// https://syzkaller.appspot.com/bug?id=278375ee84f55f36429997897a01cafae869987d // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include 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; for (i = 0; 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); } 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_RELAXED)) return 1; now = current_time_ms(); if (now - start > timeout) 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 loop(void) { int i, call, thread; int collide = 0; again: 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 (collide && (call % 2) == 0) break; event_timedwait(&th->done, 45); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); if (!collide) { collide = 1; goto again; } } uint64_t r[1] = {0xffffffffffffffff}; void execute_call(int call) { intptr_t res; switch (call) { case 0: memcpy((void*)0x20000180, "./file0\000", 8); memcpy((void*)0x20000000, "fusectl\000", 8); syscall(__NR_mount, 0, 0x20000180, 0x20000000, 3, 0); break; case 1: memcpy((void*)0x20000080, "./file0\000", 8); syscall(__NR_mkdir, 0x20000080, 0); break; case 2: memcpy((void*)0x20000180, "/dev/fuse\000", 10); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000180, 2, 0); if (res != -1) r[0] = res; break; case 3: memcpy((void*)0x20000200, "./file0\000", 8); memcpy((void*)0x20000240, "fuse\000", 5); memcpy((void*)0x20000400, "fd", 2); *(uint8_t*)0x20000402 = 0x3d; sprintf((char*)0x20000403, "0x%016llx", (long long)r[0]); *(uint8_t*)0x20000415 = 0x2c; memcpy((void*)0x20000416, "rootmode", 8); *(uint8_t*)0x2000041e = 0x3d; sprintf((char*)0x2000041f, "%023llo", (long long)0x4000); *(uint8_t*)0x20000436 = 0x2c; memcpy((void*)0x20000437, "user_id", 7); *(uint8_t*)0x2000043e = 0x3d; sprintf((char*)0x2000043f, "%020llu", (long long)0); *(uint8_t*)0x20000453 = 0x2c; memcpy((void*)0x20000454, "group_id", 8); *(uint8_t*)0x2000045c = 0x3d; sprintf((char*)0x2000045d, "%020llu", (long long)0); *(uint8_t*)0x20000471 = 0x2c; *(uint8_t*)0x20000472 = 0; syscall(__NR_mount, 0, 0x20000200, 0x20000240, 0, 0x20000400); break; case 4: syscall(__NR_read, r[0], 0x20002540, 0x1000); break; case 5: memcpy((void*)0x20000580, "./file0/file1\000", 14); syscall(__NR_stat, 0x20000580, 0); break; case 6: syscall(__NR_read, r[0], 0x20003540, 0x1000); break; case 7: *(uint32_t*)0x20000100 = 0x50; *(uint32_t*)0x20000104 = 0; *(uint64_t*)0x20000108 = 1; *(uint32_t*)0x20000110 = 7; *(uint32_t*)0x20000114 = 0x1f; *(uint32_t*)0x20000118 = 0; *(uint32_t*)0x2000011c = 0; *(uint16_t*)0x20000120 = 0; *(uint16_t*)0x20000122 = 0; *(uint32_t*)0x20000124 = 0; *(uint32_t*)0x20000128 = 0; *(uint32_t*)0x2000012c = 0; *(uint32_t*)0x20000130 = 0; *(uint32_t*)0x20000134 = 0; *(uint32_t*)0x20000138 = 0; *(uint32_t*)0x2000013c = 0; *(uint32_t*)0x20000140 = 0; *(uint32_t*)0x20000144 = 0; *(uint32_t*)0x20000148 = 0; *(uint32_t*)0x2000014c = 0; syscall(__NR_write, r[0], 0x20000100, 0x50); break; case 8: *(uint32_t*)0x20000000 = 0x2e; *(uint32_t*)0x20000004 = 6; *(uint64_t*)0x20000008 = 0; *(uint64_t*)0x20000010 = 1; *(uint64_t*)0x20000018 = 0; *(uint32_t*)0x20000020 = 5; *(uint32_t*)0x20000024 = 0; memcpy((void*)0x20000028, "fuse\000", 5); *(uint8_t*)0x2000002d = 0; syscall(__NR_write, r[0], 0x20000000, 0x2e); break; } } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); loop(); return 0; }