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[thirdparty/linux.git] / tools / testing / selftests / seccomp / seccomp_bpf.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #define _GNU_SOURCE
9 #include <sys/types.h>
10
11 /*
12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
13 * we need to use the kernel's siginfo.h file and trick glibc
14 * into accepting it.
15 */
16 #if !__GLIBC_PREREQ(2, 26)
17 # include <asm/siginfo.h>
18 # define __have_siginfo_t 1
19 # define __have_sigval_t 1
20 # define __have_sigevent_t 1
21 #endif
22
23 #include <errno.h>
24 #include <linux/filter.h>
25 #include <sys/prctl.h>
26 #include <sys/ptrace.h>
27 #include <sys/user.h>
28 #include <linux/prctl.h>
29 #include <linux/ptrace.h>
30 #include <linux/seccomp.h>
31 #include <pthread.h>
32 #include <semaphore.h>
33 #include <signal.h>
34 #include <stddef.h>
35 #include <stdbool.h>
36 #include <string.h>
37 #include <time.h>
38 #include <limits.h>
39 #include <linux/elf.h>
40 #include <sys/uio.h>
41 #include <sys/utsname.h>
42 #include <sys/fcntl.h>
43 #include <sys/mman.h>
44 #include <sys/times.h>
45 #include <sys/socket.h>
46 #include <sys/ioctl.h>
47 #include <linux/kcmp.h>
48
49 #include <unistd.h>
50 #include <sys/syscall.h>
51 #include <poll.h>
52
53 #include "../kselftest_harness.h"
54
55 #ifndef PR_SET_PTRACER
56 # define PR_SET_PTRACER 0x59616d61
57 #endif
58
59 #ifndef PR_SET_NO_NEW_PRIVS
60 #define PR_SET_NO_NEW_PRIVS 38
61 #define PR_GET_NO_NEW_PRIVS 39
62 #endif
63
64 #ifndef PR_SECCOMP_EXT
65 #define PR_SECCOMP_EXT 43
66 #endif
67
68 #ifndef SECCOMP_EXT_ACT
69 #define SECCOMP_EXT_ACT 1
70 #endif
71
72 #ifndef SECCOMP_EXT_ACT_TSYNC
73 #define SECCOMP_EXT_ACT_TSYNC 1
74 #endif
75
76 #ifndef SECCOMP_MODE_STRICT
77 #define SECCOMP_MODE_STRICT 1
78 #endif
79
80 #ifndef SECCOMP_MODE_FILTER
81 #define SECCOMP_MODE_FILTER 2
82 #endif
83
84 #ifndef SECCOMP_RET_ALLOW
85 struct seccomp_data {
86 int nr;
87 __u32 arch;
88 __u64 instruction_pointer;
89 __u64 args[6];
90 };
91 #endif
92
93 #ifndef SECCOMP_RET_KILL_PROCESS
94 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
95 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
96 #endif
97 #ifndef SECCOMP_RET_KILL
98 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
99 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
100 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
101 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
102 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
103 #endif
104 #ifndef SECCOMP_RET_LOG
105 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
106 #endif
107
108 #ifndef __NR_seccomp
109 # if defined(__i386__)
110 # define __NR_seccomp 354
111 # elif defined(__x86_64__)
112 # define __NR_seccomp 317
113 # elif defined(__arm__)
114 # define __NR_seccomp 383
115 # elif defined(__aarch64__)
116 # define __NR_seccomp 277
117 # elif defined(__riscv)
118 # define __NR_seccomp 277
119 # elif defined(__hppa__)
120 # define __NR_seccomp 338
121 # elif defined(__powerpc__)
122 # define __NR_seccomp 358
123 # elif defined(__s390__)
124 # define __NR_seccomp 348
125 # else
126 # warning "seccomp syscall number unknown for this architecture"
127 # define __NR_seccomp 0xffff
128 # endif
129 #endif
130
131 #ifndef SECCOMP_SET_MODE_STRICT
132 #define SECCOMP_SET_MODE_STRICT 0
133 #endif
134
135 #ifndef SECCOMP_SET_MODE_FILTER
136 #define SECCOMP_SET_MODE_FILTER 1
137 #endif
138
139 #ifndef SECCOMP_GET_ACTION_AVAIL
140 #define SECCOMP_GET_ACTION_AVAIL 2
141 #endif
142
143 #ifndef SECCOMP_GET_NOTIF_SIZES
144 #define SECCOMP_GET_NOTIF_SIZES 3
145 #endif
146
147 #ifndef SECCOMP_FILTER_FLAG_TSYNC
148 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
149 #endif
150
151 #ifndef SECCOMP_FILTER_FLAG_LOG
152 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
153 #endif
154
155 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
156 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
157 #endif
158
159 #ifndef PTRACE_SECCOMP_GET_METADATA
160 #define PTRACE_SECCOMP_GET_METADATA 0x420d
161
162 struct seccomp_metadata {
163 __u64 filter_off; /* Input: which filter */
164 __u64 flags; /* Output: filter's flags */
165 };
166 #endif
167
168 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
169 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
170
171 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
172
173 #define SECCOMP_IOC_MAGIC '!'
174 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
175 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
176 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
177 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
178
179 /* Flags for seccomp notification fd ioctl. */
180 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
181 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
182 struct seccomp_notif_resp)
183 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOR(2, __u64)
184
185 struct seccomp_notif {
186 __u64 id;
187 __u32 pid;
188 __u32 flags;
189 struct seccomp_data data;
190 };
191
192 struct seccomp_notif_resp {
193 __u64 id;
194 __s64 val;
195 __s32 error;
196 __u32 flags;
197 };
198
199 struct seccomp_notif_sizes {
200 __u16 seccomp_notif;
201 __u16 seccomp_notif_resp;
202 __u16 seccomp_data;
203 };
204 #endif
205
206 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
207 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
208 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
209 #endif
210
211 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
212 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
213 #endif
214
215 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
216 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
217 #endif
218
219 #ifndef seccomp
220 int seccomp(unsigned int op, unsigned int flags, void *args)
221 {
222 errno = 0;
223 return syscall(__NR_seccomp, op, flags, args);
224 }
225 #endif
226
227 #if __BYTE_ORDER == __LITTLE_ENDIAN
228 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
229 #elif __BYTE_ORDER == __BIG_ENDIAN
230 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
231 #else
232 #error "wut? Unknown __BYTE_ORDER?!"
233 #endif
234
235 #define SIBLING_EXIT_UNKILLED 0xbadbeef
236 #define SIBLING_EXIT_FAILURE 0xbadface
237 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
238
239 TEST(mode_strict_support)
240 {
241 long ret;
242
243 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
244 ASSERT_EQ(0, ret) {
245 TH_LOG("Kernel does not support CONFIG_SECCOMP");
246 }
247 syscall(__NR_exit, 0);
248 }
249
250 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
251 {
252 long ret;
253
254 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
255 ASSERT_EQ(0, ret) {
256 TH_LOG("Kernel does not support CONFIG_SECCOMP");
257 }
258 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
259 NULL, NULL, NULL);
260 EXPECT_FALSE(true) {
261 TH_LOG("Unreachable!");
262 }
263 }
264
265 /* Note! This doesn't test no new privs behavior */
266 TEST(no_new_privs_support)
267 {
268 long ret;
269
270 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
271 EXPECT_EQ(0, ret) {
272 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
273 }
274 }
275
276 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
277 TEST(mode_filter_support)
278 {
279 long ret;
280
281 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
282 ASSERT_EQ(0, ret) {
283 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
284 }
285 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
286 EXPECT_EQ(-1, ret);
287 EXPECT_EQ(EFAULT, errno) {
288 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
289 }
290 }
291
292 TEST(mode_filter_without_nnp)
293 {
294 struct sock_filter filter[] = {
295 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
296 };
297 struct sock_fprog prog = {
298 .len = (unsigned short)ARRAY_SIZE(filter),
299 .filter = filter,
300 };
301 long ret;
302
303 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
304 ASSERT_LE(0, ret) {
305 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
306 }
307 errno = 0;
308 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
309 /* Succeeds with CAP_SYS_ADMIN, fails without */
310 /* TODO(wad) check caps not euid */
311 if (geteuid()) {
312 EXPECT_EQ(-1, ret);
313 EXPECT_EQ(EACCES, errno);
314 } else {
315 EXPECT_EQ(0, ret);
316 }
317 }
318
319 #define MAX_INSNS_PER_PATH 32768
320
321 TEST(filter_size_limits)
322 {
323 int i;
324 int count = BPF_MAXINSNS + 1;
325 struct sock_filter allow[] = {
326 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
327 };
328 struct sock_filter *filter;
329 struct sock_fprog prog = { };
330 long ret;
331
332 filter = calloc(count, sizeof(*filter));
333 ASSERT_NE(NULL, filter);
334
335 for (i = 0; i < count; i++)
336 filter[i] = allow[0];
337
338 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
339 ASSERT_EQ(0, ret);
340
341 prog.filter = filter;
342 prog.len = count;
343
344 /* Too many filter instructions in a single filter. */
345 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
346 ASSERT_NE(0, ret) {
347 TH_LOG("Installing %d insn filter was allowed", prog.len);
348 }
349
350 /* One less is okay, though. */
351 prog.len -= 1;
352 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
353 ASSERT_EQ(0, ret) {
354 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
355 }
356 }
357
358 TEST(filter_chain_limits)
359 {
360 int i;
361 int count = BPF_MAXINSNS;
362 struct sock_filter allow[] = {
363 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
364 };
365 struct sock_filter *filter;
366 struct sock_fprog prog = { };
367 long ret;
368
369 filter = calloc(count, sizeof(*filter));
370 ASSERT_NE(NULL, filter);
371
372 for (i = 0; i < count; i++)
373 filter[i] = allow[0];
374
375 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
376 ASSERT_EQ(0, ret);
377
378 prog.filter = filter;
379 prog.len = 1;
380
381 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
382 ASSERT_EQ(0, ret);
383
384 prog.len = count;
385
386 /* Too many total filter instructions. */
387 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
388 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
389 if (ret != 0)
390 break;
391 }
392 ASSERT_NE(0, ret) {
393 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
394 i, count, i * (count + 4));
395 }
396 }
397
398 TEST(mode_filter_cannot_move_to_strict)
399 {
400 struct sock_filter filter[] = {
401 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
402 };
403 struct sock_fprog prog = {
404 .len = (unsigned short)ARRAY_SIZE(filter),
405 .filter = filter,
406 };
407 long ret;
408
409 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
410 ASSERT_EQ(0, ret);
411
412 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
413 ASSERT_EQ(0, ret);
414
415 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
416 EXPECT_EQ(-1, ret);
417 EXPECT_EQ(EINVAL, errno);
418 }
419
420
421 TEST(mode_filter_get_seccomp)
422 {
423 struct sock_filter filter[] = {
424 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
425 };
426 struct sock_fprog prog = {
427 .len = (unsigned short)ARRAY_SIZE(filter),
428 .filter = filter,
429 };
430 long ret;
431
432 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
433 ASSERT_EQ(0, ret);
434
435 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
436 EXPECT_EQ(0, ret);
437
438 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
439 ASSERT_EQ(0, ret);
440
441 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
442 EXPECT_EQ(2, ret);
443 }
444
445
446 TEST(ALLOW_all)
447 {
448 struct sock_filter filter[] = {
449 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
450 };
451 struct sock_fprog prog = {
452 .len = (unsigned short)ARRAY_SIZE(filter),
453 .filter = filter,
454 };
455 long ret;
456
457 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
458 ASSERT_EQ(0, ret);
459
460 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
461 ASSERT_EQ(0, ret);
462 }
463
464 TEST(empty_prog)
465 {
466 struct sock_filter filter[] = {
467 };
468 struct sock_fprog prog = {
469 .len = (unsigned short)ARRAY_SIZE(filter),
470 .filter = filter,
471 };
472 long ret;
473
474 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
475 ASSERT_EQ(0, ret);
476
477 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
478 EXPECT_EQ(-1, ret);
479 EXPECT_EQ(EINVAL, errno);
480 }
481
482 TEST(log_all)
483 {
484 struct sock_filter filter[] = {
485 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
486 };
487 struct sock_fprog prog = {
488 .len = (unsigned short)ARRAY_SIZE(filter),
489 .filter = filter,
490 };
491 long ret;
492 pid_t parent = getppid();
493
494 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
495 ASSERT_EQ(0, ret);
496
497 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
498 ASSERT_EQ(0, ret);
499
500 /* getppid() should succeed and be logged (no check for logging) */
501 EXPECT_EQ(parent, syscall(__NR_getppid));
502 }
503
504 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
505 {
506 struct sock_filter filter[] = {
507 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
508 };
509 struct sock_fprog prog = {
510 .len = (unsigned short)ARRAY_SIZE(filter),
511 .filter = filter,
512 };
513 long ret;
514
515 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
516 ASSERT_EQ(0, ret);
517
518 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
519 ASSERT_EQ(0, ret);
520 EXPECT_EQ(0, syscall(__NR_getpid)) {
521 TH_LOG("getpid() shouldn't ever return");
522 }
523 }
524
525 /* return code >= 0x80000000 is unused. */
526 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
527 {
528 struct sock_filter filter[] = {
529 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
530 };
531 struct sock_fprog prog = {
532 .len = (unsigned short)ARRAY_SIZE(filter),
533 .filter = filter,
534 };
535 long ret;
536
537 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
538 ASSERT_EQ(0, ret);
539
540 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
541 ASSERT_EQ(0, ret);
542 EXPECT_EQ(0, syscall(__NR_getpid)) {
543 TH_LOG("getpid() shouldn't ever return");
544 }
545 }
546
547 TEST_SIGNAL(KILL_all, SIGSYS)
548 {
549 struct sock_filter filter[] = {
550 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
551 };
552 struct sock_fprog prog = {
553 .len = (unsigned short)ARRAY_SIZE(filter),
554 .filter = filter,
555 };
556 long ret;
557
558 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
559 ASSERT_EQ(0, ret);
560
561 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
562 ASSERT_EQ(0, ret);
563 }
564
565 TEST_SIGNAL(KILL_one, SIGSYS)
566 {
567 struct sock_filter filter[] = {
568 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
569 offsetof(struct seccomp_data, nr)),
570 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
571 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
572 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
573 };
574 struct sock_fprog prog = {
575 .len = (unsigned short)ARRAY_SIZE(filter),
576 .filter = filter,
577 };
578 long ret;
579 pid_t parent = getppid();
580
581 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
582 ASSERT_EQ(0, ret);
583
584 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
585 ASSERT_EQ(0, ret);
586
587 EXPECT_EQ(parent, syscall(__NR_getppid));
588 /* getpid() should never return. */
589 EXPECT_EQ(0, syscall(__NR_getpid));
590 }
591
592 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
593 {
594 void *fatal_address;
595 struct sock_filter filter[] = {
596 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
597 offsetof(struct seccomp_data, nr)),
598 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
599 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
600 /* Only both with lower 32-bit for now. */
601 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
602 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
603 (unsigned long)&fatal_address, 0, 1),
604 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
605 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
606 };
607 struct sock_fprog prog = {
608 .len = (unsigned short)ARRAY_SIZE(filter),
609 .filter = filter,
610 };
611 long ret;
612 pid_t parent = getppid();
613 struct tms timebuf;
614 clock_t clock = times(&timebuf);
615
616 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
617 ASSERT_EQ(0, ret);
618
619 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
620 ASSERT_EQ(0, ret);
621
622 EXPECT_EQ(parent, syscall(__NR_getppid));
623 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
624 /* times() should never return. */
625 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
626 }
627
628 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
629 {
630 #ifndef __NR_mmap2
631 int sysno = __NR_mmap;
632 #else
633 int sysno = __NR_mmap2;
634 #endif
635 struct sock_filter filter[] = {
636 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
637 offsetof(struct seccomp_data, nr)),
638 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
639 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
640 /* Only both with lower 32-bit for now. */
641 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
642 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
643 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
644 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
645 };
646 struct sock_fprog prog = {
647 .len = (unsigned short)ARRAY_SIZE(filter),
648 .filter = filter,
649 };
650 long ret;
651 pid_t parent = getppid();
652 int fd;
653 void *map1, *map2;
654 int page_size = sysconf(_SC_PAGESIZE);
655
656 ASSERT_LT(0, page_size);
657
658 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
659 ASSERT_EQ(0, ret);
660
661 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
662 ASSERT_EQ(0, ret);
663
664 fd = open("/dev/zero", O_RDONLY);
665 ASSERT_NE(-1, fd);
666
667 EXPECT_EQ(parent, syscall(__NR_getppid));
668 map1 = (void *)syscall(sysno,
669 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
670 EXPECT_NE(MAP_FAILED, map1);
671 /* mmap2() should never return. */
672 map2 = (void *)syscall(sysno,
673 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
674 EXPECT_EQ(MAP_FAILED, map2);
675
676 /* The test failed, so clean up the resources. */
677 munmap(map1, page_size);
678 munmap(map2, page_size);
679 close(fd);
680 }
681
682 /* This is a thread task to die via seccomp filter violation. */
683 void *kill_thread(void *data)
684 {
685 bool die = (bool)data;
686
687 if (die) {
688 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
689 return (void *)SIBLING_EXIT_FAILURE;
690 }
691
692 return (void *)SIBLING_EXIT_UNKILLED;
693 }
694
695 /* Prepare a thread that will kill itself or both of us. */
696 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
697 {
698 pthread_t thread;
699 void *status;
700 /* Kill only when calling __NR_prctl. */
701 struct sock_filter filter_thread[] = {
702 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
703 offsetof(struct seccomp_data, nr)),
704 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
705 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
706 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
707 };
708 struct sock_fprog prog_thread = {
709 .len = (unsigned short)ARRAY_SIZE(filter_thread),
710 .filter = filter_thread,
711 };
712 struct sock_filter filter_process[] = {
713 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
714 offsetof(struct seccomp_data, nr)),
715 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
716 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
717 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
718 };
719 struct sock_fprog prog_process = {
720 .len = (unsigned short)ARRAY_SIZE(filter_process),
721 .filter = filter_process,
722 };
723
724 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
725 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
726 }
727
728 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
729 kill_process ? &prog_process : &prog_thread));
730
731 /*
732 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
733 * flag cannot be downgraded by a new filter.
734 */
735 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
736
737 /* Start a thread that will exit immediately. */
738 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
739 ASSERT_EQ(0, pthread_join(thread, &status));
740 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
741
742 /* Start a thread that will die immediately. */
743 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
744 ASSERT_EQ(0, pthread_join(thread, &status));
745 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
746
747 /*
748 * If we get here, only the spawned thread died. Let the parent know
749 * the whole process didn't die (i.e. this thread, the spawner,
750 * stayed running).
751 */
752 exit(42);
753 }
754
755 TEST(KILL_thread)
756 {
757 int status;
758 pid_t child_pid;
759
760 child_pid = fork();
761 ASSERT_LE(0, child_pid);
762 if (child_pid == 0) {
763 kill_thread_or_group(_metadata, false);
764 _exit(38);
765 }
766
767 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
768
769 /* If only the thread was killed, we'll see exit 42. */
770 ASSERT_TRUE(WIFEXITED(status));
771 ASSERT_EQ(42, WEXITSTATUS(status));
772 }
773
774 TEST(KILL_process)
775 {
776 int status;
777 pid_t child_pid;
778
779 child_pid = fork();
780 ASSERT_LE(0, child_pid);
781 if (child_pid == 0) {
782 kill_thread_or_group(_metadata, true);
783 _exit(38);
784 }
785
786 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
787
788 /* If the entire process was killed, we'll see SIGSYS. */
789 ASSERT_TRUE(WIFSIGNALED(status));
790 ASSERT_EQ(SIGSYS, WTERMSIG(status));
791 }
792
793 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
794 TEST(arg_out_of_range)
795 {
796 struct sock_filter filter[] = {
797 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
798 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
799 };
800 struct sock_fprog prog = {
801 .len = (unsigned short)ARRAY_SIZE(filter),
802 .filter = filter,
803 };
804 long ret;
805
806 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
807 ASSERT_EQ(0, ret);
808
809 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
810 EXPECT_EQ(-1, ret);
811 EXPECT_EQ(EINVAL, errno);
812 }
813
814 #define ERRNO_FILTER(name, errno) \
815 struct sock_filter _read_filter_##name[] = { \
816 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
817 offsetof(struct seccomp_data, nr)), \
818 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
819 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
820 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
821 }; \
822 struct sock_fprog prog_##name = { \
823 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
824 .filter = _read_filter_##name, \
825 }
826
827 /* Make sure basic errno values are correctly passed through a filter. */
828 TEST(ERRNO_valid)
829 {
830 ERRNO_FILTER(valid, E2BIG);
831 long ret;
832 pid_t parent = getppid();
833
834 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
835 ASSERT_EQ(0, ret);
836
837 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
838 ASSERT_EQ(0, ret);
839
840 EXPECT_EQ(parent, syscall(__NR_getppid));
841 EXPECT_EQ(-1, read(0, NULL, 0));
842 EXPECT_EQ(E2BIG, errno);
843 }
844
845 /* Make sure an errno of zero is correctly handled by the arch code. */
846 TEST(ERRNO_zero)
847 {
848 ERRNO_FILTER(zero, 0);
849 long ret;
850 pid_t parent = getppid();
851
852 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
853 ASSERT_EQ(0, ret);
854
855 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
856 ASSERT_EQ(0, ret);
857
858 EXPECT_EQ(parent, syscall(__NR_getppid));
859 /* "errno" of 0 is ok. */
860 EXPECT_EQ(0, read(0, NULL, 0));
861 }
862
863 /*
864 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
865 * This tests that the errno value gets capped correctly, fixed by
866 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
867 */
868 TEST(ERRNO_capped)
869 {
870 ERRNO_FILTER(capped, 4096);
871 long ret;
872 pid_t parent = getppid();
873
874 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
875 ASSERT_EQ(0, ret);
876
877 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
878 ASSERT_EQ(0, ret);
879
880 EXPECT_EQ(parent, syscall(__NR_getppid));
881 EXPECT_EQ(-1, read(0, NULL, 0));
882 EXPECT_EQ(4095, errno);
883 }
884
885 /*
886 * Filters are processed in reverse order: last applied is executed first.
887 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
888 * SECCOMP_RET_DATA mask results will follow the most recently applied
889 * matching filter return (and not the lowest or highest value).
890 */
891 TEST(ERRNO_order)
892 {
893 ERRNO_FILTER(first, 11);
894 ERRNO_FILTER(second, 13);
895 ERRNO_FILTER(third, 12);
896 long ret;
897 pid_t parent = getppid();
898
899 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
900 ASSERT_EQ(0, ret);
901
902 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
903 ASSERT_EQ(0, ret);
904
905 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
906 ASSERT_EQ(0, ret);
907
908 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
909 ASSERT_EQ(0, ret);
910
911 EXPECT_EQ(parent, syscall(__NR_getppid));
912 EXPECT_EQ(-1, read(0, NULL, 0));
913 EXPECT_EQ(12, errno);
914 }
915
916 FIXTURE(TRAP) {
917 struct sock_fprog prog;
918 };
919
920 FIXTURE_SETUP(TRAP)
921 {
922 struct sock_filter filter[] = {
923 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
924 offsetof(struct seccomp_data, nr)),
925 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
926 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
927 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
928 };
929
930 memset(&self->prog, 0, sizeof(self->prog));
931 self->prog.filter = malloc(sizeof(filter));
932 ASSERT_NE(NULL, self->prog.filter);
933 memcpy(self->prog.filter, filter, sizeof(filter));
934 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
935 }
936
937 FIXTURE_TEARDOWN(TRAP)
938 {
939 if (self->prog.filter)
940 free(self->prog.filter);
941 }
942
943 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
944 {
945 long ret;
946
947 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
948 ASSERT_EQ(0, ret);
949
950 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
951 ASSERT_EQ(0, ret);
952 syscall(__NR_getpid);
953 }
954
955 /* Ensure that SIGSYS overrides SIG_IGN */
956 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
957 {
958 long ret;
959
960 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
961 ASSERT_EQ(0, ret);
962
963 signal(SIGSYS, SIG_IGN);
964
965 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
966 ASSERT_EQ(0, ret);
967 syscall(__NR_getpid);
968 }
969
970 static siginfo_t TRAP_info;
971 static volatile int TRAP_nr;
972 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
973 {
974 memcpy(&TRAP_info, info, sizeof(TRAP_info));
975 TRAP_nr = nr;
976 }
977
978 TEST_F(TRAP, handler)
979 {
980 int ret, test;
981 struct sigaction act;
982 sigset_t mask;
983
984 memset(&act, 0, sizeof(act));
985 sigemptyset(&mask);
986 sigaddset(&mask, SIGSYS);
987
988 act.sa_sigaction = &TRAP_action;
989 act.sa_flags = SA_SIGINFO;
990 ret = sigaction(SIGSYS, &act, NULL);
991 ASSERT_EQ(0, ret) {
992 TH_LOG("sigaction failed");
993 }
994 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
995 ASSERT_EQ(0, ret) {
996 TH_LOG("sigprocmask failed");
997 }
998
999 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1000 ASSERT_EQ(0, ret);
1001 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1002 ASSERT_EQ(0, ret);
1003 TRAP_nr = 0;
1004 memset(&TRAP_info, 0, sizeof(TRAP_info));
1005 /* Expect the registers to be rolled back. (nr = error) may vary
1006 * based on arch. */
1007 ret = syscall(__NR_getpid);
1008 /* Silence gcc warning about volatile. */
1009 test = TRAP_nr;
1010 EXPECT_EQ(SIGSYS, test);
1011 struct local_sigsys {
1012 void *_call_addr; /* calling user insn */
1013 int _syscall; /* triggering system call number */
1014 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1015 } *sigsys = (struct local_sigsys *)
1016 #ifdef si_syscall
1017 &(TRAP_info.si_call_addr);
1018 #else
1019 &TRAP_info.si_pid;
1020 #endif
1021 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1022 /* Make sure arch is non-zero. */
1023 EXPECT_NE(0, sigsys->_arch);
1024 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1025 }
1026
1027 FIXTURE(precedence) {
1028 struct sock_fprog allow;
1029 struct sock_fprog log;
1030 struct sock_fprog trace;
1031 struct sock_fprog error;
1032 struct sock_fprog trap;
1033 struct sock_fprog kill;
1034 };
1035
1036 FIXTURE_SETUP(precedence)
1037 {
1038 struct sock_filter allow_insns[] = {
1039 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1040 };
1041 struct sock_filter log_insns[] = {
1042 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1043 offsetof(struct seccomp_data, nr)),
1044 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1045 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1046 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1047 };
1048 struct sock_filter trace_insns[] = {
1049 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1050 offsetof(struct seccomp_data, nr)),
1051 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1052 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1053 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1054 };
1055 struct sock_filter error_insns[] = {
1056 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1057 offsetof(struct seccomp_data, nr)),
1058 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1059 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1060 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1061 };
1062 struct sock_filter trap_insns[] = {
1063 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1064 offsetof(struct seccomp_data, nr)),
1065 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1066 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1067 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1068 };
1069 struct sock_filter kill_insns[] = {
1070 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1071 offsetof(struct seccomp_data, nr)),
1072 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1073 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1074 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1075 };
1076
1077 memset(self, 0, sizeof(*self));
1078 #define FILTER_ALLOC(_x) \
1079 self->_x.filter = malloc(sizeof(_x##_insns)); \
1080 ASSERT_NE(NULL, self->_x.filter); \
1081 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1082 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1083 FILTER_ALLOC(allow);
1084 FILTER_ALLOC(log);
1085 FILTER_ALLOC(trace);
1086 FILTER_ALLOC(error);
1087 FILTER_ALLOC(trap);
1088 FILTER_ALLOC(kill);
1089 }
1090
1091 FIXTURE_TEARDOWN(precedence)
1092 {
1093 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1094 FILTER_FREE(allow);
1095 FILTER_FREE(log);
1096 FILTER_FREE(trace);
1097 FILTER_FREE(error);
1098 FILTER_FREE(trap);
1099 FILTER_FREE(kill);
1100 }
1101
1102 TEST_F(precedence, allow_ok)
1103 {
1104 pid_t parent, res = 0;
1105 long ret;
1106
1107 parent = getppid();
1108 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1109 ASSERT_EQ(0, ret);
1110
1111 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1112 ASSERT_EQ(0, ret);
1113 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1114 ASSERT_EQ(0, ret);
1115 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1116 ASSERT_EQ(0, ret);
1117 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1118 ASSERT_EQ(0, ret);
1119 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1120 ASSERT_EQ(0, ret);
1121 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1122 ASSERT_EQ(0, ret);
1123 /* Should work just fine. */
1124 res = syscall(__NR_getppid);
1125 EXPECT_EQ(parent, res);
1126 }
1127
1128 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1129 {
1130 pid_t parent, res = 0;
1131 long ret;
1132
1133 parent = getppid();
1134 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1135 ASSERT_EQ(0, ret);
1136
1137 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1138 ASSERT_EQ(0, ret);
1139 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1140 ASSERT_EQ(0, ret);
1141 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1142 ASSERT_EQ(0, ret);
1143 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1144 ASSERT_EQ(0, ret);
1145 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1146 ASSERT_EQ(0, ret);
1147 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1148 ASSERT_EQ(0, ret);
1149 /* Should work just fine. */
1150 res = syscall(__NR_getppid);
1151 EXPECT_EQ(parent, res);
1152 /* getpid() should never return. */
1153 res = syscall(__NR_getpid);
1154 EXPECT_EQ(0, res);
1155 }
1156
1157 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1158 {
1159 pid_t parent;
1160 long ret;
1161
1162 parent = getppid();
1163 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1164 ASSERT_EQ(0, ret);
1165
1166 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1167 ASSERT_EQ(0, ret);
1168 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1169 ASSERT_EQ(0, ret);
1170 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1171 ASSERT_EQ(0, ret);
1172 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1173 ASSERT_EQ(0, ret);
1174 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1175 ASSERT_EQ(0, ret);
1176 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1177 ASSERT_EQ(0, ret);
1178 /* Should work just fine. */
1179 EXPECT_EQ(parent, syscall(__NR_getppid));
1180 /* getpid() should never return. */
1181 EXPECT_EQ(0, syscall(__NR_getpid));
1182 }
1183
1184 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1185 {
1186 pid_t parent;
1187 long ret;
1188
1189 parent = getppid();
1190 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1191 ASSERT_EQ(0, ret);
1192
1193 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1194 ASSERT_EQ(0, ret);
1195 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1196 ASSERT_EQ(0, ret);
1197 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1198 ASSERT_EQ(0, ret);
1199 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1200 ASSERT_EQ(0, ret);
1201 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1202 ASSERT_EQ(0, ret);
1203 /* Should work just fine. */
1204 EXPECT_EQ(parent, syscall(__NR_getppid));
1205 /* getpid() should never return. */
1206 EXPECT_EQ(0, syscall(__NR_getpid));
1207 }
1208
1209 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1210 {
1211 pid_t parent;
1212 long ret;
1213
1214 parent = getppid();
1215 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1216 ASSERT_EQ(0, ret);
1217
1218 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1219 ASSERT_EQ(0, ret);
1220 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1221 ASSERT_EQ(0, ret);
1222 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1223 ASSERT_EQ(0, ret);
1224 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1225 ASSERT_EQ(0, ret);
1226 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1227 ASSERT_EQ(0, ret);
1228 /* Should work just fine. */
1229 EXPECT_EQ(parent, syscall(__NR_getppid));
1230 /* getpid() should never return. */
1231 EXPECT_EQ(0, syscall(__NR_getpid));
1232 }
1233
1234 TEST_F(precedence, errno_is_third)
1235 {
1236 pid_t parent;
1237 long ret;
1238
1239 parent = getppid();
1240 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1241 ASSERT_EQ(0, ret);
1242
1243 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1244 ASSERT_EQ(0, ret);
1245 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1246 ASSERT_EQ(0, ret);
1247 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1248 ASSERT_EQ(0, ret);
1249 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1250 ASSERT_EQ(0, ret);
1251 /* Should work just fine. */
1252 EXPECT_EQ(parent, syscall(__NR_getppid));
1253 EXPECT_EQ(0, syscall(__NR_getpid));
1254 }
1255
1256 TEST_F(precedence, errno_is_third_in_any_order)
1257 {
1258 pid_t parent;
1259 long ret;
1260
1261 parent = getppid();
1262 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1263 ASSERT_EQ(0, ret);
1264
1265 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
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->trace);
1270 ASSERT_EQ(0, ret);
1271 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1272 ASSERT_EQ(0, ret);
1273 /* Should work just fine. */
1274 EXPECT_EQ(parent, syscall(__NR_getppid));
1275 EXPECT_EQ(0, syscall(__NR_getpid));
1276 }
1277
1278 TEST_F(precedence, trace_is_fourth)
1279 {
1280 pid_t parent;
1281 long ret;
1282
1283 parent = getppid();
1284 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1285 ASSERT_EQ(0, ret);
1286
1287 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1288 ASSERT_EQ(0, ret);
1289 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1290 ASSERT_EQ(0, ret);
1291 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1292 ASSERT_EQ(0, ret);
1293 /* Should work just fine. */
1294 EXPECT_EQ(parent, syscall(__NR_getppid));
1295 /* No ptracer */
1296 EXPECT_EQ(-1, syscall(__NR_getpid));
1297 }
1298
1299 TEST_F(precedence, trace_is_fourth_in_any_order)
1300 {
1301 pid_t parent;
1302 long ret;
1303
1304 parent = getppid();
1305 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1306 ASSERT_EQ(0, ret);
1307
1308 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1309 ASSERT_EQ(0, ret);
1310 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1311 ASSERT_EQ(0, ret);
1312 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1313 ASSERT_EQ(0, ret);
1314 /* Should work just fine. */
1315 EXPECT_EQ(parent, syscall(__NR_getppid));
1316 /* No ptracer */
1317 EXPECT_EQ(-1, syscall(__NR_getpid));
1318 }
1319
1320 TEST_F(precedence, log_is_fifth)
1321 {
1322 pid_t mypid, parent;
1323 long ret;
1324
1325 mypid = getpid();
1326 parent = getppid();
1327 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1328 ASSERT_EQ(0, ret);
1329
1330 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1331 ASSERT_EQ(0, ret);
1332 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1333 ASSERT_EQ(0, ret);
1334 /* Should work just fine. */
1335 EXPECT_EQ(parent, syscall(__NR_getppid));
1336 /* Should also work just fine */
1337 EXPECT_EQ(mypid, syscall(__NR_getpid));
1338 }
1339
1340 TEST_F(precedence, log_is_fifth_in_any_order)
1341 {
1342 pid_t mypid, parent;
1343 long ret;
1344
1345 mypid = getpid();
1346 parent = getppid();
1347 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1348 ASSERT_EQ(0, ret);
1349
1350 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1351 ASSERT_EQ(0, ret);
1352 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1353 ASSERT_EQ(0, ret);
1354 /* Should work just fine. */
1355 EXPECT_EQ(parent, syscall(__NR_getppid));
1356 /* Should also work just fine */
1357 EXPECT_EQ(mypid, syscall(__NR_getpid));
1358 }
1359
1360 #ifndef PTRACE_O_TRACESECCOMP
1361 #define PTRACE_O_TRACESECCOMP 0x00000080
1362 #endif
1363
1364 /* Catch the Ubuntu 12.04 value error. */
1365 #if PTRACE_EVENT_SECCOMP != 7
1366 #undef PTRACE_EVENT_SECCOMP
1367 #endif
1368
1369 #ifndef PTRACE_EVENT_SECCOMP
1370 #define PTRACE_EVENT_SECCOMP 7
1371 #endif
1372
1373 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1374 bool tracer_running;
1375 void tracer_stop(int sig)
1376 {
1377 tracer_running = false;
1378 }
1379
1380 typedef void tracer_func_t(struct __test_metadata *_metadata,
1381 pid_t tracee, int status, void *args);
1382
1383 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1384 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1385 {
1386 int ret = -1;
1387 struct sigaction action = {
1388 .sa_handler = tracer_stop,
1389 };
1390
1391 /* Allow external shutdown. */
1392 tracer_running = true;
1393 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1394
1395 errno = 0;
1396 while (ret == -1 && errno != EINVAL)
1397 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1398 ASSERT_EQ(0, ret) {
1399 kill(tracee, SIGKILL);
1400 }
1401 /* Wait for attach stop */
1402 wait(NULL);
1403
1404 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1405 PTRACE_O_TRACESYSGOOD :
1406 PTRACE_O_TRACESECCOMP);
1407 ASSERT_EQ(0, ret) {
1408 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1409 kill(tracee, SIGKILL);
1410 }
1411 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1412 tracee, NULL, 0);
1413 ASSERT_EQ(0, ret);
1414
1415 /* Unblock the tracee */
1416 ASSERT_EQ(1, write(fd, "A", 1));
1417 ASSERT_EQ(0, close(fd));
1418
1419 /* Run until we're shut down. Must assert to stop execution. */
1420 while (tracer_running) {
1421 int status;
1422
1423 if (wait(&status) != tracee)
1424 continue;
1425 if (WIFSIGNALED(status) || WIFEXITED(status))
1426 /* Child is dead. Time to go. */
1427 return;
1428
1429 /* Check if this is a seccomp event. */
1430 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1431
1432 tracer_func(_metadata, tracee, status, args);
1433
1434 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1435 tracee, NULL, 0);
1436 ASSERT_EQ(0, ret);
1437 }
1438 /* Directly report the status of our test harness results. */
1439 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1440 }
1441
1442 /* Common tracer setup/teardown functions. */
1443 void cont_handler(int num)
1444 { }
1445 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1446 tracer_func_t func, void *args, bool ptrace_syscall)
1447 {
1448 char sync;
1449 int pipefd[2];
1450 pid_t tracer_pid;
1451 pid_t tracee = getpid();
1452
1453 /* Setup a pipe for clean synchronization. */
1454 ASSERT_EQ(0, pipe(pipefd));
1455
1456 /* Fork a child which we'll promote to tracer */
1457 tracer_pid = fork();
1458 ASSERT_LE(0, tracer_pid);
1459 signal(SIGALRM, cont_handler);
1460 if (tracer_pid == 0) {
1461 close(pipefd[0]);
1462 start_tracer(_metadata, pipefd[1], tracee, func, args,
1463 ptrace_syscall);
1464 syscall(__NR_exit, 0);
1465 }
1466 close(pipefd[1]);
1467 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1468 read(pipefd[0], &sync, 1);
1469 close(pipefd[0]);
1470
1471 return tracer_pid;
1472 }
1473 void teardown_trace_fixture(struct __test_metadata *_metadata,
1474 pid_t tracer)
1475 {
1476 if (tracer) {
1477 int status;
1478 /*
1479 * Extract the exit code from the other process and
1480 * adopt it for ourselves in case its asserts failed.
1481 */
1482 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1483 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1484 if (WEXITSTATUS(status))
1485 _metadata->passed = 0;
1486 }
1487 }
1488
1489 /* "poke" tracer arguments and function. */
1490 struct tracer_args_poke_t {
1491 unsigned long poke_addr;
1492 };
1493
1494 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1495 void *args)
1496 {
1497 int ret;
1498 unsigned long msg;
1499 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1500
1501 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1502 EXPECT_EQ(0, ret);
1503 /* If this fails, don't try to recover. */
1504 ASSERT_EQ(0x1001, msg) {
1505 kill(tracee, SIGKILL);
1506 }
1507 /*
1508 * Poke in the message.
1509 * Registers are not touched to try to keep this relatively arch
1510 * agnostic.
1511 */
1512 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1513 EXPECT_EQ(0, ret);
1514 }
1515
1516 FIXTURE(TRACE_poke) {
1517 struct sock_fprog prog;
1518 pid_t tracer;
1519 long poked;
1520 struct tracer_args_poke_t tracer_args;
1521 };
1522
1523 FIXTURE_SETUP(TRACE_poke)
1524 {
1525 struct sock_filter filter[] = {
1526 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1527 offsetof(struct seccomp_data, nr)),
1528 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1529 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1530 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1531 };
1532
1533 self->poked = 0;
1534 memset(&self->prog, 0, sizeof(self->prog));
1535 self->prog.filter = malloc(sizeof(filter));
1536 ASSERT_NE(NULL, self->prog.filter);
1537 memcpy(self->prog.filter, filter, sizeof(filter));
1538 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1539
1540 /* Set up tracer args. */
1541 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1542
1543 /* Launch tracer. */
1544 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1545 &self->tracer_args, false);
1546 }
1547
1548 FIXTURE_TEARDOWN(TRACE_poke)
1549 {
1550 teardown_trace_fixture(_metadata, self->tracer);
1551 if (self->prog.filter)
1552 free(self->prog.filter);
1553 }
1554
1555 TEST_F(TRACE_poke, read_has_side_effects)
1556 {
1557 ssize_t ret;
1558
1559 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1560 ASSERT_EQ(0, ret);
1561
1562 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1563 ASSERT_EQ(0, ret);
1564
1565 EXPECT_EQ(0, self->poked);
1566 ret = read(-1, NULL, 0);
1567 EXPECT_EQ(-1, ret);
1568 EXPECT_EQ(0x1001, self->poked);
1569 }
1570
1571 TEST_F(TRACE_poke, getpid_runs_normally)
1572 {
1573 long ret;
1574
1575 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1576 ASSERT_EQ(0, ret);
1577
1578 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1579 ASSERT_EQ(0, ret);
1580
1581 EXPECT_EQ(0, self->poked);
1582 EXPECT_NE(0, syscall(__NR_getpid));
1583 EXPECT_EQ(0, self->poked);
1584 }
1585
1586 #if defined(__x86_64__)
1587 # define ARCH_REGS struct user_regs_struct
1588 # define SYSCALL_NUM orig_rax
1589 # define SYSCALL_RET rax
1590 #elif defined(__i386__)
1591 # define ARCH_REGS struct user_regs_struct
1592 # define SYSCALL_NUM orig_eax
1593 # define SYSCALL_RET eax
1594 #elif defined(__arm__)
1595 # define ARCH_REGS struct pt_regs
1596 # define SYSCALL_NUM ARM_r7
1597 # define SYSCALL_RET ARM_r0
1598 #elif defined(__aarch64__)
1599 # define ARCH_REGS struct user_pt_regs
1600 # define SYSCALL_NUM regs[8]
1601 # define SYSCALL_RET regs[0]
1602 #elif defined(__riscv) && __riscv_xlen == 64
1603 # define ARCH_REGS struct user_regs_struct
1604 # define SYSCALL_NUM a7
1605 # define SYSCALL_RET a0
1606 #elif defined(__hppa__)
1607 # define ARCH_REGS struct user_regs_struct
1608 # define SYSCALL_NUM gr[20]
1609 # define SYSCALL_RET gr[28]
1610 #elif defined(__powerpc__)
1611 # define ARCH_REGS struct pt_regs
1612 # define SYSCALL_NUM gpr[0]
1613 # define SYSCALL_RET gpr[3]
1614 #elif defined(__s390__)
1615 # define ARCH_REGS s390_regs
1616 # define SYSCALL_NUM gprs[2]
1617 # define SYSCALL_RET gprs[2]
1618 #elif defined(__mips__)
1619 # define ARCH_REGS struct pt_regs
1620 # define SYSCALL_NUM regs[2]
1621 # define SYSCALL_SYSCALL_NUM regs[4]
1622 # define SYSCALL_RET regs[2]
1623 # define SYSCALL_NUM_RET_SHARE_REG
1624 #else
1625 # error "Do not know how to find your architecture's registers and syscalls"
1626 #endif
1627
1628 /* When the syscall return can't be changed, stub out the tests for it. */
1629 #ifdef SYSCALL_NUM_RET_SHARE_REG
1630 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1631 #else
1632 # define EXPECT_SYSCALL_RETURN(val, action) \
1633 do { \
1634 errno = 0; \
1635 if (val < 0) { \
1636 EXPECT_EQ(-1, action); \
1637 EXPECT_EQ(-(val), errno); \
1638 } else { \
1639 EXPECT_EQ(val, action); \
1640 } \
1641 } while (0)
1642 #endif
1643
1644 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1645 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1646 */
1647 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1648 #define HAVE_GETREGS
1649 #endif
1650
1651 /* Architecture-specific syscall fetching routine. */
1652 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1653 {
1654 ARCH_REGS regs;
1655 #ifdef HAVE_GETREGS
1656 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
1657 TH_LOG("PTRACE_GETREGS failed");
1658 return -1;
1659 }
1660 #else
1661 struct iovec iov;
1662
1663 iov.iov_base = &regs;
1664 iov.iov_len = sizeof(regs);
1665 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1666 TH_LOG("PTRACE_GETREGSET failed");
1667 return -1;
1668 }
1669 #endif
1670
1671 #if defined(__mips__)
1672 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1673 return regs.SYSCALL_SYSCALL_NUM;
1674 #endif
1675 return regs.SYSCALL_NUM;
1676 }
1677
1678 /* Architecture-specific syscall changing routine. */
1679 void change_syscall(struct __test_metadata *_metadata,
1680 pid_t tracee, int syscall, int result)
1681 {
1682 int ret;
1683 ARCH_REGS regs;
1684 #ifdef HAVE_GETREGS
1685 ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
1686 #else
1687 struct iovec iov;
1688 iov.iov_base = &regs;
1689 iov.iov_len = sizeof(regs);
1690 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1691 #endif
1692 EXPECT_EQ(0, ret) {}
1693
1694 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1695 defined(__s390__) || defined(__hppa__) || defined(__riscv)
1696 {
1697 regs.SYSCALL_NUM = syscall;
1698 }
1699 #elif defined(__mips__)
1700 {
1701 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1702 regs.SYSCALL_SYSCALL_NUM = syscall;
1703 else
1704 regs.SYSCALL_NUM = syscall;
1705 }
1706
1707 #elif defined(__arm__)
1708 # ifndef PTRACE_SET_SYSCALL
1709 # define PTRACE_SET_SYSCALL 23
1710 # endif
1711 {
1712 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1713 EXPECT_EQ(0, ret);
1714 }
1715
1716 #elif defined(__aarch64__)
1717 # ifndef NT_ARM_SYSTEM_CALL
1718 # define NT_ARM_SYSTEM_CALL 0x404
1719 # endif
1720 {
1721 iov.iov_base = &syscall;
1722 iov.iov_len = sizeof(syscall);
1723 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1724 &iov);
1725 EXPECT_EQ(0, ret);
1726 }
1727
1728 #else
1729 ASSERT_EQ(1, 0) {
1730 TH_LOG("How is the syscall changed on this architecture?");
1731 }
1732 #endif
1733
1734 /* If syscall is skipped, change return value. */
1735 if (syscall == -1)
1736 #ifdef SYSCALL_NUM_RET_SHARE_REG
1737 TH_LOG("Can't modify syscall return on this architecture");
1738 #else
1739 regs.SYSCALL_RET = result;
1740 #endif
1741
1742 #ifdef HAVE_GETREGS
1743 ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
1744 #else
1745 iov.iov_base = &regs;
1746 iov.iov_len = sizeof(regs);
1747 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1748 #endif
1749 EXPECT_EQ(0, ret);
1750 }
1751
1752 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1753 int status, void *args)
1754 {
1755 int ret;
1756 unsigned long msg;
1757
1758 /* Make sure we got the right message. */
1759 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1760 EXPECT_EQ(0, ret);
1761
1762 /* Validate and take action on expected syscalls. */
1763 switch (msg) {
1764 case 0x1002:
1765 /* change getpid to getppid. */
1766 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1767 change_syscall(_metadata, tracee, __NR_getppid, 0);
1768 break;
1769 case 0x1003:
1770 /* skip gettid with valid return code. */
1771 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1772 change_syscall(_metadata, tracee, -1, 45000);
1773 break;
1774 case 0x1004:
1775 /* skip openat with error. */
1776 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
1777 change_syscall(_metadata, tracee, -1, -ESRCH);
1778 break;
1779 case 0x1005:
1780 /* do nothing (allow getppid) */
1781 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1782 break;
1783 default:
1784 EXPECT_EQ(0, msg) {
1785 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1786 kill(tracee, SIGKILL);
1787 }
1788 }
1789
1790 }
1791
1792 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1793 int status, void *args)
1794 {
1795 int ret, nr;
1796 unsigned long msg;
1797 static bool entry;
1798
1799 /*
1800 * The traditional way to tell PTRACE_SYSCALL entry/exit
1801 * is by counting.
1802 */
1803 entry = !entry;
1804
1805 /* Make sure we got an appropriate message. */
1806 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1807 EXPECT_EQ(0, ret);
1808 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
1809 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
1810
1811 if (!entry)
1812 return;
1813
1814 nr = get_syscall(_metadata, tracee);
1815
1816 if (nr == __NR_getpid)
1817 change_syscall(_metadata, tracee, __NR_getppid, 0);
1818 if (nr == __NR_gettid)
1819 change_syscall(_metadata, tracee, -1, 45000);
1820 if (nr == __NR_openat)
1821 change_syscall(_metadata, tracee, -1, -ESRCH);
1822 }
1823
1824 FIXTURE(TRACE_syscall) {
1825 struct sock_fprog prog;
1826 pid_t tracer, mytid, mypid, parent;
1827 };
1828
1829 FIXTURE_SETUP(TRACE_syscall)
1830 {
1831 struct sock_filter filter[] = {
1832 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1833 offsetof(struct seccomp_data, nr)),
1834 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1835 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1836 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1837 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1838 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
1839 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1840 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1841 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
1842 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1843 };
1844
1845 memset(&self->prog, 0, sizeof(self->prog));
1846 self->prog.filter = malloc(sizeof(filter));
1847 ASSERT_NE(NULL, self->prog.filter);
1848 memcpy(self->prog.filter, filter, sizeof(filter));
1849 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1850
1851 /* Prepare some testable syscall results. */
1852 self->mytid = syscall(__NR_gettid);
1853 ASSERT_GT(self->mytid, 0);
1854 ASSERT_NE(self->mytid, 1) {
1855 TH_LOG("Running this test as init is not supported. :)");
1856 }
1857
1858 self->mypid = getpid();
1859 ASSERT_GT(self->mypid, 0);
1860 ASSERT_EQ(self->mytid, self->mypid);
1861
1862 self->parent = getppid();
1863 ASSERT_GT(self->parent, 0);
1864 ASSERT_NE(self->parent, self->mypid);
1865
1866 /* Launch tracer. */
1867 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1868 false);
1869 }
1870
1871 FIXTURE_TEARDOWN(TRACE_syscall)
1872 {
1873 teardown_trace_fixture(_metadata, self->tracer);
1874 if (self->prog.filter)
1875 free(self->prog.filter);
1876 }
1877
1878 TEST_F(TRACE_syscall, ptrace_syscall_redirected)
1879 {
1880 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1881 teardown_trace_fixture(_metadata, self->tracer);
1882 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1883 true);
1884
1885 /* Tracer will redirect getpid to getppid. */
1886 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1887 }
1888
1889 TEST_F(TRACE_syscall, ptrace_syscall_errno)
1890 {
1891 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1892 teardown_trace_fixture(_metadata, self->tracer);
1893 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1894 true);
1895
1896 /* Tracer should skip the open syscall, resulting in ESRCH. */
1897 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
1898 }
1899
1900 TEST_F(TRACE_syscall, ptrace_syscall_faked)
1901 {
1902 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1903 teardown_trace_fixture(_metadata, self->tracer);
1904 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1905 true);
1906
1907 /* Tracer should skip the gettid syscall, resulting fake pid. */
1908 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
1909 }
1910
1911 TEST_F(TRACE_syscall, syscall_allowed)
1912 {
1913 long ret;
1914
1915 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1916 ASSERT_EQ(0, ret);
1917
1918 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1919 ASSERT_EQ(0, ret);
1920
1921 /* getppid works as expected (no changes). */
1922 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1923 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1924 }
1925
1926 TEST_F(TRACE_syscall, syscall_redirected)
1927 {
1928 long ret;
1929
1930 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1931 ASSERT_EQ(0, ret);
1932
1933 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1934 ASSERT_EQ(0, ret);
1935
1936 /* getpid has been redirected to getppid as expected. */
1937 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1938 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1939 }
1940
1941 TEST_F(TRACE_syscall, syscall_errno)
1942 {
1943 long ret;
1944
1945 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1946 ASSERT_EQ(0, ret);
1947
1948 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1949 ASSERT_EQ(0, ret);
1950
1951 /* openat has been skipped and an errno return. */
1952 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
1953 }
1954
1955 TEST_F(TRACE_syscall, syscall_faked)
1956 {
1957 long ret;
1958
1959 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1960 ASSERT_EQ(0, ret);
1961
1962 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1963 ASSERT_EQ(0, ret);
1964
1965 /* gettid has been skipped and an altered return value stored. */
1966 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
1967 }
1968
1969 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1970 {
1971 struct sock_filter filter[] = {
1972 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1973 offsetof(struct seccomp_data, nr)),
1974 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1975 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1976 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1977 };
1978 struct sock_fprog prog = {
1979 .len = (unsigned short)ARRAY_SIZE(filter),
1980 .filter = filter,
1981 };
1982 long ret;
1983
1984 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1985 ASSERT_EQ(0, ret);
1986
1987 /* Install fixture filter. */
1988 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1989 ASSERT_EQ(0, ret);
1990
1991 /* Install "errno on getppid" filter. */
1992 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1993 ASSERT_EQ(0, ret);
1994
1995 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1996 errno = 0;
1997 EXPECT_EQ(-1, syscall(__NR_getpid));
1998 EXPECT_EQ(EPERM, errno);
1999 }
2000
2001 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
2002 {
2003 struct sock_filter filter[] = {
2004 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2005 offsetof(struct seccomp_data, nr)),
2006 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2007 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2008 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2009 };
2010 struct sock_fprog prog = {
2011 .len = (unsigned short)ARRAY_SIZE(filter),
2012 .filter = filter,
2013 };
2014 long ret;
2015
2016 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2017 ASSERT_EQ(0, ret);
2018
2019 /* Install fixture filter. */
2020 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
2021 ASSERT_EQ(0, ret);
2022
2023 /* Install "death on getppid" filter. */
2024 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2025 ASSERT_EQ(0, ret);
2026
2027 /* Tracer will redirect getpid to getppid, and we should die. */
2028 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2029 }
2030
2031 TEST_F(TRACE_syscall, skip_after_ptrace)
2032 {
2033 struct sock_filter filter[] = {
2034 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2035 offsetof(struct seccomp_data, nr)),
2036 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2037 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2038 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2039 };
2040 struct sock_fprog prog = {
2041 .len = (unsigned short)ARRAY_SIZE(filter),
2042 .filter = filter,
2043 };
2044 long ret;
2045
2046 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
2047 teardown_trace_fixture(_metadata, self->tracer);
2048 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
2049 true);
2050
2051 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2052 ASSERT_EQ(0, ret);
2053
2054 /* Install "errno on getppid" filter. */
2055 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2056 ASSERT_EQ(0, ret);
2057
2058 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2059 EXPECT_EQ(-1, syscall(__NR_getpid));
2060 EXPECT_EQ(EPERM, errno);
2061 }
2062
2063 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
2064 {
2065 struct sock_filter filter[] = {
2066 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2067 offsetof(struct seccomp_data, nr)),
2068 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2069 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2070 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2071 };
2072 struct sock_fprog prog = {
2073 .len = (unsigned short)ARRAY_SIZE(filter),
2074 .filter = filter,
2075 };
2076 long ret;
2077
2078 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
2079 teardown_trace_fixture(_metadata, self->tracer);
2080 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
2081 true);
2082
2083 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2084 ASSERT_EQ(0, ret);
2085
2086 /* Install "death on getppid" filter. */
2087 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2088 ASSERT_EQ(0, ret);
2089
2090 /* Tracer will redirect getpid to getppid, and we should die. */
2091 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2092 }
2093
2094 TEST(seccomp_syscall)
2095 {
2096 struct sock_filter filter[] = {
2097 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2098 };
2099 struct sock_fprog prog = {
2100 .len = (unsigned short)ARRAY_SIZE(filter),
2101 .filter = filter,
2102 };
2103 long ret;
2104
2105 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2106 ASSERT_EQ(0, ret) {
2107 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2108 }
2109
2110 /* Reject insane operation. */
2111 ret = seccomp(-1, 0, &prog);
2112 ASSERT_NE(ENOSYS, errno) {
2113 TH_LOG("Kernel does not support seccomp syscall!");
2114 }
2115 EXPECT_EQ(EINVAL, errno) {
2116 TH_LOG("Did not reject crazy op value!");
2117 }
2118
2119 /* Reject strict with flags or pointer. */
2120 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2121 EXPECT_EQ(EINVAL, errno) {
2122 TH_LOG("Did not reject mode strict with flags!");
2123 }
2124 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2125 EXPECT_EQ(EINVAL, errno) {
2126 TH_LOG("Did not reject mode strict with uargs!");
2127 }
2128
2129 /* Reject insane args for filter. */
2130 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2131 EXPECT_EQ(EINVAL, errno) {
2132 TH_LOG("Did not reject crazy filter flags!");
2133 }
2134 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2135 EXPECT_EQ(EFAULT, errno) {
2136 TH_LOG("Did not reject NULL filter!");
2137 }
2138
2139 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2140 EXPECT_EQ(0, errno) {
2141 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2142 strerror(errno));
2143 }
2144 }
2145
2146 TEST(seccomp_syscall_mode_lock)
2147 {
2148 struct sock_filter filter[] = {
2149 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2150 };
2151 struct sock_fprog prog = {
2152 .len = (unsigned short)ARRAY_SIZE(filter),
2153 .filter = filter,
2154 };
2155 long ret;
2156
2157 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2158 ASSERT_EQ(0, ret) {
2159 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2160 }
2161
2162 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2163 ASSERT_NE(ENOSYS, errno) {
2164 TH_LOG("Kernel does not support seccomp syscall!");
2165 }
2166 EXPECT_EQ(0, ret) {
2167 TH_LOG("Could not install filter!");
2168 }
2169
2170 /* Make sure neither entry point will switch to strict. */
2171 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2172 EXPECT_EQ(EINVAL, errno) {
2173 TH_LOG("Switched to mode strict!");
2174 }
2175
2176 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2177 EXPECT_EQ(EINVAL, errno) {
2178 TH_LOG("Switched to mode strict!");
2179 }
2180 }
2181
2182 /*
2183 * Test detection of known and unknown filter flags. Userspace needs to be able
2184 * to check if a filter flag is supported by the current kernel and a good way
2185 * of doing that is by attempting to enter filter mode, with the flag bit in
2186 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2187 * that the flag is valid and EINVAL indicates that the flag is invalid.
2188 */
2189 TEST(detect_seccomp_filter_flags)
2190 {
2191 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2192 SECCOMP_FILTER_FLAG_LOG,
2193 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2194 SECCOMP_FILTER_FLAG_NEW_LISTENER,
2195 SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
2196 unsigned int exclusive[] = {
2197 SECCOMP_FILTER_FLAG_TSYNC,
2198 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2199 unsigned int flag, all_flags, exclusive_mask;
2200 int i;
2201 long ret;
2202
2203 /* Test detection of individual known-good filter flags */
2204 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2205 int bits = 0;
2206
2207 flag = flags[i];
2208 /* Make sure the flag is a single bit! */
2209 while (flag) {
2210 if (flag & 0x1)
2211 bits ++;
2212 flag >>= 1;
2213 }
2214 ASSERT_EQ(1, bits);
2215 flag = flags[i];
2216
2217 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2218 ASSERT_NE(ENOSYS, errno) {
2219 TH_LOG("Kernel does not support seccomp syscall!");
2220 }
2221 EXPECT_EQ(-1, ret);
2222 EXPECT_EQ(EFAULT, errno) {
2223 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2224 flag);
2225 }
2226
2227 all_flags |= flag;
2228 }
2229
2230 /*
2231 * Test detection of all known-good filter flags combined. But
2232 * for the exclusive flags we need to mask them out and try them
2233 * individually for the "all flags" testing.
2234 */
2235 exclusive_mask = 0;
2236 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2237 exclusive_mask |= exclusive[i];
2238 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2239 flag = all_flags & ~exclusive_mask;
2240 flag |= exclusive[i];
2241
2242 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2243 EXPECT_EQ(-1, ret);
2244 EXPECT_EQ(EFAULT, errno) {
2245 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2246 flag);
2247 }
2248 }
2249
2250 /* Test detection of an unknown filter flags, without exclusives. */
2251 flag = -1;
2252 flag &= ~exclusive_mask;
2253 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2254 EXPECT_EQ(-1, ret);
2255 EXPECT_EQ(EINVAL, errno) {
2256 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2257 flag);
2258 }
2259
2260 /*
2261 * Test detection of an unknown filter flag that may simply need to be
2262 * added to this test
2263 */
2264 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2265 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2266 EXPECT_EQ(-1, ret);
2267 EXPECT_EQ(EINVAL, errno) {
2268 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?",
2269 flag);
2270 }
2271 }
2272
2273 TEST(TSYNC_first)
2274 {
2275 struct sock_filter filter[] = {
2276 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2277 };
2278 struct sock_fprog prog = {
2279 .len = (unsigned short)ARRAY_SIZE(filter),
2280 .filter = filter,
2281 };
2282 long ret;
2283
2284 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2285 ASSERT_EQ(0, ret) {
2286 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2287 }
2288
2289 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2290 &prog);
2291 ASSERT_NE(ENOSYS, errno) {
2292 TH_LOG("Kernel does not support seccomp syscall!");
2293 }
2294 EXPECT_EQ(0, ret) {
2295 TH_LOG("Could not install initial filter with TSYNC!");
2296 }
2297 }
2298
2299 #define TSYNC_SIBLINGS 2
2300 struct tsync_sibling {
2301 pthread_t tid;
2302 pid_t system_tid;
2303 sem_t *started;
2304 pthread_cond_t *cond;
2305 pthread_mutex_t *mutex;
2306 int diverge;
2307 int num_waits;
2308 struct sock_fprog *prog;
2309 struct __test_metadata *metadata;
2310 };
2311
2312 /*
2313 * To avoid joining joined threads (which is not allowed by Bionic),
2314 * make sure we both successfully join and clear the tid to skip a
2315 * later join attempt during fixture teardown. Any remaining threads
2316 * will be directly killed during teardown.
2317 */
2318 #define PTHREAD_JOIN(tid, status) \
2319 do { \
2320 int _rc = pthread_join(tid, status); \
2321 if (_rc) { \
2322 TH_LOG("pthread_join of tid %u failed: %d\n", \
2323 (unsigned int)tid, _rc); \
2324 } else { \
2325 tid = 0; \
2326 } \
2327 } while (0)
2328
2329 FIXTURE(TSYNC) {
2330 struct sock_fprog root_prog, apply_prog;
2331 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2332 sem_t started;
2333 pthread_cond_t cond;
2334 pthread_mutex_t mutex;
2335 int sibling_count;
2336 };
2337
2338 FIXTURE_SETUP(TSYNC)
2339 {
2340 struct sock_filter root_filter[] = {
2341 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2342 };
2343 struct sock_filter apply_filter[] = {
2344 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2345 offsetof(struct seccomp_data, nr)),
2346 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2347 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2348 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2349 };
2350
2351 memset(&self->root_prog, 0, sizeof(self->root_prog));
2352 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2353 memset(&self->sibling, 0, sizeof(self->sibling));
2354 self->root_prog.filter = malloc(sizeof(root_filter));
2355 ASSERT_NE(NULL, self->root_prog.filter);
2356 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2357 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2358
2359 self->apply_prog.filter = malloc(sizeof(apply_filter));
2360 ASSERT_NE(NULL, self->apply_prog.filter);
2361 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2362 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2363
2364 self->sibling_count = 0;
2365 pthread_mutex_init(&self->mutex, NULL);
2366 pthread_cond_init(&self->cond, NULL);
2367 sem_init(&self->started, 0, 0);
2368 self->sibling[0].tid = 0;
2369 self->sibling[0].cond = &self->cond;
2370 self->sibling[0].started = &self->started;
2371 self->sibling[0].mutex = &self->mutex;
2372 self->sibling[0].diverge = 0;
2373 self->sibling[0].num_waits = 1;
2374 self->sibling[0].prog = &self->root_prog;
2375 self->sibling[0].metadata = _metadata;
2376 self->sibling[1].tid = 0;
2377 self->sibling[1].cond = &self->cond;
2378 self->sibling[1].started = &self->started;
2379 self->sibling[1].mutex = &self->mutex;
2380 self->sibling[1].diverge = 0;
2381 self->sibling[1].prog = &self->root_prog;
2382 self->sibling[1].num_waits = 1;
2383 self->sibling[1].metadata = _metadata;
2384 }
2385
2386 FIXTURE_TEARDOWN(TSYNC)
2387 {
2388 int sib = 0;
2389
2390 if (self->root_prog.filter)
2391 free(self->root_prog.filter);
2392 if (self->apply_prog.filter)
2393 free(self->apply_prog.filter);
2394
2395 for ( ; sib < self->sibling_count; ++sib) {
2396 struct tsync_sibling *s = &self->sibling[sib];
2397
2398 if (!s->tid)
2399 continue;
2400 /*
2401 * If a thread is still running, it may be stuck, so hit
2402 * it over the head really hard.
2403 */
2404 pthread_kill(s->tid, 9);
2405 }
2406 pthread_mutex_destroy(&self->mutex);
2407 pthread_cond_destroy(&self->cond);
2408 sem_destroy(&self->started);
2409 }
2410
2411 void *tsync_sibling(void *data)
2412 {
2413 long ret = 0;
2414 struct tsync_sibling *me = data;
2415
2416 me->system_tid = syscall(__NR_gettid);
2417
2418 pthread_mutex_lock(me->mutex);
2419 if (me->diverge) {
2420 /* Just re-apply the root prog to fork the tree */
2421 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2422 me->prog, 0, 0);
2423 }
2424 sem_post(me->started);
2425 /* Return outside of started so parent notices failures. */
2426 if (ret) {
2427 pthread_mutex_unlock(me->mutex);
2428 return (void *)SIBLING_EXIT_FAILURE;
2429 }
2430 do {
2431 pthread_cond_wait(me->cond, me->mutex);
2432 me->num_waits = me->num_waits - 1;
2433 } while (me->num_waits);
2434 pthread_mutex_unlock(me->mutex);
2435
2436 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2437 if (!ret)
2438 return (void *)SIBLING_EXIT_NEWPRIVS;
2439 read(0, NULL, 0);
2440 return (void *)SIBLING_EXIT_UNKILLED;
2441 }
2442
2443 void tsync_start_sibling(struct tsync_sibling *sibling)
2444 {
2445 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2446 }
2447
2448 TEST_F(TSYNC, siblings_fail_prctl)
2449 {
2450 long ret;
2451 void *status;
2452 struct sock_filter filter[] = {
2453 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2454 offsetof(struct seccomp_data, nr)),
2455 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2456 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2457 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2458 };
2459 struct sock_fprog prog = {
2460 .len = (unsigned short)ARRAY_SIZE(filter),
2461 .filter = filter,
2462 };
2463
2464 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2465 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2466 }
2467
2468 /* Check prctl failure detection by requesting sib 0 diverge. */
2469 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2470 ASSERT_NE(ENOSYS, errno) {
2471 TH_LOG("Kernel does not support seccomp syscall!");
2472 }
2473 ASSERT_EQ(0, ret) {
2474 TH_LOG("setting filter failed");
2475 }
2476
2477 self->sibling[0].diverge = 1;
2478 tsync_start_sibling(&self->sibling[0]);
2479 tsync_start_sibling(&self->sibling[1]);
2480
2481 while (self->sibling_count < TSYNC_SIBLINGS) {
2482 sem_wait(&self->started);
2483 self->sibling_count++;
2484 }
2485
2486 /* Signal the threads to clean up*/
2487 pthread_mutex_lock(&self->mutex);
2488 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2489 TH_LOG("cond broadcast non-zero");
2490 }
2491 pthread_mutex_unlock(&self->mutex);
2492
2493 /* Ensure diverging sibling failed to call prctl. */
2494 PTHREAD_JOIN(self->sibling[0].tid, &status);
2495 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2496 PTHREAD_JOIN(self->sibling[1].tid, &status);
2497 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2498 }
2499
2500 TEST_F(TSYNC, two_siblings_with_ancestor)
2501 {
2502 long ret;
2503 void *status;
2504
2505 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2506 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2507 }
2508
2509 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2510 ASSERT_NE(ENOSYS, errno) {
2511 TH_LOG("Kernel does not support seccomp syscall!");
2512 }
2513 ASSERT_EQ(0, ret) {
2514 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2515 }
2516 tsync_start_sibling(&self->sibling[0]);
2517 tsync_start_sibling(&self->sibling[1]);
2518
2519 while (self->sibling_count < TSYNC_SIBLINGS) {
2520 sem_wait(&self->started);
2521 self->sibling_count++;
2522 }
2523
2524 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2525 &self->apply_prog);
2526 ASSERT_EQ(0, ret) {
2527 TH_LOG("Could install filter on all threads!");
2528 }
2529 /* Tell the siblings to test the policy */
2530 pthread_mutex_lock(&self->mutex);
2531 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2532 TH_LOG("cond broadcast non-zero");
2533 }
2534 pthread_mutex_unlock(&self->mutex);
2535 /* Ensure they are both killed and don't exit cleanly. */
2536 PTHREAD_JOIN(self->sibling[0].tid, &status);
2537 EXPECT_EQ(0x0, (long)status);
2538 PTHREAD_JOIN(self->sibling[1].tid, &status);
2539 EXPECT_EQ(0x0, (long)status);
2540 }
2541
2542 TEST_F(TSYNC, two_sibling_want_nnp)
2543 {
2544 void *status;
2545
2546 /* start siblings before any prctl() operations */
2547 tsync_start_sibling(&self->sibling[0]);
2548 tsync_start_sibling(&self->sibling[1]);
2549 while (self->sibling_count < TSYNC_SIBLINGS) {
2550 sem_wait(&self->started);
2551 self->sibling_count++;
2552 }
2553
2554 /* Tell the siblings to test no policy */
2555 pthread_mutex_lock(&self->mutex);
2556 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2557 TH_LOG("cond broadcast non-zero");
2558 }
2559 pthread_mutex_unlock(&self->mutex);
2560
2561 /* Ensure they are both upset about lacking nnp. */
2562 PTHREAD_JOIN(self->sibling[0].tid, &status);
2563 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2564 PTHREAD_JOIN(self->sibling[1].tid, &status);
2565 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2566 }
2567
2568 TEST_F(TSYNC, two_siblings_with_no_filter)
2569 {
2570 long ret;
2571 void *status;
2572
2573 /* start siblings before any prctl() operations */
2574 tsync_start_sibling(&self->sibling[0]);
2575 tsync_start_sibling(&self->sibling[1]);
2576 while (self->sibling_count < TSYNC_SIBLINGS) {
2577 sem_wait(&self->started);
2578 self->sibling_count++;
2579 }
2580
2581 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2582 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2583 }
2584
2585 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2586 &self->apply_prog);
2587 ASSERT_NE(ENOSYS, errno) {
2588 TH_LOG("Kernel does not support seccomp syscall!");
2589 }
2590 ASSERT_EQ(0, ret) {
2591 TH_LOG("Could install filter on all threads!");
2592 }
2593
2594 /* Tell the siblings to test the policy */
2595 pthread_mutex_lock(&self->mutex);
2596 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2597 TH_LOG("cond broadcast non-zero");
2598 }
2599 pthread_mutex_unlock(&self->mutex);
2600
2601 /* Ensure they are both killed and don't exit cleanly. */
2602 PTHREAD_JOIN(self->sibling[0].tid, &status);
2603 EXPECT_EQ(0x0, (long)status);
2604 PTHREAD_JOIN(self->sibling[1].tid, &status);
2605 EXPECT_EQ(0x0, (long)status);
2606 }
2607
2608 TEST_F(TSYNC, two_siblings_with_one_divergence)
2609 {
2610 long ret;
2611 void *status;
2612
2613 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2614 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2615 }
2616
2617 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2618 ASSERT_NE(ENOSYS, errno) {
2619 TH_LOG("Kernel does not support seccomp syscall!");
2620 }
2621 ASSERT_EQ(0, ret) {
2622 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2623 }
2624 self->sibling[0].diverge = 1;
2625 tsync_start_sibling(&self->sibling[0]);
2626 tsync_start_sibling(&self->sibling[1]);
2627
2628 while (self->sibling_count < TSYNC_SIBLINGS) {
2629 sem_wait(&self->started);
2630 self->sibling_count++;
2631 }
2632
2633 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2634 &self->apply_prog);
2635 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2636 TH_LOG("Did not fail on diverged sibling.");
2637 }
2638
2639 /* Wake the threads */
2640 pthread_mutex_lock(&self->mutex);
2641 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2642 TH_LOG("cond broadcast non-zero");
2643 }
2644 pthread_mutex_unlock(&self->mutex);
2645
2646 /* Ensure they are both unkilled. */
2647 PTHREAD_JOIN(self->sibling[0].tid, &status);
2648 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2649 PTHREAD_JOIN(self->sibling[1].tid, &status);
2650 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2651 }
2652
2653 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
2654 {
2655 long ret, flags;
2656 void *status;
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 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2663 ASSERT_NE(ENOSYS, errno) {
2664 TH_LOG("Kernel does not support seccomp syscall!");
2665 }
2666 ASSERT_EQ(0, ret) {
2667 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2668 }
2669 self->sibling[0].diverge = 1;
2670 tsync_start_sibling(&self->sibling[0]);
2671 tsync_start_sibling(&self->sibling[1]);
2672
2673 while (self->sibling_count < TSYNC_SIBLINGS) {
2674 sem_wait(&self->started);
2675 self->sibling_count++;
2676 }
2677
2678 flags = SECCOMP_FILTER_FLAG_TSYNC | \
2679 SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
2680 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
2681 ASSERT_EQ(ESRCH, errno) {
2682 TH_LOG("Did not return ESRCH for diverged sibling.");
2683 }
2684 ASSERT_EQ(-1, ret) {
2685 TH_LOG("Did not fail on diverged sibling.");
2686 }
2687
2688 /* Wake the threads */
2689 pthread_mutex_lock(&self->mutex);
2690 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2691 TH_LOG("cond broadcast non-zero");
2692 }
2693 pthread_mutex_unlock(&self->mutex);
2694
2695 /* Ensure they are both unkilled. */
2696 PTHREAD_JOIN(self->sibling[0].tid, &status);
2697 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2698 PTHREAD_JOIN(self->sibling[1].tid, &status);
2699 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2700 }
2701
2702 TEST_F(TSYNC, two_siblings_not_under_filter)
2703 {
2704 long ret, sib;
2705 void *status;
2706 struct timespec delay = { .tv_nsec = 100000000 };
2707
2708 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2709 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2710 }
2711
2712 /*
2713 * Sibling 0 will have its own seccomp policy
2714 * and Sibling 1 will not be under seccomp at
2715 * all. Sibling 1 will enter seccomp and 0
2716 * will cause failure.
2717 */
2718 self->sibling[0].diverge = 1;
2719 tsync_start_sibling(&self->sibling[0]);
2720 tsync_start_sibling(&self->sibling[1]);
2721
2722 while (self->sibling_count < TSYNC_SIBLINGS) {
2723 sem_wait(&self->started);
2724 self->sibling_count++;
2725 }
2726
2727 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2728 ASSERT_NE(ENOSYS, errno) {
2729 TH_LOG("Kernel does not support seccomp syscall!");
2730 }
2731 ASSERT_EQ(0, ret) {
2732 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2733 }
2734
2735 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2736 &self->apply_prog);
2737 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2738 TH_LOG("Did not fail on diverged sibling.");
2739 }
2740 sib = 1;
2741 if (ret == self->sibling[0].system_tid)
2742 sib = 0;
2743
2744 pthread_mutex_lock(&self->mutex);
2745
2746 /* Increment the other siblings num_waits so we can clean up
2747 * the one we just saw.
2748 */
2749 self->sibling[!sib].num_waits += 1;
2750
2751 /* Signal the thread to clean up*/
2752 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2753 TH_LOG("cond broadcast non-zero");
2754 }
2755 pthread_mutex_unlock(&self->mutex);
2756 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2757 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2758 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2759 while (!kill(self->sibling[sib].system_tid, 0))
2760 nanosleep(&delay, NULL);
2761 /* Switch to the remaining sibling */
2762 sib = !sib;
2763
2764 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2765 &self->apply_prog);
2766 ASSERT_EQ(0, ret) {
2767 TH_LOG("Expected the remaining sibling to sync");
2768 };
2769
2770 pthread_mutex_lock(&self->mutex);
2771
2772 /* If remaining sibling didn't have a chance to wake up during
2773 * the first broadcast, manually reduce the num_waits now.
2774 */
2775 if (self->sibling[sib].num_waits > 1)
2776 self->sibling[sib].num_waits = 1;
2777 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2778 TH_LOG("cond broadcast non-zero");
2779 }
2780 pthread_mutex_unlock(&self->mutex);
2781 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2782 EXPECT_EQ(0, (long)status);
2783 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2784 while (!kill(self->sibling[sib].system_tid, 0))
2785 nanosleep(&delay, NULL);
2786
2787 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2788 &self->apply_prog);
2789 ASSERT_EQ(0, ret); /* just us chickens */
2790 }
2791
2792 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2793 TEST(syscall_restart)
2794 {
2795 long ret;
2796 unsigned long msg;
2797 pid_t child_pid;
2798 int pipefd[2];
2799 int status;
2800 siginfo_t info = { };
2801 struct sock_filter filter[] = {
2802 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2803 offsetof(struct seccomp_data, nr)),
2804
2805 #ifdef __NR_sigreturn
2806 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2807 #endif
2808 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2809 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2810 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2811 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2812 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2813
2814 /* Allow __NR_write for easy logging. */
2815 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2816 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2817 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2818 /* The nanosleep jump target. */
2819 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2820 /* The restart_syscall jump target. */
2821 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2822 };
2823 struct sock_fprog prog = {
2824 .len = (unsigned short)ARRAY_SIZE(filter),
2825 .filter = filter,
2826 };
2827 #if defined(__arm__)
2828 struct utsname utsbuf;
2829 #endif
2830
2831 ASSERT_EQ(0, pipe(pipefd));
2832
2833 child_pid = fork();
2834 ASSERT_LE(0, child_pid);
2835 if (child_pid == 0) {
2836 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2837 char buf = ' ';
2838 struct timespec timeout = { };
2839
2840 /* Attach parent as tracer and stop. */
2841 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2842 EXPECT_EQ(0, raise(SIGSTOP));
2843
2844 EXPECT_EQ(0, close(pipefd[1]));
2845
2846 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2847 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2848 }
2849
2850 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2851 EXPECT_EQ(0, ret) {
2852 TH_LOG("Failed to install filter!");
2853 }
2854
2855 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2856 TH_LOG("Failed to read() sync from parent");
2857 }
2858 EXPECT_EQ('.', buf) {
2859 TH_LOG("Failed to get sync data from read()");
2860 }
2861
2862 /* Start nanosleep to be interrupted. */
2863 timeout.tv_sec = 1;
2864 errno = 0;
2865 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2866 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2867 }
2868
2869 /* Read final sync from parent. */
2870 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2871 TH_LOG("Failed final read() from parent");
2872 }
2873 EXPECT_EQ('!', buf) {
2874 TH_LOG("Failed to get final data from read()");
2875 }
2876
2877 /* Directly report the status of our test harness results. */
2878 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2879 : EXIT_FAILURE);
2880 }
2881 EXPECT_EQ(0, close(pipefd[0]));
2882
2883 /* Attach to child, setup options, and release. */
2884 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2885 ASSERT_EQ(true, WIFSTOPPED(status));
2886 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2887 PTRACE_O_TRACESECCOMP));
2888 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2889 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2890
2891 /* Wait for nanosleep() to start. */
2892 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2893 ASSERT_EQ(true, WIFSTOPPED(status));
2894 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2895 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2896 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2897 ASSERT_EQ(0x100, msg);
2898 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2899
2900 /* Might as well check siginfo for sanity while we're here. */
2901 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2902 ASSERT_EQ(SIGTRAP, info.si_signo);
2903 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2904 EXPECT_EQ(0, info.si_errno);
2905 EXPECT_EQ(getuid(), info.si_uid);
2906 /* Verify signal delivery came from child (seccomp-triggered). */
2907 EXPECT_EQ(child_pid, info.si_pid);
2908
2909 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2910 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2911 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2912 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2913 ASSERT_EQ(true, WIFSTOPPED(status));
2914 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2915 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2916 /*
2917 * There is no siginfo on SIGSTOP any more, so we can't verify
2918 * signal delivery came from parent now (getpid() == info.si_pid).
2919 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
2920 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
2921 */
2922 EXPECT_EQ(SIGSTOP, info.si_signo);
2923
2924 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2925 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2926 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2927 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2928 ASSERT_EQ(true, WIFSTOPPED(status));
2929 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2930 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2931
2932 /* Wait for restart_syscall() to start. */
2933 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2934 ASSERT_EQ(true, WIFSTOPPED(status));
2935 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2936 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2937 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2938
2939 ASSERT_EQ(0x200, msg);
2940 ret = get_syscall(_metadata, child_pid);
2941 #if defined(__arm__)
2942 /*
2943 * FIXME:
2944 * - native ARM registers do NOT expose true syscall.
2945 * - compat ARM registers on ARM64 DO expose true syscall.
2946 */
2947 ASSERT_EQ(0, uname(&utsbuf));
2948 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2949 EXPECT_EQ(__NR_nanosleep, ret);
2950 } else
2951 #endif
2952 {
2953 EXPECT_EQ(__NR_restart_syscall, ret);
2954 }
2955
2956 /* Write again to end test. */
2957 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2958 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2959 EXPECT_EQ(0, close(pipefd[1]));
2960
2961 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2962 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2963 _metadata->passed = 0;
2964 }
2965
2966 TEST_SIGNAL(filter_flag_log, SIGSYS)
2967 {
2968 struct sock_filter allow_filter[] = {
2969 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2970 };
2971 struct sock_filter kill_filter[] = {
2972 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2973 offsetof(struct seccomp_data, nr)),
2974 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2975 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2976 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2977 };
2978 struct sock_fprog allow_prog = {
2979 .len = (unsigned short)ARRAY_SIZE(allow_filter),
2980 .filter = allow_filter,
2981 };
2982 struct sock_fprog kill_prog = {
2983 .len = (unsigned short)ARRAY_SIZE(kill_filter),
2984 .filter = kill_filter,
2985 };
2986 long ret;
2987 pid_t parent = getppid();
2988
2989 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2990 ASSERT_EQ(0, ret);
2991
2992 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
2993 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
2994 &allow_prog);
2995 ASSERT_NE(ENOSYS, errno) {
2996 TH_LOG("Kernel does not support seccomp syscall!");
2997 }
2998 EXPECT_NE(0, ret) {
2999 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
3000 }
3001 EXPECT_EQ(EINVAL, errno) {
3002 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
3003 }
3004
3005 /* Verify that a simple, permissive filter can be added with no flags */
3006 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
3007 EXPECT_EQ(0, ret);
3008
3009 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
3010 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3011 &allow_prog);
3012 ASSERT_NE(EINVAL, errno) {
3013 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
3014 }
3015 EXPECT_EQ(0, ret);
3016
3017 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
3018 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3019 &kill_prog);
3020 EXPECT_EQ(0, ret);
3021
3022 EXPECT_EQ(parent, syscall(__NR_getppid));
3023 /* getpid() should never return. */
3024 EXPECT_EQ(0, syscall(__NR_getpid));
3025 }
3026
3027 TEST(get_action_avail)
3028 {
3029 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
3030 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
3031 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
3032 __u32 unknown_action = 0x10000000U;
3033 int i;
3034 long ret;
3035
3036 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
3037 ASSERT_NE(ENOSYS, errno) {
3038 TH_LOG("Kernel does not support seccomp syscall!");
3039 }
3040 ASSERT_NE(EINVAL, errno) {
3041 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
3042 }
3043 EXPECT_EQ(ret, 0);
3044
3045 for (i = 0; i < ARRAY_SIZE(actions); i++) {
3046 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
3047 EXPECT_EQ(ret, 0) {
3048 TH_LOG("Expected action (0x%X) not available!",
3049 actions[i]);
3050 }
3051 }
3052
3053 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
3054 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
3055 EXPECT_EQ(ret, -1);
3056 EXPECT_EQ(errno, EOPNOTSUPP);
3057 }
3058
3059 TEST(get_metadata)
3060 {
3061 pid_t pid;
3062 int pipefd[2];
3063 char buf;
3064 struct seccomp_metadata md;
3065 long ret;
3066
3067 /* Only real root can get metadata. */
3068 if (geteuid()) {
3069 XFAIL(return, "get_metadata requires real root");
3070 return;
3071 }
3072
3073 ASSERT_EQ(0, pipe(pipefd));
3074
3075 pid = fork();
3076 ASSERT_GE(pid, 0);
3077 if (pid == 0) {
3078 struct sock_filter filter[] = {
3079 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3080 };
3081 struct sock_fprog prog = {
3082 .len = (unsigned short)ARRAY_SIZE(filter),
3083 .filter = filter,
3084 };
3085
3086 /* one with log, one without */
3087 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3088 SECCOMP_FILTER_FLAG_LOG, &prog));
3089 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3090
3091 EXPECT_EQ(0, close(pipefd[0]));
3092 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3093 ASSERT_EQ(0, close(pipefd[1]));
3094
3095 while (1)
3096 sleep(100);
3097 }
3098
3099 ASSERT_EQ(0, close(pipefd[1]));
3100 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3101
3102 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3103 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3104
3105 /* Past here must not use ASSERT or child process is never killed. */
3106
3107 md.filter_off = 0;
3108 errno = 0;
3109 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3110 EXPECT_EQ(sizeof(md), ret) {
3111 if (errno == EINVAL)
3112 XFAIL(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3113 }
3114
3115 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3116 EXPECT_EQ(md.filter_off, 0);
3117
3118 md.filter_off = 1;
3119 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3120 EXPECT_EQ(sizeof(md), ret);
3121 EXPECT_EQ(md.flags, 0);
3122 EXPECT_EQ(md.filter_off, 1);
3123
3124 skip:
3125 ASSERT_EQ(0, kill(pid, SIGKILL));
3126 }
3127
3128 static int user_trap_syscall(int nr, unsigned int flags)
3129 {
3130 struct sock_filter filter[] = {
3131 BPF_STMT(BPF_LD+BPF_W+BPF_ABS,
3132 offsetof(struct seccomp_data, nr)),
3133 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, nr, 0, 1),
3134 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_USER_NOTIF),
3135 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
3136 };
3137
3138 struct sock_fprog prog = {
3139 .len = (unsigned short)ARRAY_SIZE(filter),
3140 .filter = filter,
3141 };
3142
3143 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3144 }
3145
3146 #define USER_NOTIF_MAGIC INT_MAX
3147 TEST(user_notification_basic)
3148 {
3149 pid_t pid;
3150 long ret;
3151 int status, listener;
3152 struct seccomp_notif req = {};
3153 struct seccomp_notif_resp resp = {};
3154 struct pollfd pollfd;
3155
3156 struct sock_filter filter[] = {
3157 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3158 };
3159 struct sock_fprog prog = {
3160 .len = (unsigned short)ARRAY_SIZE(filter),
3161 .filter = filter,
3162 };
3163
3164 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3165 ASSERT_EQ(0, ret) {
3166 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3167 }
3168
3169 pid = fork();
3170 ASSERT_GE(pid, 0);
3171
3172 /* Check that we get -ENOSYS with no listener attached */
3173 if (pid == 0) {
3174 if (user_trap_syscall(__NR_getppid, 0) < 0)
3175 exit(1);
3176 ret = syscall(__NR_getppid);
3177 exit(ret >= 0 || errno != ENOSYS);
3178 }
3179
3180 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3181 EXPECT_EQ(true, WIFEXITED(status));
3182 EXPECT_EQ(0, WEXITSTATUS(status));
3183
3184 /* Add some no-op filters for grins. */
3185 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3186 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3187 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3188 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3189
3190 /* Check that the basic notification machinery works */
3191 listener = user_trap_syscall(__NR_getppid,
3192 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3193 ASSERT_GE(listener, 0);
3194
3195 /* Installing a second listener in the chain should EBUSY */
3196 EXPECT_EQ(user_trap_syscall(__NR_getppid,
3197 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3198 -1);
3199 EXPECT_EQ(errno, EBUSY);
3200
3201 pid = fork();
3202 ASSERT_GE(pid, 0);
3203
3204 if (pid == 0) {
3205 ret = syscall(__NR_getppid);
3206 exit(ret != USER_NOTIF_MAGIC);
3207 }
3208
3209 pollfd.fd = listener;
3210 pollfd.events = POLLIN | POLLOUT;
3211
3212 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3213 EXPECT_EQ(pollfd.revents, POLLIN);
3214
3215 /* Test that we can't pass garbage to the kernel. */
3216 memset(&req, 0, sizeof(req));
3217 req.pid = -1;
3218 errno = 0;
3219 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
3220 EXPECT_EQ(-1, ret);
3221 EXPECT_EQ(EINVAL, errno);
3222
3223 if (ret) {
3224 req.pid = 0;
3225 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3226 }
3227
3228 pollfd.fd = listener;
3229 pollfd.events = POLLIN | POLLOUT;
3230
3231 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3232 EXPECT_EQ(pollfd.revents, POLLOUT);
3233
3234 EXPECT_EQ(req.data.nr, __NR_getppid);
3235
3236 resp.id = req.id;
3237 resp.error = 0;
3238 resp.val = USER_NOTIF_MAGIC;
3239
3240 /* check that we make sure flags == 0 */
3241 resp.flags = 1;
3242 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3243 EXPECT_EQ(errno, EINVAL);
3244
3245 resp.flags = 0;
3246 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3247
3248 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3249 EXPECT_EQ(true, WIFEXITED(status));
3250 EXPECT_EQ(0, WEXITSTATUS(status));
3251 }
3252
3253 TEST(user_notification_with_tsync)
3254 {
3255 int ret;
3256 unsigned int flags;
3257
3258 /* these were exclusive */
3259 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
3260 SECCOMP_FILTER_FLAG_TSYNC;
3261 ASSERT_EQ(-1, user_trap_syscall(__NR_getppid, flags));
3262 ASSERT_EQ(EINVAL, errno);
3263
3264 /* but now they're not */
3265 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
3266 ret = user_trap_syscall(__NR_getppid, flags);
3267 close(ret);
3268 ASSERT_LE(0, ret);
3269 }
3270
3271 TEST(user_notification_kill_in_middle)
3272 {
3273 pid_t pid;
3274 long ret;
3275 int listener;
3276 struct seccomp_notif req = {};
3277 struct seccomp_notif_resp resp = {};
3278
3279 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3280 ASSERT_EQ(0, ret) {
3281 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3282 }
3283
3284 listener = user_trap_syscall(__NR_getppid,
3285 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3286 ASSERT_GE(listener, 0);
3287
3288 /*
3289 * Check that nothing bad happens when we kill the task in the middle
3290 * of a syscall.
3291 */
3292 pid = fork();
3293 ASSERT_GE(pid, 0);
3294
3295 if (pid == 0) {
3296 ret = syscall(__NR_getppid);
3297 exit(ret != USER_NOTIF_MAGIC);
3298 }
3299
3300 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3301 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3302
3303 EXPECT_EQ(kill(pid, SIGKILL), 0);
3304 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3305
3306 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3307
3308 resp.id = req.id;
3309 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3310 EXPECT_EQ(ret, -1);
3311 EXPECT_EQ(errno, ENOENT);
3312 }
3313
3314 static int handled = -1;
3315
3316 static void signal_handler(int signal)
3317 {
3318 if (write(handled, "c", 1) != 1)
3319 perror("write from signal");
3320 }
3321
3322 TEST(user_notification_signal)
3323 {
3324 pid_t pid;
3325 long ret;
3326 int status, listener, sk_pair[2];
3327 struct seccomp_notif req = {};
3328 struct seccomp_notif_resp resp = {};
3329 char c;
3330
3331 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3332 ASSERT_EQ(0, ret) {
3333 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3334 }
3335
3336 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3337
3338 listener = user_trap_syscall(__NR_gettid,
3339 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3340 ASSERT_GE(listener, 0);
3341
3342 pid = fork();
3343 ASSERT_GE(pid, 0);
3344
3345 if (pid == 0) {
3346 close(sk_pair[0]);
3347 handled = sk_pair[1];
3348 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3349 perror("signal");
3350 exit(1);
3351 }
3352 /*
3353 * ERESTARTSYS behavior is a bit hard to test, because we need
3354 * to rely on a signal that has not yet been handled. Let's at
3355 * least check that the error code gets propagated through, and
3356 * hope that it doesn't break when there is actually a signal :)
3357 */
3358 ret = syscall(__NR_gettid);
3359 exit(!(ret == -1 && errno == 512));
3360 }
3361
3362 close(sk_pair[1]);
3363
3364 memset(&req, 0, sizeof(req));
3365 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3366
3367 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3368
3369 /*
3370 * Make sure the signal really is delivered, which means we're not
3371 * stuck in the user notification code any more and the notification
3372 * should be dead.
3373 */
3374 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3375
3376 resp.id = req.id;
3377 resp.error = -EPERM;
3378 resp.val = 0;
3379
3380 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3381 EXPECT_EQ(errno, ENOENT);
3382
3383 memset(&req, 0, sizeof(req));
3384 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3385
3386 resp.id = req.id;
3387 resp.error = -512; /* -ERESTARTSYS */
3388 resp.val = 0;
3389
3390 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3391
3392 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3393 EXPECT_EQ(true, WIFEXITED(status));
3394 EXPECT_EQ(0, WEXITSTATUS(status));
3395 }
3396
3397 TEST(user_notification_closed_listener)
3398 {
3399 pid_t pid;
3400 long ret;
3401 int status, listener;
3402
3403 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3404 ASSERT_EQ(0, ret) {
3405 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3406 }
3407
3408 listener = user_trap_syscall(__NR_getppid,
3409 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3410 ASSERT_GE(listener, 0);
3411
3412 /*
3413 * Check that we get an ENOSYS when the listener is closed.
3414 */
3415 pid = fork();
3416 ASSERT_GE(pid, 0);
3417 if (pid == 0) {
3418 close(listener);
3419 ret = syscall(__NR_getppid);
3420 exit(ret != -1 && errno != ENOSYS);
3421 }
3422
3423 close(listener);
3424
3425 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3426 EXPECT_EQ(true, WIFEXITED(status));
3427 EXPECT_EQ(0, WEXITSTATUS(status));
3428 }
3429
3430 /*
3431 * Check that a pid in a child namespace still shows up as valid in ours.
3432 */
3433 TEST(user_notification_child_pid_ns)
3434 {
3435 pid_t pid;
3436 int status, listener;
3437 struct seccomp_notif req = {};
3438 struct seccomp_notif_resp resp = {};
3439
3440 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0);
3441
3442 listener = user_trap_syscall(__NR_getppid,
3443 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3444 ASSERT_GE(listener, 0);
3445
3446 pid = fork();
3447 ASSERT_GE(pid, 0);
3448
3449 if (pid == 0)
3450 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3451
3452 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3453 EXPECT_EQ(req.pid, pid);
3454
3455 resp.id = req.id;
3456 resp.error = 0;
3457 resp.val = USER_NOTIF_MAGIC;
3458
3459 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3460
3461 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3462 EXPECT_EQ(true, WIFEXITED(status));
3463 EXPECT_EQ(0, WEXITSTATUS(status));
3464 close(listener);
3465 }
3466
3467 /*
3468 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3469 * invalid.
3470 */
3471 TEST(user_notification_sibling_pid_ns)
3472 {
3473 pid_t pid, pid2;
3474 int status, listener;
3475 struct seccomp_notif req = {};
3476 struct seccomp_notif_resp resp = {};
3477
3478 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3479 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3480 }
3481
3482 listener = user_trap_syscall(__NR_getppid,
3483 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3484 ASSERT_GE(listener, 0);
3485
3486 pid = fork();
3487 ASSERT_GE(pid, 0);
3488
3489 if (pid == 0) {
3490 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3491
3492 pid2 = fork();
3493 ASSERT_GE(pid2, 0);
3494
3495 if (pid2 == 0)
3496 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3497
3498 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3499 EXPECT_EQ(true, WIFEXITED(status));
3500 EXPECT_EQ(0, WEXITSTATUS(status));
3501 exit(WEXITSTATUS(status));
3502 }
3503
3504 /* Create the sibling ns, and sibling in it. */
3505 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3506 ASSERT_EQ(errno, 0);
3507
3508 pid2 = fork();
3509 ASSERT_GE(pid2, 0);
3510
3511 if (pid2 == 0) {
3512 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3513 /*
3514 * The pid should be 0, i.e. the task is in some namespace that
3515 * we can't "see".
3516 */
3517 EXPECT_EQ(req.pid, 0);
3518
3519 resp.id = req.id;
3520 resp.error = 0;
3521 resp.val = USER_NOTIF_MAGIC;
3522
3523 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3524 exit(0);
3525 }
3526
3527 close(listener);
3528
3529 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3530 EXPECT_EQ(true, WIFEXITED(status));
3531 EXPECT_EQ(0, WEXITSTATUS(status));
3532
3533 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3534 EXPECT_EQ(true, WIFEXITED(status));
3535 EXPECT_EQ(0, WEXITSTATUS(status));
3536 }
3537
3538 TEST(user_notification_fault_recv)
3539 {
3540 pid_t pid;
3541 int status, listener;
3542 struct seccomp_notif req = {};
3543 struct seccomp_notif_resp resp = {};
3544
3545 ASSERT_EQ(unshare(CLONE_NEWUSER), 0);
3546
3547 listener = user_trap_syscall(__NR_getppid,
3548 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3549 ASSERT_GE(listener, 0);
3550
3551 pid = fork();
3552 ASSERT_GE(pid, 0);
3553
3554 if (pid == 0)
3555 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3556
3557 /* Do a bad recv() */
3558 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3559 EXPECT_EQ(errno, EFAULT);
3560
3561 /* We should still be able to receive this notification, though. */
3562 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3563 EXPECT_EQ(req.pid, pid);
3564
3565 resp.id = req.id;
3566 resp.error = 0;
3567 resp.val = USER_NOTIF_MAGIC;
3568
3569 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3570
3571 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3572 EXPECT_EQ(true, WIFEXITED(status));
3573 EXPECT_EQ(0, WEXITSTATUS(status));
3574 }
3575
3576 TEST(seccomp_get_notif_sizes)
3577 {
3578 struct seccomp_notif_sizes sizes;
3579
3580 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3581 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3582 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3583 }
3584
3585 static int filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
3586 {
3587 #ifdef __NR_kcmp
3588 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
3589 #else
3590 errno = ENOSYS;
3591 return -1;
3592 #endif
3593 }
3594
3595 TEST(user_notification_continue)
3596 {
3597 pid_t pid;
3598 long ret;
3599 int status, listener;
3600 struct seccomp_notif req = {};
3601 struct seccomp_notif_resp resp = {};
3602 struct pollfd pollfd;
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_trap_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3610 ASSERT_GE(listener, 0);
3611
3612 pid = fork();
3613 ASSERT_GE(pid, 0);
3614
3615 if (pid == 0) {
3616 int dup_fd, pipe_fds[2];
3617 pid_t self;
3618
3619 ret = pipe(pipe_fds);
3620 if (ret < 0)
3621 exit(1);
3622
3623 dup_fd = dup(pipe_fds[0]);
3624 if (dup_fd < 0)
3625 exit(1);
3626
3627 self = getpid();
3628
3629 ret = filecmp(self, self, pipe_fds[0], dup_fd);
3630 if (ret)
3631 exit(2);
3632
3633 exit(0);
3634 }
3635
3636 pollfd.fd = listener;
3637 pollfd.events = POLLIN | POLLOUT;
3638
3639 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3640 EXPECT_EQ(pollfd.revents, POLLIN);
3641
3642 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3643
3644 pollfd.fd = listener;
3645 pollfd.events = POLLIN | POLLOUT;
3646
3647 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3648 EXPECT_EQ(pollfd.revents, POLLOUT);
3649
3650 EXPECT_EQ(req.data.nr, __NR_dup);
3651
3652 resp.id = req.id;
3653 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
3654
3655 /*
3656 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
3657 * args be set to 0.
3658 */
3659 resp.error = 0;
3660 resp.val = USER_NOTIF_MAGIC;
3661 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3662 EXPECT_EQ(errno, EINVAL);
3663
3664 resp.error = USER_NOTIF_MAGIC;
3665 resp.val = 0;
3666 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3667 EXPECT_EQ(errno, EINVAL);
3668
3669 resp.error = 0;
3670 resp.val = 0;
3671 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
3672 if (errno == EINVAL)
3673 XFAIL(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
3674 }
3675
3676 skip:
3677 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3678 EXPECT_EQ(true, WIFEXITED(status));
3679 EXPECT_EQ(0, WEXITSTATUS(status)) {
3680 if (WEXITSTATUS(status) == 2) {
3681 XFAIL(return, "Kernel does not support kcmp() syscall");
3682 return;
3683 }
3684 }
3685 }
3686
3687 /*
3688 * TODO:
3689 * - add microbenchmarks
3690 * - expand NNP testing
3691 * - better arch-specific TRACE and TRAP handlers.
3692 * - endianness checking when appropriate
3693 * - 64-bit arg prodding
3694 * - arch value testing (x86 modes especially)
3695 * - verify that FILTER_FLAG_LOG filters generate log messages
3696 * - verify that RET_LOG generates log messages
3697 * - ...
3698 */
3699
3700 TEST_HARNESS_MAIN
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