// https://syzkaller.appspot.com/bug?id=06bf6d5e0baeabdedeba2bc300abf20a7a150e11 // 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 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 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"); } #define USLEEP_FORKED_CHILD (3 * 50 * 1000) static long handle_clone_ret(long ret) { if (ret != 0) { return ret; } usleep(USLEEP_FORKED_CHILD); syscall(__NR_exit, 0); while (1) { } } static long syz_clone(volatile long flags, volatile long stack, volatile long stack_len, volatile long ptid, volatile long ctid, volatile long tls) { long sp = (stack + stack_len) & ~15; long ret = (long)syscall(__NR_clone, flags & ~CLONE_VM, sp, ptid, ctid, tls); return handle_clone_ret(ret); } 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[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // syz_clone arguments: [ // flags: clone_flags = 0x81000180 (8 bytes) // stack: ptr[in, buffer] { // buffer: {} (length 0x0) // } // stack_len: bytesize = 0x0 (8 bytes) // parentid: ptr[out, int32] { // int32 = 0x0 (4 bytes) // } // childtid: nil // tls: nil // ] // returns pid syz_clone( /*flags=CLONE_NEWTIME|CLONE_IO|CLONE_CHILD_SETTID|CLONE_VM*/ 0x81000180, /*stack=*/0x200000000100, /*stack_len=*/0, /*parentid=*/0x200000000200, /*childtid=*/0, /*tls=*/0); // mkdirat arguments: [ // fd: fd_dir (resource) // path: nil // mode: open_mode = 0x22 (8 bytes) // ] syscall(__NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0ul, /*mode=S_IWOTH|S_IRGRP*/ 0x22ul); // openat$fuse arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 66 75 73 65 00} (length 0xa) // } // flags: const = 0x2 (4 bytes) // mode: const = 0x0 (2 bytes) // ] // returns fd_fuse memcpy((void*)0x200000000300, "/dev/fuse\000", 10); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000300ul, /*flags=*/2, /*mode=*/0); if (res != -1) r[0] = res; // arch_prctl$ARCH_SHSTK_LOCK arguments: [ // cmd: const = 0x5003 (8 bytes) // features: shadow_stack_features = 0x1 (8 bytes) // ] syscall(__NR_arch_prctl, /*cmd=*/0x5003ul, /*features=ARCH_SHSTK_SHSTK*/ 1ul); // read$FUSE arguments: [ // fd: fd_fuse (resource) // buf: nil // len: bytesize = 0x0 (8 bytes) // ] syscall(__NR_read, /*fd=*/r[0], /*buf=*/0ul, /*len=*/0ul); // write arguments: [ // fd: fd (resource) // buf: nil // count: len = 0x0 (8 bytes) // ] syscall(__NR_write, /*fd=*/(intptr_t)-1, /*buf=*/0ul, /*count=*/0ul); } 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 < 4; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }