| // BUG: soft lockup in d_walk |
| // https://syzkaller.appspot.com/bug?id=02ec3472b31d55cb8cb425aa8e7c0b94acde6503 |
| // status:fixed |
| // autogenerated by syzkaller (http://github.com/google/syzkaller) |
| |
| #define _GNU_SOURCE |
| #include <dirent.h> |
| #include <endian.h> |
| #include <errno.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/futex.h> |
| #include <linux/loop.h> |
| #include <pthread.h> |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/ioctl.h> |
| #include <sys/mount.h> |
| #include <sys/mount.h> |
| #include <sys/prctl.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| __attribute__((noreturn)) static void doexit(int status) |
| { |
| volatile unsigned i; |
| syscall(__NR_exit_group, status); |
| for (i = 0;; i++) { |
| } |
| } |
| #include <errno.h> |
| #include <stdarg.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| |
| const int kFailStatus = 67; |
| const int kRetryStatus = 69; |
| |
| static void fail(const char* msg, ...) |
| { |
| int e = errno; |
| va_list args; |
| va_start(args, msg); |
| vfprintf(stderr, msg, args); |
| va_end(args); |
| fprintf(stderr, " (errno %d)\n", e); |
| doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); |
| } |
| |
| static void exitf(const char* msg, ...) |
| { |
| int e = errno; |
| va_list args; |
| va_start(args, msg); |
| vfprintf(stderr, msg, args); |
| va_end(args); |
| fprintf(stderr, " (errno %d)\n", e); |
| doexit(kRetryStatus); |
| } |
| |
| static uint64_t current_time_ms() |
| { |
| struct timespec ts; |
| |
| if (clock_gettime(CLOCK_MONOTONIC, &ts)) |
| fail("clock_gettime failed"); |
| return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; |
| } |
| |
| static void use_temporary_dir() |
| { |
| char tmpdir_template[] = "./syzkaller.XXXXXX"; |
| char* tmpdir = mkdtemp(tmpdir_template); |
| if (!tmpdir) |
| fail("failed to mkdtemp"); |
| if (chmod(tmpdir, 0777)) |
| fail("failed to chmod"); |
| if (chdir(tmpdir)) |
| fail("failed to chdir"); |
| } |
| |
| extern unsigned long long procid; |
| |
| struct fs_image_segment { |
| void* data; |
| uintptr_t size; |
| uintptr_t offset; |
| }; |
| |
| #define IMAGE_MAX_SEGMENTS 4096 |
| #define IMAGE_MAX_SIZE (129 << 20) |
| |
| #define SYZ_memfd_create 319 |
| |
| static uintptr_t syz_mount_image(uintptr_t fs, uintptr_t dir, uintptr_t size, |
| uintptr_t nsegs, uintptr_t segments, |
| uintptr_t flags, uintptr_t opts) |
| { |
| char loopname[64]; |
| int loopfd, err = 0, res = -1; |
| uintptr_t i; |
| struct fs_image_segment* segs = (struct fs_image_segment*)segments; |
| |
| if (nsegs > IMAGE_MAX_SEGMENTS) |
| nsegs = IMAGE_MAX_SEGMENTS; |
| for (i = 0; i < nsegs; i++) { |
| if (segs[i].size > IMAGE_MAX_SIZE) |
| segs[i].size = IMAGE_MAX_SIZE; |
| segs[i].offset %= IMAGE_MAX_SIZE; |
| if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size) |
| segs[i].offset = IMAGE_MAX_SIZE - segs[i].size; |
| if (size < segs[i].offset + segs[i].offset) |
| size = segs[i].offset + segs[i].offset; |
| } |
| if (size > IMAGE_MAX_SIZE) |
| size = IMAGE_MAX_SIZE; |
| int memfd = syscall(SYZ_memfd_create, "syz_mount_image", 0); |
| if (memfd == -1) { |
| err = errno; |
| goto error; |
| } |
| if (ftruncate(memfd, size)) { |
| err = errno; |
| goto error_close_memfd; |
| } |
| for (i = 0; i < nsegs; i++) { |
| if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { |
| } |
| } |
| snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); |
| 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; |
| } |
| } |
| mkdir((char*)dir, 0777); |
| if (strcmp((char*)fs, "iso9660") == 0) |
| flags |= MS_RDONLY; |
| if (mount(loopname, (char*)dir, (char*)fs, flags, (char*)opts)) { |
| err = errno; |
| goto error_clear_loop; |
| } |
| res = 0; |
| error_clear_loop: |
| ioctl(loopfd, LOOP_CLR_FD, 0); |
| error_close_loop: |
| close(loopfd); |
| error_close_memfd: |
| close(memfd); |
| error: |
| errno = err; |
| return res; |
| } |
| |
| static void remove_dir(const char* dir) |
| { |
| DIR* dp; |
| struct dirent* ep; |
| int iter = 0; |
| retry: |
| while (umount2(dir, MNT_DETACH) == 0) { |
| } |
| dp = opendir(dir); |
| if (dp == NULL) { |
| if (errno == EMFILE) { |
| exitf("opendir(%s) failed due to NOFILE, exiting", dir); |
| } |
| exitf("opendir(%s) failed", dir); |
| } |
| 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); |
| struct stat st; |
| if (lstat(filename, &st)) |
| exitf("lstat(%s) failed", filename); |
| if (S_ISDIR(st.st_mode)) { |
| remove_dir(filename); |
| continue; |
| } |
| int i; |
| for (i = 0;; i++) { |
| if (unlink(filename) == 0) |
| break; |
| if (errno == EROFS) { |
| break; |
| } |
| if (errno != EBUSY || i > 100) |
| exitf("unlink(%s) failed", filename); |
| if (umount2(filename, MNT_DETACH)) |
| exitf("umount(%s) failed", filename); |
| } |
| } |
| closedir(dp); |
| int i; |
| for (i = 0;; i++) { |
| if (rmdir(dir) == 0) |
| break; |
| if (i < 100) { |
| if (errno == EROFS) { |
| break; |
| } |
| if (errno == EBUSY) { |
| if (umount2(dir, MNT_DETACH)) |
| exitf("umount(%s) failed", dir); |
| continue; |
| } |
| if (errno == ENOTEMPTY) { |
| if (iter < 100) { |
| iter++; |
| goto retry; |
| } |
| } |
| } |
| exitf("rmdir(%s) failed", dir); |
| } |
| } |
| |
| static void execute_one(); |
| extern unsigned long long procid; |
| |
| static void loop() |
| { |
| int iter; |
| for (iter = 0;; iter++) { |
| char cwdbuf[32]; |
| sprintf(cwdbuf, "./%d", iter); |
| if (mkdir(cwdbuf, 0777)) |
| fail("failed to mkdir"); |
| 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); |
| } |
| int pid = fork(); |
| if (pid < 0) |
| fail("clone failed"); |
| if (pid == 0) { |
| prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); |
| setpgrp(); |
| if (chdir(cwdbuf)) |
| fail("failed to chdir"); |
| execute_one(); |
| doexit(0); |
| } |
| |
| int status = 0; |
| uint64_t start = current_time_ms(); |
| for (;;) { |
| int res = waitpid(-1, &status, __WALL | WNOHANG); |
| if (res == pid) { |
| break; |
| } |
| usleep(1000); |
| if (current_time_ms() - start < 3 * 1000) |
| continue; |
| kill(-pid, SIGKILL); |
| kill(pid, SIGKILL); |
| while (waitpid(-1, &status, __WALL) != pid) { |
| } |
| break; |
| } |
| remove_dir(cwdbuf); |
| } |
| } |
| |
| struct thread_t { |
| int created, running, call; |
| pthread_t th; |
| }; |
| |
| static struct thread_t threads[16]; |
| static void execute_call(int call); |
| static int running; |
| static int collide; |
| |
| static void* thr(void* arg) |
| { |
| struct thread_t* th = (struct thread_t*)arg; |
| for (;;) { |
| while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) |
| syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); |
| execute_call(th->call); |
| __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); |
| __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); |
| syscall(SYS_futex, &th->running, FUTEX_WAKE); |
| } |
| return 0; |
| } |
| |
| static void execute(int num_calls) |
| { |
| int call, thread; |
| running = 0; |
| for (call = 0; call < num_calls; call++) { |
| for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { |
| struct thread_t* th = &threads[thread]; |
| if (!th->created) { |
| th->created = 1; |
| pthread_attr_t attr; |
| pthread_attr_init(&attr); |
| pthread_attr_setstacksize(&attr, 128 << 10); |
| pthread_create(&th->th, &attr, thr, th); |
| } |
| if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { |
| th->call = call; |
| __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); |
| __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); |
| syscall(SYS_futex, &th->running, FUTEX_WAKE); |
| if (collide && call % 2) |
| break; |
| struct timespec ts; |
| ts.tv_sec = 0; |
| ts.tv_nsec = 20 * 1000 * 1000; |
| syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); |
| if (running) |
| usleep((call == num_calls - 1) ? 10000 : 1000); |
| break; |
| } |
| } |
| } |
| } |
| |
| unsigned long long procid; |
| void execute_call(int call) |
| { |
| switch (call) { |
| case 0: |
| memcpy((void*)0x20000000, "./file0", 8); |
| memcpy((void*)0x20abf000, "./file0", 8); |
| memcpy((void*)0x20f4c000, "jfs", 4); |
| syscall(__NR_mount, 0x20000000, 0x20abf000, 0x20f4c000, 0x1023402, 0); |
| break; |
| case 1: |
| *(uint32_t*)0x20000040 = 0; |
| *(uint32_t*)0x20000044 = -1; |
| syscall(__NR_ioctl, -1, 0x4008af22, 0x20000040); |
| break; |
| case 2: |
| memcpy((void*)0x200000c0, "bfs", 4); |
| memcpy((void*)0x20000100, "./file0", 8); |
| syz_mount_image(0x200000c0, 0x20000100, 0, 0, 0x20000240, 0x2000420, 0); |
| break; |
| } |
| } |
| |
| void execute_one() |
| { |
| execute(3); |
| collide = 1; |
| execute(3); |
| } |
| |
| int main() |
| { |
| syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); |
| char* cwd = get_current_dir_name(); |
| for (procid = 0; procid < 8; procid++) { |
| if (fork() == 0) { |
| for (;;) { |
| if (chdir(cwd)) |
| fail("failed to chdir"); |
| use_temporary_dir(); |
| loop(); |
| } |
| } |
| } |
| sleep(1000000); |
| return 0; |
| } |