// https://syzkaller.appspot.com/bug?id=76f8203fef423375d230f14b8f5b45617ab945e2 // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #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 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 loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 160 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 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); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } int wait_for_loop(int pid) { if (pid < 0) fail("sandbox fork failed"); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } 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[1] = {0xffffffffffffffff}; void execute_call(int call) { long res; switch (call) { case 0: memcpy((void*)0x20000000, "./file0", 8); syscall(__NR_mkdirat, 0xffffff9c, 0x20000000, 0); break; case 1: memcpy((void*)0x20000100, "/dev/fuse", 10); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000100, 2, 0); if (res != -1) r[0] = res; break; case 2: memcpy((void*)0x20000280, "./file0", 8); memcpy((void*)0x20000240, "fuse", 5); memcpy((void*)0x20000480, "fd", 2); *(uint8_t*)0x20000482 = 0x3d; sprintf((char*)0x20000483, "0x%016llx", (long long)r[0]); *(uint8_t*)0x20000495 = 0x2c; memcpy((void*)0x20000496, "rootmode", 8); *(uint8_t*)0x2000049e = 0x3d; sprintf((char*)0x2000049f, "%023llo", (long long)0x4000); *(uint8_t*)0x200004b6 = 0x2c; memcpy((void*)0x200004b7, "user_id", 7); *(uint8_t*)0x200004be = 0x3d; sprintf((char*)0x200004bf, "%020llu", (long long)0); *(uint8_t*)0x200004d3 = 0x2c; memcpy((void*)0x200004d4, "group_id", 8); *(uint8_t*)0x200004dc = 0x3d; sprintf((char*)0x200004dd, "%020llu", (long long)0); *(uint8_t*)0x200004f1 = 0x2c; *(uint8_t*)0x200004f2 = 0; syscall(__NR_mount, 0, 0x20000280, 0x20000240, 0, 0x20000480); break; case 3: syscall(__NR_read, r[0], 0x20001000, 0x1000); break; case 4: *(uint32_t*)0x20000100 = 0x50; *(uint32_t*)0x20000104 = 0; *(uint64_t*)0x20000108 = 1; *(uint32_t*)0x20000110 = 7; *(uint32_t*)0x20000114 = 0x1b; *(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 5: syscall(__NR_read, r[0], 0x20001000, 0x1000); break; case 6: syscall(__NR_unshare, 0x2000400); break; case 7: memcpy((void*)0x20000080, "./file0/file0", 14); *(uint64_t*)0x200001c0 = 0x96; *(uint64_t*)0x200001c8 = 5; syscall(__NR_utime, 0x20000080, 0x200001c0); break; } } void loop() { execute(8); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); do_sandbox_none(); return 0; }