// https://syzkaller.appspot.com/bug?id=20185b6047d7371885412b56ff188be88f740eab // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static unsigned long long procid; static void kill_and_wait(int pid, int* status) { kill(pid, SIGKILL); while (waitpid(-1, status, 0) != pid) { } } static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } static void __attribute__((noinline)) remove_dir(const char* dir) { DIR* dp = opendir(dir); if (dp == NULL) { if (errno == EACCES) { if (rmdir(dir)) exit(1); return; } exit(1); } struct dirent* ep = 0; 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)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } if (unlink(filename)) exit(1); } closedir(dp); if (rmdir(dir)) exit(1); } static void thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } typedef struct { pthread_mutex_t mu; pthread_cond_t cv; int state; } event_t; static void event_init(event_t* ev) { if (pthread_mutex_init(&ev->mu, 0)) exit(1); if (pthread_cond_init(&ev->cv, 0)) exit(1); ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { pthread_mutex_lock(&ev->mu); if (ev->state) exit(1); ev->state = 1; pthread_mutex_unlock(&ev->mu); pthread_cond_broadcast(&ev->cv); } static void event_wait(event_t* ev) { pthread_mutex_lock(&ev->mu); while (!ev->state) pthread_cond_wait(&ev->cv, &ev->mu); pthread_mutex_unlock(&ev->mu); } static int event_isset(event_t* ev) { pthread_mutex_lock(&ev->mu); int res = ev->state; pthread_mutex_unlock(&ev->mu); return res; } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; pthread_mutex_lock(&ev->mu); for (;;) { if (ev->state) break; uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; pthread_cond_timedwait(&ev->cv, &ev->mu, &ts); now = current_time_ms(); if (now - start > timeout) break; } int res = ev->state; pthread_mutex_unlock(&ev->mu); return res; } static void sandbox_common() { struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); } static void loop(); static int do_sandbox_none(void) { sandbox_common(); loop(); return 0; } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void execute_one(void) { int i, call, thread; for (call = 0; call < 14; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } static void execute_one(void); #define WAIT_FLAGS 0 static void loop(void) { int iter = 0; for (;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[4] = {0x0, 0x0, 0x0, 0x0}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: *(uint32_t*)0x20000000 = 0x3f; *(uint32_t*)0x20000004 = 8; *(uint32_t*)0x20000008 = 0x1000; *(uint32_t*)0x2000000c = 7; syscall(SYS_sigsuspend, 0x20000000ul); break; case 1: syscall(SYS_setgid, 0); break; case 2: syscall(SYS_getgroups, 0ul, 0ul); break; case 3: syscall(SYS_setegid, 0); break; case 4: res = syscall(SYS_shmget, 0ul, 0x2000ul, 0x420ul, 0x20ffd000ul); if (res != -1) r[0] = res; break; case 5: res = syscall(SYS_getpid); if (res != -1) r[1] = res; break; case 6: *(uint32_t*)0x20000200 = -1; *(uint32_t*)0x20000204 = 0; *(uint32_t*)0x20000208 = -1; *(uint32_t*)0x2000020c = 0; *(uint16_t*)0x20000210 = 0xf965; *(uint16_t*)0x20000212 = 0x2000; *(uint32_t*)0x20000214 = 0; *(uint64_t*)0x20000218 = 0x2d; *(uint32_t*)0x20000220 = 0x1f; *(uint64_t*)0x20000228 = 2; *(uint64_t*)0x20000230 = 4; *(uint64_t*)0x20000238 = 0; *(uint32_t*)0x20000240 = r[1]; *(uint32_t*)0x20000244 = -1; *(uint16_t*)0x20000248 = 7; *(uint16_t*)0x2000024a = 0; *(uint64_t*)0x20000250 = 0; *(uint64_t*)0x20000258 = 0; syscall(SYS_shmctl, r[0], 1ul, 0x20000200ul); break; case 7: syscall(SYS_getgid); break; case 8: syscall(SYS___semctl, 0, 0ul, 1ul, 0ul); break; case 9: *(uint32_t*)0x20000300 = 4; *(uint32_t*)0x20000304 = 0; *(uint16_t*)0x20000308 = 7; *(uint16_t*)0x2000030a = 6; memcpy((void*)0x2000030c, "\x26\xb9\x52\x60\x70\xe1\xb8\x97\x99\x4b\x39\xd3\xea\x42\xe7\xed", 16); syscall(SYS_fhstat, 0x20000300ul, 0ul); break; case 10: res = syscall(SYS_getgid); if (res != -1) r[2] = res; break; case 11: *(uint32_t*)0x20000440 = 3; *(uint32_t*)0x20000444 = 0; *(uint32_t*)0x20000448 = r[1]; *(uint32_t*)0x2000044c = 0x81; *(uint32_t*)0x20000450 = r[1]; memset((void*)0x20000454, 0, 60); res = syscall(SYS_procctl, 0ul, r[1], 6ul, 0x20000440ul); if (res != -1) r[3] = *(uint32_t*)0x20000450; break; case 12: *(uint32_t*)0x200004c0 = 0; *(uint32_t*)0x200004c4 = 0; *(uint32_t*)0x200004c8 = 0; *(uint32_t*)0x200004cc = r[2]; *(uint16_t*)0x200004d0 = 0x100; *(uint16_t*)0x200004d2 = 8; *(uint32_t*)0x200004d4 = 0; *(uint64_t*)0x200004d8 = 0x7ff; *(uint64_t*)0x200004e0 = 0x7f; *(uint64_t*)0x200004e8 = 0x81; *(uint64_t*)0x200004f0 = 0xfff; *(uint64_t*)0x200004f8 = 0x3a; *(uint64_t*)0x20000500 = 0x100000000; *(uint64_t*)0x20000508 = 9; *(uint32_t*)0x20000510 = r[1]; *(uint32_t*)0x20000514 = r[3]; *(uint64_t*)0x20000518 = 0; *(uint64_t*)0x20000520 = 0; syscall(SYS_msgctl, -1, 1ul, 0x200004c0ul); break; case 13: syscall(SYS_ioctl, -1, 0xc0f24425ul, 0ul); break; } } int main(void) { syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); for (procid = 0; procid < 4; procid++) { if (fork() == 0) { use_temporary_dir(); do_sandbox_none(); } } sleep(1000000); return 0; }