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 <linux/elf.h>
39 #include <sys/uio.h>
40 #include <sys/utsname.h>
41 #include <sys/fcntl.h>
42 #include <sys/mman.h>
43 #include <sys/times.h>
44 #include <sys/socket.h>
45 #include <sys/ioctl.h>
46
47 #include <unistd.h>
48 #include <sys/syscall.h>
49 #include <poll.h>
50
51 #include "../kselftest_harness.h"
52
53 #ifndef PR_SET_PTRACER
54 # define PR_SET_PTRACER 0x59616d61
55 #endif
56
57 #ifndef PR_SET_NO_NEW_PRIVS
58 #define PR_SET_NO_NEW_PRIVS 38
59 #define PR_GET_NO_NEW_PRIVS 39
60 #endif
61
62 #ifndef PR_SECCOMP_EXT
63 #define PR_SECCOMP_EXT 43
64 #endif
65
66 #ifndef SECCOMP_EXT_ACT
67 #define SECCOMP_EXT_ACT 1
68 #endif
69
70 #ifndef SECCOMP_EXT_ACT_TSYNC
71 #define SECCOMP_EXT_ACT_TSYNC 1
72 #endif
73
74 #ifndef SECCOMP_MODE_STRICT
75 #define SECCOMP_MODE_STRICT 1
76 #endif
77
78 #ifndef SECCOMP_MODE_FILTER
79 #define SECCOMP_MODE_FILTER 2
80 #endif
81
82 #ifndef SECCOMP_RET_ALLOW
83 struct seccomp_data {
84 int nr;
85 __u32 arch;
86 __u64 instruction_pointer;
87 __u64 args[6];
88 };
89 #endif
90
91 #ifndef SECCOMP_RET_KILL_PROCESS
92 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
93 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
94 #endif
95 #ifndef SECCOMP_RET_KILL
96 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
97 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
98 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
99 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
100 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
101 #endif
102 #ifndef SECCOMP_RET_LOG
103 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
104 #endif
105
106 #ifndef __NR_seccomp
107 # if defined(__i386__)
108 # define __NR_seccomp 354
109 # elif defined(__x86_64__)
110 # define __NR_seccomp 317
111 # elif defined(__arm__)
112 # define __NR_seccomp 383
113 # elif defined(__aarch64__)
114 # define __NR_seccomp 277
115 # elif defined(__hppa__)
116 # define __NR_seccomp 338
117 # elif defined(__powerpc__)
118 # define __NR_seccomp 358
119 # elif defined(__s390__)
120 # define __NR_seccomp 348
121 # else
122 # warning "seccomp syscall number unknown for this architecture"
123 # define __NR_seccomp 0xffff
124 # endif
125 #endif
126
127 #ifndef SECCOMP_SET_MODE_STRICT
128 #define SECCOMP_SET_MODE_STRICT 0
129 #endif
130
131 #ifndef SECCOMP_SET_MODE_FILTER
132 #define SECCOMP_SET_MODE_FILTER 1
133 #endif
134
135 #ifndef SECCOMP_GET_ACTION_AVAIL
136 #define SECCOMP_GET_ACTION_AVAIL 2
137 #endif
138
139 #ifndef SECCOMP_GET_NOTIF_SIZES
140 #define SECCOMP_GET_NOTIF_SIZES 3
141 #endif
142
143 #ifndef SECCOMP_FILTER_FLAG_TSYNC
144 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
145 #endif
146
147 #ifndef SECCOMP_FILTER_FLAG_LOG
148 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
149 #endif
150
151 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
152 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
153 #endif
154
155 #ifndef PTRACE_SECCOMP_GET_METADATA
156 #define PTRACE_SECCOMP_GET_METADATA 0x420d
157
158 struct seccomp_metadata {
159 __u64 filter_off; /* Input: which filter */
160 __u64 flags; /* Output: filter's flags */
161 };
162 #endif
163
164 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
165 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
166
167 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
168
169 #define SECCOMP_IOC_MAGIC '!'
170 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
171 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
172 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
173 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
174
175 /* Flags for seccomp notification fd ioctl. */
176 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
177 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
178 struct seccomp_notif_resp)
179 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOR(2, __u64)
180
181 struct seccomp_notif {
182 __u64 id;
183 __u32 pid;
184 __u32 flags;
185 struct seccomp_data data;
186 };
187
188 struct seccomp_notif_resp {
189 __u64 id;
190 __s64 val;
191 __s32 error;
192 __u32 flags;
193 };
194
195 struct seccomp_notif_sizes {
196 __u16 seccomp_notif;
197 __u16 seccomp_notif_resp;
198 __u16 seccomp_data;
199 };
200 #endif
201
202 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
203 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
204 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
205 #endif
206
207 #ifndef seccomp
seccomp(unsigned int op,unsigned int flags,void * args)208 int seccomp(unsigned int op, unsigned int flags, void *args)
209 {
210 errno = 0;
211 return syscall(__NR_seccomp, op, flags, args);
212 }
213 #endif
214
215 #if __BYTE_ORDER == __LITTLE_ENDIAN
216 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
217 #elif __BYTE_ORDER == __BIG_ENDIAN
218 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
219 #else
220 #error "wut? Unknown __BYTE_ORDER?!"
221 #endif
222
223 #define SIBLING_EXIT_UNKILLED 0xbadbeef
224 #define SIBLING_EXIT_FAILURE 0xbadface
225 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
226
TEST(mode_strict_support)227 TEST(mode_strict_support)
228 {
229 long ret;
230
231 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
232 ASSERT_EQ(0, ret) {
233 TH_LOG("Kernel does not support CONFIG_SECCOMP");
234 }
235 syscall(__NR_exit, 0);
236 }
237
TEST_SIGNAL(mode_strict_cannot_call_prctl,SIGKILL)238 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
239 {
240 long ret;
241
242 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
243 ASSERT_EQ(0, ret) {
244 TH_LOG("Kernel does not support CONFIG_SECCOMP");
245 }
246 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
247 NULL, NULL, NULL);
248 EXPECT_FALSE(true) {
249 TH_LOG("Unreachable!");
250 }
251 }
252
253 /* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)254 TEST(no_new_privs_support)
255 {
256 long ret;
257
258 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
259 EXPECT_EQ(0, ret) {
260 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
261 }
262 }
263
264 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)265 TEST(mode_filter_support)
266 {
267 long ret;
268
269 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
270 ASSERT_EQ(0, ret) {
271 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
272 }
273 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
274 EXPECT_EQ(-1, ret);
275 EXPECT_EQ(EFAULT, errno) {
276 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
277 }
278 }
279
TEST(mode_filter_without_nnp)280 TEST(mode_filter_without_nnp)
281 {
282 struct sock_filter filter[] = {
283 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
284 };
285 struct sock_fprog prog = {
286 .len = (unsigned short)ARRAY_SIZE(filter),
287 .filter = filter,
288 };
289 long ret;
290
291 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
292 ASSERT_LE(0, ret) {
293 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
294 }
295 errno = 0;
296 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
297 /* Succeeds with CAP_SYS_ADMIN, fails without */
298 /* TODO(wad) check caps not euid */
299 if (geteuid()) {
300 EXPECT_EQ(-1, ret);
301 EXPECT_EQ(EACCES, errno);
302 } else {
303 EXPECT_EQ(0, ret);
304 }
305 }
306
307 #define MAX_INSNS_PER_PATH 32768
308
TEST(filter_size_limits)309 TEST(filter_size_limits)
310 {
311 int i;
312 int count = BPF_MAXINSNS + 1;
313 struct sock_filter allow[] = {
314 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
315 };
316 struct sock_filter *filter;
317 struct sock_fprog prog = { };
318 long ret;
319
320 filter = calloc(count, sizeof(*filter));
321 ASSERT_NE(NULL, filter);
322
323 for (i = 0; i < count; i++)
324 filter[i] = allow[0];
325
326 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
327 ASSERT_EQ(0, ret);
328
329 prog.filter = filter;
330 prog.len = count;
331
332 /* Too many filter instructions in a single filter. */
333 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
334 ASSERT_NE(0, ret) {
335 TH_LOG("Installing %d insn filter was allowed", prog.len);
336 }
337
338 /* One less is okay, though. */
339 prog.len -= 1;
340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
341 ASSERT_EQ(0, ret) {
342 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
343 }
344 }
345
TEST(filter_chain_limits)346 TEST(filter_chain_limits)
347 {
348 int i;
349 int count = BPF_MAXINSNS;
350 struct sock_filter allow[] = {
351 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
352 };
353 struct sock_filter *filter;
354 struct sock_fprog prog = { };
355 long ret;
356
357 filter = calloc(count, sizeof(*filter));
358 ASSERT_NE(NULL, filter);
359
360 for (i = 0; i < count; i++)
361 filter[i] = allow[0];
362
363 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
364 ASSERT_EQ(0, ret);
365
366 prog.filter = filter;
367 prog.len = 1;
368
369 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
370 ASSERT_EQ(0, ret);
371
372 prog.len = count;
373
374 /* Too many total filter instructions. */
375 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
376 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
377 if (ret != 0)
378 break;
379 }
380 ASSERT_NE(0, ret) {
381 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
382 i, count, i * (count + 4));
383 }
384 }
385
TEST(mode_filter_cannot_move_to_strict)386 TEST(mode_filter_cannot_move_to_strict)
387 {
388 struct sock_filter filter[] = {
389 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
390 };
391 struct sock_fprog prog = {
392 .len = (unsigned short)ARRAY_SIZE(filter),
393 .filter = filter,
394 };
395 long ret;
396
397 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
398 ASSERT_EQ(0, ret);
399
400 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
401 ASSERT_EQ(0, ret);
402
403 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
404 EXPECT_EQ(-1, ret);
405 EXPECT_EQ(EINVAL, errno);
406 }
407
408
TEST(mode_filter_get_seccomp)409 TEST(mode_filter_get_seccomp)
410 {
411 struct sock_filter filter[] = {
412 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
413 };
414 struct sock_fprog prog = {
415 .len = (unsigned short)ARRAY_SIZE(filter),
416 .filter = filter,
417 };
418 long ret;
419
420 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
421 ASSERT_EQ(0, ret);
422
423 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
424 EXPECT_EQ(0, ret);
425
426 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
427 ASSERT_EQ(0, ret);
428
429 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
430 EXPECT_EQ(2, ret);
431 }
432
433
TEST(ALLOW_all)434 TEST(ALLOW_all)
435 {
436 struct sock_filter filter[] = {
437 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
438 };
439 struct sock_fprog prog = {
440 .len = (unsigned short)ARRAY_SIZE(filter),
441 .filter = filter,
442 };
443 long ret;
444
445 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
446 ASSERT_EQ(0, ret);
447
448 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
449 ASSERT_EQ(0, ret);
450 }
451
TEST(empty_prog)452 TEST(empty_prog)
453 {
454 struct sock_filter filter[] = {
455 };
456 struct sock_fprog prog = {
457 .len = (unsigned short)ARRAY_SIZE(filter),
458 .filter = filter,
459 };
460 long ret;
461
462 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
463 ASSERT_EQ(0, ret);
464
465 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
466 EXPECT_EQ(-1, ret);
467 EXPECT_EQ(EINVAL, errno);
468 }
469
TEST(log_all)470 TEST(log_all)
471 {
472 struct sock_filter filter[] = {
473 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
474 };
475 struct sock_fprog prog = {
476 .len = (unsigned short)ARRAY_SIZE(filter),
477 .filter = filter,
478 };
479 long ret;
480 pid_t parent = getppid();
481
482 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
483 ASSERT_EQ(0, ret);
484
485 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
486 ASSERT_EQ(0, ret);
487
488 /* getppid() should succeed and be logged (no check for logging) */
489 EXPECT_EQ(parent, syscall(__NR_getppid));
490 }
491
TEST_SIGNAL(unknown_ret_is_kill_inside,SIGSYS)492 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
493 {
494 struct sock_filter filter[] = {
495 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
496 };
497 struct sock_fprog prog = {
498 .len = (unsigned short)ARRAY_SIZE(filter),
499 .filter = filter,
500 };
501 long ret;
502
503 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
504 ASSERT_EQ(0, ret);
505
506 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
507 ASSERT_EQ(0, ret);
508 EXPECT_EQ(0, syscall(__NR_getpid)) {
509 TH_LOG("getpid() shouldn't ever return");
510 }
511 }
512
513 /* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow,SIGSYS)514 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
515 {
516 struct sock_filter filter[] = {
517 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
518 };
519 struct sock_fprog prog = {
520 .len = (unsigned short)ARRAY_SIZE(filter),
521 .filter = filter,
522 };
523 long ret;
524
525 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
526 ASSERT_EQ(0, ret);
527
528 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
529 ASSERT_EQ(0, ret);
530 EXPECT_EQ(0, syscall(__NR_getpid)) {
531 TH_LOG("getpid() shouldn't ever return");
532 }
533 }
534
TEST_SIGNAL(KILL_all,SIGSYS)535 TEST_SIGNAL(KILL_all, SIGSYS)
536 {
537 struct sock_filter filter[] = {
538 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
539 };
540 struct sock_fprog prog = {
541 .len = (unsigned short)ARRAY_SIZE(filter),
542 .filter = filter,
543 };
544 long ret;
545
546 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
547 ASSERT_EQ(0, ret);
548
549 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
550 ASSERT_EQ(0, ret);
551 }
552
TEST_SIGNAL(KILL_one,SIGSYS)553 TEST_SIGNAL(KILL_one, SIGSYS)
554 {
555 struct sock_filter filter[] = {
556 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
557 offsetof(struct seccomp_data, nr)),
558 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
559 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
560 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
561 };
562 struct sock_fprog prog = {
563 .len = (unsigned short)ARRAY_SIZE(filter),
564 .filter = filter,
565 };
566 long ret;
567 pid_t parent = getppid();
568
569 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
570 ASSERT_EQ(0, ret);
571
572 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
573 ASSERT_EQ(0, ret);
574
575 EXPECT_EQ(parent, syscall(__NR_getppid));
576 /* getpid() should never return. */
577 EXPECT_EQ(0, syscall(__NR_getpid));
578 }
579
TEST_SIGNAL(KILL_one_arg_one,SIGSYS)580 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
581 {
582 void *fatal_address;
583 struct sock_filter filter[] = {
584 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
585 offsetof(struct seccomp_data, nr)),
586 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
587 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
588 /* Only both with lower 32-bit for now. */
589 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
590 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
591 (unsigned long)&fatal_address, 0, 1),
592 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
593 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
594 };
595 struct sock_fprog prog = {
596 .len = (unsigned short)ARRAY_SIZE(filter),
597 .filter = filter,
598 };
599 long ret;
600 pid_t parent = getppid();
601 struct tms timebuf;
602 clock_t clock = times(&timebuf);
603
604 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
605 ASSERT_EQ(0, ret);
606
607 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
608 ASSERT_EQ(0, ret);
609
610 EXPECT_EQ(parent, syscall(__NR_getppid));
611 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
612 /* times() should never return. */
613 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
614 }
615
TEST_SIGNAL(KILL_one_arg_six,SIGSYS)616 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
617 {
618 #ifndef __NR_mmap2
619 int sysno = __NR_mmap;
620 #else
621 int sysno = __NR_mmap2;
622 #endif
623 struct sock_filter filter[] = {
624 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
625 offsetof(struct seccomp_data, nr)),
626 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
627 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
628 /* Only both with lower 32-bit for now. */
629 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
630 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
631 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
632 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
633 };
634 struct sock_fprog prog = {
635 .len = (unsigned short)ARRAY_SIZE(filter),
636 .filter = filter,
637 };
638 long ret;
639 pid_t parent = getppid();
640 int fd;
641 void *map1, *map2;
642 int page_size = sysconf(_SC_PAGESIZE);
643
644 ASSERT_LT(0, page_size);
645
646 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
647 ASSERT_EQ(0, ret);
648
649 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
650 ASSERT_EQ(0, ret);
651
652 fd = open("/dev/zero", O_RDONLY);
653 ASSERT_NE(-1, fd);
654
655 EXPECT_EQ(parent, syscall(__NR_getppid));
656 map1 = (void *)syscall(sysno,
657 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
658 EXPECT_NE(MAP_FAILED, map1);
659 /* mmap2() should never return. */
660 map2 = (void *)syscall(sysno,
661 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
662 EXPECT_EQ(MAP_FAILED, map2);
663
664 /* The test failed, so clean up the resources. */
665 munmap(map1, page_size);
666 munmap(map2, page_size);
667 close(fd);
668 }
669
670 /* This is a thread task to die via seccomp filter violation. */
kill_thread(void * data)671 void *kill_thread(void *data)
672 {
673 bool die = (bool)data;
674
675 if (die) {
676 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
677 return (void *)SIBLING_EXIT_FAILURE;
678 }
679
680 return (void *)SIBLING_EXIT_UNKILLED;
681 }
682
683 /* Prepare a thread that will kill itself or both of us. */
kill_thread_or_group(struct __test_metadata * _metadata,bool kill_process)684 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
685 {
686 pthread_t thread;
687 void *status;
688 /* Kill only when calling __NR_prctl. */
689 struct sock_filter filter_thread[] = {
690 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
691 offsetof(struct seccomp_data, nr)),
692 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
693 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
694 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
695 };
696 struct sock_fprog prog_thread = {
697 .len = (unsigned short)ARRAY_SIZE(filter_thread),
698 .filter = filter_thread,
699 };
700 struct sock_filter filter_process[] = {
701 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
702 offsetof(struct seccomp_data, nr)),
703 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
704 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
705 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
706 };
707 struct sock_fprog prog_process = {
708 .len = (unsigned short)ARRAY_SIZE(filter_process),
709 .filter = filter_process,
710 };
711
712 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
713 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
714 }
715
716 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
717 kill_process ? &prog_process : &prog_thread));
718
719 /*
720 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
721 * flag cannot be downgraded by a new filter.
722 */
723 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
724
725 /* Start a thread that will exit immediately. */
726 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
727 ASSERT_EQ(0, pthread_join(thread, &status));
728 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
729
730 /* Start a thread that will die immediately. */
731 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
732 ASSERT_EQ(0, pthread_join(thread, &status));
733 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
734
735 /*
736 * If we get here, only the spawned thread died. Let the parent know
737 * the whole process didn't die (i.e. this thread, the spawner,
738 * stayed running).
739 */
740 exit(42);
741 }
742
TEST(KILL_thread)743 TEST(KILL_thread)
744 {
745 int status;
746 pid_t child_pid;
747
748 child_pid = fork();
749 ASSERT_LE(0, child_pid);
750 if (child_pid == 0) {
751 kill_thread_or_group(_metadata, false);
752 _exit(38);
753 }
754
755 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
756
757 /* If only the thread was killed, we'll see exit 42. */
758 ASSERT_TRUE(WIFEXITED(status));
759 ASSERT_EQ(42, WEXITSTATUS(status));
760 }
761
TEST(KILL_process)762 TEST(KILL_process)
763 {
764 int status;
765 pid_t child_pid;
766
767 child_pid = fork();
768 ASSERT_LE(0, child_pid);
769 if (child_pid == 0) {
770 kill_thread_or_group(_metadata, true);
771 _exit(38);
772 }
773
774 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
775
776 /* If the entire process was killed, we'll see SIGSYS. */
777 ASSERT_TRUE(WIFSIGNALED(status));
778 ASSERT_EQ(SIGSYS, WTERMSIG(status));
779 }
780
781 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)782 TEST(arg_out_of_range)
783 {
784 struct sock_filter filter[] = {
785 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
786 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
787 };
788 struct sock_fprog prog = {
789 .len = (unsigned short)ARRAY_SIZE(filter),
790 .filter = filter,
791 };
792 long ret;
793
794 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
795 ASSERT_EQ(0, ret);
796
797 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
798 EXPECT_EQ(-1, ret);
799 EXPECT_EQ(EINVAL, errno);
800 }
801
802 #define ERRNO_FILTER(name, errno) \
803 struct sock_filter _read_filter_##name[] = { \
804 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
805 offsetof(struct seccomp_data, nr)), \
806 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
807 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
808 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
809 }; \
810 struct sock_fprog prog_##name = { \
811 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
812 .filter = _read_filter_##name, \
813 }
814
815 /* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)816 TEST(ERRNO_valid)
817 {
818 ERRNO_FILTER(valid, E2BIG);
819 long ret;
820 pid_t parent = getppid();
821
822 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
823 ASSERT_EQ(0, ret);
824
825 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
826 ASSERT_EQ(0, ret);
827
828 EXPECT_EQ(parent, syscall(__NR_getppid));
829 EXPECT_EQ(-1, read(0, NULL, 0));
830 EXPECT_EQ(E2BIG, errno);
831 }
832
833 /* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)834 TEST(ERRNO_zero)
835 {
836 ERRNO_FILTER(zero, 0);
837 long ret;
838 pid_t parent = getppid();
839
840 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
841 ASSERT_EQ(0, ret);
842
843 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
844 ASSERT_EQ(0, ret);
845
846 EXPECT_EQ(parent, syscall(__NR_getppid));
847 /* "errno" of 0 is ok. */
848 EXPECT_EQ(0, read(0, NULL, 0));
849 }
850
851 /*
852 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
853 * This tests that the errno value gets capped correctly, fixed by
854 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
855 */
TEST(ERRNO_capped)856 TEST(ERRNO_capped)
857 {
858 ERRNO_FILTER(capped, 4096);
859 long ret;
860 pid_t parent = getppid();
861
862 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
863 ASSERT_EQ(0, ret);
864
865 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
866 ASSERT_EQ(0, ret);
867
868 EXPECT_EQ(parent, syscall(__NR_getppid));
869 EXPECT_EQ(-1, read(0, NULL, 0));
870 EXPECT_EQ(4095, errno);
871 }
872
873 /*
874 * Filters are processed in reverse order: last applied is executed first.
875 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
876 * SECCOMP_RET_DATA mask results will follow the most recently applied
877 * matching filter return (and not the lowest or highest value).
878 */
TEST(ERRNO_order)879 TEST(ERRNO_order)
880 {
881 ERRNO_FILTER(first, 11);
882 ERRNO_FILTER(second, 13);
883 ERRNO_FILTER(third, 12);
884 long ret;
885 pid_t parent = getppid();
886
887 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
888 ASSERT_EQ(0, ret);
889
890 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
891 ASSERT_EQ(0, ret);
892
893 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
894 ASSERT_EQ(0, ret);
895
896 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
897 ASSERT_EQ(0, ret);
898
899 EXPECT_EQ(parent, syscall(__NR_getppid));
900 EXPECT_EQ(-1, read(0, NULL, 0));
901 EXPECT_EQ(12, errno);
902 }
903
FIXTURE_DATA(TRAP)904 FIXTURE_DATA(TRAP) {
905 struct sock_fprog prog;
906 };
907
FIXTURE_SETUP(TRAP)908 FIXTURE_SETUP(TRAP)
909 {
910 struct sock_filter filter[] = {
911 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
912 offsetof(struct seccomp_data, nr)),
913 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
914 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
915 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
916 };
917
918 memset(&self->prog, 0, sizeof(self->prog));
919 self->prog.filter = malloc(sizeof(filter));
920 ASSERT_NE(NULL, self->prog.filter);
921 memcpy(self->prog.filter, filter, sizeof(filter));
922 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
923 }
924
FIXTURE_TEARDOWN(TRAP)925 FIXTURE_TEARDOWN(TRAP)
926 {
927 if (self->prog.filter)
928 free(self->prog.filter);
929 }
930
TEST_F_SIGNAL(TRAP,dfl,SIGSYS)931 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
932 {
933 long ret;
934
935 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
936 ASSERT_EQ(0, ret);
937
938 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
939 ASSERT_EQ(0, ret);
940 syscall(__NR_getpid);
941 }
942
943 /* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP,ign,SIGSYS)944 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
945 {
946 long ret;
947
948 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
949 ASSERT_EQ(0, ret);
950
951 signal(SIGSYS, SIG_IGN);
952
953 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
954 ASSERT_EQ(0, ret);
955 syscall(__NR_getpid);
956 }
957
958 static siginfo_t TRAP_info;
959 static volatile int TRAP_nr;
TRAP_action(int nr,siginfo_t * info,void * void_context)960 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
961 {
962 memcpy(&TRAP_info, info, sizeof(TRAP_info));
963 TRAP_nr = nr;
964 }
965
TEST_F(TRAP,handler)966 TEST_F(TRAP, handler)
967 {
968 int ret, test;
969 struct sigaction act;
970 sigset_t mask;
971
972 memset(&act, 0, sizeof(act));
973 sigemptyset(&mask);
974 sigaddset(&mask, SIGSYS);
975
976 act.sa_sigaction = &TRAP_action;
977 act.sa_flags = SA_SIGINFO;
978 ret = sigaction(SIGSYS, &act, NULL);
979 ASSERT_EQ(0, ret) {
980 TH_LOG("sigaction failed");
981 }
982 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
983 ASSERT_EQ(0, ret) {
984 TH_LOG("sigprocmask failed");
985 }
986
987 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
988 ASSERT_EQ(0, ret);
989 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
990 ASSERT_EQ(0, ret);
991 TRAP_nr = 0;
992 memset(&TRAP_info, 0, sizeof(TRAP_info));
993 /* Expect the registers to be rolled back. (nr = error) may vary
994 * based on arch. */
995 ret = syscall(__NR_getpid);
996 /* Silence gcc warning about volatile. */
997 test = TRAP_nr;
998 EXPECT_EQ(SIGSYS, test);
999 struct local_sigsys {
1000 void *_call_addr; /* calling user insn */
1001 int _syscall; /* triggering system call number */
1002 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1003 } *sigsys = (struct local_sigsys *)
1004 #ifdef si_syscall
1005 &(TRAP_info.si_call_addr);
1006 #else
1007 &TRAP_info.si_pid;
1008 #endif
1009 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1010 /* Make sure arch is non-zero. */
1011 EXPECT_NE(0, sigsys->_arch);
1012 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1013 }
1014
FIXTURE_DATA(precedence)1015 FIXTURE_DATA(precedence) {
1016 struct sock_fprog allow;
1017 struct sock_fprog log;
1018 struct sock_fprog trace;
1019 struct sock_fprog error;
1020 struct sock_fprog trap;
1021 struct sock_fprog kill;
1022 };
1023
FIXTURE_SETUP(precedence)1024 FIXTURE_SETUP(precedence)
1025 {
1026 struct sock_filter allow_insns[] = {
1027 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1028 };
1029 struct sock_filter log_insns[] = {
1030 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1031 offsetof(struct seccomp_data, nr)),
1032 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1033 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1034 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1035 };
1036 struct sock_filter trace_insns[] = {
1037 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1038 offsetof(struct seccomp_data, nr)),
1039 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1040 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1041 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1042 };
1043 struct sock_filter error_insns[] = {
1044 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1045 offsetof(struct seccomp_data, nr)),
1046 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1047 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1048 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1049 };
1050 struct sock_filter trap_insns[] = {
1051 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1052 offsetof(struct seccomp_data, nr)),
1053 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1054 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1055 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1056 };
1057 struct sock_filter kill_insns[] = {
1058 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1059 offsetof(struct seccomp_data, nr)),
1060 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1061 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1062 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1063 };
1064
1065 memset(self, 0, sizeof(*self));
1066 #define FILTER_ALLOC(_x) \
1067 self->_x.filter = malloc(sizeof(_x##_insns)); \
1068 ASSERT_NE(NULL, self->_x.filter); \
1069 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1070 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1071 FILTER_ALLOC(allow);
1072 FILTER_ALLOC(log);
1073 FILTER_ALLOC(trace);
1074 FILTER_ALLOC(error);
1075 FILTER_ALLOC(trap);
1076 FILTER_ALLOC(kill);
1077 }
1078
FIXTURE_TEARDOWN(precedence)1079 FIXTURE_TEARDOWN(precedence)
1080 {
1081 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1082 FILTER_FREE(allow);
1083 FILTER_FREE(log);
1084 FILTER_FREE(trace);
1085 FILTER_FREE(error);
1086 FILTER_FREE(trap);
1087 FILTER_FREE(kill);
1088 }
1089
TEST_F(precedence,allow_ok)1090 TEST_F(precedence, allow_ok)
1091 {
1092 pid_t parent, res = 0;
1093 long ret;
1094
1095 parent = getppid();
1096 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1097 ASSERT_EQ(0, ret);
1098
1099 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1100 ASSERT_EQ(0, ret);
1101 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1102 ASSERT_EQ(0, ret);
1103 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1104 ASSERT_EQ(0, ret);
1105 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1106 ASSERT_EQ(0, ret);
1107 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1108 ASSERT_EQ(0, ret);
1109 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1110 ASSERT_EQ(0, ret);
1111 /* Should work just fine. */
1112 res = syscall(__NR_getppid);
1113 EXPECT_EQ(parent, res);
1114 }
1115
TEST_F_SIGNAL(precedence,kill_is_highest,SIGSYS)1116 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1117 {
1118 pid_t parent, res = 0;
1119 long ret;
1120
1121 parent = getppid();
1122 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1123 ASSERT_EQ(0, ret);
1124
1125 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1126 ASSERT_EQ(0, ret);
1127 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1128 ASSERT_EQ(0, ret);
1129 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1130 ASSERT_EQ(0, ret);
1131 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1132 ASSERT_EQ(0, ret);
1133 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1134 ASSERT_EQ(0, ret);
1135 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1136 ASSERT_EQ(0, ret);
1137 /* Should work just fine. */
1138 res = syscall(__NR_getppid);
1139 EXPECT_EQ(parent, res);
1140 /* getpid() should never return. */
1141 res = syscall(__NR_getpid);
1142 EXPECT_EQ(0, res);
1143 }
1144
TEST_F_SIGNAL(precedence,kill_is_highest_in_any_order,SIGSYS)1145 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1146 {
1147 pid_t parent;
1148 long ret;
1149
1150 parent = getppid();
1151 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1152 ASSERT_EQ(0, ret);
1153
1154 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1155 ASSERT_EQ(0, ret);
1156 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1157 ASSERT_EQ(0, ret);
1158 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1159 ASSERT_EQ(0, ret);
1160 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1161 ASSERT_EQ(0, ret);
1162 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1163 ASSERT_EQ(0, ret);
1164 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1165 ASSERT_EQ(0, ret);
1166 /* Should work just fine. */
1167 EXPECT_EQ(parent, syscall(__NR_getppid));
1168 /* getpid() should never return. */
1169 EXPECT_EQ(0, syscall(__NR_getpid));
1170 }
1171
TEST_F_SIGNAL(precedence,trap_is_second,SIGSYS)1172 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1173 {
1174 pid_t parent;
1175 long ret;
1176
1177 parent = getppid();
1178 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1179 ASSERT_EQ(0, ret);
1180
1181 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1182 ASSERT_EQ(0, ret);
1183 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1184 ASSERT_EQ(0, ret);
1185 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1186 ASSERT_EQ(0, ret);
1187 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1188 ASSERT_EQ(0, ret);
1189 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1190 ASSERT_EQ(0, ret);
1191 /* Should work just fine. */
1192 EXPECT_EQ(parent, syscall(__NR_getppid));
1193 /* getpid() should never return. */
1194 EXPECT_EQ(0, syscall(__NR_getpid));
1195 }
1196
TEST_F_SIGNAL(precedence,trap_is_second_in_any_order,SIGSYS)1197 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1198 {
1199 pid_t parent;
1200 long ret;
1201
1202 parent = getppid();
1203 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1204 ASSERT_EQ(0, ret);
1205
1206 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1207 ASSERT_EQ(0, ret);
1208 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1209 ASSERT_EQ(0, ret);
1210 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1211 ASSERT_EQ(0, ret);
1212 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1213 ASSERT_EQ(0, ret);
1214 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1215 ASSERT_EQ(0, ret);
1216 /* Should work just fine. */
1217 EXPECT_EQ(parent, syscall(__NR_getppid));
1218 /* getpid() should never return. */
1219 EXPECT_EQ(0, syscall(__NR_getpid));
1220 }
1221
TEST_F(precedence,errno_is_third)1222 TEST_F(precedence, errno_is_third)
1223 {
1224 pid_t parent;
1225 long ret;
1226
1227 parent = getppid();
1228 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1229 ASSERT_EQ(0, ret);
1230
1231 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1232 ASSERT_EQ(0, ret);
1233 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1234 ASSERT_EQ(0, ret);
1235 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1236 ASSERT_EQ(0, ret);
1237 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1238 ASSERT_EQ(0, ret);
1239 /* Should work just fine. */
1240 EXPECT_EQ(parent, syscall(__NR_getppid));
1241 EXPECT_EQ(0, syscall(__NR_getpid));
1242 }
1243
TEST_F(precedence,errno_is_third_in_any_order)1244 TEST_F(precedence, errno_is_third_in_any_order)
1245 {
1246 pid_t parent;
1247 long ret;
1248
1249 parent = getppid();
1250 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1251 ASSERT_EQ(0, ret);
1252
1253 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1254 ASSERT_EQ(0, ret);
1255 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1256 ASSERT_EQ(0, ret);
1257 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1258 ASSERT_EQ(0, ret);
1259 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1260 ASSERT_EQ(0, ret);
1261 /* Should work just fine. */
1262 EXPECT_EQ(parent, syscall(__NR_getppid));
1263 EXPECT_EQ(0, syscall(__NR_getpid));
1264 }
1265
TEST_F(precedence,trace_is_fourth)1266 TEST_F(precedence, trace_is_fourth)
1267 {
1268 pid_t parent;
1269 long ret;
1270
1271 parent = getppid();
1272 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1273 ASSERT_EQ(0, ret);
1274
1275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1276 ASSERT_EQ(0, ret);
1277 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1278 ASSERT_EQ(0, ret);
1279 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1280 ASSERT_EQ(0, ret);
1281 /* Should work just fine. */
1282 EXPECT_EQ(parent, syscall(__NR_getppid));
1283 /* No ptracer */
1284 EXPECT_EQ(-1, syscall(__NR_getpid));
1285 }
1286
TEST_F(precedence,trace_is_fourth_in_any_order)1287 TEST_F(precedence, trace_is_fourth_in_any_order)
1288 {
1289 pid_t parent;
1290 long ret;
1291
1292 parent = getppid();
1293 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1294 ASSERT_EQ(0, ret);
1295
1296 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1297 ASSERT_EQ(0, ret);
1298 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1299 ASSERT_EQ(0, ret);
1300 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1301 ASSERT_EQ(0, ret);
1302 /* Should work just fine. */
1303 EXPECT_EQ(parent, syscall(__NR_getppid));
1304 /* No ptracer */
1305 EXPECT_EQ(-1, syscall(__NR_getpid));
1306 }
1307
TEST_F(precedence,log_is_fifth)1308 TEST_F(precedence, log_is_fifth)
1309 {
1310 pid_t mypid, parent;
1311 long ret;
1312
1313 mypid = getpid();
1314 parent = getppid();
1315 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1316 ASSERT_EQ(0, ret);
1317
1318 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1319 ASSERT_EQ(0, ret);
1320 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1321 ASSERT_EQ(0, ret);
1322 /* Should work just fine. */
1323 EXPECT_EQ(parent, syscall(__NR_getppid));
1324 /* Should also work just fine */
1325 EXPECT_EQ(mypid, syscall(__NR_getpid));
1326 }
1327
TEST_F(precedence,log_is_fifth_in_any_order)1328 TEST_F(precedence, log_is_fifth_in_any_order)
1329 {
1330 pid_t mypid, parent;
1331 long ret;
1332
1333 mypid = getpid();
1334 parent = getppid();
1335 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1336 ASSERT_EQ(0, ret);
1337
1338 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1339 ASSERT_EQ(0, ret);
1340 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1341 ASSERT_EQ(0, ret);
1342 /* Should work just fine. */
1343 EXPECT_EQ(parent, syscall(__NR_getppid));
1344 /* Should also work just fine */
1345 EXPECT_EQ(mypid, syscall(__NR_getpid));
1346 }
1347
1348 #ifndef PTRACE_O_TRACESECCOMP
1349 #define PTRACE_O_TRACESECCOMP 0x00000080
1350 #endif
1351
1352 /* Catch the Ubuntu 12.04 value error. */
1353 #if PTRACE_EVENT_SECCOMP != 7
1354 #undef PTRACE_EVENT_SECCOMP
1355 #endif
1356
1357 #ifndef PTRACE_EVENT_SECCOMP
1358 #define PTRACE_EVENT_SECCOMP 7
1359 #endif
1360
1361 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1362 bool tracer_running;
tracer_stop(int sig)1363 void tracer_stop(int sig)
1364 {
1365 tracer_running = false;
1366 }
1367
1368 typedef void tracer_func_t(struct __test_metadata *_metadata,
1369 pid_t tracee, int status, void *args);
1370
start_tracer(struct __test_metadata * _metadata,int fd,pid_t tracee,tracer_func_t tracer_func,void * args,bool ptrace_syscall)1371 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1372 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1373 {
1374 int ret = -1;
1375 struct sigaction action = {
1376 .sa_handler = tracer_stop,
1377 };
1378
1379 /* Allow external shutdown. */
1380 tracer_running = true;
1381 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1382
1383 errno = 0;
1384 while (ret == -1 && errno != EINVAL)
1385 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1386 ASSERT_EQ(0, ret) {
1387 kill(tracee, SIGKILL);
1388 }
1389 /* Wait for attach stop */
1390 wait(NULL);
1391
1392 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1393 PTRACE_O_TRACESYSGOOD :
1394 PTRACE_O_TRACESECCOMP);
1395 ASSERT_EQ(0, ret) {
1396 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1397 kill(tracee, SIGKILL);
1398 }
1399 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1400 tracee, NULL, 0);
1401 ASSERT_EQ(0, ret);
1402
1403 /* Unblock the tracee */
1404 ASSERT_EQ(1, write(fd, "A", 1));
1405 ASSERT_EQ(0, close(fd));
1406
1407 /* Run until we're shut down. Must assert to stop execution. */
1408 while (tracer_running) {
1409 int status;
1410
1411 if (wait(&status) != tracee)
1412 continue;
1413 if (WIFSIGNALED(status) || WIFEXITED(status))
1414 /* Child is dead. Time to go. */
1415 return;
1416
1417 /* Check if this is a seccomp event. */
1418 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1419
1420 tracer_func(_metadata, tracee, status, args);
1421
1422 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1423 tracee, NULL, 0);
1424 ASSERT_EQ(0, ret);
1425 }
1426 /* Directly report the status of our test harness results. */
1427 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1428 }
1429
1430 /* Common tracer setup/teardown functions. */
cont_handler(int num)1431 void cont_handler(int num)
1432 { }
setup_trace_fixture(struct __test_metadata * _metadata,tracer_func_t func,void * args,bool ptrace_syscall)1433 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1434 tracer_func_t func, void *args, bool ptrace_syscall)
1435 {
1436 char sync;
1437 int pipefd[2];
1438 pid_t tracer_pid;
1439 pid_t tracee = getpid();
1440
1441 /* Setup a pipe for clean synchronization. */
1442 ASSERT_EQ(0, pipe(pipefd));
1443
1444 /* Fork a child which we'll promote to tracer */
1445 tracer_pid = fork();
1446 ASSERT_LE(0, tracer_pid);
1447 signal(SIGALRM, cont_handler);
1448 if (tracer_pid == 0) {
1449 close(pipefd[0]);
1450 start_tracer(_metadata, pipefd[1], tracee, func, args,
1451 ptrace_syscall);
1452 syscall(__NR_exit, 0);
1453 }
1454 close(pipefd[1]);
1455 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1456 read(pipefd[0], &sync, 1);
1457 close(pipefd[0]);
1458
1459 return tracer_pid;
1460 }
teardown_trace_fixture(struct __test_metadata * _metadata,pid_t tracer)1461 void teardown_trace_fixture(struct __test_metadata *_metadata,
1462 pid_t tracer)
1463 {
1464 if (tracer) {
1465 int status;
1466 /*
1467 * Extract the exit code from the other process and
1468 * adopt it for ourselves in case its asserts failed.
1469 */
1470 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1471 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1472 if (WEXITSTATUS(status))
1473 _metadata->passed = 0;
1474 }
1475 }
1476
1477 /* "poke" tracer arguments and function. */
1478 struct tracer_args_poke_t {
1479 unsigned long poke_addr;
1480 };
1481
tracer_poke(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1482 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1483 void *args)
1484 {
1485 int ret;
1486 unsigned long msg;
1487 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1488
1489 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1490 EXPECT_EQ(0, ret);
1491 /* If this fails, don't try to recover. */
1492 ASSERT_EQ(0x1001, msg) {
1493 kill(tracee, SIGKILL);
1494 }
1495 /*
1496 * Poke in the message.
1497 * Registers are not touched to try to keep this relatively arch
1498 * agnostic.
1499 */
1500 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1501 EXPECT_EQ(0, ret);
1502 }
1503
FIXTURE_DATA(TRACE_poke)1504 FIXTURE_DATA(TRACE_poke) {
1505 struct sock_fprog prog;
1506 pid_t tracer;
1507 long poked;
1508 struct tracer_args_poke_t tracer_args;
1509 };
1510
FIXTURE_SETUP(TRACE_poke)1511 FIXTURE_SETUP(TRACE_poke)
1512 {
1513 struct sock_filter filter[] = {
1514 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1515 offsetof(struct seccomp_data, nr)),
1516 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1517 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1518 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1519 };
1520
1521 self->poked = 0;
1522 memset(&self->prog, 0, sizeof(self->prog));
1523 self->prog.filter = malloc(sizeof(filter));
1524 ASSERT_NE(NULL, self->prog.filter);
1525 memcpy(self->prog.filter, filter, sizeof(filter));
1526 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1527
1528 /* Set up tracer args. */
1529 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1530
1531 /* Launch tracer. */
1532 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1533 &self->tracer_args, false);
1534 }
1535
FIXTURE_TEARDOWN(TRACE_poke)1536 FIXTURE_TEARDOWN(TRACE_poke)
1537 {
1538 teardown_trace_fixture(_metadata, self->tracer);
1539 if (self->prog.filter)
1540 free(self->prog.filter);
1541 }
1542
TEST_F(TRACE_poke,read_has_side_effects)1543 TEST_F(TRACE_poke, read_has_side_effects)
1544 {
1545 ssize_t ret;
1546
1547 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1548 ASSERT_EQ(0, ret);
1549
1550 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1551 ASSERT_EQ(0, ret);
1552
1553 EXPECT_EQ(0, self->poked);
1554 ret = read(-1, NULL, 0);
1555 EXPECT_EQ(-1, ret);
1556 EXPECT_EQ(0x1001, self->poked);
1557 }
1558
TEST_F(TRACE_poke,getpid_runs_normally)1559 TEST_F(TRACE_poke, getpid_runs_normally)
1560 {
1561 long ret;
1562
1563 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1564 ASSERT_EQ(0, ret);
1565
1566 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1567 ASSERT_EQ(0, ret);
1568
1569 EXPECT_EQ(0, self->poked);
1570 EXPECT_NE(0, syscall(__NR_getpid));
1571 EXPECT_EQ(0, self->poked);
1572 }
1573
1574 #if defined(__x86_64__)
1575 # define ARCH_REGS struct user_regs_struct
1576 # define SYSCALL_NUM orig_rax
1577 # define SYSCALL_RET rax
1578 #elif defined(__i386__)
1579 # define ARCH_REGS struct user_regs_struct
1580 # define SYSCALL_NUM orig_eax
1581 # define SYSCALL_RET eax
1582 #elif defined(__arm__)
1583 # define ARCH_REGS struct pt_regs
1584 # define SYSCALL_NUM ARM_r7
1585 # define SYSCALL_RET ARM_r0
1586 #elif defined(__aarch64__)
1587 # define ARCH_REGS struct user_pt_regs
1588 # define SYSCALL_NUM regs[8]
1589 # define SYSCALL_RET regs[0]
1590 #elif defined(__hppa__)
1591 # define ARCH_REGS struct user_regs_struct
1592 # define SYSCALL_NUM gr[20]
1593 # define SYSCALL_RET gr[28]
1594 #elif defined(__powerpc__)
1595 # define ARCH_REGS struct pt_regs
1596 # define SYSCALL_NUM gpr[0]
1597 # define SYSCALL_RET gpr[3]
1598 #elif defined(__s390__)
1599 # define ARCH_REGS s390_regs
1600 # define SYSCALL_NUM gprs[2]
1601 # define SYSCALL_RET gprs[2]
1602 #elif defined(__mips__)
1603 # define ARCH_REGS struct pt_regs
1604 # define SYSCALL_NUM regs[2]
1605 # define SYSCALL_SYSCALL_NUM regs[4]
1606 # define SYSCALL_RET regs[2]
1607 # define SYSCALL_NUM_RET_SHARE_REG
1608 #else
1609 # error "Do not know how to find your architecture's registers and syscalls"
1610 #endif
1611
1612 /* When the syscall return can't be changed, stub out the tests for it. */
1613 #ifdef SYSCALL_NUM_RET_SHARE_REG
1614 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1615 #else
1616 # define EXPECT_SYSCALL_RETURN(val, action) \
1617 do { \
1618 errno = 0; \
1619 if (val < 0) { \
1620 EXPECT_EQ(-1, action); \
1621 EXPECT_EQ(-(val), errno); \
1622 } else { \
1623 EXPECT_EQ(val, action); \
1624 } \
1625 } while (0)
1626 #endif
1627
1628 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1629 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1630 */
1631 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1632 #define HAVE_GETREGS
1633 #endif
1634
1635 /* Architecture-specific syscall fetching routine. */
get_syscall(struct __test_metadata * _metadata,pid_t tracee)1636 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1637 {
1638 ARCH_REGS regs;
1639 #ifdef HAVE_GETREGS
1640 EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, ®s)) {
1641 TH_LOG("PTRACE_GETREGS failed");
1642 return -1;
1643 }
1644 #else
1645 struct iovec iov;
1646
1647 iov.iov_base = ®s;
1648 iov.iov_len = sizeof(regs);
1649 EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1650 TH_LOG("PTRACE_GETREGSET failed");
1651 return -1;
1652 }
1653 #endif
1654
1655 #if defined(__mips__)
1656 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1657 return regs.SYSCALL_SYSCALL_NUM;
1658 #endif
1659 return regs.SYSCALL_NUM;
1660 }
1661
1662 /* Architecture-specific syscall changing routine. */
change_syscall(struct __test_metadata * _metadata,pid_t tracee,int syscall,int result)1663 void change_syscall(struct __test_metadata *_metadata,
1664 pid_t tracee, int syscall, int result)
1665 {
1666 int ret;
1667 ARCH_REGS regs;
1668 #ifdef HAVE_GETREGS
1669 ret = ptrace(PTRACE_GETREGS, tracee, 0, ®s);
1670 #else
1671 struct iovec iov;
1672 iov.iov_base = ®s;
1673 iov.iov_len = sizeof(regs);
1674 ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1675 #endif
1676 EXPECT_EQ(0, ret) {}
1677
1678 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1679 defined(__s390__) || defined(__hppa__)
1680 {
1681 regs.SYSCALL_NUM = syscall;
1682 }
1683 #elif defined(__mips__)
1684 {
1685 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1686 regs.SYSCALL_SYSCALL_NUM = syscall;
1687 else
1688 regs.SYSCALL_NUM = syscall;
1689 }
1690
1691 #elif defined(__arm__)
1692 # ifndef PTRACE_SET_SYSCALL
1693 # define PTRACE_SET_SYSCALL 23
1694 # endif
1695 {
1696 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1697 EXPECT_EQ(0, ret);
1698 }
1699
1700 #elif defined(__aarch64__)
1701 # ifndef NT_ARM_SYSTEM_CALL
1702 # define NT_ARM_SYSTEM_CALL 0x404
1703 # endif
1704 {
1705 iov.iov_base = &syscall;
1706 iov.iov_len = sizeof(syscall);
1707 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1708 &iov);
1709 EXPECT_EQ(0, ret);
1710 }
1711
1712 #else
1713 ASSERT_EQ(1, 0) {
1714 TH_LOG("How is the syscall changed on this architecture?");
1715 }
1716 #endif
1717
1718 /* If syscall is skipped, change return value. */
1719 if (syscall == -1)
1720 #ifdef SYSCALL_NUM_RET_SHARE_REG
1721 TH_LOG("Can't modify syscall return on this architecture");
1722 #else
1723 regs.SYSCALL_RET = result;
1724 #endif
1725
1726 #ifdef HAVE_GETREGS
1727 ret = ptrace(PTRACE_SETREGS, tracee, 0, ®s);
1728 #else
1729 iov.iov_base = ®s;
1730 iov.iov_len = sizeof(regs);
1731 ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1732 #endif
1733 EXPECT_EQ(0, ret);
1734 }
1735
tracer_syscall(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1736 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1737 int status, void *args)
1738 {
1739 int ret;
1740 unsigned long msg;
1741
1742 /* Make sure we got the right message. */
1743 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1744 EXPECT_EQ(0, ret);
1745
1746 /* Validate and take action on expected syscalls. */
1747 switch (msg) {
1748 case 0x1002:
1749 /* change getpid to getppid. */
1750 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1751 change_syscall(_metadata, tracee, __NR_getppid, 0);
1752 break;
1753 case 0x1003:
1754 /* skip gettid with valid return code. */
1755 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1756 change_syscall(_metadata, tracee, -1, 45000);
1757 break;
1758 case 0x1004:
1759 /* skip openat with error. */
1760 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
1761 change_syscall(_metadata, tracee, -1, -ESRCH);
1762 break;
1763 case 0x1005:
1764 /* do nothing (allow getppid) */
1765 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1766 break;
1767 default:
1768 EXPECT_EQ(0, msg) {
1769 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1770 kill(tracee, SIGKILL);
1771 }
1772 }
1773
1774 }
1775
tracer_ptrace(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1776 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1777 int status, void *args)
1778 {
1779 int ret, nr;
1780 unsigned long msg;
1781 static bool entry;
1782
1783 /*
1784 * The traditional way to tell PTRACE_SYSCALL entry/exit
1785 * is by counting.
1786 */
1787 entry = !entry;
1788
1789 /* Make sure we got an appropriate message. */
1790 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1791 EXPECT_EQ(0, ret);
1792 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
1793 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
1794
1795 if (!entry)
1796 return;
1797
1798 nr = get_syscall(_metadata, tracee);
1799
1800 if (nr == __NR_getpid)
1801 change_syscall(_metadata, tracee, __NR_getppid, 0);
1802 if (nr == __NR_gettid)
1803 change_syscall(_metadata, tracee, -1, 45000);
1804 if (nr == __NR_openat)
1805 change_syscall(_metadata, tracee, -1, -ESRCH);
1806 }
1807
FIXTURE_DATA(TRACE_syscall)1808 FIXTURE_DATA(TRACE_syscall) {
1809 struct sock_fprog prog;
1810 pid_t tracer, mytid, mypid, parent;
1811 };
1812
FIXTURE_SETUP(TRACE_syscall)1813 FIXTURE_SETUP(TRACE_syscall)
1814 {
1815 struct sock_filter filter[] = {
1816 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1817 offsetof(struct seccomp_data, nr)),
1818 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1819 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1820 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1821 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1822 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
1823 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1824 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1825 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
1826 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1827 };
1828
1829 memset(&self->prog, 0, sizeof(self->prog));
1830 self->prog.filter = malloc(sizeof(filter));
1831 ASSERT_NE(NULL, self->prog.filter);
1832 memcpy(self->prog.filter, filter, sizeof(filter));
1833 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1834
1835 /* Prepare some testable syscall results. */
1836 self->mytid = syscall(__NR_gettid);
1837 ASSERT_GT(self->mytid, 0);
1838 ASSERT_NE(self->mytid, 1) {
1839 TH_LOG("Running this test as init is not supported. :)");
1840 }
1841
1842 self->mypid = getpid();
1843 ASSERT_GT(self->mypid, 0);
1844 ASSERT_EQ(self->mytid, self->mypid);
1845
1846 self->parent = getppid();
1847 ASSERT_GT(self->parent, 0);
1848 ASSERT_NE(self->parent, self->mypid);
1849
1850 /* Launch tracer. */
1851 self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1852 false);
1853 }
1854
FIXTURE_TEARDOWN(TRACE_syscall)1855 FIXTURE_TEARDOWN(TRACE_syscall)
1856 {
1857 teardown_trace_fixture(_metadata, self->tracer);
1858 if (self->prog.filter)
1859 free(self->prog.filter);
1860 }
1861
TEST_F(TRACE_syscall,ptrace_syscall_redirected)1862 TEST_F(TRACE_syscall, ptrace_syscall_redirected)
1863 {
1864 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1865 teardown_trace_fixture(_metadata, self->tracer);
1866 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1867 true);
1868
1869 /* Tracer will redirect getpid to getppid. */
1870 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1871 }
1872
TEST_F(TRACE_syscall,ptrace_syscall_errno)1873 TEST_F(TRACE_syscall, ptrace_syscall_errno)
1874 {
1875 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1876 teardown_trace_fixture(_metadata, self->tracer);
1877 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1878 true);
1879
1880 /* Tracer should skip the open syscall, resulting in ESRCH. */
1881 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
1882 }
1883
TEST_F(TRACE_syscall,ptrace_syscall_faked)1884 TEST_F(TRACE_syscall, ptrace_syscall_faked)
1885 {
1886 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1887 teardown_trace_fixture(_metadata, self->tracer);
1888 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1889 true);
1890
1891 /* Tracer should skip the gettid syscall, resulting fake pid. */
1892 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
1893 }
1894
TEST_F(TRACE_syscall,syscall_allowed)1895 TEST_F(TRACE_syscall, syscall_allowed)
1896 {
1897 long ret;
1898
1899 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1900 ASSERT_EQ(0, ret);
1901
1902 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1903 ASSERT_EQ(0, ret);
1904
1905 /* getppid works as expected (no changes). */
1906 EXPECT_EQ(self->parent, syscall(__NR_getppid));
1907 EXPECT_NE(self->mypid, syscall(__NR_getppid));
1908 }
1909
TEST_F(TRACE_syscall,syscall_redirected)1910 TEST_F(TRACE_syscall, syscall_redirected)
1911 {
1912 long ret;
1913
1914 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1915 ASSERT_EQ(0, ret);
1916
1917 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1918 ASSERT_EQ(0, ret);
1919
1920 /* getpid has been redirected to getppid as expected. */
1921 EXPECT_EQ(self->parent, syscall(__NR_getpid));
1922 EXPECT_NE(self->mypid, syscall(__NR_getpid));
1923 }
1924
TEST_F(TRACE_syscall,syscall_errno)1925 TEST_F(TRACE_syscall, syscall_errno)
1926 {
1927 long ret;
1928
1929 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1930 ASSERT_EQ(0, ret);
1931
1932 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1933 ASSERT_EQ(0, ret);
1934
1935 /* openat has been skipped and an errno return. */
1936 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
1937 }
1938
TEST_F(TRACE_syscall,syscall_faked)1939 TEST_F(TRACE_syscall, syscall_faked)
1940 {
1941 long ret;
1942
1943 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1944 ASSERT_EQ(0, ret);
1945
1946 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1947 ASSERT_EQ(0, ret);
1948
1949 /* gettid has been skipped and an altered return value stored. */
1950 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
1951 }
1952
TEST_F(TRACE_syscall,skip_after_RET_TRACE)1953 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1954 {
1955 struct sock_filter filter[] = {
1956 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1957 offsetof(struct seccomp_data, nr)),
1958 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1959 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1960 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1961 };
1962 struct sock_fprog prog = {
1963 .len = (unsigned short)ARRAY_SIZE(filter),
1964 .filter = filter,
1965 };
1966 long ret;
1967
1968 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1969 ASSERT_EQ(0, ret);
1970
1971 /* Install fixture filter. */
1972 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1973 ASSERT_EQ(0, ret);
1974
1975 /* Install "errno on getppid" filter. */
1976 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1977 ASSERT_EQ(0, ret);
1978
1979 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1980 errno = 0;
1981 EXPECT_EQ(-1, syscall(__NR_getpid));
1982 EXPECT_EQ(EPERM, errno);
1983 }
1984
TEST_F_SIGNAL(TRACE_syscall,kill_after_RET_TRACE,SIGSYS)1985 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1986 {
1987 struct sock_filter filter[] = {
1988 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1989 offsetof(struct seccomp_data, nr)),
1990 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1991 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1992 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1993 };
1994 struct sock_fprog prog = {
1995 .len = (unsigned short)ARRAY_SIZE(filter),
1996 .filter = filter,
1997 };
1998 long ret;
1999
2000 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2001 ASSERT_EQ(0, ret);
2002
2003 /* Install fixture filter. */
2004 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
2005 ASSERT_EQ(0, ret);
2006
2007 /* Install "death on getppid" filter. */
2008 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2009 ASSERT_EQ(0, ret);
2010
2011 /* Tracer will redirect getpid to getppid, and we should die. */
2012 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2013 }
2014
TEST_F(TRACE_syscall,skip_after_ptrace)2015 TEST_F(TRACE_syscall, skip_after_ptrace)
2016 {
2017 struct sock_filter filter[] = {
2018 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2019 offsetof(struct seccomp_data, nr)),
2020 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2021 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2022 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2023 };
2024 struct sock_fprog prog = {
2025 .len = (unsigned short)ARRAY_SIZE(filter),
2026 .filter = filter,
2027 };
2028 long ret;
2029
2030 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
2031 teardown_trace_fixture(_metadata, self->tracer);
2032 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
2033 true);
2034
2035 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2036 ASSERT_EQ(0, ret);
2037
2038 /* Install "errno on getppid" filter. */
2039 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2040 ASSERT_EQ(0, ret);
2041
2042 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2043 EXPECT_EQ(-1, syscall(__NR_getpid));
2044 EXPECT_EQ(EPERM, errno);
2045 }
2046
TEST_F_SIGNAL(TRACE_syscall,kill_after_ptrace,SIGSYS)2047 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
2048 {
2049 struct sock_filter filter[] = {
2050 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2051 offsetof(struct seccomp_data, nr)),
2052 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2053 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2054 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2055 };
2056 struct sock_fprog prog = {
2057 .len = (unsigned short)ARRAY_SIZE(filter),
2058 .filter = filter,
2059 };
2060 long ret;
2061
2062 /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
2063 teardown_trace_fixture(_metadata, self->tracer);
2064 self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
2065 true);
2066
2067 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2068 ASSERT_EQ(0, ret);
2069
2070 /* Install "death on getppid" filter. */
2071 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2072 ASSERT_EQ(0, ret);
2073
2074 /* Tracer will redirect getpid to getppid, and we should die. */
2075 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2076 }
2077
TEST(seccomp_syscall)2078 TEST(seccomp_syscall)
2079 {
2080 struct sock_filter filter[] = {
2081 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2082 };
2083 struct sock_fprog prog = {
2084 .len = (unsigned short)ARRAY_SIZE(filter),
2085 .filter = filter,
2086 };
2087 long ret;
2088
2089 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2090 ASSERT_EQ(0, ret) {
2091 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2092 }
2093
2094 /* Reject insane operation. */
2095 ret = seccomp(-1, 0, &prog);
2096 ASSERT_NE(ENOSYS, errno) {
2097 TH_LOG("Kernel does not support seccomp syscall!");
2098 }
2099 EXPECT_EQ(EINVAL, errno) {
2100 TH_LOG("Did not reject crazy op value!");
2101 }
2102
2103 /* Reject strict with flags or pointer. */
2104 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2105 EXPECT_EQ(EINVAL, errno) {
2106 TH_LOG("Did not reject mode strict with flags!");
2107 }
2108 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2109 EXPECT_EQ(EINVAL, errno) {
2110 TH_LOG("Did not reject mode strict with uargs!");
2111 }
2112
2113 /* Reject insane args for filter. */
2114 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2115 EXPECT_EQ(EINVAL, errno) {
2116 TH_LOG("Did not reject crazy filter flags!");
2117 }
2118 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2119 EXPECT_EQ(EFAULT, errno) {
2120 TH_LOG("Did not reject NULL filter!");
2121 }
2122
2123 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2124 EXPECT_EQ(0, errno) {
2125 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2126 strerror(errno));
2127 }
2128 }
2129
TEST(seccomp_syscall_mode_lock)2130 TEST(seccomp_syscall_mode_lock)
2131 {
2132 struct sock_filter filter[] = {
2133 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2134 };
2135 struct sock_fprog prog = {
2136 .len = (unsigned short)ARRAY_SIZE(filter),
2137 .filter = filter,
2138 };
2139 long ret;
2140
2141 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2142 ASSERT_EQ(0, ret) {
2143 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2144 }
2145
2146 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2147 ASSERT_NE(ENOSYS, errno) {
2148 TH_LOG("Kernel does not support seccomp syscall!");
2149 }
2150 EXPECT_EQ(0, ret) {
2151 TH_LOG("Could not install filter!");
2152 }
2153
2154 /* Make sure neither entry point will switch to strict. */
2155 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2156 EXPECT_EQ(EINVAL, errno) {
2157 TH_LOG("Switched to mode strict!");
2158 }
2159
2160 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2161 EXPECT_EQ(EINVAL, errno) {
2162 TH_LOG("Switched to mode strict!");
2163 }
2164 }
2165
2166 /*
2167 * Test detection of known and unknown filter flags. Userspace needs to be able
2168 * to check if a filter flag is supported by the current kernel and a good way
2169 * of doing that is by attempting to enter filter mode, with the flag bit in
2170 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2171 * that the flag is valid and EINVAL indicates that the flag is invalid.
2172 */
TEST(detect_seccomp_filter_flags)2173 TEST(detect_seccomp_filter_flags)
2174 {
2175 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2176 SECCOMP_FILTER_FLAG_LOG,
2177 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2178 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2179 unsigned int exclusive[] = {
2180 SECCOMP_FILTER_FLAG_TSYNC,
2181 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2182 unsigned int flag, all_flags, exclusive_mask;
2183 int i;
2184 long ret;
2185
2186 /* Test detection of individual known-good filter flags */
2187 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2188 int bits = 0;
2189
2190 flag = flags[i];
2191 /* Make sure the flag is a single bit! */
2192 while (flag) {
2193 if (flag & 0x1)
2194 bits ++;
2195 flag >>= 1;
2196 }
2197 ASSERT_EQ(1, bits);
2198 flag = flags[i];
2199
2200 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2201 ASSERT_NE(ENOSYS, errno) {
2202 TH_LOG("Kernel does not support seccomp syscall!");
2203 }
2204 EXPECT_EQ(-1, ret);
2205 EXPECT_EQ(EFAULT, errno) {
2206 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2207 flag);
2208 }
2209
2210 all_flags |= flag;
2211 }
2212
2213 /*
2214 * Test detection of all known-good filter flags combined. But
2215 * for the exclusive flags we need to mask them out and try them
2216 * individually for the "all flags" testing.
2217 */
2218 exclusive_mask = 0;
2219 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2220 exclusive_mask |= exclusive[i];
2221 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2222 flag = all_flags & ~exclusive_mask;
2223 flag |= exclusive[i];
2224
2225 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2226 EXPECT_EQ(-1, ret);
2227 EXPECT_EQ(EFAULT, errno) {
2228 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2229 flag);
2230 }
2231 }
2232
2233 /* Test detection of an unknown filter flags, without exclusives. */
2234 flag = -1;
2235 flag &= ~exclusive_mask;
2236 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2237 EXPECT_EQ(-1, ret);
2238 EXPECT_EQ(EINVAL, errno) {
2239 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2240 flag);
2241 }
2242
2243 /*
2244 * Test detection of an unknown filter flag that may simply need to be
2245 * added to this test
2246 */
2247 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2248 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2249 EXPECT_EQ(-1, ret);
2250 EXPECT_EQ(EINVAL, errno) {
2251 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
2252 flag);
2253 }
2254 }
2255
TEST(TSYNC_first)2256 TEST(TSYNC_first)
2257 {
2258 struct sock_filter filter[] = {
2259 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2260 };
2261 struct sock_fprog prog = {
2262 .len = (unsigned short)ARRAY_SIZE(filter),
2263 .filter = filter,
2264 };
2265 long ret;
2266
2267 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2268 ASSERT_EQ(0, ret) {
2269 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2270 }
2271
2272 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2273 &prog);
2274 ASSERT_NE(ENOSYS, errno) {
2275 TH_LOG("Kernel does not support seccomp syscall!");
2276 }
2277 EXPECT_EQ(0, ret) {
2278 TH_LOG("Could not install initial filter with TSYNC!");
2279 }
2280 }
2281
2282 #define TSYNC_SIBLINGS 2
2283 struct tsync_sibling {
2284 pthread_t tid;
2285 pid_t system_tid;
2286 sem_t *started;
2287 pthread_cond_t *cond;
2288 pthread_mutex_t *mutex;
2289 int diverge;
2290 int num_waits;
2291 struct sock_fprog *prog;
2292 struct __test_metadata *metadata;
2293 };
2294
2295 /*
2296 * To avoid joining joined threads (which is not allowed by Bionic),
2297 * make sure we both successfully join and clear the tid to skip a
2298 * later join attempt during fixture teardown. Any remaining threads
2299 * will be directly killed during teardown.
2300 */
2301 #define PTHREAD_JOIN(tid, status) \
2302 do { \
2303 int _rc = pthread_join(tid, status); \
2304 if (_rc) { \
2305 TH_LOG("pthread_join of tid %u failed: %d\n", \
2306 (unsigned int)tid, _rc); \
2307 } else { \
2308 tid = 0; \
2309 } \
2310 } while (0)
2311
FIXTURE_DATA(TSYNC)2312 FIXTURE_DATA(TSYNC) {
2313 struct sock_fprog root_prog, apply_prog;
2314 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2315 sem_t started;
2316 pthread_cond_t cond;
2317 pthread_mutex_t mutex;
2318 int sibling_count;
2319 };
2320
FIXTURE_SETUP(TSYNC)2321 FIXTURE_SETUP(TSYNC)
2322 {
2323 struct sock_filter root_filter[] = {
2324 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2325 };
2326 struct sock_filter apply_filter[] = {
2327 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2328 offsetof(struct seccomp_data, nr)),
2329 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2330 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2331 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2332 };
2333
2334 memset(&self->root_prog, 0, sizeof(self->root_prog));
2335 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2336 memset(&self->sibling, 0, sizeof(self->sibling));
2337 self->root_prog.filter = malloc(sizeof(root_filter));
2338 ASSERT_NE(NULL, self->root_prog.filter);
2339 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2340 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2341
2342 self->apply_prog.filter = malloc(sizeof(apply_filter));
2343 ASSERT_NE(NULL, self->apply_prog.filter);
2344 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2345 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2346
2347 self->sibling_count = 0;
2348 pthread_mutex_init(&self->mutex, NULL);
2349 pthread_cond_init(&self->cond, NULL);
2350 sem_init(&self->started, 0, 0);
2351 self->sibling[0].tid = 0;
2352 self->sibling[0].cond = &self->cond;
2353 self->sibling[0].started = &self->started;
2354 self->sibling[0].mutex = &self->mutex;
2355 self->sibling[0].diverge = 0;
2356 self->sibling[0].num_waits = 1;
2357 self->sibling[0].prog = &self->root_prog;
2358 self->sibling[0].metadata = _metadata;
2359 self->sibling[1].tid = 0;
2360 self->sibling[1].cond = &self->cond;
2361 self->sibling[1].started = &self->started;
2362 self->sibling[1].mutex = &self->mutex;
2363 self->sibling[1].diverge = 0;
2364 self->sibling[1].prog = &self->root_prog;
2365 self->sibling[1].num_waits = 1;
2366 self->sibling[1].metadata = _metadata;
2367 }
2368
FIXTURE_TEARDOWN(TSYNC)2369 FIXTURE_TEARDOWN(TSYNC)
2370 {
2371 int sib = 0;
2372
2373 if (self->root_prog.filter)
2374 free(self->root_prog.filter);
2375 if (self->apply_prog.filter)
2376 free(self->apply_prog.filter);
2377
2378 for ( ; sib < self->sibling_count; ++sib) {
2379 struct tsync_sibling *s = &self->sibling[sib];
2380
2381 if (!s->tid)
2382 continue;
2383 /*
2384 * If a thread is still running, it may be stuck, so hit
2385 * it over the head really hard.
2386 */
2387 pthread_kill(s->tid, 9);
2388 }
2389 pthread_mutex_destroy(&self->mutex);
2390 pthread_cond_destroy(&self->cond);
2391 sem_destroy(&self->started);
2392 }
2393
tsync_sibling(void * data)2394 void *tsync_sibling(void *data)
2395 {
2396 long ret = 0;
2397 struct tsync_sibling *me = data;
2398
2399 me->system_tid = syscall(__NR_gettid);
2400
2401 pthread_mutex_lock(me->mutex);
2402 if (me->diverge) {
2403 /* Just re-apply the root prog to fork the tree */
2404 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2405 me->prog, 0, 0);
2406 }
2407 sem_post(me->started);
2408 /* Return outside of started so parent notices failures. */
2409 if (ret) {
2410 pthread_mutex_unlock(me->mutex);
2411 return (void *)SIBLING_EXIT_FAILURE;
2412 }
2413 do {
2414 pthread_cond_wait(me->cond, me->mutex);
2415 me->num_waits = me->num_waits - 1;
2416 } while (me->num_waits);
2417 pthread_mutex_unlock(me->mutex);
2418
2419 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2420 if (!ret)
2421 return (void *)SIBLING_EXIT_NEWPRIVS;
2422 read(0, NULL, 0);
2423 return (void *)SIBLING_EXIT_UNKILLED;
2424 }
2425
tsync_start_sibling(struct tsync_sibling * sibling)2426 void tsync_start_sibling(struct tsync_sibling *sibling)
2427 {
2428 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2429 }
2430
TEST_F(TSYNC,siblings_fail_prctl)2431 TEST_F(TSYNC, siblings_fail_prctl)
2432 {
2433 long ret;
2434 void *status;
2435 struct sock_filter filter[] = {
2436 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2437 offsetof(struct seccomp_data, nr)),
2438 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2439 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2440 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2441 };
2442 struct sock_fprog prog = {
2443 .len = (unsigned short)ARRAY_SIZE(filter),
2444 .filter = filter,
2445 };
2446
2447 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2448 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2449 }
2450
2451 /* Check prctl failure detection by requesting sib 0 diverge. */
2452 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2453 ASSERT_NE(ENOSYS, errno) {
2454 TH_LOG("Kernel does not support seccomp syscall!");
2455 }
2456 ASSERT_EQ(0, ret) {
2457 TH_LOG("setting filter failed");
2458 }
2459
2460 self->sibling[0].diverge = 1;
2461 tsync_start_sibling(&self->sibling[0]);
2462 tsync_start_sibling(&self->sibling[1]);
2463
2464 while (self->sibling_count < TSYNC_SIBLINGS) {
2465 sem_wait(&self->started);
2466 self->sibling_count++;
2467 }
2468
2469 /* Signal the threads to clean up*/
2470 pthread_mutex_lock(&self->mutex);
2471 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2472 TH_LOG("cond broadcast non-zero");
2473 }
2474 pthread_mutex_unlock(&self->mutex);
2475
2476 /* Ensure diverging sibling failed to call prctl. */
2477 PTHREAD_JOIN(self->sibling[0].tid, &status);
2478 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2479 PTHREAD_JOIN(self->sibling[1].tid, &status);
2480 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2481 }
2482
TEST_F(TSYNC,two_siblings_with_ancestor)2483 TEST_F(TSYNC, two_siblings_with_ancestor)
2484 {
2485 long ret;
2486 void *status;
2487
2488 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2489 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2490 }
2491
2492 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2493 ASSERT_NE(ENOSYS, errno) {
2494 TH_LOG("Kernel does not support seccomp syscall!");
2495 }
2496 ASSERT_EQ(0, ret) {
2497 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2498 }
2499 tsync_start_sibling(&self->sibling[0]);
2500 tsync_start_sibling(&self->sibling[1]);
2501
2502 while (self->sibling_count < TSYNC_SIBLINGS) {
2503 sem_wait(&self->started);
2504 self->sibling_count++;
2505 }
2506
2507 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2508 &self->apply_prog);
2509 ASSERT_EQ(0, ret) {
2510 TH_LOG("Could install filter on all threads!");
2511 }
2512 /* Tell the siblings to test the policy */
2513 pthread_mutex_lock(&self->mutex);
2514 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2515 TH_LOG("cond broadcast non-zero");
2516 }
2517 pthread_mutex_unlock(&self->mutex);
2518 /* Ensure they are both killed and don't exit cleanly. */
2519 PTHREAD_JOIN(self->sibling[0].tid, &status);
2520 EXPECT_EQ(0x0, (long)status);
2521 PTHREAD_JOIN(self->sibling[1].tid, &status);
2522 EXPECT_EQ(0x0, (long)status);
2523 }
2524
TEST_F(TSYNC,two_sibling_want_nnp)2525 TEST_F(TSYNC, two_sibling_want_nnp)
2526 {
2527 void *status;
2528
2529 /* start siblings before any prctl() operations */
2530 tsync_start_sibling(&self->sibling[0]);
2531 tsync_start_sibling(&self->sibling[1]);
2532 while (self->sibling_count < TSYNC_SIBLINGS) {
2533 sem_wait(&self->started);
2534 self->sibling_count++;
2535 }
2536
2537 /* Tell the siblings to test no policy */
2538 pthread_mutex_lock(&self->mutex);
2539 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2540 TH_LOG("cond broadcast non-zero");
2541 }
2542 pthread_mutex_unlock(&self->mutex);
2543
2544 /* Ensure they are both upset about lacking nnp. */
2545 PTHREAD_JOIN(self->sibling[0].tid, &status);
2546 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2547 PTHREAD_JOIN(self->sibling[1].tid, &status);
2548 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2549 }
2550
TEST_F(TSYNC,two_siblings_with_no_filter)2551 TEST_F(TSYNC, two_siblings_with_no_filter)
2552 {
2553 long ret;
2554 void *status;
2555
2556 /* start siblings before any prctl() operations */
2557 tsync_start_sibling(&self->sibling[0]);
2558 tsync_start_sibling(&self->sibling[1]);
2559 while (self->sibling_count < TSYNC_SIBLINGS) {
2560 sem_wait(&self->started);
2561 self->sibling_count++;
2562 }
2563
2564 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2565 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2566 }
2567
2568 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2569 &self->apply_prog);
2570 ASSERT_NE(ENOSYS, errno) {
2571 TH_LOG("Kernel does not support seccomp syscall!");
2572 }
2573 ASSERT_EQ(0, ret) {
2574 TH_LOG("Could install filter on all threads!");
2575 }
2576
2577 /* Tell the siblings to test the policy */
2578 pthread_mutex_lock(&self->mutex);
2579 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2580 TH_LOG("cond broadcast non-zero");
2581 }
2582 pthread_mutex_unlock(&self->mutex);
2583
2584 /* Ensure they are both killed and don't exit cleanly. */
2585 PTHREAD_JOIN(self->sibling[0].tid, &status);
2586 EXPECT_EQ(0x0, (long)status);
2587 PTHREAD_JOIN(self->sibling[1].tid, &status);
2588 EXPECT_EQ(0x0, (long)status);
2589 }
2590
TEST_F(TSYNC,two_siblings_with_one_divergence)2591 TEST_F(TSYNC, two_siblings_with_one_divergence)
2592 {
2593 long ret;
2594 void *status;
2595
2596 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2597 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2598 }
2599
2600 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2601 ASSERT_NE(ENOSYS, errno) {
2602 TH_LOG("Kernel does not support seccomp syscall!");
2603 }
2604 ASSERT_EQ(0, ret) {
2605 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2606 }
2607 self->sibling[0].diverge = 1;
2608 tsync_start_sibling(&self->sibling[0]);
2609 tsync_start_sibling(&self->sibling[1]);
2610
2611 while (self->sibling_count < TSYNC_SIBLINGS) {
2612 sem_wait(&self->started);
2613 self->sibling_count++;
2614 }
2615
2616 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2617 &self->apply_prog);
2618 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2619 TH_LOG("Did not fail on diverged sibling.");
2620 }
2621
2622 /* Wake the threads */
2623 pthread_mutex_lock(&self->mutex);
2624 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2625 TH_LOG("cond broadcast non-zero");
2626 }
2627 pthread_mutex_unlock(&self->mutex);
2628
2629 /* Ensure they are both unkilled. */
2630 PTHREAD_JOIN(self->sibling[0].tid, &status);
2631 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2632 PTHREAD_JOIN(self->sibling[1].tid, &status);
2633 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2634 }
2635
TEST_F(TSYNC,two_siblings_not_under_filter)2636 TEST_F(TSYNC, two_siblings_not_under_filter)
2637 {
2638 long ret, sib;
2639 void *status;
2640 struct timespec delay = { .tv_nsec = 100000000 };
2641
2642 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2643 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2644 }
2645
2646 /*
2647 * Sibling 0 will have its own seccomp policy
2648 * and Sibling 1 will not be under seccomp at
2649 * all. Sibling 1 will enter seccomp and 0
2650 * will cause failure.
2651 */
2652 self->sibling[0].diverge = 1;
2653 tsync_start_sibling(&self->sibling[0]);
2654 tsync_start_sibling(&self->sibling[1]);
2655
2656 while (self->sibling_count < TSYNC_SIBLINGS) {
2657 sem_wait(&self->started);
2658 self->sibling_count++;
2659 }
2660
2661 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2662 ASSERT_NE(ENOSYS, errno) {
2663 TH_LOG("Kernel does not support seccomp syscall!");
2664 }
2665 ASSERT_EQ(0, ret) {
2666 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2667 }
2668
2669 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2670 &self->apply_prog);
2671 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2672 TH_LOG("Did not fail on diverged sibling.");
2673 }
2674 sib = 1;
2675 if (ret == self->sibling[0].system_tid)
2676 sib = 0;
2677
2678 pthread_mutex_lock(&self->mutex);
2679
2680 /* Increment the other siblings num_waits so we can clean up
2681 * the one we just saw.
2682 */
2683 self->sibling[!sib].num_waits += 1;
2684
2685 /* Signal the thread to clean up*/
2686 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2687 TH_LOG("cond broadcast non-zero");
2688 }
2689 pthread_mutex_unlock(&self->mutex);
2690 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2691 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2692 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2693 while (!kill(self->sibling[sib].system_tid, 0))
2694 nanosleep(&delay, NULL);
2695 /* Switch to the remaining sibling */
2696 sib = !sib;
2697
2698 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2699 &self->apply_prog);
2700 ASSERT_EQ(0, ret) {
2701 TH_LOG("Expected the remaining sibling to sync");
2702 };
2703
2704 pthread_mutex_lock(&self->mutex);
2705
2706 /* If remaining sibling didn't have a chance to wake up during
2707 * the first broadcast, manually reduce the num_waits now.
2708 */
2709 if (self->sibling[sib].num_waits > 1)
2710 self->sibling[sib].num_waits = 1;
2711 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2712 TH_LOG("cond broadcast non-zero");
2713 }
2714 pthread_mutex_unlock(&self->mutex);
2715 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2716 EXPECT_EQ(0, (long)status);
2717 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2718 while (!kill(self->sibling[sib].system_tid, 0))
2719 nanosleep(&delay, NULL);
2720
2721 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2722 &self->apply_prog);
2723 ASSERT_EQ(0, ret); /* just us chickens */
2724 }
2725
2726 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)2727 TEST(syscall_restart)
2728 {
2729 long ret;
2730 unsigned long msg;
2731 pid_t child_pid;
2732 int pipefd[2];
2733 int status;
2734 siginfo_t info = { };
2735 struct sock_filter filter[] = {
2736 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2737 offsetof(struct seccomp_data, nr)),
2738
2739 #ifdef __NR_sigreturn
2740 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2741 #endif
2742 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2743 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2744 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2745 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2746 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2747
2748 /* Allow __NR_write for easy logging. */
2749 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2750 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2751 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2752 /* The nanosleep jump target. */
2753 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2754 /* The restart_syscall jump target. */
2755 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2756 };
2757 struct sock_fprog prog = {
2758 .len = (unsigned short)ARRAY_SIZE(filter),
2759 .filter = filter,
2760 };
2761 #if defined(__arm__)
2762 struct utsname utsbuf;
2763 #endif
2764
2765 ASSERT_EQ(0, pipe(pipefd));
2766
2767 child_pid = fork();
2768 ASSERT_LE(0, child_pid);
2769 if (child_pid == 0) {
2770 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2771 char buf = ' ';
2772 struct timespec timeout = { };
2773
2774 /* Attach parent as tracer and stop. */
2775 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2776 EXPECT_EQ(0, raise(SIGSTOP));
2777
2778 EXPECT_EQ(0, close(pipefd[1]));
2779
2780 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2781 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2782 }
2783
2784 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2785 EXPECT_EQ(0, ret) {
2786 TH_LOG("Failed to install filter!");
2787 }
2788
2789 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2790 TH_LOG("Failed to read() sync from parent");
2791 }
2792 EXPECT_EQ('.', buf) {
2793 TH_LOG("Failed to get sync data from read()");
2794 }
2795
2796 /* Start nanosleep to be interrupted. */
2797 timeout.tv_sec = 1;
2798 errno = 0;
2799 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2800 TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2801 }
2802
2803 /* Read final sync from parent. */
2804 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2805 TH_LOG("Failed final read() from parent");
2806 }
2807 EXPECT_EQ('!', buf) {
2808 TH_LOG("Failed to get final data from read()");
2809 }
2810
2811 /* Directly report the status of our test harness results. */
2812 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2813 : EXIT_FAILURE);
2814 }
2815 EXPECT_EQ(0, close(pipefd[0]));
2816
2817 /* Attach to child, setup options, and release. */
2818 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2819 ASSERT_EQ(true, WIFSTOPPED(status));
2820 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2821 PTRACE_O_TRACESECCOMP));
2822 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2823 ASSERT_EQ(1, write(pipefd[1], ".", 1));
2824
2825 /* Wait for nanosleep() to start. */
2826 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2827 ASSERT_EQ(true, WIFSTOPPED(status));
2828 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2829 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2830 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2831 ASSERT_EQ(0x100, msg);
2832 EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2833
2834 /* Might as well check siginfo for sanity while we're here. */
2835 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2836 ASSERT_EQ(SIGTRAP, info.si_signo);
2837 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2838 EXPECT_EQ(0, info.si_errno);
2839 EXPECT_EQ(getuid(), info.si_uid);
2840 /* Verify signal delivery came from child (seccomp-triggered). */
2841 EXPECT_EQ(child_pid, info.si_pid);
2842
2843 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2844 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2845 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2846 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2847 ASSERT_EQ(true, WIFSTOPPED(status));
2848 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2849 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2850 /*
2851 * There is no siginfo on SIGSTOP any more, so we can't verify
2852 * signal delivery came from parent now (getpid() == info.si_pid).
2853 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
2854 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
2855 */
2856 EXPECT_EQ(SIGSTOP, info.si_signo);
2857
2858 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2859 ASSERT_EQ(0, kill(child_pid, SIGCONT));
2860 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2861 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2862 ASSERT_EQ(true, WIFSTOPPED(status));
2863 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2864 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2865
2866 /* Wait for restart_syscall() to start. */
2867 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2868 ASSERT_EQ(true, WIFSTOPPED(status));
2869 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2870 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2871 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2872
2873 ASSERT_EQ(0x200, msg);
2874 ret = get_syscall(_metadata, child_pid);
2875 #if defined(__arm__)
2876 /*
2877 * FIXME:
2878 * - native ARM registers do NOT expose true syscall.
2879 * - compat ARM registers on ARM64 DO expose true syscall.
2880 */
2881 ASSERT_EQ(0, uname(&utsbuf));
2882 if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2883 EXPECT_EQ(__NR_nanosleep, ret);
2884 } else
2885 #endif
2886 {
2887 EXPECT_EQ(__NR_restart_syscall, ret);
2888 }
2889
2890 /* Write again to end test. */
2891 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2892 ASSERT_EQ(1, write(pipefd[1], "!", 1));
2893 EXPECT_EQ(0, close(pipefd[1]));
2894
2895 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2896 if (WIFSIGNALED(status) || WEXITSTATUS(status))
2897 _metadata->passed = 0;
2898 }
2899
TEST_SIGNAL(filter_flag_log,SIGSYS)2900 TEST_SIGNAL(filter_flag_log, SIGSYS)
2901 {
2902 struct sock_filter allow_filter[] = {
2903 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2904 };
2905 struct sock_filter kill_filter[] = {
2906 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2907 offsetof(struct seccomp_data, nr)),
2908 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2909 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2910 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2911 };
2912 struct sock_fprog allow_prog = {
2913 .len = (unsigned short)ARRAY_SIZE(allow_filter),
2914 .filter = allow_filter,
2915 };
2916 struct sock_fprog kill_prog = {
2917 .len = (unsigned short)ARRAY_SIZE(kill_filter),
2918 .filter = kill_filter,
2919 };
2920 long ret;
2921 pid_t parent = getppid();
2922
2923 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2924 ASSERT_EQ(0, ret);
2925
2926 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
2927 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
2928 &allow_prog);
2929 ASSERT_NE(ENOSYS, errno) {
2930 TH_LOG("Kernel does not support seccomp syscall!");
2931 }
2932 EXPECT_NE(0, ret) {
2933 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
2934 }
2935 EXPECT_EQ(EINVAL, errno) {
2936 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
2937 }
2938
2939 /* Verify that a simple, permissive filter can be added with no flags */
2940 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
2941 EXPECT_EQ(0, ret);
2942
2943 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
2944 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2945 &allow_prog);
2946 ASSERT_NE(EINVAL, errno) {
2947 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
2948 }
2949 EXPECT_EQ(0, ret);
2950
2951 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
2952 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2953 &kill_prog);
2954 EXPECT_EQ(0, ret);
2955
2956 EXPECT_EQ(parent, syscall(__NR_getppid));
2957 /* getpid() should never return. */
2958 EXPECT_EQ(0, syscall(__NR_getpid));
2959 }
2960
TEST(get_action_avail)2961 TEST(get_action_avail)
2962 {
2963 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
2964 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
2965 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
2966 __u32 unknown_action = 0x10000000U;
2967 int i;
2968 long ret;
2969
2970 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
2971 ASSERT_NE(ENOSYS, errno) {
2972 TH_LOG("Kernel does not support seccomp syscall!");
2973 }
2974 ASSERT_NE(EINVAL, errno) {
2975 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
2976 }
2977 EXPECT_EQ(ret, 0);
2978
2979 for (i = 0; i < ARRAY_SIZE(actions); i++) {
2980 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
2981 EXPECT_EQ(ret, 0) {
2982 TH_LOG("Expected action (0x%X) not available!",
2983 actions[i]);
2984 }
2985 }
2986
2987 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
2988 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
2989 EXPECT_EQ(ret, -1);
2990 EXPECT_EQ(errno, EOPNOTSUPP);
2991 }
2992
TEST(get_metadata)2993 TEST(get_metadata)
2994 {
2995 pid_t pid;
2996 int pipefd[2];
2997 char buf;
2998 struct seccomp_metadata md;
2999 long ret;
3000
3001 /* Only real root can get metadata. */
3002 if (geteuid()) {
3003 XFAIL(return, "get_metadata requires real root");
3004 return;
3005 }
3006
3007 ASSERT_EQ(0, pipe(pipefd));
3008
3009 pid = fork();
3010 ASSERT_GE(pid, 0);
3011 if (pid == 0) {
3012 struct sock_filter filter[] = {
3013 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3014 };
3015 struct sock_fprog prog = {
3016 .len = (unsigned short)ARRAY_SIZE(filter),
3017 .filter = filter,
3018 };
3019
3020 /* one with log, one without */
3021 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3022 SECCOMP_FILTER_FLAG_LOG, &prog));
3023 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3024
3025 EXPECT_EQ(0, close(pipefd[0]));
3026 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3027 ASSERT_EQ(0, close(pipefd[1]));
3028
3029 while (1)
3030 sleep(100);
3031 }
3032
3033 ASSERT_EQ(0, close(pipefd[1]));
3034 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3035
3036 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3037 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3038
3039 /* Past here must not use ASSERT or child process is never killed. */
3040
3041 md.filter_off = 0;
3042 errno = 0;
3043 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3044 EXPECT_EQ(sizeof(md), ret) {
3045 if (errno == EINVAL)
3046 XFAIL(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3047 }
3048
3049 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3050 EXPECT_EQ(md.filter_off, 0);
3051
3052 md.filter_off = 1;
3053 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3054 EXPECT_EQ(sizeof(md), ret);
3055 EXPECT_EQ(md.flags, 0);
3056 EXPECT_EQ(md.filter_off, 1);
3057
3058 skip:
3059 ASSERT_EQ(0, kill(pid, SIGKILL));
3060 }
3061
user_trap_syscall(int nr,unsigned int flags)3062 static int user_trap_syscall(int nr, unsigned int flags)
3063 {
3064 struct sock_filter filter[] = {
3065 BPF_STMT(BPF_LD+BPF_W+BPF_ABS,
3066 offsetof(struct seccomp_data, nr)),
3067 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, nr, 0, 1),
3068 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_USER_NOTIF),
3069 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
3070 };
3071
3072 struct sock_fprog prog = {
3073 .len = (unsigned short)ARRAY_SIZE(filter),
3074 .filter = filter,
3075 };
3076
3077 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3078 }
3079
3080 #define USER_NOTIF_MAGIC 116983961184613L
TEST(user_notification_basic)3081 TEST(user_notification_basic)
3082 {
3083 pid_t pid;
3084 long ret;
3085 int status, listener;
3086 struct seccomp_notif req = {};
3087 struct seccomp_notif_resp resp = {};
3088 struct pollfd pollfd;
3089
3090 struct sock_filter filter[] = {
3091 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3092 };
3093 struct sock_fprog prog = {
3094 .len = (unsigned short)ARRAY_SIZE(filter),
3095 .filter = filter,
3096 };
3097
3098 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3099 ASSERT_EQ(0, ret) {
3100 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3101 }
3102
3103 pid = fork();
3104 ASSERT_GE(pid, 0);
3105
3106 /* Check that we get -ENOSYS with no listener attached */
3107 if (pid == 0) {
3108 if (user_trap_syscall(__NR_getppid, 0) < 0)
3109 exit(1);
3110 ret = syscall(__NR_getppid);
3111 exit(ret >= 0 || errno != ENOSYS);
3112 }
3113
3114 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3115 EXPECT_EQ(true, WIFEXITED(status));
3116 EXPECT_EQ(0, WEXITSTATUS(status));
3117
3118 /* Add some no-op filters for grins. */
3119 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3120 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3121 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3122 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3123
3124 /* Check that the basic notification machinery works */
3125 listener = user_trap_syscall(__NR_getppid,
3126 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3127 ASSERT_GE(listener, 0);
3128
3129 /* Installing a second listener in the chain should EBUSY */
3130 EXPECT_EQ(user_trap_syscall(__NR_getppid,
3131 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3132 -1);
3133 EXPECT_EQ(errno, EBUSY);
3134
3135 pid = fork();
3136 ASSERT_GE(pid, 0);
3137
3138 if (pid == 0) {
3139 ret = syscall(__NR_getppid);
3140 exit(ret != USER_NOTIF_MAGIC);
3141 }
3142
3143 pollfd.fd = listener;
3144 pollfd.events = POLLIN | POLLOUT;
3145
3146 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3147 EXPECT_EQ(pollfd.revents, POLLIN);
3148
3149 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3150
3151 pollfd.fd = listener;
3152 pollfd.events = POLLIN | POLLOUT;
3153
3154 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3155 EXPECT_EQ(pollfd.revents, POLLOUT);
3156
3157 EXPECT_EQ(req.data.nr, __NR_getppid);
3158
3159 resp.id = req.id;
3160 resp.error = 0;
3161 resp.val = USER_NOTIF_MAGIC;
3162
3163 /* check that we make sure flags == 0 */
3164 resp.flags = 1;
3165 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3166 EXPECT_EQ(errno, EINVAL);
3167
3168 resp.flags = 0;
3169 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3170
3171 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3172 EXPECT_EQ(true, WIFEXITED(status));
3173 EXPECT_EQ(0, WEXITSTATUS(status));
3174 }
3175
TEST(user_notification_kill_in_middle)3176 TEST(user_notification_kill_in_middle)
3177 {
3178 pid_t pid;
3179 long ret;
3180 int listener;
3181 struct seccomp_notif req = {};
3182 struct seccomp_notif_resp resp = {};
3183
3184 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3185 ASSERT_EQ(0, ret) {
3186 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3187 }
3188
3189 listener = user_trap_syscall(__NR_getppid,
3190 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3191 ASSERT_GE(listener, 0);
3192
3193 /*
3194 * Check that nothing bad happens when we kill the task in the middle
3195 * of a syscall.
3196 */
3197 pid = fork();
3198 ASSERT_GE(pid, 0);
3199
3200 if (pid == 0) {
3201 ret = syscall(__NR_getppid);
3202 exit(ret != USER_NOTIF_MAGIC);
3203 }
3204
3205 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3206 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3207
3208 EXPECT_EQ(kill(pid, SIGKILL), 0);
3209 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3210
3211 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3212
3213 resp.id = req.id;
3214 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3215 EXPECT_EQ(ret, -1);
3216 EXPECT_EQ(errno, ENOENT);
3217 }
3218
3219 static int handled = -1;
3220
signal_handler(int signal)3221 static void signal_handler(int signal)
3222 {
3223 if (write(handled, "c", 1) != 1)
3224 perror("write from signal");
3225 }
3226
TEST(user_notification_signal)3227 TEST(user_notification_signal)
3228 {
3229 pid_t pid;
3230 long ret;
3231 int status, listener, sk_pair[2];
3232 struct seccomp_notif req = {};
3233 struct seccomp_notif_resp resp = {};
3234 char c;
3235
3236 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3237 ASSERT_EQ(0, ret) {
3238 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3239 }
3240
3241 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3242
3243 listener = user_trap_syscall(__NR_gettid,
3244 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3245 ASSERT_GE(listener, 0);
3246
3247 pid = fork();
3248 ASSERT_GE(pid, 0);
3249
3250 if (pid == 0) {
3251 close(sk_pair[0]);
3252 handled = sk_pair[1];
3253 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3254 perror("signal");
3255 exit(1);
3256 }
3257 /*
3258 * ERESTARTSYS behavior is a bit hard to test, because we need
3259 * to rely on a signal that has not yet been handled. Let's at
3260 * least check that the error code gets propagated through, and
3261 * hope that it doesn't break when there is actually a signal :)
3262 */
3263 ret = syscall(__NR_gettid);
3264 exit(!(ret == -1 && errno == 512));
3265 }
3266
3267 close(sk_pair[1]);
3268
3269 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3270
3271 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3272
3273 /*
3274 * Make sure the signal really is delivered, which means we're not
3275 * stuck in the user notification code any more and the notification
3276 * should be dead.
3277 */
3278 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3279
3280 resp.id = req.id;
3281 resp.error = -EPERM;
3282 resp.val = 0;
3283
3284 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3285 EXPECT_EQ(errno, ENOENT);
3286
3287 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3288
3289 resp.id = req.id;
3290 resp.error = -512; /* -ERESTARTSYS */
3291 resp.val = 0;
3292
3293 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3294
3295 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3296 EXPECT_EQ(true, WIFEXITED(status));
3297 EXPECT_EQ(0, WEXITSTATUS(status));
3298 }
3299
TEST(user_notification_closed_listener)3300 TEST(user_notification_closed_listener)
3301 {
3302 pid_t pid;
3303 long ret;
3304 int status, listener;
3305
3306 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3307 ASSERT_EQ(0, ret) {
3308 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3309 }
3310
3311 listener = user_trap_syscall(__NR_getppid,
3312 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3313 ASSERT_GE(listener, 0);
3314
3315 /*
3316 * Check that we get an ENOSYS when the listener is closed.
3317 */
3318 pid = fork();
3319 ASSERT_GE(pid, 0);
3320 if (pid == 0) {
3321 close(listener);
3322 ret = syscall(__NR_getppid);
3323 exit(ret != -1 && errno != ENOSYS);
3324 }
3325
3326 close(listener);
3327
3328 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3329 EXPECT_EQ(true, WIFEXITED(status));
3330 EXPECT_EQ(0, WEXITSTATUS(status));
3331 }
3332
3333 /*
3334 * Check that a pid in a child namespace still shows up as valid in ours.
3335 */
TEST(user_notification_child_pid_ns)3336 TEST(user_notification_child_pid_ns)
3337 {
3338 pid_t pid;
3339 int status, listener;
3340 struct seccomp_notif req = {};
3341 struct seccomp_notif_resp resp = {};
3342
3343 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0);
3344
3345 listener = user_trap_syscall(__NR_getppid,
3346 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3347 ASSERT_GE(listener, 0);
3348
3349 pid = fork();
3350 ASSERT_GE(pid, 0);
3351
3352 if (pid == 0)
3353 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3354
3355 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3356 EXPECT_EQ(req.pid, pid);
3357
3358 resp.id = req.id;
3359 resp.error = 0;
3360 resp.val = USER_NOTIF_MAGIC;
3361
3362 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3363
3364 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3365 EXPECT_EQ(true, WIFEXITED(status));
3366 EXPECT_EQ(0, WEXITSTATUS(status));
3367 close(listener);
3368 }
3369
3370 /*
3371 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3372 * invalid.
3373 */
TEST(user_notification_sibling_pid_ns)3374 TEST(user_notification_sibling_pid_ns)
3375 {
3376 pid_t pid, pid2;
3377 int status, listener;
3378 struct seccomp_notif req = {};
3379 struct seccomp_notif_resp resp = {};
3380
3381 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3382 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3383 }
3384
3385 listener = user_trap_syscall(__NR_getppid,
3386 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3387 ASSERT_GE(listener, 0);
3388
3389 pid = fork();
3390 ASSERT_GE(pid, 0);
3391
3392 if (pid == 0) {
3393 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3394
3395 pid2 = fork();
3396 ASSERT_GE(pid2, 0);
3397
3398 if (pid2 == 0)
3399 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3400
3401 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3402 EXPECT_EQ(true, WIFEXITED(status));
3403 EXPECT_EQ(0, WEXITSTATUS(status));
3404 exit(WEXITSTATUS(status));
3405 }
3406
3407 /* Create the sibling ns, and sibling in it. */
3408 ASSERT_EQ(unshare(CLONE_NEWPID), 0);
3409 ASSERT_EQ(errno, 0);
3410
3411 pid2 = fork();
3412 ASSERT_GE(pid2, 0);
3413
3414 if (pid2 == 0) {
3415 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3416 /*
3417 * The pid should be 0, i.e. the task is in some namespace that
3418 * we can't "see".
3419 */
3420 EXPECT_EQ(req.pid, 0);
3421
3422 resp.id = req.id;
3423 resp.error = 0;
3424 resp.val = USER_NOTIF_MAGIC;
3425
3426 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3427 exit(0);
3428 }
3429
3430 close(listener);
3431
3432 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3433 EXPECT_EQ(true, WIFEXITED(status));
3434 EXPECT_EQ(0, WEXITSTATUS(status));
3435
3436 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3437 EXPECT_EQ(true, WIFEXITED(status));
3438 EXPECT_EQ(0, WEXITSTATUS(status));
3439 }
3440
TEST(user_notification_fault_recv)3441 TEST(user_notification_fault_recv)
3442 {
3443 pid_t pid;
3444 int status, listener;
3445 struct seccomp_notif req = {};
3446 struct seccomp_notif_resp resp = {};
3447
3448 ASSERT_EQ(unshare(CLONE_NEWUSER), 0);
3449
3450 listener = user_trap_syscall(__NR_getppid,
3451 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3452 ASSERT_GE(listener, 0);
3453
3454 pid = fork();
3455 ASSERT_GE(pid, 0);
3456
3457 if (pid == 0)
3458 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3459
3460 /* Do a bad recv() */
3461 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3462 EXPECT_EQ(errno, EFAULT);
3463
3464 /* We should still be able to receive this notification, though. */
3465 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3466 EXPECT_EQ(req.pid, pid);
3467
3468 resp.id = req.id;
3469 resp.error = 0;
3470 resp.val = USER_NOTIF_MAGIC;
3471
3472 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3473
3474 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3475 EXPECT_EQ(true, WIFEXITED(status));
3476 EXPECT_EQ(0, WEXITSTATUS(status));
3477 }
3478
TEST(seccomp_get_notif_sizes)3479 TEST(seccomp_get_notif_sizes)
3480 {
3481 struct seccomp_notif_sizes sizes;
3482
3483 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3484 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3485 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3486 }
3487
3488 /*
3489 * TODO:
3490 * - add microbenchmarks
3491 * - expand NNP testing
3492 * - better arch-specific TRACE and TRAP handlers.
3493 * - endianness checking when appropriate
3494 * - 64-bit arg prodding
3495 * - arch value testing (x86 modes especially)
3496 * - verify that FILTER_FLAG_LOG filters generate log messages
3497 * - verify that RET_LOG generates log messages
3498 * - ...
3499 */
3500
3501 TEST_HARNESS_MAIN
3502
