// https://syzkaller.appspot.com/bug?id=819280bd1e860c7f37afb728df27deed3c425d19 // 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; 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; } } 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); int i; for (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 < 12; 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); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter; for (iter = 0;; 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 < 5 * 1000) continue; kill_and_wait(pid, &status); break; } } } #ifndef __NR_close #define __NR_close 6 #endif #ifndef __NR_creat #define __NR_creat 8 #endif #ifndef __NR_fchdir #define __NR_fchdir 133 #endif #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_open #define __NR_open 5 #endif #ifndef __NR_openat #define __NR_openat 295 #endif #ifndef __NR_pipe #define __NR_pipe 42 #endif #ifndef __NR_socket #define __NR_socket 359 #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[6] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { intptr_t res; switch (call) { case 0: res = syscall(__NR_pipe, 0x20000140); if (res != -1) { r[0] = *(uint32_t*)0x20000140; r[1] = *(uint32_t*)0x20000144; } break; case 1: res = syscall(__NR_socket, 2, 2, 0); if (res != -1) r[2] = res; break; case 2: syscall(__NR_close, (intptr_t)r[2]); break; case 3: sprintf((char*)0x20000080, "0x%016llx", (long long)0); syscall(__NR_write, (intptr_t)r[1], 0x20000080, 0xfffffeec); break; case 4: memcpy((void*)0x20000480, "/selinux/commit_pending_bools\000", 30); syscall(__NR_openat, 0xffffff9c, 0x20000480, 1, 0); break; case 5: syscall(__NR_splice, (intptr_t)r[0], 0, (intptr_t)r[2], 0, 0x8100000, 0); break; case 6: memcpy((void*)0x20000100, "./cgroup.cpu\000", 13); res = syscall(__NR_openat, 0xffffff9c, 0x20000100, 0x200002, 0); if (res != -1) r[3] = res; break; case 7: syscall(__NR_fchdir, (intptr_t)r[3]); break; case 8: memcpy((void*)0x20000040, "./bus\000", 6); syscall(__NR_creat, 0x20000040, 2); break; case 9: res = syscall(__NR_pipe, 0x20000380); if (res != -1) r[4] = *(uint32_t*)0x20000380; break; case 10: memcpy((void*)0x20000040, "./bus\000", 6); res = syscall(__NR_open, 0x20000040, 0x82, 0); if (res != -1) r[5] = res; break; case 11: syscall(__NR_splice, (intptr_t)r[4], 0, (intptr_t)r[5], 0, -1, 0); break; } } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); loop(); return 0; }