// https://syzkaller.appspot.com/bug?id=cbdad6e44b0fbf349f6bf250bc036db6d5f43fe6 // 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 #include 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 (skip && valid) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); 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 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 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 { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); } 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 < 9; 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); if (call == 7) break; 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 __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); 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; } } } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0x0}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: syscall(__NR_creat, /*file=*/0ul, /*mode=S_IROTH|S_IWGRP*/ 0x14ul); break; case 1: syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0ul, /*flags=O_SYNC|O_NOATIME|O_CREAT|FASYNC|O_RDWR*/ 0x143042, /*mode=*/0); break; case 2: res = syscall(__NR_socket, /*domain=*/0x11ul, /*type=SOCK_DGRAM*/ 2ul, /*proto=*/0x300); if (res != -1) r[0] = res; break; case 3: res = syscall(__NR_socket, /*domain=*/0x11ul, /*type=SOCK_RAW*/ 3ul, /*proto=*/0x300); if (res != -1) r[1] = res; break; case 4: res = syscall(__NR_socket, /*domain=*/2ul, /*type=*/3ul, /*proto=*/1); if (res != -1) r[2] = res; break; case 5: NONFAILING(memcpy( (void*)0x20000040, "lo\000\000\000\000\000\000\000\000\000\000\000\000\000\000", 16)); res = syscall(__NR_ioctl, /*fd=*/r[2], /*cmd=*/0x8933, /*arg=*/0x20000040ul); if (res != -1) NONFAILING(r[3] = *(uint32_t*)0x20000050); break; case 6: NONFAILING(memcpy((void*)0x20000080, "\xa9\x9c\x38\x3d\x33\xc9\xc6\x07\xb1\xb9\xd4\x96\x88\xa8" "\x83\x4a\x88\xa8", 18)); NONFAILING(*(uint16_t*)0x20000000 = 0x11); NONFAILING(*(uint16_t*)0x20000002 = htobe16(0)); NONFAILING(*(uint32_t*)0x20000004 = r[3]); NONFAILING(*(uint16_t*)0x20000008 = 1); NONFAILING(*(uint8_t*)0x2000000a = 0); NONFAILING(*(uint8_t*)0x2000000b = 6); NONFAILING(*(uint8_t*)0x2000000c = 1); NONFAILING(*(uint8_t*)0x2000000d = 0x80); NONFAILING(*(uint8_t*)0x2000000e = 0xc2); NONFAILING(*(uint8_t*)0x2000000f = 0); NONFAILING(*(uint8_t*)0x20000010 = 0); NONFAILING(*(uint8_t*)0x20000011 = 0); NONFAILING(memset((void*)0x20000012, 0, 2)); syscall(__NR_sendto, /*fd=*/r[1], /*buf=*/0x20000080ul, /*len=*/0x1000eul, /*f=*/0ul, /*addr=*/0x20000000ul, /*addrlen=*/0x14ul); break; case 7: NONFAILING(*(uint64_t*)0x20000480 = 0); NONFAILING(*(uint32_t*)0x20000488 = 0); NONFAILING(*(uint64_t*)0x20000490 = 0); NONFAILING(*(uint64_t*)0x20000498 = 0); NONFAILING(*(uint64_t*)0x200004a0 = 0); NONFAILING(*(uint64_t*)0x200004a8 = 0); NONFAILING(*(uint32_t*)0x200004b0 = 0); NONFAILING(*(uint32_t*)0x200004b8 = 0); syscall(__NR_recvmmsg, /*fd=*/r[0], /*mmsg=*/0x20000480ul, /*vlen=*/1ul, /*f=MSG_WAITFORONE|MSG_TRUNC|MSG_PEEK*/ 0x10022ul, /*timeout=*/0ul); break; case 8: NONFAILING(*(uint64_t*)0x20000480 = 0); NONFAILING(*(uint32_t*)0x20000488 = 0); NONFAILING(*(uint64_t*)0x20000490 = 0); NONFAILING(*(uint64_t*)0x20000498 = 0); NONFAILING(*(uint64_t*)0x200004a0 = 0); NONFAILING(*(uint64_t*)0x200004a8 = 0); NONFAILING(*(uint32_t*)0x200004b0 = 0); NONFAILING(*(uint32_t*)0x200004b8 = 0); syscall(__NR_recvmmsg, /*fd=*/r[0], /*mmsg=*/0x20000480ul, /*vlen=*/1ul, /*f=MSG_WAITFORONE|MSG_TRUNC|MSG_PEEK*/ 0x10022ul, /*timeout=*/0ul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); const char* reason; (void)reason; install_segv_handler(); loop(); return 0; }