// https://syzkaller.appspot.com/bug?id=90a4811c99d6a2df7b252971b754612ca632894d // 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 static unsigned long long procid; static __thread int clone_ongoing; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { exit(sig); } 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_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ ({ \ int ok = 1; \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } else \ ok = 0; \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ ok; \ }) static void kill_and_wait(int pid, int* status) { kill(pid, SIGKILL); while (waitpid(-1, status, 0) != pid) { } } 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 __attribute__((noinline)) remove_dir(const char* dir) { DIR* dp = opendir(dir); if (dp == NULL) { if (errno == EACCES) { if (rmdir(dir)) exit(1); return; } 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); struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } if (unlink(filename)) exit(1); } closedir(dp); if (rmdir(dir)) exit(1); } #define __syscall syscall static void sandbox_common() { if (setsid() == -1) exit(1); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); } static void loop(); static int do_sandbox_none(void) { sandbox_common(); loop(); return 0; } static void execute_one(void); #define WAIT_FLAGS 0 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); 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); } } uint64_t r[5] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; res = syscall(SYS_socketpair, 1ul, 1ul, 0, 0x20000140ul); if (res != -1) NONFAILING(r[0] = *(uint32_t*)0x20000140); res = syscall(SYS_socket, 0x18ul, 0xc002ul, 0); if (res != -1) r[1] = res; res = syscall(SYS_socket, 0x18ul, 2ul, 0); if (res != -1) r[2] = res; NONFAILING(*(uint16_t*)0x200000c0 = 0x18e6); NONFAILING(*(uint8_t*)0x200000c2 = 7); NONFAILING(*(uint32_t*)0x200000c4 = 0); syscall(SYS_connect, r[2], 0x200000c0ul, 0x1cul); NONFAILING(*(uint32_t*)0x20000040 = 0xffffff19); syscall(SYS_getsockname, r[2], 0x200000c0ul, 0x20000040ul); NONFAILING(*(uint16_t*)0x200000c0 = 0x18e6); NONFAILING(*(uint8_t*)0x200000c2 = 7); NONFAILING(*(uint32_t*)0x200000c4 = 0); syscall(SYS_connect, r[1], 0x200000c0ul, 0x1cul); syscall(SYS_dup2, r[1], r[0]); res = syscall(SYS_dup, r[0]); if (res != -1) r[3] = res; syscall(SYS_ioctl, -1, 0x80085762ul, 0ul); res = syscall(SYS_socket, 0x400000000018ul, 3ul, 0x3a); if (res != -1) r[4] = res; syscall(SYS_ioctl, -1, 0x802c7414ul, 0ul); syscall(SYS_socket, 0x18ul, 2ul, 0); syscall(SYS_getsockname, r[2], 0ul, 0ul); syscall(SYS_connect, r[1], 0ul, 0ul); syscall(SYS_setsockopt, r[4], 0x29, 0x6c, 0ul, 0ul); syscall(SYS_sendto, r[3], 0ul, 0ul, 0ul, 0ul, 0ul); } int main(void) { syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x1012ul, -1, 0ul); install_segv_handler(); for (procid = 0; procid < 8; procid++) { if (fork() == 0) { use_temporary_dir(); do_sandbox_none(); } } sleep(1000000); return 0; }