// https://syzkaller.appspot.com/bug?id=659c6d9af70cf46de2e8231f72f11097df44f72e // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include const int kFailStatus = 67; const int kRetryStatus = 69; static void fail(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); } static void use_temporary_dir() { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } static uintptr_t syz_open_pts(uintptr_t a0, uintptr_t a1) { int ptyno = 0; if (ioctl(a0, TIOCGPTN, &ptyno)) return -1; char buf[128]; sprintf(buf, "/dev/pts/%d", ptyno); return open(buf, a1, 0); } struct thread_t { int created, running, call; pthread_t th; }; 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 (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (__atomic_load_n(&running, __ATOMIC_RELAXED)) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { long res; switch (call) { case 0: memcpy((void*)0x20000480, "/dev/ptmx", 10); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000480, 0x201, 0); if (res != -1) r[0] = res; break; case 1: *(uint32_t*)0x20000040 = 0; *(uint32_t*)0x20000044 = 0; *(uint32_t*)0x20000048 = 0; *(uint32_t*)0x2000004c = 0xffff779a; *(uint8_t*)0x20000050 = 0; *(uint8_t*)0x20000051 = 0; *(uint8_t*)0x20000052 = 0; *(uint8_t*)0x20000053 = 0; *(uint32_t*)0x20000054 = 0; *(uint32_t*)0x20000058 = 0; *(uint32_t*)0x2000005c = 0; *(uint32_t*)0x20000060 = 0; syscall(__NR_ioctl, r[0], 0x5403, 0x20000040); break; case 2: syscall(__NR_write, r[0], 0x200000c0, 0xffffff78); break; case 3: *(uint32_t*)0x20000000 = 0; *(uint32_t*)0x20000004 = 0; *(uint32_t*)0x20000008 = 0; *(uint32_t*)0x2000000c = 0; *(uint8_t*)0x20000010 = 0; *(uint8_t*)0x20000011 = 0; *(uint8_t*)0x20000012 = 0; *(uint8_t*)0x20000013 = 0; *(uint32_t*)0x20000014 = 0; *(uint32_t*)0x20000018 = 0; *(uint32_t*)0x2000001c = 0; *(uint32_t*)0x20000020 = 0; syscall(__NR_ioctl, r[0], 0x40045431, 0x20000000); break; case 4: res = syscall(__NR_dup, r[0]); if (res != -1) r[1] = res; break; case 5: res = syz_open_pts(r[1], 0); if (res != -1) r[2] = res; break; case 6: syscall(__NR_read, r[2], 0x20000080, 0xffffff5c); break; case 7: *(uint32_t*)0x20000000 = 0; *(uint64_t*)0x20000004 = 0; syscall(__NR_epoll_ctl, -1, 3, -1, 0x20000000); break; } } void loop() { execute(8); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); use_temporary_dir(); loop(); return 0; }