// https://syzkaller.appspot.com/bug?id=cf4c0a08d26692dc8f22b0fcc50db08fd17dd709 // 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 #include #ifndef SYS_aio_writev #define SYS_aio_writev 578 #endif static __thread int clone_ongoing; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { exit(sig); } uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; int valid = addr < prog_start || addr > prog_end; if (sig == SIGBUS) valid = 1; if (skip && valid) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ ({ \ int ok = 1; \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } else \ ok = 0; \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ ok; \ }) 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 reset_flags(const char* filename) { struct stat st; if (lstat(filename, &st)) exit(1); st.st_flags &= ~(SF_NOUNLINK | UF_NOUNLINK | SF_IMMUTABLE | UF_IMMUTABLE | SF_APPEND | UF_APPEND); if (lchflags(filename, st.st_flags)) 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)) { if (errno == EPERM) { reset_flags(filename); reset_flags(dir); if (unlink(filename) == 0) continue; } exit(1); } } closedir(dp); while (rmdir(dir)) { if (errno == EPERM) { reset_flags(dir); if (rmdir(dir) == 0) break; } 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) { if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } int i, call, thread; for (call = 0; call < 24; 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 (;;) { sleep_ms(10); if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: res = syscall(SYS_socket, /*domain=AF_INET6*/ 0x1cul, /*type=SOCK_STREAM*/ 1ul, /*proto=*/0); if (res != -1) r[0] = res; break; case 1: NONFAILING(*(uint32_t*)0x200000c0 = 0x101); syscall(SYS_setsockopt, /*fd=*/r[0], /*level=*/0xffff, /*optname=SO_SNDBUF*/ 0x1001, /*optval=*/0x200000c0ul, /*optlen=*/4ul); break; case 2: NONFAILING(*(uint8_t*)0x20000140 = 0x1c); NONFAILING(*(uint8_t*)0x20000141 = 0x1c); NONFAILING(*(uint16_t*)0x20000142 = htobe16(0x4e23)); NONFAILING(*(uint32_t*)0x20000144 = 0); NONFAILING(memset((void*)0x20000148, 0, 16)); NONFAILING(*(uint32_t*)0x20000158 = 0); syscall(SYS_bind, /*fd=*/r[0], /*addr=*/0x20000140ul, /*addrlen=*/0x1cul); break; case 3: NONFAILING(*(uint32_t*)0x20000500 = r[0]); NONFAILING(*(uint64_t*)0x20000508 = 0); NONFAILING(*(uint64_t*)0x20000510 = 0); NONFAILING(*(uint64_t*)0x20000518 = 0); NONFAILING(*(uint32_t*)0x20000520 = 4); NONFAILING(*(uint32_t*)0x20000524 = 0); NONFAILING(*(uint64_t*)0x20000528 = 0); NONFAILING(*(uint32_t*)0x20000530 = 0); NONFAILING(*(uint32_t*)0x20000534 = 4); NONFAILING(*(uint64_t*)0x20000538 = 0x822e); NONFAILING(*(uint64_t*)0x20000540 = 0); NONFAILING(*(uint64_t*)0x20000548 = 0x20000340); NONFAILING(*(uint32_t*)0x20000550 = 0); NONFAILING(*(uint32_t*)0x20000554 = 0); NONFAILING(*(uint64_t*)0x20000558 = 0xfffffffffffffffe); NONFAILING(*(uint64_t*)0x20000560 = 0); NONFAILING(*(uint64_t*)0x20000568 = 0x20000380); NONFAILING(memcpy((void*)0x20000380, "\x3c\x88\x80", 3)); syscall(SYS_aio_writev, /*iocb=*/0x20000500ul); break; case 4: NONFAILING(*(uint8_t*)0x20000180 = 0x1c); NONFAILING(*(uint8_t*)0x20000181 = 0x1c); NONFAILING(*(uint16_t*)0x20000182 = htobe16(0x4e23)); NONFAILING(*(uint32_t*)0x20000184 = 0); NONFAILING(memset((void*)0x20000188, 0, 16)); NONFAILING(*(uint32_t*)0x20000198 = 0); syscall(SYS_connect, /*fd=*/r[0], /*addr=*/0x20000180ul, /*addrlen=*/0x1cul); break; case 5: NONFAILING(memset((void*)0x20000200, 14, 1)); syscall(SYS_sendto, /*fd=*/r[0], /*buf=*/0x20000200ul, /*len=*/0xff66ul, /*f=*/0ul, /*addr=*/0ul, /*addrlen=*/0ul); break; case 6: syscall(SYS_sendmsg, /*fd=*/r[0], /*msg=*/0ul, /*f=*/0ul); break; case 7: syscall(SYS_socket, /*domain=AF_INET*/ 2ul, /*type=SOCK_STREAM*/ 1ul, /*proto=*/0); break; case 8: res = syscall(SYS_socket, /*domain=*/2ul, /*type=SOCK_SEQPACKET*/ 5ul, /*proto=*/0x84); if (res != -1) r[1] = res; break; case 9: syscall(SYS_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul, /*flags=O_RDWR*/ 2ul, /*mode=*/0ul); break; case 10: syscall(SYS_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul, /*flags=O_RDWR*/ 2ul, /*mode=*/0ul); break; case 11: syscall(SYS_socket, /*domain=*/2ul, /*type=SOCK_SEQPACKET*/ 5ul, /*proto=*/0x84); break; case 12: syscall(SYS_socket, /*domain=*/0x1cul, /*type=*/1ul, /*proto=*/0); break; case 13: syscall(SYS_shutdown, /*fd=*/-1, /*how=*/0ul); break; case 14: syscall(SYS_shutdown, /*fd=*/-1, /*how=*/0ul); break; case 15: syscall(SYS_sendto, /*fd=*/-1, /*buf=*/0ul, /*len=*/0ul, /*f=*/0ul, /*addr=*/0ul, /*addrlen=*/0ul); break; case 16: syscall(SYS_sendmsg, /*fd=*/-1, /*msg=*/0ul, /*f=*/0ul); break; case 17: syscall(SYS_rfork, /*flags=RFMEM|RFTHREAD|RFCFDG|RFNOWAIT*/ 0x3060ul); break; case 18: syscall(SYS_rfork, /*flags=RFMEM|RFTHREAD|RFCFDG|RFNOWAIT*/ 0x3060ul); break; case 19: syscall(SYS_openat, /*fd=*/0xffffff9cul, /*file=*/0ul, /*flags=O_APPEND*/ 8ul, /*mode=*/0ul); break; case 20: syscall(SYS_openat, /*fd=*/0xffffff9cul, /*file=*/0ul, /*flags=O_APPEND*/ 8ul, /*mode=*/0ul); break; case 21: syscall(SYS_connect, /*fd=*/r[1], /*addr=*/0ul, /*addrlen=*/0ul); break; case 22: res = syscall(SYS_socket, /*domain=*/2ul, /*type=SOCK_STREAM*/ 1ul, /*proto=*/0x84); if (res != -1) r[2] = res; break; case 23: NONFAILING(*(uint32_t*)0x200001c0 = 0); syscall(SYS_getsockopt, /*fd=*/r[2], /*level=*/0x84, /*opt=*/0xc, /*val=*/0ul, /*len=*/0x200001c0ul); break; } } int main(void) { syscall(SYS_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x1012ul, /*fd=*/-1, /*offset=*/0ul); const char* reason; (void)reason; install_segv_handler(); use_temporary_dir(); do_sandbox_none(); return 0; }