1
2
3#define _GNU_SOURCE
4#include <errno.h>
5#include <fcntl.h>
6#include <pthread.h>
7#include <sched.h>
8#include <stdbool.h>
9#include <stdio.h>
10#include <stdlib.h>
11#include <string.h>
12#include <sys/fsuid.h>
13#include <sys/ioctl.h>
14#include <sys/mount.h>
15#include <sys/socket.h>
16#include <sys/stat.h>
17#include <sys/sysinfo.h>
18#include <sys/types.h>
19#include <sys/wait.h>
20#include <unistd.h>
21#include <linux/android/binder.h>
22#include <linux/android/binderfs.h>
23
24#include "../../kselftest_harness.h"
25
26#define DEFAULT_THREADS 4
27
28#define PTR_TO_INT(p) ((int)((intptr_t)(p)))
29#define INT_TO_PTR(u) ((void *)((intptr_t)(u)))
30
31#define close_prot_errno_disarm(fd) \
32 if (fd >= 0) { \
33 int _e_ = errno; \
34 close(fd); \
35 errno = _e_; \
36 fd = -EBADF; \
37 }
38
39static void change_mountns(struct __test_metadata *_metadata)
40{
41 int ret;
42
43 ret = unshare(CLONE_NEWNS);
44 ASSERT_EQ(ret, 0) {
45 TH_LOG("%s - Failed to unshare mount namespace",
46 strerror(errno));
47 }
48
49 ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0);
50 ASSERT_EQ(ret, 0) {
51 TH_LOG("%s - Failed to mount / as private",
52 strerror(errno));
53 }
54}
55
56static int __do_binderfs_test(struct __test_metadata *_metadata)
57{
58 int fd, ret, saved_errno, result = 1;
59 size_t len;
60 ssize_t wret;
61 struct binderfs_device device = { 0 };
62 struct binder_version version = { 0 };
63 char binderfs_mntpt[] = P_tmpdir "/binderfs_XXXXXX",
64 device_path[sizeof(P_tmpdir "/binderfs_XXXXXX/") + BINDERFS_MAX_NAME];
65 static const char * const binder_features[] = {
66 "oneway_spam_detection",
67 };
68
69 change_mountns(_metadata);
70
71 EXPECT_NE(mkdtemp(binderfs_mntpt), NULL) {
72 TH_LOG("%s - Failed to create binderfs mountpoint",
73 strerror(errno));
74 goto out;
75 }
76
77 ret = mount(NULL, binderfs_mntpt, "binder", 0, 0);
78 EXPECT_EQ(ret, 0) {
79 if (errno == ENODEV)
80 SKIP(goto out, "binderfs missing");
81 TH_LOG("%s - Failed to mount binderfs", strerror(errno));
82 goto rmdir;
83 }
84
85
86
87 memcpy(device.name, "my-binder", strlen("my-binder"));
88
89 snprintf(device_path, sizeof(device_path), "%s/binder-control", binderfs_mntpt);
90 fd = open(device_path, O_RDONLY | O_CLOEXEC);
91 EXPECT_GE(fd, 0) {
92 TH_LOG("%s - Failed to open binder-control device",
93 strerror(errno));
94 goto umount;
95 }
96
97 ret = ioctl(fd, BINDER_CTL_ADD, &device);
98 saved_errno = errno;
99 close(fd);
100 errno = saved_errno;
101 EXPECT_GE(ret, 0) {
102 TH_LOG("%s - Failed to allocate new binder device",
103 strerror(errno));
104 goto umount;
105 }
106
107 TH_LOG("Allocated new binder device with major %d, minor %d, and name %s",
108 device.major, device.minor, device.name);
109
110
111
112 snprintf(device_path, sizeof(device_path), "%s/my-binder", binderfs_mntpt);
113 fd = open(device_path, O_CLOEXEC | O_RDONLY);
114 EXPECT_GE(fd, 0) {
115 TH_LOG("%s - Failed to open my-binder device",
116 strerror(errno));
117 goto umount;
118 }
119
120 ret = ioctl(fd, BINDER_VERSION, &version);
121 saved_errno = errno;
122 close(fd);
123 errno = saved_errno;
124 EXPECT_GE(ret, 0) {
125 TH_LOG("%s - Failed to open perform BINDER_VERSION request",
126 strerror(errno));
127 goto umount;
128 }
129
130 TH_LOG("Detected binder version: %d", version.protocol_version);
131
132
133
134 ret = unlink(device_path);
135 EXPECT_EQ(ret, 0) {
136 TH_LOG("%s - Failed to delete binder device",
137 strerror(errno));
138 goto umount;
139 }
140
141
142
143 snprintf(device_path, sizeof(device_path), "%s/binder-control", binderfs_mntpt);
144 ret = unlink(device_path);
145 EXPECT_NE(ret, 0) {
146 TH_LOG("Managed to delete binder-control device");
147 goto umount;
148 }
149 EXPECT_EQ(errno, EPERM) {
150 TH_LOG("%s - Failed to delete binder-control device but exited with unexpected error code",
151 strerror(errno));
152 goto umount;
153 }
154
155
156
157 for (int i = 0; i < ARRAY_SIZE(binder_features); i++) {
158 snprintf(device_path, sizeof(device_path), "%s/features/%s",
159 binderfs_mntpt, binder_features[i]);
160 fd = open(device_path, O_CLOEXEC | O_RDONLY);
161 EXPECT_GE(fd, 0) {
162 TH_LOG("%s - Failed to open binder feature: %s",
163 strerror(errno), binder_features[i]);
164 goto umount;
165 }
166 close(fd);
167 }
168
169
170 result = 0;
171
172umount:
173 ret = umount2(binderfs_mntpt, MNT_DETACH);
174 EXPECT_EQ(ret, 0) {
175 TH_LOG("%s - Failed to unmount binderfs", strerror(errno));
176 }
177rmdir:
178 ret = rmdir(binderfs_mntpt);
179 EXPECT_EQ(ret, 0) {
180 TH_LOG("%s - Failed to rmdir binderfs mount", strerror(errno));
181 }
182out:
183 return result;
184}
185
186static int wait_for_pid(pid_t pid)
187{
188 int status, ret;
189
190again:
191 ret = waitpid(pid, &status, 0);
192 if (ret == -1) {
193 if (errno == EINTR)
194 goto again;
195
196 return -1;
197 }
198
199 if (!WIFEXITED(status))
200 return -1;
201
202 return WEXITSTATUS(status);
203}
204
205static int setid_userns_root(void)
206{
207 if (setuid(0))
208 return -1;
209 if (setgid(0))
210 return -1;
211
212 setfsuid(0);
213 setfsgid(0);
214
215 return 0;
216}
217
218enum idmap_type {
219 UID_MAP,
220 GID_MAP,
221};
222
223static ssize_t read_nointr(int fd, void *buf, size_t count)
224{
225 ssize_t ret;
226again:
227 ret = read(fd, buf, count);
228 if (ret < 0 && errno == EINTR)
229 goto again;
230
231 return ret;
232}
233
234static ssize_t write_nointr(int fd, const void *buf, size_t count)
235{
236 ssize_t ret;
237again:
238 ret = write(fd, buf, count);
239 if (ret < 0 && errno == EINTR)
240 goto again;
241
242 return ret;
243}
244
245static int write_id_mapping(enum idmap_type type, pid_t pid, const char *buf,
246 size_t buf_size)
247{
248 int fd;
249 int ret;
250 char path[4096];
251
252 if (type == GID_MAP) {
253 int setgroups_fd;
254
255 snprintf(path, sizeof(path), "/proc/%d/setgroups", pid);
256 setgroups_fd = open(path, O_WRONLY | O_CLOEXEC | O_NOFOLLOW);
257 if (setgroups_fd < 0 && errno != ENOENT)
258 return -1;
259
260 if (setgroups_fd >= 0) {
261 ret = write_nointr(setgroups_fd, "deny", sizeof("deny") - 1);
262 close_prot_errno_disarm(setgroups_fd);
263 if (ret != sizeof("deny") - 1)
264 return -1;
265 }
266 }
267
268 switch (type) {
269 case UID_MAP:
270 ret = snprintf(path, sizeof(path), "/proc/%d/uid_map", pid);
271 break;
272 case GID_MAP:
273 ret = snprintf(path, sizeof(path), "/proc/%d/gid_map", pid);
274 break;
275 default:
276 return -1;
277 }
278 if (ret < 0 || ret >= sizeof(path))
279 return -E2BIG;
280
281 fd = open(path, O_WRONLY | O_CLOEXEC | O_NOFOLLOW);
282 if (fd < 0)
283 return -1;
284
285 ret = write_nointr(fd, buf, buf_size);
286 close_prot_errno_disarm(fd);
287 if (ret != buf_size)
288 return -1;
289
290 return 0;
291}
292
293static void change_userns(struct __test_metadata *_metadata, int syncfds[2])
294{
295 int ret;
296 char buf;
297
298 close_prot_errno_disarm(syncfds[1]);
299
300 ret = unshare(CLONE_NEWUSER);
301 ASSERT_EQ(ret, 0) {
302 TH_LOG("%s - Failed to unshare user namespace",
303 strerror(errno));
304 }
305
306 ret = write_nointr(syncfds[0], "1", 1);
307 ASSERT_EQ(ret, 1) {
308 TH_LOG("write_nointr() failed");
309 }
310
311 ret = read_nointr(syncfds[0], &buf, 1);
312 ASSERT_EQ(ret, 1) {
313 TH_LOG("read_nointr() failed");
314 }
315
316 close_prot_errno_disarm(syncfds[0]);
317
318 ASSERT_EQ(setid_userns_root(), 0) {
319 TH_LOG("setid_userns_root() failed");
320 }
321}
322
323static void change_idmaps(struct __test_metadata *_metadata, int syncfds[2], pid_t pid)
324{
325 int ret;
326 char buf;
327 char id_map[4096];
328
329 close_prot_errno_disarm(syncfds[0]);
330
331 ret = read_nointr(syncfds[1], &buf, 1);
332 ASSERT_EQ(ret, 1) {
333 TH_LOG("read_nointr() failed");
334 }
335
336 snprintf(id_map, sizeof(id_map), "0 %d 1\n", getuid());
337 ret = write_id_mapping(UID_MAP, pid, id_map, strlen(id_map));
338 ASSERT_EQ(ret, 0) {
339 TH_LOG("write_id_mapping(UID_MAP) failed");
340 }
341
342 snprintf(id_map, sizeof(id_map), "0 %d 1\n", getgid());
343 ret = write_id_mapping(GID_MAP, pid, id_map, strlen(id_map));
344 ASSERT_EQ(ret, 0) {
345 TH_LOG("write_id_mapping(GID_MAP) failed");
346 }
347
348 ret = write_nointr(syncfds[1], "1", 1);
349 ASSERT_EQ(ret, 1) {
350 TH_LOG("write_nointr() failed");
351 }
352
353 close_prot_errno_disarm(syncfds[1]);
354}
355
356struct __test_metadata *_thread_metadata;
357static void *binder_version_thread(void *data)
358{
359 struct __test_metadata *_metadata = _thread_metadata;
360 int fd = PTR_TO_INT(data);
361 struct binder_version version = { 0 };
362 int ret;
363
364 ret = ioctl(fd, BINDER_VERSION, &version);
365 if (ret < 0)
366 TH_LOG("%s - Failed to open perform BINDER_VERSION request\n",
367 strerror(errno));
368
369 pthread_exit(data);
370}
371
372
373
374
375
376
377
378TEST(binderfs_stress)
379{
380 int fds[1000];
381 int syncfds[2];
382 pid_t pid;
383 int fd, ret;
384 size_t len;
385 struct binderfs_device device = { 0 };
386 char binderfs_mntpt[] = P_tmpdir "/binderfs_XXXXXX",
387 device_path[sizeof(P_tmpdir "/binderfs_XXXXXX/") + BINDERFS_MAX_NAME];
388
389 ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, syncfds);
390 ASSERT_EQ(ret, 0) {
391 TH_LOG("%s - Failed to create socket pair", strerror(errno));
392 }
393
394 pid = fork();
395 ASSERT_GE(pid, 0) {
396 TH_LOG("%s - Failed to fork", strerror(errno));
397 close_prot_errno_disarm(syncfds[0]);
398 close_prot_errno_disarm(syncfds[1]);
399 }
400
401 if (pid == 0) {
402 int i, j, k, nthreads;
403 pthread_attr_t attr;
404 pthread_t threads[DEFAULT_THREADS];
405 change_userns(_metadata, syncfds);
406 change_mountns(_metadata);
407
408 ASSERT_NE(mkdtemp(binderfs_mntpt), NULL) {
409 TH_LOG("%s - Failed to create binderfs mountpoint",
410 strerror(errno));
411 }
412
413 ret = mount(NULL, binderfs_mntpt, "binder", 0, 0);
414 ASSERT_EQ(ret, 0) {
415 TH_LOG("%s - Failed to mount binderfs", strerror(errno));
416 }
417
418 for (int i = 0; i < ARRAY_SIZE(fds); i++) {
419
420 snprintf(device_path, sizeof(device_path),
421 "%s/binder-control", binderfs_mntpt);
422 fd = open(device_path, O_RDONLY | O_CLOEXEC);
423 ASSERT_GE(fd, 0) {
424 TH_LOG("%s - Failed to open binder-control device",
425 strerror(errno));
426 }
427
428 memset(&device, 0, sizeof(device));
429 snprintf(device.name, sizeof(device.name), "%d", i);
430 ret = ioctl(fd, BINDER_CTL_ADD, &device);
431 close_prot_errno_disarm(fd);
432 ASSERT_EQ(ret, 0) {
433 TH_LOG("%s - Failed to allocate new binder device",
434 strerror(errno));
435 }
436
437 snprintf(device_path, sizeof(device_path), "%s/%d",
438 binderfs_mntpt, i);
439 fds[i] = open(device_path, O_RDONLY | O_CLOEXEC);
440 ASSERT_GE(fds[i], 0) {
441 TH_LOG("%s - Failed to open binder device", strerror(errno));
442 }
443 }
444
445 ret = umount2(binderfs_mntpt, MNT_DETACH);
446 ASSERT_EQ(ret, 0) {
447 TH_LOG("%s - Failed to unmount binderfs", strerror(errno));
448 rmdir(binderfs_mntpt);
449 }
450
451 nthreads = get_nprocs_conf();
452 if (nthreads > DEFAULT_THREADS)
453 nthreads = DEFAULT_THREADS;
454
455 _thread_metadata = _metadata;
456 pthread_attr_init(&attr);
457 for (k = 0; k < ARRAY_SIZE(fds); k++) {
458 for (i = 0; i < nthreads; i++) {
459 ret = pthread_create(&threads[i], &attr, binder_version_thread, INT_TO_PTR(fds[k]));
460 if (ret) {
461 TH_LOG("%s - Failed to create thread %d",
462 strerror(errno), i);
463 break;
464 }
465 }
466
467 for (j = 0; j < i; j++) {
468 void *fdptr = NULL;
469
470 ret = pthread_join(threads[j], &fdptr);
471 if (ret)
472 TH_LOG("%s - Failed to join thread %d for fd %d",
473 strerror(errno), j, PTR_TO_INT(fdptr));
474 }
475 }
476 pthread_attr_destroy(&attr);
477
478 for (k = 0; k < ARRAY_SIZE(fds); k++)
479 close(fds[k]);
480
481 exit(EXIT_SUCCESS);
482 }
483
484 change_idmaps(_metadata, syncfds, pid);
485
486 ret = wait_for_pid(pid);
487 ASSERT_EQ(ret, 0) {
488 TH_LOG("wait_for_pid() failed");
489 }
490}
491
492TEST(binderfs_test_privileged)
493{
494 if (geteuid() != 0)
495 SKIP(return, "Tests are not run as root. Skipping privileged tests");
496
497 if (__do_binderfs_test(_metadata))
498 SKIP(return, "The Android binderfs filesystem is not available");
499}
500
501TEST(binderfs_test_unprivileged)
502{
503 int ret;
504 int syncfds[2];
505 pid_t pid;
506
507 ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, syncfds);
508 ASSERT_EQ(ret, 0) {
509 TH_LOG("%s - Failed to create socket pair", strerror(errno));
510 }
511
512 pid = fork();
513 ASSERT_GE(pid, 0) {
514 close_prot_errno_disarm(syncfds[0]);
515 close_prot_errno_disarm(syncfds[1]);
516 TH_LOG("%s - Failed to fork", strerror(errno));
517 }
518
519 if (pid == 0) {
520 change_userns(_metadata, syncfds);
521 if (__do_binderfs_test(_metadata))
522 exit(2);
523 exit(EXIT_SUCCESS);
524 }
525
526 change_idmaps(_metadata, syncfds, pid);
527
528 ret = wait_for_pid(pid);
529 if (ret) {
530 if (ret == 2)
531 SKIP(return, "The Android binderfs filesystem is not available");
532 ASSERT_EQ(ret, 0) {
533 TH_LOG("wait_for_pid() failed");
534 }
535 }
536}
537
538TEST_HARNESS_MAIN
539
