signo);
3099 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
3100 EXPECT_EQ(0, info.si_errno);
3101 EXPECT_EQ(getuid(), info.si_uid);
3102 /* Verify signal delivery came from child (seccomp-triggered). */
3103 EXPECT_EQ(child_pid, info.si_pid);
3104
3105 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
3106 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
3107 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3108 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3109 ASSERT_EQ(true, WIFSTOPPED(status));
3110 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
3111 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3112 /*
3113 * There is no siginfo on SIGSTOP any more, so we can't verify
3114 * signal delivery came from parent now (getpid() == info.si_pid).
3115 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
3116 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
3117 */
3118 EXPECT_EQ(SIGSTOP, info.si_signo);
3119
3120 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
3121 ASSERT_EQ(0, kill(child_pid, SIGCONT));
3122 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3123 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3124 ASSERT_EQ(true, WIFSTOPPED(status));
3125 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
3126 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3127
3128 /* Wait for restart_syscall() to start. */
3129 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3130 ASSERT_EQ(true, WIFSTOPPED(status));
3131 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3132 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3133 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3134
3135 ASSERT_EQ(0x200, msg);
3136 ret = get_syscall(_metadata, child_pid);
3137 #if defined(__arm__)
3138 /*
3139 * FIXME:
3140 * - native ARM registers do NOT expose true syscall.
3141 * - compat ARM registers on ARM64 DO expose true syscall.
3142 */
3143 ASSERT_EQ(0, uname(&utsbuf));
3144 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
3145 EXPECT_EQ(__NR_nanosleep, ret);
3146 } else
3147 #endif
3148 {
3149 EXPECT_EQ(__NR_restart_syscall, ret);
3150 }
3151
3152 /* Write again to end test. */
3153 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3154 ASSERT_EQ(1, write(pipefd[1], "!", 1));
3155 EXPECT_EQ(0, close(pipefd[1]));
3156
3157 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3158 if (WIFSIGNALED(status) || WEXITSTATUS(status))
3159 _metadata->passed = 0;
3160 }
3161
TEST_SIGNAL(filter_flag_log,SIGSYS)3162 TEST_SIGNAL(filter_flag_log, SIGSYS)
3163 {
3164 struct sock_filter allow_filter[] = {
3165 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3166 };
3167 struct sock_filter kill_filter[] = {
3168 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3169 offsetof(struct seccomp_data, nr)),
3170 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
3171 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
3172 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3173 };
3174 struct sock_fprog allow_prog = {
3175 .len = (unsigned short)ARRAY_SIZE(allow_filter),
3176 .filter = allow_filter,
3177 };
3178 struct sock_fprog kill_prog = {
3179 .len = (unsigned short)ARRAY_SIZE(kill_filter),
3180 .filter = kill_filter,
3181 };
3182 long ret;
3183 pid_t parent = getppid();
3184
3185 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3186 ASSERT_EQ(0, ret);
3187
3188 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
3189 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
3190 &allow_prog);
3191 ASSERT_NE(ENOSYS, errno) {
3192 TH_LOG("Kernel does not support seccomp syscall!");
3193 }
3194 EXPECT_NE(0, ret) {
3195 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
3196 }
3197 EXPECT_EQ(EINVAL, errno) {
3198 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
3199 }
3200
3201 /* Verify that a simple, permissive filter can be added with no flags */
3202 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
3203 EXPECT_EQ(0, ret);
3204
3205 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
3206 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3207 &allow_prog);
3208 ASSERT_NE(EINVAL, errno) {
3209 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
3210 }
3211 EXPECT_EQ(0, ret);
3212
3213 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
3214 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3215 &kill_prog);
3216 EXPECT_EQ(0, ret);
3217
3218 EXPECT_EQ(parent, syscall(__NR_getppid));
3219 /* getpid() should never return. */
3220 EXPECT_EQ(0, syscall(__NR_getpid));
3221 }
3222
TEST(get_action_avail)3223 TEST(get_action_avail)
3224 {
3225 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
3226 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
3227 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
3228 __u32 unknown_action = 0x10000000U;
3229 int i;
3230 long ret;
3231
3232 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
3233 ASSERT_NE(ENOSYS, errno) {
3234 TH_LOG("Kernel does not support seccomp syscall!");
3235 }
3236 ASSERT_NE(EINVAL, errno) {
3237 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
3238 }
3239 EXPECT_EQ(ret, 0);
3240
3241 for (i = 0; i < ARRAY_SIZE(actions); i++) {
3242 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
3243 EXPECT_EQ(ret, 0) {
3244 TH_LOG("Expected action (0x%X) not available!",
3245 actions[i]);
3246 }
3247 }
3248
3249 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
3250 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
3251 EXPECT_EQ(ret, -1);
3252 EXPECT_EQ(errno, EOPNOTSUPP);
3253 }
3254
TEST(get_metadata)3255 TEST(get_metadata)
3256 {
3257 pid_t pid;
3258 int pipefd[2];
3259 char buf;
3260 struct seccomp_metadata md;
3261 long ret;
3262
3263 /* Only real root can get metadata. */
3264 if (geteuid()) {
3265 SKIP(return, "get_metadata requires real root");
3266 return;
3267 }
3268
3269 ASSERT_EQ(0, pipe(pipefd));
3270
3271 pid = fork();
3272 ASSERT_GE(pid, 0);
3273 if (pid == 0) {
3274 struct sock_filter filter[] = {
3275 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3276 };
3277 struct sock_fprog prog = {
3278 .len = (unsigned short)ARRAY_SIZE(filter),
3279 .filter = filter,
3280 };
3281
3282 /* one with log, one without */
3283 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3284 SECCOMP_FILTER_FLAG_LOG, &prog));
3285 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3286
3287 EXPECT_EQ(0, close(pipefd[0]));
3288 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3289 ASSERT_EQ(0, close(pipefd[1]));
3290
3291 while (1)
3292 sleep(100);
3293 }
3294
3295 ASSERT_EQ(0, close(pipefd[1]));
3296 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3297
3298 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3299 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3300
3301 /* Past here must not use ASSERT or child process is never killed. */
3302
3303 md.filter_off = 0;
3304 errno = 0;
3305 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3306 EXPECT_EQ(sizeof(md), ret) {
3307 if (errno == EINVAL)
3308 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3309 }
3310
3311 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3312 EXPECT_EQ(md.filter_off, 0);
3313
3314 md.filter_off = 1;
3315 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3316 EXPECT_EQ(sizeof(md), ret);
3317 EXPECT_EQ(md.flags, 0);
3318 EXPECT_EQ(md.filter_off, 1);
3319
3320 skip:
3321 ASSERT_EQ(0, kill(pid, SIGKILL));
3322 }
3323
user_notif_syscall(int nr,unsigned int flags)3324 static int user_notif_syscall(int nr, unsigned int flags)
3325 {
3326 struct sock_filter filter[] = {
3327 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3328 offsetof(struct seccomp_data, nr)),
3329 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
3330 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
3331 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3332 };
3333
3334 struct sock_fprog prog = {
3335 .len = (unsigned short)ARRAY_SIZE(filter),
3336 .filter = filter,
3337 };
3338
3339 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3340 }
3341
3342 #define USER_NOTIF_MAGIC INT_MAX
TEST(user_notification_basic)3343 TEST(user_notification_basic)
3344 {
3345 pid_t pid;
3346 long ret;
3347 int status, listener;
3348 struct seccomp_notif req = {};
3349 struct seccomp_notif_resp resp = {};
3350 struct pollfd pollfd;
3351
3352 struct sock_filter filter[] = {
3353 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3354 };
3355 struct sock_fprog prog = {
3356 .len = (unsigned short)ARRAY_SIZE(filter),
3357 .filter = filter,
3358 };
3359
3360 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3361 ASSERT_EQ(0, ret) {
3362 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3363 }
3364
3365 pid = fork();
3366 ASSERT_GE(pid, 0);
3367
3368 /* Check that we get -ENOSYS with no listener attached */
3369 if (pid == 0) {
3370 if (user_notif_syscall(__NR_getppid, 0) < 0)
3371 exit(1);
3372 ret = syscall(__NR_getppid);
3373 exit(ret >= 0 || errno != ENOSYS);
3374 }
3375
3376 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3377 EXPECT_EQ(true, WIFEXITED(status));
3378 EXPECT_EQ(0, WEXITSTATUS(status));
3379
3380 /* Add some no-op filters for grins. */
3381 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3382 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3383 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3384 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3385
3386 /* Check that the basic notification machinery works */
3387 listener = user_notif_syscall(__NR_getppid,
3388 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3389 ASSERT_GE(listener, 0);
3390
3391 /* Installing a second listener in the chain should EBUSY */
3392 EXPECT_EQ(user_notif_syscall(__NR_getppid,
3393 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3394 -1);
3395 EXPECT_EQ(errno, EBUSY);
3396
3397 pid = fork();
3398 ASSERT_GE(pid, 0);
3399
3400 if (pid == 0) {
3401 ret = syscall(__NR_getppid);
3402 exit(ret != USER_NOTIF_MAGIC);
3403 }
3404
3405 pollfd.fd = listener;
3406 pollfd.events = POLLIN | POLLOUT;
3407
3408 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3409 EXPECT_EQ(pollfd.revents, POLLIN);
3410
3411 /* Test that we can't pass garbage to the kernel. */
3412 memset(&req, 0, sizeof(req));
3413 req.pid = -1;
3414 errno = 0;
3415 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
3416 EXPECT_EQ(-1, ret);
3417 EXPECT_EQ(EINVAL, errno);
3418
3419 if (ret) {
3420 req.pid = 0;
3421 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3422 }
3423
3424 pollfd.fd = listener;
3425 pollfd.events = POLLIN | POLLOUT;
3426
3427 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3428 EXPECT_EQ(pollfd.revents, POLLOUT);
3429
3430 EXPECT_EQ(req.data.nr, __NR_getppid);
3431
3432 resp.id = req.id;
3433 resp.error = 0;
3434 resp.val = USER_NOTIF_MAGIC;
3435
3436 /* check that we make sure flags == 0 */
3437 resp.flags = 1;
3438 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3439 EXPECT_EQ(errno, EINVAL);
3440
3441 resp.flags = 0;
3442 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3443
3444 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3445 EXPECT_EQ(true, WIFEXITED(status));
3446 EXPECT_EQ(0, WEXITSTATUS(status));
3447 }
3448
TEST(user_notification_with_tsync)3449 TEST(user_notification_with_tsync)
3450 {
3451 int ret;
3452 unsigned int flags;
3453
3454 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3455 ASSERT_EQ(0, ret) {
3456 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3457 }
3458
3459 /* these were exclusive */
3460 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
3461 SECCOMP_FILTER_FLAG_TSYNC;
3462 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags));
3463 ASSERT_EQ(EINVAL, errno);
3464
3465 /* but now they're not */
3466 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
3467 ret = user_notif_syscall(__NR_getppid, flags);
3468 close(ret);
3469 ASSERT_LE(0, ret);
3470 }
3471
TEST(user_notification_kill_in_middle)3472 TEST(user_notification_kill_in_middle)
3473 {
3474 pid_t pid;
3475 long ret;
3476 int listener;
3477 struct seccomp_notif req = {};
3478 struct seccomp_notif_resp resp = {};
3479
3480 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3481 ASSERT_EQ(0, ret) {
3482 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3483 }
3484
3485 listener = user_notif_syscall(__NR_getppid,
3486 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3487 ASSERT_GE(listener, 0);
3488
3489 /*
3490 * Check that nothing bad happens when we kill the task in the middle
3491 * of a syscall.
3492 */
3493 pid = fork();
3494 ASSERT_GE(pid, 0);
3495
3496 if (pid == 0) {
3497 ret = syscall(__NR_getppid);
3498 exit(ret != USER_NOTIF_MAGIC);
3499 }
3500
3501 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3502 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3503
3504 EXPECT_EQ(kill(pid, SIGKILL), 0);
3505 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3506
3507 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3508
3509 resp.id = req.id;
3510 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3511 EXPECT_EQ(ret, -1);
3512 EXPECT_EQ(errno, ENOENT);
3513 }
3514
3515 static int handled = -1;
3516
signal_handler(int signal)3517 static void signal_handler(int signal)
3518 {
3519 if (write(handled, "c", 1) != 1)
3520 perror("write from signal");
3521 }
3522
TEST(user_notification_signal)3523 TEST(user_notification_signal)
3524 {
3525 pid_t pid;
3526 long ret;
3527 int status, listener, sk_pair[2];
3528 struct seccomp_notif req = {};
3529 struct seccomp_notif_resp resp = {};
3530 char c;
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 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3538
3539 listener = user_notif_syscall(__NR_gettid,
3540 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3541 ASSERT_GE(listener, 0);
3542
3543 pid = fork();
3544 ASSERT_GE(pid, 0);
3545
3546 if (pid == 0) {
3547 close(sk_pair[0]);
3548 handled = sk_pair[1];
3549 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3550 perror("signal");
3551 exit(1);
3552 }
3553 /*
3554 * ERESTARTSYS behavior is a bit hard to test, because we need
3555 * to rely on a signal that has not yet been handled. Let's at
3556 * least check that the error code gets propagated through, and
3557 * hope that it doesn't break when there is actually a signal :)
3558 */
3559 ret = syscall(__NR_gettid);
3560 exit(!(ret == -1 && errno == 512));
3561 }
3562
3563 close(sk_pair[1]);
3564
3565 memset(&req, 0, sizeof(req));
3566 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3567
3568 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3569
3570 /*
3571 * Make sure the signal really is delivered, which means we're not
3572 * stuck in the user notification code any more and the notification
3573 * should be dead.
3574 */
3575 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3576
3577 resp.id = req.id;
3578 resp.error = -EPERM;
3579 resp.val = 0;
3580
3581 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3582 EXPECT_EQ(errno, ENOENT);
3583
3584 memset(&req, 0, sizeof(req));
3585 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3586
3587 resp.id = req.id;
3588 resp.error = -512; /* -ERESTARTSYS */
3589 resp.val = 0;
3590
3591 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3592
3593 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3594 EXPECT_EQ(true, WIFEXITED(status));
3595 EXPECT_EQ(0, WEXITSTATUS(status));
3596 }
3597
TEST(user_notification_closed_listener)3598 TEST(user_notification_closed_listener)
3599 {
3600 pid_t pid;
3601 long ret;
3602 int status, listener;
3603
3604 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3605 ASSERT_EQ(0, ret) {
3606 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3607 }
3608
3609 listener = user_notif_syscall(__NR_getppid,
3610 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3611 ASSERT_GE(listener, 0);
3612
3613 /*
3614 * Check that we get an ENOSYS when the listener is closed.
3615 */
3616 pid = fork();
3617 ASSERT_GE(pid, 0);
3618 if (pid == 0) {
3619 close(listener);
3620 ret = syscall(__NR_getppid);
3621 exit(ret != -1 && errno != ENOSYS);
3622 }
3623
3624 close(listener);
3625
3626 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3627 EXPECT_EQ(true, WIFEXITED(status));
3628 EXPECT_EQ(0, WEXITSTATUS(status));
3629 }
3630
3631 /*
3632 * Check that a pid in a child namespace still shows up as valid in ours.
3633 */
TEST(user_notification_child_pid_ns)3634 TEST(user_notification_child_pid_ns)
3635 {
3636 pid_t pid;
3637 int status, listener;
3638 struct seccomp_notif req = {};
3639 struct seccomp_notif_resp resp = {};
3640
3641 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
3642 if (errno == EINVAL)
3643 SKIP(return, "kernel missing CLONE_NEWUSER support");
3644 };
3645
3646 listener = user_notif_syscall(__NR_getppid,
3647 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3648 ASSERT_GE(listener, 0);
3649
3650 pid = fork();
3651 ASSERT_GE(pid, 0);
3652
3653 if (pid == 0)
3654 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3655
3656 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3657 EXPECT_EQ(req.pid, pid);
3658
3659 resp.id = req.id;
3660 resp.error = 0;
3661 resp.val = USER_NOTIF_MAGIC;
3662
3663 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3664
3665 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3666 EXPECT_EQ(true, WIFEXITED(status));
3667 EXPECT_EQ(0, WEXITSTATUS(status));
3668 close(listener);
3669 }
3670
3671 /*
3672 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3673 * invalid.
3674 */
TEST(user_notification_sibling_pid_ns)3675 TEST(user_notification_sibling_pid_ns)
3676 {
3677 pid_t pid, pid2;
3678 int status, listener;
3679 struct seccomp_notif req = {};
3680 struct seccomp_notif_resp resp = {};
3681
3682 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3683 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3684 }
3685
3686 listener = user_notif_syscall(__NR_getppid,
3687 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3688 ASSERT_GE(listener, 0);
3689
3690 pid = fork();
3691 ASSERT_GE(pid, 0);
3692
3693 if (pid == 0) {
3694 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3695
3696 pid2 = fork();
3697 ASSERT_GE(pid2, 0);
3698
3699 if (pid2 == 0)
3700 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3701
3702 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3703 EXPECT_EQ(true, WIFEXITED(status));
3704 EXPECT_EQ(0, WEXITSTATUS(status));
3705 exit(WEXITSTATUS(status));
3706 }
3707
3708 /* Create the sibling ns, and sibling in it. */
3709 ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
3710 if (errno == EPERM)
3711 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
3712 }
3713 ASSERT_EQ(errno, 0);
3714
3715 pid2 = fork();
3716 ASSERT_GE(pid2, 0);
3717
3718 if (pid2 == 0) {
3719 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3720 /*
3721 * The pid should be 0, i.e. the task is in some namespace that
3722 * we can't "see".
3723 */
3724 EXPECT_EQ(req.pid, 0);
3725
3726 resp.id = req.id;
3727 resp.error = 0;
3728 resp.val = USER_NOTIF_MAGIC;
3729
3730 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3731 exit(0);
3732 }
3733
3734 close(listener);
3735
3736 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3737 EXPECT_EQ(true, WIFEXITED(status));
3738 EXPECT_EQ(0, WEXITSTATUS(status));
3739
3740 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3741 EXPECT_EQ(true, WIFEXITED(status));
3742 EXPECT_EQ(0, WEXITSTATUS(status));
3743 }
3744
TEST(user_notification_fault_recv)3745 TEST(user_notification_fault_recv)
3746 {
3747 pid_t pid;
3748 int status, listener;
3749 struct seccomp_notif req = {};
3750 struct seccomp_notif_resp resp = {};
3751
3752 ASSERT_EQ(unshare(CLONE_NEWUSER), 0) {
3753 if (errno == EINVAL)
3754 SKIP(return, "kernel missing CLONE_NEWUSER support");
3755 }
3756
3757 listener = user_notif_syscall(__NR_getppid,
3758 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3759 ASSERT_GE(listener, 0);
3760
3761 pid = fork();
3762 ASSERT_GE(pid, 0);
3763
3764 if (pid == 0)
3765 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3766
3767 /* Do a bad recv() */
3768 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3769 EXPECT_EQ(errno, EFAULT);
3770
3771 /* We should still be able to receive this notification, though. */
3772 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3773 EXPECT_EQ(req.pid, pid);
3774
3775 resp.id = req.id;
3776 resp.error = 0;
3777 resp.val = USER_NOTIF_MAGIC;
3778
3779 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3780
3781 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3782 EXPECT_EQ(true, WIFEXITED(status));
3783 EXPECT_EQ(0, WEXITSTATUS(status));
3784 }
3785
TEST(seccomp_get_notif_sizes)3786 TEST(seccomp_get_notif_sizes)
3787 {
3788 struct seccomp_notif_sizes sizes;
3789
3790 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3791 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3792 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3793 }
3794
TEST(user_notification_continue)3795 TEST(user_notification_continue)
3796 {
3797 pid_t pid;
3798 long ret;
3799 int status, listener;
3800 struct seccomp_notif req = {};
3801 struct seccomp_notif_resp resp = {};
3802 struct pollfd pollfd;
3803
3804 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3805 ASSERT_EQ(0, ret) {
3806 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3807 }
3808
3809 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3810 ASSERT_GE(listener, 0);
3811
3812 pid = fork();
3813 ASSERT_GE(pid, 0);
3814
3815 if (pid == 0) {
3816 int dup_fd, pipe_fds[2];
3817 pid_t self;
3818
3819 ASSERT_GE(pipe(pipe_fds), 0);
3820
3821 dup_fd = dup(pipe_fds[0]);
3822 ASSERT_GE(dup_fd, 0);
3823 EXPECT_NE(pipe_fds[0], dup_fd);
3824
3825 self = getpid();
3826 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
3827 exit(0);
3828 }
3829
3830 pollfd.fd = listener;
3831 pollfd.events = POLLIN | POLLOUT;
3832
3833 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3834 EXPECT_EQ(pollfd.revents, POLLIN);
3835
3836 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3837
3838 pollfd.fd = listener;
3839 pollfd.events = POLLIN | POLLOUT;
3840
3841 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3842 EXPECT_EQ(pollfd.revents, POLLOUT);
3843
3844 EXPECT_EQ(req.data.nr, __NR_dup);
3845
3846 resp.id = req.id;
3847 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
3848
3849 /*
3850 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
3851 * args be set to 0.
3852 */
3853 resp.error = 0;
3854 resp.val = USER_NOTIF_MAGIC;
3855 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3856 EXPECT_EQ(errno, EINVAL);
3857
3858 resp.error = USER_NOTIF_MAGIC;
3859 resp.val = 0;
3860 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3861 EXPECT_EQ(errno, EINVAL);
3862
3863 resp.error = 0;
3864 resp.val = 0;
3865 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
3866 if (errno == EINVAL)
3867 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
3868 }
3869
3870 skip:
3871 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3872 EXPECT_EQ(true, WIFEXITED(status));
3873 EXPECT_EQ(0, WEXITSTATUS(status)) {
3874 if (WEXITSTATUS(status) == 2) {
3875 SKIP(return, "Kernel does not support kcmp() syscall");
3876 return;
3877 }
3878 }
3879 }
3880
TEST(user_notification_filter_empty)3881 TEST(user_notification_filter_empty)
3882 {
3883 pid_t pid;
3884 long ret;
3885 int status;
3886 struct pollfd pollfd;
3887 struct __clone_args args = {
3888 .flags = CLONE_FILES,
3889 .exit_signal = SIGCHLD,
3890 };
3891
3892 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3893 ASSERT_EQ(0, ret) {
3894 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3895 }
3896
3897 pid = sys_clone3(&args, sizeof(args));
3898 ASSERT_GE(pid, 0);
3899
3900 if (pid == 0) {
3901 int listener;
3902
3903 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3904 if (listener < 0)
3905 _exit(EXIT_FAILURE);
3906
3907 if (dup2(listener, 200) != 200)
3908 _exit(EXIT_FAILURE);
3909
3910 close(listener);
3911
3912 _exit(EXIT_SUCCESS);
3913 }
3914
3915 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3916 EXPECT_EQ(true, WIFEXITED(status));
3917 EXPECT_EQ(0, WEXITSTATUS(status));
3918
3919 /*
3920 * The seccomp filter has become unused so we should be notified once
3921 * the kernel gets around to cleaning up task struct.
3922 */
3923 pollfd.fd = 200;
3924 pollfd.events = POLLHUP;
3925
3926 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
3927 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
3928 }
3929
do_thread(void * data)3930 static void *do_thread(void *data)
3931 {
3932 return NULL;
3933 }
3934
TEST(user_notification_filter_empty_threaded)3935 TEST(user_notification_filter_empty_threaded)
3936 {
3937 pid_t pid;
3938 long ret;
3939 int status;
3940 struct pollfd pollfd;
3941 struct __clone_args args = {
3942 .flags = CLONE_FILES,
3943 .exit_signal = SIGCHLD,
3944 };
3945
3946 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3947 ASSERT_EQ(0, ret) {
3948 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3949 }
3950
3951 pid = sys_clone3(&args, sizeof(args));
3952 ASSERT_GE(pid, 0);
3953
3954 if (pid == 0) {
3955 pid_t pid1, pid2;
3956 int listener, status;
3957 pthread_t thread;
3958
3959 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3960 if (listener < 0)
3961 _exit(EXIT_FAILURE);
3962
3963 if (dup2(listener, 200) != 200)
3964 _exit(EXIT_FAILURE);
3965
3966 close(listener);
3967
3968 pid1 = fork();
3969 if (pid1 < 0)
3970 _exit(EXIT_FAILURE);
3971
3972 if (pid1 == 0)
3973 _exit(EXIT_SUCCESS);
3974
3975 pid2 = fork();
3976 if (pid2 < 0)
3977 _exit(EXIT_FAILURE);
3978
3979 if (pid2 == 0)
3980 _exit(EXIT_SUCCESS);
3981
3982 if (pthread_create(&thread, NULL, do_thread, NULL) ||
3983 pthread_join(thread, NULL))
3984 _exit(EXIT_FAILURE);
3985
3986 if (pthread_create(&thread, NULL, do_thread, NULL) ||
3987 pthread_join(thread, NULL))
3988 _exit(EXIT_FAILURE);
3989
3990 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) ||
3991 WEXITSTATUS(status))
3992 _exit(EXIT_FAILURE);
3993
3994 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) ||
3995 WEXITSTATUS(status))
3996 _exit(EXIT_FAILURE);
3997
3998 exit(EXIT_SUCCESS);
3999 }
4000
4001 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4002 EXPECT_EQ(true, WIFEXITED(status));
4003 EXPECT_EQ(0, WEXITSTATUS(status));
4004
4005 /*
4006 * The seccomp filter has become unused so we should be notified once
4007 * the kernel gets around to cleaning up task struct.
4008 */
4009 pollfd.fd = 200;
4010 pollfd.events = POLLHUP;
4011
4012 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
4013 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
4014 }
4015
TEST(user_notification_addfd)4016 TEST(user_notification_addfd)
4017 {
4018 pid_t pid;
4019 long ret;
4020 int status, listener, memfd, fd, nextfd;
4021 struct seccomp_notif_addfd addfd = {};
4022 struct seccomp_notif_addfd_small small = {};
4023 struct seccomp_notif_addfd_big big = {};
4024 struct seccomp_notif req = {};
4025 struct seccomp_notif_resp resp = {};
4026 /* 100 ms */
4027 struct timespec delay = { .tv_nsec = 100000000 };
4028
4029 /* There may be arbitrary already-open fds at test start. */
4030 memfd = memfd_create("test", 0);
4031 ASSERT_GE(memfd, 0);
4032 nextfd = memfd + 1;
4033
4034 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4035 ASSERT_EQ(0, ret) {
4036 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4037 }
4038
4039 /* fd: 4 */
4040 /* Check that the basic notification machinery works */
4041 listener = user_notif_syscall(__NR_getppid,
4042 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4043 ASSERT_EQ(listener, nextfd++);
4044
4045 pid = fork();
4046 ASSERT_GE(pid, 0);
4047
4048 if (pid == 0) {
4049 /* fds will be added and this value is expected */
4050 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC)
4051 exit(1);
4052
4053 /* Atomic addfd+send is received here. Check it is a valid fd */
4054 if (fcntl(syscall(__NR_getppid), F_GETFD) == -1)
4055 exit(1);
4056
4057 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4058 }
4059
4060 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4061
4062 addfd.srcfd = memfd;
4063 addfd.newfd = 0;
4064 addfd.id = req.id;
4065 addfd.flags = 0x0;
4066
4067 /* Verify bad newfd_flags cannot be set */
4068 addfd.newfd_flags = ~O_CLOEXEC;
4069 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4070 EXPECT_EQ(errno, EINVAL);
4071 addfd.newfd_flags = O_CLOEXEC;
4072
4073 /* Verify bad flags cannot be set */
4074 addfd.flags = 0xff;
4075 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4076 EXPECT_EQ(errno, EINVAL);
4077 addfd.flags = 0;
4078
4079 /* Verify that remote_fd cannot be set without setting flags */
4080 addfd.newfd = 1;
4081 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4082 EXPECT_EQ(errno, EINVAL);
4083 addfd.newfd = 0;
4084
4085 /* Verify small size cannot be set */
4086 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1);
4087 EXPECT_EQ(errno, EINVAL);
4088
4089 /* Verify we can't send bits filled in unknown buffer area */
4090 memset(&big, 0xAA, sizeof(big));
4091 big.addfd = addfd;
4092 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1);
4093 EXPECT_EQ(errno, E2BIG);
4094
4095
4096 /* Verify we can set an arbitrary remote fd */
4097 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4098 EXPECT_EQ(fd, nextfd++);
4099 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4100
4101 /* Verify we can set an arbitrary remote fd with large size */
4102 memset(&big, 0x0, sizeof(big));
4103 big.addfd = addfd;
4104 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
4105 EXPECT_EQ(fd, nextfd++);
4106
4107 /* Verify we can set a specific remote fd */
4108 addfd.newfd = 42;
4109 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4110 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4111 EXPECT_EQ(fd, 42);
4112 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4113
4114 /* Resume syscall */
4115 resp.id = req.id;
4116 resp.error = 0;
4117 resp.val = USER_NOTIF_MAGIC;
4118 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4119
4120 /*
4121 * This sets the ID of the ADD FD to the last request plus 1. The
4122 * notification ID increments 1 per notification.
4123 */
4124 addfd.id = req.id + 1;
4125
4126 /* This spins until the underlying notification is generated */
4127 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4128 errno != -EINPROGRESS)
4129 nanosleep(&delay, NULL);
4130
4131 memset(&req, 0, sizeof(req));
4132 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4133 ASSERT_EQ(addfd.id, req.id);
4134
4135 /* Verify we can do an atomic addfd and send */
4136 addfd.newfd = 0;
4137 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4138 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4139 /*
4140 * Child has earlier "low" fds and now 42, so we expect the next
4141 * lowest available fd to be assigned here.
4142 */
4143 EXPECT_EQ(fd, nextfd++);
4144 ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4145
4146 /*
4147 * This sets the ID of the ADD FD to the last request plus 1. The
4148 * notification ID increments 1 per notification.
4149 */
4150 addfd.id = req.id + 1;
4151
4152 /* This spins until the underlying notification is generated */
4153 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4154 errno != -EINPROGRESS)
4155 nanosleep(&delay, NULL);
4156
4157 memset(&req, 0, sizeof(req));
4158 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4159 ASSERT_EQ(addfd.id, req.id);
4160
4161 resp.id = req.id;
4162 resp.error = 0;
4163 resp.val = USER_NOTIF_MAGIC;
4164 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4165
4166 /* Wait for child to finish. */
4167 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4168 EXPECT_EQ(true, WIFEXITED(status));
4169 EXPECT_EQ(0, WEXITSTATUS(status));
4170
4171 close(memfd);
4172 }
4173
TEST(user_notification_addfd_rlimit)4174 TEST(user_notification_addfd_rlimit)
4175 {
4176 pid_t pid;
4177 long ret;
4178 int status, listener, memfd;
4179 struct seccomp_notif_addfd addfd = {};
4180 struct seccomp_notif req = {};
4181 struct seccomp_notif_resp resp = {};
4182 const struct rlimit lim = {
4183 .rlim_cur = 0,
4184 .rlim_max = 0,
4185 };
4186
4187 memfd = memfd_create("test", 0);
4188 ASSERT_GE(memfd, 0);
4189
4190 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4191 ASSERT_EQ(0, ret) {
4192 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4193 }
4194
4195 /* Check that the basic notification machinery works */
4196 listener = user_notif_syscall(__NR_getppid,
4197 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4198 ASSERT_GE(listener, 0);
4199
4200 pid = fork();
4201 ASSERT_GE(pid, 0);
4202
4203 if (pid == 0)
4204 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4205
4206
4207 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4208
4209 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0);
4210
4211 addfd.srcfd = memfd;
4212 addfd.newfd_flags = O_CLOEXEC;
4213 addfd.newfd = 0;
4214 addfd.id = req.id;
4215 addfd.flags = 0;
4216
4217 /* Should probably spot check /proc/sys/fs/file-nr */
4218 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4219 EXPECT_EQ(errno, EMFILE);
4220
4221 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4222 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4223 EXPECT_EQ(errno, EMFILE);
4224
4225 addfd.newfd = 100;
4226 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4227 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4228 EXPECT_EQ(errno, EBADF);
4229
4230 resp.id = req.id;
4231 resp.error = 0;
4232 resp.val = USER_NOTIF_MAGIC;
4233
4234 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4235
4236 /* Wait for child to finish. */
4237 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4238 EXPECT_EQ(true, WIFEXITED(status));
4239 EXPECT_EQ(0, WEXITSTATUS(status));
4240
4241 close(memfd);
4242 }
4243
4244 /* Make sure PTRACE_O_SUSPEND_SECCOMP requires CAP_SYS_ADMIN. */
FIXTURE(O_SUSPEND_SECCOMP)4245 FIXTURE(O_SUSPEND_SECCOMP) {
4246 pid_t pid;
4247 };
4248
FIXTURE_SETUP(O_SUSPEND_SECCOMP)4249 FIXTURE_SETUP(O_SUSPEND_SECCOMP)
4250 {
4251 ERRNO_FILTER(block_read, E2BIG);
4252 cap_value_t cap_list[] = { CAP_SYS_ADMIN };
4253 cap_t caps;
4254
4255 self->pid = 0;
4256
4257 /* make sure we don't have CAP_SYS_ADMIN */
4258 caps = cap_get_proc();
4259 ASSERT_NE(NULL, caps);
4260 ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, cap_list, CAP_CLEAR));
4261 ASSERT_EQ(0, cap_set_proc(caps));
4262 cap_free(caps);
4263
4264 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
4265 ASSERT_EQ(0, prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_block_read));
4266
4267 self->pid = fork();
4268 ASSERT_GE(self->pid, 0);
4269
4270 if (self->pid == 0) {
4271 while (1)
4272 pause();
4273 _exit(127);
4274 }
4275 }
4276
FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP)4277 FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP)
4278 {
4279 if (self->pid)
4280 kill(self->pid, SIGKILL);
4281 }
4282
TEST_F(O_SUSPEND_SECCOMP,setoptions)4283 TEST_F(O_SUSPEND_SECCOMP, setoptions)
4284 {
4285 int wstatus;
4286
4287 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, self->pid, NULL, 0));
4288 ASSERT_EQ(self->pid, wait(&wstatus));
4289 ASSERT_EQ(-1, ptrace(PTRACE_SETOPTIONS, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP));
4290 if (errno == EINVAL)
4291 SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
4292 ASSERT_EQ(EPERM, errno);
4293 }
4294
TEST_F(O_SUSPEND_SECCOMP,seize)4295 TEST_F(O_SUSPEND_SECCOMP, seize)
4296 {
4297 int ret;
4298
4299 ret = ptrace(PTRACE_SEIZE, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP);
4300 ASSERT_EQ(-1, ret);
4301 if (errno == EINVAL)
4302 SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
4303 ASSERT_EQ(EPERM, errno);
4304 }
4305
4306 /*
4307 * get_nth - Get the nth, space separated entry in a file.
4308 *
4309 * Returns the length of the read field.
4310 * Throws error if field is zero-lengthed.
4311 */
get_nth(struct __test_metadata * _metadata,const char * path,const unsigned int position,char ** entry)4312 static ssize_t get_nth(struct __test_metadata *_metadata, const char *path,
4313 const unsigned int position, char **entry)
4314 {
4315 char *line = NULL;
4316 unsigned int i;
4317 ssize_t nread;
4318 size_t len = 0;
4319 FILE *f;
4320
4321 f = fopen(path, "r");
4322 ASSERT_NE(f, NULL) {
4323 TH_LOG("Could not open %s: %s", path, strerror(errno));
4324 }
4325
4326 for (i = 0; i < position; i++) {
4327 nread = getdelim(&line, &len, ' ', f);
4328 ASSERT_GE(nread, 0) {
4329 TH_LOG("Failed to read %d entry in file %s", i, path);
4330 }
4331 }
4332 fclose(f);
4333
4334 ASSERT_GT(nread, 0) {
4335 TH_LOG("Entry in file %s had zero length", path);
4336 }
4337
4338 *entry = line;
4339 return nread - 1;
4340 }
4341
4342 /* For a given PID, get the task state (D, R, etc...) */
get_proc_stat(struct __test_metadata * _metadata,pid_t pid)4343 static char get_proc_stat(struct __test_metadata *_metadata, pid_t pid)
4344 {
4345 char proc_path[100] = {0};
4346 char status;
4347 char *line;
4348
4349 snprintf(proc_path, sizeof(proc_path), "/proc/%d/stat", pid);
4350 ASSERT_EQ(get_nth(_metadata, proc_path, 3, &line), 1);
4351
4352 status = *line;
4353 free(line);
4354
4355 return status;
4356 }
4357
TEST(user_notification_fifo)4358 TEST(user_notification_fifo)
4359 {
4360 struct seccomp_notif_resp resp = {};
4361 struct seccomp_notif req = {};
4362 int i, status, listener;
4363 pid_t pid, pids[3];
4364 __u64 baseid;
4365 long ret;
4366 /* 100 ms */
4367 struct timespec delay = { .tv_nsec = 100000000 };
4368
4369 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4370 ASSERT_EQ(0, ret) {
4371 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4372 }
4373
4374 /* Setup a listener */
4375 listener = user_notif_syscall(__NR_getppid,
4376 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4377 ASSERT_GE(listener, 0);
4378
4379 pid = fork();
4380 ASSERT_GE(pid, 0);
4381
4382 if (pid == 0) {
4383 ret = syscall(__NR_getppid);
4384 exit(ret != USER_NOTIF_MAGIC);
4385 }
4386
4387 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4388 baseid = req.id + 1;
4389
4390 resp.id = req.id;
4391 resp.error = 0;
4392 resp.val = USER_NOTIF_MAGIC;
4393
4394 /* check that we make sure flags == 0 */
4395 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4396
4397 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4398 EXPECT_EQ(true, WIFEXITED(status));
4399 EXPECT_EQ(0, WEXITSTATUS(status));
4400
4401 /* Start children, and generate notifications */
4402 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4403 pid = fork();
4404 if (pid == 0) {
4405 ret = syscall(__NR_getppid);
4406 exit(ret != USER_NOTIF_MAGIC);
4407 }
4408 pids[i] = pid;
4409 }
4410
4411 /* This spins until all of the children are sleeping */
4412 restart_wait:
4413 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4414 if (get_proc_stat(_metadata, pids[i]) != 'S') {
4415 nanosleep(&delay, NULL);
4416 goto restart_wait;
4417 }
4418 }
4419
4420 /* Read the notifications in order (and respond) */
4421 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4422 memset(&req, 0, sizeof(req));
4423 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4424 EXPECT_EQ(req.id, baseid + i);
4425 resp.id = req.id;
4426 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4427 }
4428
4429 /* Make sure notifications were received */
4430 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4431 EXPECT_EQ(waitpid(pids[i], &status, 0), pids[i]);
4432 EXPECT_EQ(true, WIFEXITED(status));
4433 EXPECT_EQ(0, WEXITSTATUS(status));
4434 }
4435 }
4436
4437 /* get_proc_syscall - Get the syscall in progress for a given pid
4438 *
4439 * Returns the current syscall number for a given process
4440 * Returns -1 if not in syscall (running or blocked)
4441 */
get_proc_syscall(struct __test_metadata * _metadata,int pid)4442 static long get_proc_syscall(struct __test_metadata *_metadata, int pid)
4443 {
4444 char proc_path[100] = {0};
4445 long ret = -1;
4446 ssize_t nread;
4447 char *line;
4448
4449 snprintf(proc_path, sizeof(proc_path), "/proc/%d/syscall", pid);
4450 nread = get_nth(_metadata, proc_path, 1, &line);
4451 ASSERT_GT(nread, 0);
4452
4453 if (!strncmp("running", line, MIN(7, nread)))
4454 ret = strtol(line, NULL, 16);
4455
4456 free(line);
4457 return ret;
4458 }
4459
4460 /* Ensure non-fatal signals prior to receive are unmodified */
TEST(user_notification_wait_killable_pre_notification)4461 TEST(user_notification_wait_killable_pre_notification)
4462 {
4463 struct sigaction new_action = {
4464 .sa_handler = signal_handler,
4465 };
4466 int listener, status, sk_pair[2];
4467 pid_t pid;
4468 long ret;
4469 char c;
4470 /* 100 ms */
4471 struct timespec delay = { .tv_nsec = 100000000 };
4472
4473 ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
4474
4475 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4476 ASSERT_EQ(0, ret)
4477 {
4478 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4479 }
4480
4481 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
4482
4483 listener = user_notif_syscall(
4484 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4485 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4486 ASSERT_GE(listener, 0);
4487
4488 /*
4489 * Check that we can kill the process with SIGUSR1 prior to receiving
4490 * the notification. SIGUSR1 is wired up to a custom signal handler,
4491 * and make sure it gets called.
4492 */
4493 pid = fork();
4494 ASSERT_GE(pid, 0);
4495
4496 if (pid == 0) {
4497 close(sk_pair[0]);
4498 handled = sk_pair[1];
4499
4500 /* Setup the non-fatal sigaction without SA_RESTART */
4501 if (sigaction(SIGUSR1, &new_action, NULL)) {
4502 perror("sigaction");
4503 exit(1);
4504 }
4505
4506 ret = syscall(__NR_getppid);
4507 /* Make sure we got a return from a signal interruption */
4508 exit(ret != -1 || errno != EINTR);
4509 }
4510
4511 /*
4512 * Make sure we've gotten to the seccomp user notification wait
4513 * from getppid prior to sending any signals
4514 */
4515 while (get_proc_syscall(_metadata, pid) != __NR_getppid &&
4516 get_proc_stat(_metadata, pid) != 'S')
4517 nanosleep(&delay, NULL);
4518
4519 /* Send non-fatal kill signal */
4520 EXPECT_EQ(kill(pid, SIGUSR1), 0);
4521
4522 /* wait for process to exit (exit checks for EINTR) */
4523 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4524 EXPECT_EQ(true, WIFEXITED(status));
4525 EXPECT_EQ(0, WEXITSTATUS(status));
4526
4527 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
4528 }
4529
4530 /* Ensure non-fatal signals after receive are blocked */
TEST(user_notification_wait_killable)4531 TEST(user_notification_wait_killable)
4532 {
4533 struct sigaction new_action = {
4534 .sa_handler = signal_handler,
4535 };
4536 struct seccomp_notif_resp resp = {};
4537 struct seccomp_notif req = {};
4538 int listener, status, sk_pair[2];
4539 pid_t pid;
4540 long ret;
4541 char c;
4542 /* 100 ms */
4543 struct timespec delay = { .tv_nsec = 100000000 };
4544
4545 ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
4546
4547 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4548 ASSERT_EQ(0, ret)
4549 {
4550 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4551 }
4552
4553 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
4554
4555 listener = user_notif_syscall(
4556 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4557 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4558 ASSERT_GE(listener, 0);
4559
4560 pid = fork();
4561 ASSERT_GE(pid, 0);
4562
4563 if (pid == 0) {
4564 close(sk_pair[0]);
4565 handled = sk_pair[1];
4566
4567 /* Setup the sigaction without SA_RESTART */
4568 if (sigaction(SIGUSR1, &new_action, NULL)) {
4569 perror("sigaction");
4570 exit(1);
4571 }
4572
4573 /* Make sure that the syscall is completed (no EINTR) */
4574 ret = syscall(__NR_getppid);
4575 exit(ret != USER_NOTIF_MAGIC);
4576 }
4577
4578 /*
4579 * Get the notification, to make move the notifying process into a
4580 * non-preemptible (TASK_KILLABLE) state.
4581 */
4582 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4583 /* Send non-fatal kill signal */
4584 EXPECT_EQ(kill(pid, SIGUSR1), 0);
4585
4586 /*
4587 * Make sure the task enters moves to TASK_KILLABLE by waiting for
4588 * D (Disk Sleep) state after receiving non-fatal signal.
4589 */
4590 while (get_proc_stat(_metadata, pid) != 'D')
4591 nanosleep(&delay, NULL);
4592
4593 resp.id = req.id;
4594 resp.val = USER_NOTIF_MAGIC;
4595 /* Make sure the notification is found and able to be replied to */
4596 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4597
4598 /*
4599 * Make sure that the signal handler does get called once we're back in
4600 * userspace.
4601 */
4602 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
4603 /* wait for process to exit (exit checks for USER_NOTIF_MAGIC) */
4604 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4605 EXPECT_EQ(true, WIFEXITED(status));
4606 EXPECT_EQ(0, WEXITSTATUS(status));
4607 }
4608
4609 /* Ensure fatal signals after receive are not blocked */
TEST(user_notification_wait_killable_fatal)4610 TEST(user_notification_wait_killable_fatal)
4611 {
4612 struct seccomp_notif req = {};
4613 int listener, status;
4614 pid_t pid;
4615 long ret;
4616 /* 100 ms */
4617 struct timespec delay = { .tv_nsec = 100000000 };
4618
4619 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4620 ASSERT_EQ(0, ret)
4621 {
4622 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4623 }
4624
4625 listener = user_notif_syscall(
4626 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4627 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4628 ASSERT_GE(listener, 0);
4629
4630 pid = fork();
4631 ASSERT_GE(pid, 0);
4632
4633 if (pid == 0) {
4634 /* This should never complete as it should get a SIGTERM */
4635 syscall(__NR_getppid);
4636 exit(1);
4637 }
4638
4639 while (get_proc_stat(_metadata, pid) != 'S')
4640 nanosleep(&delay, NULL);
4641
4642 /*
4643 * Get the notification, to make move the notifying process into a
4644 * non-preemptible (TASK_KILLABLE) state.
4645 */
4646 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4647 /* Kill the process with a fatal signal */
4648 EXPECT_EQ(kill(pid, SIGTERM), 0);
4649
4650 /*
4651 * Wait for the process to exit, and make sure the process terminated
4652 * due to the SIGTERM signal.
4653 */
4654 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4655 EXPECT_EQ(true, WIFSIGNALED(status));
4656 EXPECT_EQ(SIGTERM, WTERMSIG(status));
4657 }
4658
4659 /*
4660 * TODO:
4661 * - expand NNP testing
4662 * - better arch-specific TRACE and TRAP handlers.
4663 * - endianness checking when appropriate
4664 * - 64-bit arg prodding
4665 * - arch value testing (x86 modes especially)
4666 * - verify that FILTER_FLAG_LOG filters generate log messages
4667 * - verify that RET_LOG generates log messages
4668 */
4669
4670 TEST_HARNESS_MAIN
4671
