// 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 #include #include #ifndef __NR_memfd_create #define __NR_memfd_create 319 #endif 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; } const int kInitNetNsFd = 201; static long syz_init_net_socket(volatile long domain, volatile long type, volatile long proto) { return syscall(__NR_socket, domain, type, proto); } struct fs_image_segment { void* data; uintptr_t size; uintptr_t offset; }; static int setup_loop_device(long unsigned size, long unsigned nsegs, struct fs_image_segment* segs, const char* loopname, int* memfd_p, int* loopfd_p) { int err = 0, loopfd = -1; int memfd = syscall(__NR_memfd_create, "syzkaller", 0); if (memfd == -1) { err = errno; goto error; } if (ftruncate(memfd, size)) { err = errno; goto error_close_memfd; } for (size_t i = 0; i < nsegs; i++) { if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { } } loopfd = open(loopname, O_RDWR); if (loopfd == -1) { err = errno; goto error_close_memfd; } if (ioctl(loopfd, LOOP_SET_FD, memfd)) { if (errno != EBUSY) { err = errno; goto error_close_loop; } ioctl(loopfd, LOOP_CLR_FD, 0); usleep(1000); if (ioctl(loopfd, LOOP_SET_FD, memfd)) { err = errno; goto error_close_loop; } } *memfd_p = memfd; *loopfd_p = loopfd; return 0; error_close_loop: close(loopfd); error_close_memfd: close(memfd); error: errno = err; return -1; } static long syz_mount_image(volatile long fsarg, volatile long dir, volatile unsigned long size, volatile unsigned long nsegs, volatile long segments, volatile long flags, volatile long optsarg, volatile long change_dir) { struct fs_image_segment* segs = (struct fs_image_segment*)segments; int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs; char* mount_opts = (char*)optsarg; char* target = (char*)dir; char* fs = (char*)fsarg; char* source = NULL; char loopname[64]; if (need_loop_device) { memset(loopname, 0, sizeof(loopname)); snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); if (setup_loop_device(size, nsegs, segs, loopname, &memfd, &loopfd) == -1) return -1; source = loopname; } mkdir(target, 0777); char opts[256]; memset(opts, 0, sizeof(opts)); if (strlen(mount_opts) > (sizeof(opts) - 32)) { } strncpy(opts, mount_opts, sizeof(opts) - 32); if (strcmp(fs, "iso9660") == 0) { flags |= MS_RDONLY; } else if (strncmp(fs, "ext", 3) == 0) { if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0) strcat(opts, ",errors=continue"); } else if (strcmp(fs, "xfs") == 0) { strcat(opts, ",nouuid"); } res = mount(source, target, fs, flags, opts); if (res == -1) { err = errno; goto error_clear_loop; } res = open(target, O_RDONLY | O_DIRECTORY); if (res == -1) { err = errno; goto error_clear_loop; } if (change_dir) { res = chdir(target); if (res == -1) { err = errno; } } error_clear_loop: if (need_loop_device) { ioctl(loopfd, LOOP_CLR_FD, 0); close(loopfd); close(memfd); } errno = err; return res; } #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 | UMOUNT_NOFOLLOW) == 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 | UMOUNT_NOFOLLOW) == 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 | UMOUNT_NOFOLLOW)) 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 | UMOUNT_NOFOLLOW)) 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 reset_loop() { char buf[64]; snprintf(buf, sizeof(buf), "/dev/loop%llu", procid); int loopfd = open(buf, O_RDWR); if (loopfd != -1) { ioctl(loopfd, LOOP_CLR_FD, 0); close(loopfd); } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); if (symlink("/dev/binderfs", "./binderfs")) { } } static void setup_sysctl() { char mypid[32]; snprintf(mypid, sizeof(mypid), "%d", getpid()); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", mypid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) printf("write to %s failed: %s\n", files[i].name, strerror(errno)); } } 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 < 13; 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 + (call == 6 ? 50 : 0)); 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++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); reset_loop(); 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*)0x20000780 = 1; *(uint32_t*)0x20000784 = 0x80; *(uint8_t*)0x20000788 = 0; *(uint8_t*)0x20000789 = 0; *(uint8_t*)0x2000078a = 0; *(uint8_t*)0x2000078b = 0; *(uint32_t*)0x2000078c = 0; *(uint64_t*)0x20000790 = 5; *(uint64_t*)0x20000798 = 0x14002; *(uint64_t*)0x200007a0 = 0; STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 0, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 1, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 2, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 3, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 4, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 5, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 6, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 7, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 8, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 9, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 10, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 11, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 12, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 13, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 14, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 15, 2); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 17, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 18, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 19, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 20, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 21, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 22, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 23, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 24, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 25, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 26, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 27, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 28, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 29, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 30, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 31, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 32, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 33, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 34, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 35, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 36, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 37, 1); STORE_BY_BITMASK(uint64_t, , 0x200007a8, 0, 38, 26); *(uint32_t*)0x200007b0 = 0x20000; *(uint32_t*)0x200007b4 = 0; *(uint64_t*)0x200007b8 = 0; *(uint64_t*)0x200007c0 = 0; *(uint64_t*)0x200007c8 = 0x6012; *(uint64_t*)0x200007d0 = 0; *(uint32_t*)0x200007d8 = 0; *(uint32_t*)0x200007dc = 0; *(uint64_t*)0x200007e0 = 0; *(uint32_t*)0x200007e8 = 0x10; *(uint16_t*)0x200007ec = 0; *(uint16_t*)0x200007ee = 0; *(uint32_t*)0x200007f0 = 0; *(uint32_t*)0x200007f4 = 0; *(uint64_t*)0x200007f8 = 0; syscall(__NR_perf_event_open, 0x20000780ul, 0, -1ul, -1, 0ul); break; case 1: syscall(__NR_chdir, 0ul); break; case 2: memcpy((void*)0x20000040, "/dev/input/mice\000", 16); syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000040ul, 0x2000ul, 0); break; case 3: memcpy((void*)0x20000400, "./file1\000", 8); syscall(__NR_mkdir, 0x20000400ul, 0ul); break; case 4: syz_init_net_socket(6, 5, 0); break; case 5: memcpy((void*)0x20000640, "./bus\000", 6); syscall(__NR_mkdir, 0x20000640ul, 0ul); break; case 6: memcpy((void*)0x200001c0, "ubifs\000", 6); memcpy((void*)0x20000580, "./bus/file0\000", 12); syz_mount_image(0x200001c0, 0x20000580, 0, 0, 0x20000000, 0, 0x20000500, 0); break; case 7: memcpy((void*)0x20000180, "./file0\000", 8); syscall(__NR_mkdir, 0x20000180ul, 0ul); break; case 8: 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 9: memcpy((void*)0x20000040, "./bus\000", 6); memcpy((void*)0x20000080, "overlay\000", 8); memcpy((void*)0x20000340, "upperdir=./bus,workdir=./file1,lowerdir=./file0", 47); syscall(__NR_mount, 0ul, 0x20000040ul, 0x20000080ul, 0ul, 0x20000340ul); break; case 10: memcpy((void*)0x200002c0, "./bus\000", 6); memcpy((void*)0x20000300, "system.posix_acl_access\000", 24); *(uint32_t*)0x20000980 = 2; *(uint16_t*)0x20000984 = 1; *(uint16_t*)0x20000986 = 0; *(uint32_t*)0x20000988 = 0; *(uint16_t*)0x2000098c = 2; *(uint16_t*)0x2000098e = 0; *(uint32_t*)0x20000990 = 0; *(uint16_t*)0x20000994 = 2; *(uint16_t*)0x20000996 = 0; *(uint32_t*)0x20000998 = 0; *(uint16_t*)0x2000099c = 2; *(uint16_t*)0x2000099e = 0; *(uint32_t*)0x200009a0 = 0xee00; *(uint16_t*)0x200009a4 = 2; *(uint16_t*)0x200009a6 = 0; *(uint32_t*)0x200009a8 = 0; *(uint16_t*)0x200009ac = 2; *(uint16_t*)0x200009ae = 0; *(uint32_t*)0x200009b0 = 0; *(uint16_t*)0x200009b4 = 4; *(uint16_t*)0x200009b6 = 0; *(uint32_t*)0x200009b8 = 0; *(uint16_t*)0x200009bc = 8; *(uint16_t*)0x200009be = 0; *(uint32_t*)0x200009c0 = 0xee01; *(uint16_t*)0x200009c4 = 8; *(uint16_t*)0x200009c6 = 1; *(uint32_t*)0x200009c8 = 0xee00; *(uint16_t*)0x200009cc = 8; *(uint16_t*)0x200009ce = 1; *(uint32_t*)0x200009d0 = 0; *(uint16_t*)0x200009d4 = 0x10; *(uint16_t*)0x200009d6 = 1; *(uint32_t*)0x200009d8 = 0; *(uint16_t*)0x200009dc = 0x20; *(uint16_t*)0x200009de = 0; *(uint32_t*)0x200009e0 = 0; syscall(__NR_lsetxattr, 0x200002c0ul, 0x20000300ul, 0x20000980ul, 0x64ul, 0ul); break; case 11: memcpy((void*)0x20000540, "./bus\000", 6); syscall(__NR_chdir, 0x20000540ul); break; case 12: memcpy((void*)0x20000100, "./bus/file0\000", 12); memcpy((void*)0x20000440, "./file0\000", 8); syscall(__NR_rename, 0x20000100ul, 0x20000440ul); 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); setup_sysctl(); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { use_temporary_dir(); loop(); } } sleep(1000000); return 0; }