// https://syzkaller.appspot.com/bug?id=c82773a3bdc9c1074543b9da0e865b945a3e9ef0 // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include const int kFailStatus = 67; const int kRetryStatus = 69; static void fail(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); } static void exitf(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit(kRetryStatus); } static uint64_t current_time_ms() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir() { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting"); } exitf("opendir(%s) failed", dir); } while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); struct stat st; if (lstat(filename, &st)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } } static void test(); void loop() { int iter; for (iter = 0;; iter++) { char cwdbuf[256]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); test(); doexit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(-1, &status, __WALL | WNOHANG); if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } } remove_dir(cwdbuf); } } long r[2]; void test() { memset(r, -1, sizeof(r)); syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); r[0] = syscall(__NR_socket, 0x26ul, 0x5ul, 0x0ul); *(uint16_t*)0x20b5efa8 = (uint16_t)0x26; memcpy((void*)0x20b5efaa, "\x61\x65\x61\x64\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 14); *(uint32_t*)0x20b5efb8 = (uint32_t)0x0; *(uint32_t*)0x20b5efbc = (uint32_t)0x0; memcpy((void*)0x20b5efc0, "\x70\x63\x72\x79\x70\x74\x28\x73\x65\x71\x69\x76\x28\x70\x63" "\x72\x79\x70\x74\x28\x67\x63\x6d\x28\x61\x65\x73\x29\x29\x29" "\x29\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00", 64); syscall(__NR_bind, r[0], 0x20b5efa8ul, 0x58ul); r[1] = syscall(__NR_socket, 0x26ul, 0x5ul, 0x0ul); *(uint16_t*)0x20269000 = (uint16_t)0x26; memcpy((void*)0x20269002, "\x61\x65\x61\x64\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 14); *(uint32_t*)0x20269010 = (uint32_t)0x0; *(uint32_t*)0x20269014 = (uint32_t)0x0; memcpy((void*)0x20269018, "\x70\x63\x72\x79\x70\x74\x28\x67\x63\x6d\x5f\x62\x61\x73\x65" "\x28\x63\x74\x72\x28\x61\x65\x73\x2d\x61\x65\x73\x6e\x69\x29" "\x2c\x67\x68\x61\x73\x68\x2d\x67\x65\x6e\x65\x72\x69\x63\x29" "\x29\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00", 64); syscall(__NR_bind, r[1], 0x20269000ul, 0x58ul); } int main() { int i; for (i = 0; i < 8; i++) { if (fork() == 0) { use_temporary_dir(); loop(); return 0; } } sleep(1000000); return 0; }