// https://syzkaller.appspot.com/bug?id=f9e1639c36b944b467c0ceb7bd13491049e2cdd9 // 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 #include #include static unsigned long long procid; 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 use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } 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); } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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; } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; retry: while (umount2(dir, MNT_DETACH) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } struct dirent* ep = 0; while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); while (umount2(filename, MNT_DETACH) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, MNT_DETACH)) exit(1); } } closedir(dp); for (int i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } 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; int collide = 0; again: for (call = 0; call < 10; 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); if (collide && (call % 2) == 0) break; event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); if (!collide) { collide = 1; goto again; } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); 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; } remove_dir(cwdbuf); } } void execute_call(int call) { switch (call) { case 0: *(uint32_t*)0x20000580 = 1; *(uint32_t*)0x20000584 = 0x80; *(uint8_t*)0x20000588 = 0; *(uint8_t*)0x20000589 = 0; *(uint8_t*)0x2000058a = 0; *(uint8_t*)0x2000058b = 0; *(uint32_t*)0x2000058c = 0; *(uint64_t*)0x20000590 = 6; *(uint64_t*)0x20000598 = 0; *(uint64_t*)0x200005a0 = 0; STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 0, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 1, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 2, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 3, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 4, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 5, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 6, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 7, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 8, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 9, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 10, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 11, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 12, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 13, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 14, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 15, 2); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 17, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 18, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 19, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 20, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 21, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 22, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 23, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 24, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 25, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 26, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 27, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 28, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 29, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 30, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 31, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 32, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 33, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 34, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 35, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 36, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 37, 1); STORE_BY_BITMASK(uint64_t, , 0x200005a8, 0, 38, 26); *(uint32_t*)0x200005b0 = 0; *(uint32_t*)0x200005b4 = 0; *(uint64_t*)0x200005b8 = 0; *(uint64_t*)0x200005c0 = 0; *(uint64_t*)0x200005c8 = 0; *(uint64_t*)0x200005d0 = 0; *(uint32_t*)0x200005d8 = 0; *(uint32_t*)0x200005dc = 0; *(uint64_t*)0x200005e0 = 0; *(uint32_t*)0x200005e8 = 0; *(uint16_t*)0x200005ec = 0; *(uint16_t*)0x200005ee = 0; *(uint32_t*)0x200005f0 = 0; *(uint32_t*)0x200005f4 = 0; *(uint64_t*)0x200005f8 = 0; syscall(__NR_perf_event_open, 0x20000580ul, 0, -1ul, -1, 0ul); break; case 1: memcpy((void*)0x200003c0, "./file0\000", 8); syscall(__NR_mkdir, 0x200003c0ul, 0ul); break; case 2: memcpy((void*)0x20000300, "./bus\000", 6); syscall(__NR_mkdir, 0x20000300ul, 0ul); break; case 3: memcpy((void*)0x20000200, "./file0\000", 8); memcpy((void*)0x200000c0, "overlay\000", 8); memcpy((void*)0x20000240, "lowerdir=.:file0", 16); syscall(__NR_mount, 0ul, 0x20000200ul, 0x200000c0ul, 0ul, 0x20000240ul); break; case 4: memcpy((void*)0x200002c0, "./file1\000", 8); syscall(__NR_mkdir, 0x200002c0ul, 0ul); break; case 5: memcpy((void*)0x20000040, "./bus\000", 6); memcpy((void*)0x20000080, "overlay\000", 8); memcpy((void*)0x20000280, "upperdir=./bus,workdir=./file1,lowerdir=./file0", 47); syscall(__NR_mount, 0ul, 0x20000040ul, 0x20000080ul, 0ul, 0x20000280ul); break; case 6: memcpy((void*)0x200001c0, "./bus\000", 6); syscall(__NR_chdir, 0x200001c0ul); break; case 7: memcpy((void*)0x20000380, "./file0\000", 8); memcpy((void*)0x20000440, "./bus/file0\000", 12); syscall(__NR_rename, 0x20000380ul, 0x20000440ul); break; case 8: memcpy((void*)0x200002c0, "./bus\000", 6); syscall(__NR_mkdir, 0x200002c0ul, 0ul); break; case 9: memcpy((void*)0x20000080, "./bus/file0\000", 12); syscall(__NR_creat, 0x20000080ul, 0ul); 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); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { use_temporary_dir(); loop(); } } sleep(1000000); return 0; }