// https://syzkaller.appspot.com/bug?id=b5e5707c258fcfaed6c22fc2a8c1ea5d8147920f // 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) { if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } int i, call, thread; for (call = 0; call < 7; 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 (;;) { sleep_ms(10); if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0x0}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: // mknodat$loop arguments: [ // dirfd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // mode: mknod_mode = 0x1000 (8 bytes) // dev: proc = 0x0 (4 bytes) // ] memcpy((void*)0x200000000080, "./file0\000", 8); syscall(__NR_mknodat, /*dirfd=*/0xffffff9c, /*file=*/0x200000000080ul, /*mode=S_IFIFO*/ 0x1000ul, /*dev=*/0x700); break; case 1: // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // flags: open_flags = 0x20842 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd memcpy((void*)0x20000000c380, "./file0\000", 8); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x20000000c380ul, /*flags=O_NONBLOCK|O_NOFOLLOW|O_CREAT|O_RDWR*/ 0x20842, /*mode=*/0); if (res != -1) r[0] = res; break; case 2: // fanotify_init arguments: [ // flags: fanotify_flags = 0xf00 (8 bytes) // events: fanotify_events = 0x0 (8 bytes) // ] // returns fd_fanotify res = syscall(__NR_fanotify_init, /*flags=*/0xf00ul, /*events=*/0ul); if (res != -1) r[1] = res; break; case 3: // mount$9p_fd arguments: [ // src: const = 0x0 (8 bytes) // dst: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // type: ptr[in, buffer] { // buffer: {39 70 00} (length 0x3) // } // flags: mount_flags = 0x0 (8 bytes) // opts: ptr[in, p9_options_fd] { // p9_options_fd { // trans: buffer: {74 72 61 6e 73 3d 66 64 2c} (length 0x9) // rfdno: fs_opt["rfdno", fmt[hex, rfd9p]] { // name: buffer: {72 66 64 6e 6f} (length 0x5) // eq: const = 0x3d (1 bytes) // val: rfd9p (resource) // } // comma0: const = 0x2c (1 bytes) // wfdno: fs_opt["wfdno", fmt[hex, fd]] { // name: buffer: {77 66 64 6e 6f} (length 0x5) // eq: const = 0x3d (1 bytes) // val: fd (resource) // } // comma1: const = 0x2c (1 bytes) // opts: fs_options[p9_options] { // elems: array[fs_opt_elem[p9_options]] { // } // common: array[fs_opt_elem[fs_options_common]] { // } // null: const = 0x0 (1 bytes) // } // } // } // ] memcpy((void*)0x200000000180, "./file0\000", 8); memcpy((void*)0x200000000540, "9p\000", 3); memcpy((void*)0x200000000580, "trans=fd,", 9); memcpy((void*)0x200000000589, "rfdno", 5); *(uint8_t*)0x20000000058e = 0x3d; sprintf((char*)0x20000000058f, "0x%016llx", (long long)r[0]); *(uint8_t*)0x2000000005a1 = 0x2c; memcpy((void*)0x2000000005a2, "wfdno", 5); *(uint8_t*)0x2000000005a7 = 0x3d; sprintf((char*)0x2000000005a8, "0x%016llx", (long long)r[1]); *(uint8_t*)0x2000000005ba = 0x2c; *(uint8_t*)0x2000000005bb = 0; syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000180ul, /*type=*/0x200000000540ul, /*flags=*/0ul, /*opts=*/0x200000000580ul); break; case 4: // fcntl$setstatus arguments: [ // fd: fd (resource) // cmd: const = 0x4 (8 bytes) // flags: fcntl_status = 0x42000 (8 bytes) // ] syscall(__NR_fcntl, /*fd=*/r[0], /*cmd=*/4ul, /*flags=O_NOATIME|FASYNC*/ 0x42000ul); break; case 5: // read$FUSE arguments: [ // fd: fd_fuse (resource) // buf: ptr[out, fuse_in[read_buffer]] { // fuse_in[read_buffer] { // len: len = 0x2020 (4 bytes) // opcode: int32 = 0x0 (4 bytes) // unique: fuse_unique (resource) // uid: uid (resource) // gid: gid (resource) // pid: pid (resource) // padding: int32 = 0x0 (4 bytes) // payload: buffer: (DirOut) // } // } // len: bytesize = 0x2020 (8 bytes) // ] res = syscall(__NR_read, /*fd=*/r[0], /*buf=*/0x200000003480ul, /*len=*/0x2020ul); if (res != -1) r[2] = *(uint64_t*)0x200000003488; break; case 6: // write$FUSE_STATFS arguments: [ // fd: fd_fuse (resource) // arg: ptr[in, fuse_out_t[fuse_unique, fuse_statfs_out]] { // fuse_out_t[fuse_unique, fuse_statfs_out] { // len: len = 0x60 (4 bytes) // err: fuse_errors = 0x0 (4 bytes) // unique: fuse_unique (resource) // payload: fuse_statfs_out { // st: fuse_kstatfs { // blocks: int64 = 0x9 (8 bytes) // bfree: int64 = 0x5 (8 bytes) // bavail: int64 = 0x1 (8 bytes) // files: int64 = 0x7d4 (8 bytes) // ffree: int64 = 0x400069a (8 bytes) // bsize: int32 = 0xae (4 bytes) // namelen: int32 = 0x2400000 (4 bytes) // frsize: int32 = 0x800 (4 bytes) // padding: const = 0x0 (4 bytes) // spare: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // 00 00 00 00 00 00 00 00 00} (length 0x18) // } // } // } // } // len: bytesize = 0x60 (8 bytes) // ] *(uint32_t*)0x200000000200 = 0x60; *(uint32_t*)0x200000000204 = 0; *(uint64_t*)0x200000000208 = r[2]; *(uint64_t*)0x200000000210 = 9; *(uint64_t*)0x200000000218 = 5; *(uint64_t*)0x200000000220 = 1; *(uint64_t*)0x200000000228 = 0x7d4; *(uint64_t*)0x200000000230 = 0x400069a; *(uint32_t*)0x200000000238 = 0xae; *(uint32_t*)0x20000000023c = 0x2400000; *(uint32_t*)0x200000000240 = 0x800; *(uint32_t*)0x200000000244 = 0; memset((void*)0x200000000248, 0, 24); syscall(__NR_write, /*fd=*/r[0], /*arg=*/0x200000000200ul, /*len=*/0x60ul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; loop(); return 0; }