// https://syzkaller.appspot.com/bug?id=d229f74aba6a7a9700e4cf1997ac1ae5236862c9 // 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 static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; int valid = addr < prog_start || addr > prog_end; if (skip && valid) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ { \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ } 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 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; retry: while (umount2(dir, MNT_DETACH) == 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) == 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)) 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)) 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"); } 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 (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5 * 1000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; res = syscall(__NR_socket, 0x1eul, 1ul, 0); if (res != -1) r[0] = res; NONFAILING(*(uint64_t*)0x20000000 = 0x20000080); NONFAILING(*(uint16_t*)0x20000080 = 0x1e); NONFAILING(memcpy((void*)0x20000082, "\x02\xff\x01\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00" "\x0a\xe7\x7f\x5b\xf8\x6c\x48\x02\x00\x02\x00\x00\x00\xf1" "\xff\xff\xff\x00\x9a\x48\x00\x75\xe6\xa5\x00\x00\xde\x01" "\x03\x00\x00\x00\x00\xe4\xff\x06\x4b\x3f\x01\x3a\x00\x00" "\x00\x08\x00\x00\x00\x8f\x00\x00\x00\x00\xac\x50\xd5\xfe" "\x32\xc4\x00\x00\x00\x00\x7f\xff\xff\xff\x6a\x00\x83\x56" "\xed\xb9\xa6\x34\x1c\x1f\xd4\x56\x24\x28\x1e\x00\x07\x0e" "\xcd\xdd\x02\x06\xc3\x97\x50\xc4\x00\x00\xfd\x00\x00\x09" "\x00\x00\x00\x00\x00\x0b\x00\x00\xdb\x00\x00\x04\xda\x36", 126)); NONFAILING(*(uint32_t*)0x20000008 = 0x80); NONFAILING(*(uint64_t*)0x20000010 = 0); NONFAILING(*(uint64_t*)0x20000018 = 0); NONFAILING(*(uint64_t*)0x20000020 = 0); NONFAILING(*(uint64_t*)0x20000028 = 0); NONFAILING(*(uint32_t*)0x20000030 = 0); syscall(__NR_sendmsg, r[0], 0x20000000ul, 0ul); syscall(__NR_write, r[0], 0x200001c0ul, 0xfffffd6dul); } 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); install_segv_handler(); use_temporary_dir(); loop(); return 0; }