// https://syzkaller.appspot.com/bug?id=c905c82285226236abc44f3140e9290e96374cab // 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 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) { 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); 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 (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[2] = {0xffffffffffffffff, 0x0}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: memcpy((void*)0x20002040, "./file0\000", 8); syscall(__NR_mkdirat, 0xffffff9c, 0x20002040ul, 0ul); break; case 1: memcpy((void*)0x20000040, "/dev/fuse\000", 10); res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000040ul, 0x42ul, 0ul); if (res != -1) r[0] = res; break; case 2: memcpy((void*)0x200020c0, "./file0\000", 8); memcpy((void*)0x20002100, "fuse\000", 5); memcpy((void*)0x20002140, "fd", 2); *(uint8_t*)0x20002142 = 0x3d; sprintf((char*)0x20002143, "0x%016llx", (long long)r[0]); *(uint8_t*)0x20002155 = 0x2c; memcpy((void*)0x20002156, "rootmode", 8); *(uint8_t*)0x2000215e = 0x3d; sprintf((char*)0x2000215f, "%023llo", (long long)0x4000); *(uint8_t*)0x20002176 = 0x2c; memcpy((void*)0x20002177, "user_id", 7); *(uint8_t*)0x2000217e = 0x3d; sprintf((char*)0x2000217f, "%020llu", (long long)0); *(uint8_t*)0x20002193 = 0x2c; memcpy((void*)0x20002194, "group_id", 8); *(uint8_t*)0x2000219c = 0x3d; sprintf((char*)0x2000219d, "%020llu", (long long)0); *(uint8_t*)0x200021b1 = 0x2c; *(uint8_t*)0x200021b2 = 0; syscall(__NR_mount, 0ul, 0x200020c0ul, 0x20002100ul, 0ul, 0x20002140ul); break; case 3: res = syscall(__NR_read, r[0], 0x200021c0ul, 0x2020ul); if (res != -1) r[1] = *(uint64_t*)0x200021c8; break; case 4: *(uint32_t*)0x20004200 = 0x50; *(uint32_t*)0x20004204 = 0; *(uint64_t*)0x20004208 = r[1]; *(uint32_t*)0x20004210 = 7; *(uint32_t*)0x20004214 = 0x1f; *(uint32_t*)0x20004218 = 0; *(uint32_t*)0x2000421c = 0x2023015; *(uint16_t*)0x20004220 = 0; *(uint16_t*)0x20004222 = 0; *(uint32_t*)0x20004224 = 0; *(uint32_t*)0x20004228 = 0; *(uint16_t*)0x2000422c = 0; *(uint16_t*)0x2000422e = 0; memset((void*)0x20004230, 0, 32); syscall(__NR_write, r[0], 0x20004200ul, 0x50ul); break; case 5: syscall(__NR_read, r[0], 0x20006380ul, 0x2020ul); break; case 6: memcpy((void*)0x20000000, "./file0\000", 8); memcpy((void*)0x20000100, "./file0\000", 8); syscall(__NR_pivot_root, 0x20000000ul, 0x20000100ul); break; case 7: memcpy((void*)0x20000180, "/proc/self/attr/exec\000", 21); syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000180ul, 2ul, 0ul); break; case 8: *(uint32_t*)0x200000c0 = 0x2c; *(uint32_t*)0x200000c4 = 6; *(uint64_t*)0x200000c8 = 0; *(uint64_t*)0x200000d0 = 1; *(uint64_t*)0x200000d8 = 2; *(uint32_t*)0x200000e0 = 3; *(uint32_t*)0x200000e4 = 0; memcpy((void*)0x200000e8, "(9\\", 3); *(uint8_t*)0x200000eb = 0; syscall(__NR_write, r[0], 0x200000c0ul, 0x2cul); break; } } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); loop(); return 0; }