// https://syzkaller.appspot.com/bug?id=7349616606afa3c986c377792f7ccbf9daae1142 // 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); } 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; const int umount_flags = MNT_FORCE | UMOUNT_NOFOLLOW; retry: while (umount2(dir, umount_flags) == 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, umount_flags) == 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, umount_flags)) 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, umount_flags)) 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"); if (symlink("/dev/binderfs", "./binderfs")) { } } 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 < 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, 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++) { 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 (;;) { 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; } remove_dir(cwdbuf); } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: // prlimit64 arguments: [ // pid: pid (resource) // res: rlimit_type = 0xe (8 bytes) // new: ptr[in, rlimit] { // rlimit { // soft: intptr = 0x7 (8 bytes) // hard: intptr = 0x100 (8 bytes) // } // } // old: nil // ] *(uint64_t*)0x200000000140 = 7; *(uint64_t*)0x200000000148 = 0x100; syscall(__NR_prlimit64, /*pid=*/0, /*res=RLIMIT_RTPRIO*/ 0xeul, /*new=*/0x200000000140ul, /*old=*/0ul); break; case 1: // sched_setscheduler arguments: [ // pid: pid (resource) // policy: sched_policy = 0x1 (8 bytes) // prio: ptr[in, int32] { // int32 = 0x7 (4 bytes) // } // ] *(uint32_t*)0x200000000240 = 7; syscall(__NR_sched_setscheduler, /*pid=*/0, /*policy=SCHED_FIFO*/ 1ul, /*prio=*/0x200000000240ul); break; case 2: // openat$vhost_vsock arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 76 68 6f 73 74 2d 76 73 6f 63 6b 00} (length // 0x11) // } // flags: const = 0x2 (4 bytes) // mode: const = 0x0 (2 bytes) // ] // returns vhost_vsock memcpy((void*)0x2000000015c0, "/dev/vhost-vsock\000", 17); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x2000000015c0ul, /*flags=*/2, /*mode=*/0); if (res != -1) r[0] = res; break; case 3: // ioctl$VHOST_SET_VRING_BASE arguments: [ // fd: fd_vhost (resource) // cmd: const = 0xaf01 (4 bytes) // arg: nil // ] syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xaf01, /*arg=*/0ul); break; case 4: // eventfd arguments: [ // initval: int32 = 0x0 (4 bytes) // ] // returns fd_event res = syscall(__NR_eventfd, /*initval=*/0); if (res != -1) r[1] = res; break; case 5: // ioctl$VHOST_SET_LOG_FD arguments: [ // fd: fd_vhost (resource) // cmd: const = 0x4004af07 (4 bytes) // arg: ptr[in, fd_event] { // fd_event (resource) // } // ] *(uint32_t*)0x200000000000 = r[1]; syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4004af07, /*arg=*/0x200000000000ul); break; case 6: // ioctl$VHOST_SET_VRING_KICK arguments: [ // fd: fd_vhost (resource) // cmd: const = 0x4008af20 (4 bytes) // arg: ptr[in, vhost_vring_file] { // vhost_vring_file { // index: vhost_vring_index = 0x1 (4 bytes) // fd: fd_event (resource) // } // } // ] *(uint32_t*)0x200000000040 = 1; *(uint32_t*)0x200000000044 = r[1]; syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4008af20, /*arg=*/0x200000000040ul); break; case 7: // ioctl$VHOST_SET_VRING_ADDR arguments: [ // fd: fd_vhost (resource) // cmd: const = 0x4028af11 (4 bytes) // arg: ptr[in, vhost_vring_addr] { // vhost_vring_addr { // index: vhost_vring_index = 0x0 (4 bytes) // flags: int32 = 0x0 (4 bytes) // desc_user_addr: nil // used_user_addr: ptr[out, buffer] { // buffer: (DirOut) // } // avail_user_addr: nil // log_guest_addr: kvm_guest_addrs = 0x0 (8 bytes) // } // } // ] *(uint32_t*)0x200000000140 = 0; *(uint32_t*)0x200000000144 = 0; *(uint64_t*)0x200000000148 = 0; *(uint64_t*)0x200000000150 = 0x200000000180; *(uint64_t*)0x200000000158 = 0; *(uint64_t*)0x200000000160 = 0; syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4028af11, /*arg=*/0x200000000140ul); break; case 8: // ioctl$VHOST_SET_VRING_ADDR arguments: [ // fd: fd_vhost (resource) // cmd: const = 0x4028af11 (4 bytes) // arg: ptr[in, vhost_vring_addr] { // vhost_vring_addr { // index: vhost_vring_index = 0x1 (4 bytes) // flags: int32 = 0x1 (4 bytes) // desc_user_addr: nil // used_user_addr: ptr[out, buffer] { // buffer: (DirOut) // } // avail_user_addr: ptr[out, buffer] { // buffer: (DirOut) // } // log_guest_addr: kvm_guest_addrs = 0x0 (8 bytes) // } // } // ] *(uint32_t*)0x200000000780 = 1; *(uint32_t*)0x200000000784 = 1; *(uint64_t*)0x200000000788 = 0; *(uint64_t*)0x200000000790 = 0x200000000900; *(uint64_t*)0x200000000798 = 0x2000000000c0; *(uint64_t*)0x2000000007a0 = 0; syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4028af11, /*arg=*/0x200000000780ul); break; case 9: // ioctl$VHOST_SET_MEM_TABLE arguments: [ // fd: fd_vhost (resource) // cmd: const = 0x4008af03 (4 bytes) // arg: ptr[in, vhost_memory] { // vhost_memory { // nregions: len = 0x1 (4 bytes) // padding: const = 0x0 (4 bytes) // regions: array[vhost_memory_region] { // vhost_memory_region { // guest_phys_addr: kvm_guest_addrs = 0x0 (8 bytes) // memory_size: bytesize = 0xfffffeac (8 bytes) // userspace_addr: ptr[out, buffer] { // buffer: (DirOut) // } // flags_padding: const = 0x0 (8 bytes) // } // } // } // } // ] *(uint32_t*)0x200000000680 = 1; *(uint32_t*)0x200000000684 = 0; *(uint64_t*)0x200000000688 = 0; *(uint64_t*)0x200000000690 = 0xfffffeac; *(uint64_t*)0x200000000698 = 0x2000000001c0; *(uint64_t*)0x2000000006a0 = 0; syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4008af03, /*arg=*/0x200000000680ul); break; case 10: // ioctl$VHOST_VSOCK_SET_RUNNING arguments: [ // fd: vhost_vsock (resource) // cmd: const = 0x4004af61 (4 bytes) // arg: ptr[in, int32] { // int32 = 0x1 (4 bytes) // } // ] *(uint32_t*)0x200000000980 = 1; syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4004af61, /*arg=*/0x200000000980ul); break; case 11: // prctl$PR_SCHED_CORE arguments: [ // option: const = 0x3e (8 bytes) // cmd: intptr = 0x1 (8 bytes) // pid: pid (resource) // type: pid_type = 0x2 (8 bytes) // uaddr: nil // ] syscall(__NR_prctl, /*option=*/0x3eul, /*cmd=*/1ul, /*pid=*/0, /*type=PIDTYPE_PGID*/ 2ul, /*uaddr=*/0ul); 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; for (procid = 0; procid < 5; procid++) { if (fork() == 0) { use_temporary_dir(); loop(); } } sleep(1000000); return 0; }