// https://syzkaller.appspot.com/bug?id=ba670e411169ae8edf299e9711590436294b3fb6 // 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; for (call = 0; call < 7; 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, 45); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } #ifndef __NR_clone #define __NR_clone 120 #endif #ifndef __NR_execve #define __NR_execve 11 #endif #ifndef __NR_mknod #define __NR_mknod 14 #endif #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_openat #define __NR_openat 295 #endif #ifndef __NR_pipe #define __NR_pipe 42 #endif #ifndef __NR_splice #define __NR_splice 313 #endif #ifndef __NR_write #define __NR_write 4 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { long res; switch (call) { case 0: syscall(__NR_clone, 0x200, 0, 0, 0, 0); break; case 1: memcpy((void*)0x20000040, "./file0\000", 8); syscall(__NR_mknod, 0x20000040, 0x1040, 0); break; case 2: memcpy((void*)0x20000340, "./file0\000", 8); syscall(__NR_execve, 0x20000340, 0, 0); break; case 3: res = syscall(__NR_pipe, 0x20000300); if (res != -1) { r[0] = *(uint32_t*)0x20000300; r[1] = *(uint32_t*)0x20000304; } break; case 4: syscall(__NR_write, (long)r[1], 0x20000040, 0xfffffdea); break; case 5: memcpy((void*)0x20000040, "/proc/thread-self/attr/exec\000", 28); res = syscall(__NR_openat, 0xffffff9c, 0x20000040, 2, 0); if (res != -1) r[2] = res; break; case 6: syscall(__NR_splice, (long)r[0], 0, (long)r[2], 0, 3, 9); break; } } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); loop(); return 0; }