// autogenerated by syzkaller (http://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 __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include 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 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"); } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_AS, &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); unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_IO); } 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) { close(fd); return false; } close(fd); return true; } static int real_uid; static int real_gid; __attribute__((aligned(64 << 10))) static char sandbox_stack[1 << 20]; static int namespace_sandbox_proc(void* arg) { sandbox_common(); write_file("/proc/self/setgroups", "deny"); if (!write_file("/proc/self/uid_map", "0 %d 1\n", real_uid)) fail("write of /proc/self/uid_map failed"); if (!write_file("/proc/self/gid_map", "0 %d 1\n", real_gid)) fail("write of /proc/self/gid_map failed"); if (mkdir("./syz-tmp", 0777)) fail("mkdir(syz-tmp) failed"); if (mount("", "./syz-tmp", "tmpfs", 0, NULL)) fail("mount(tmpfs) failed"); if (mkdir("./syz-tmp/newroot", 0777)) fail("mkdir failed"); if (mkdir("./syz-tmp/newroot/dev", 0700)) fail("mkdir failed"); if (mount("/dev", "./syz-tmp/newroot/dev", NULL, MS_BIND | MS_REC | MS_PRIVATE, NULL)) fail("mount(dev) failed"); if (mkdir("./syz-tmp/newroot/proc", 0700)) fail("mkdir failed"); if (mount(NULL, "./syz-tmp/newroot/proc", "proc", 0, NULL)) fail("mount(proc) failed"); if (mkdir("./syz-tmp/pivot", 0777)) fail("mkdir failed"); if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) { if (chdir("./syz-tmp")) fail("chdir failed"); } else { if (chdir("/")) fail("chdir failed"); if (umount2("./pivot", MNT_DETACH)) fail("umount failed"); } if (chroot("./newroot")) fail("chroot failed"); if (chdir("/")) fail("chdir failed"); struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) fail("capget failed"); cap_data[0].effective &= ~(1 << CAP_SYS_PTRACE); cap_data[0].permitted &= ~(1 << CAP_SYS_PTRACE); cap_data[0].inheritable &= ~(1 << CAP_SYS_PTRACE); if (syscall(SYS_capset, &cap_hdr, &cap_data)) fail("capset failed"); loop(); doexit(1); } static int do_sandbox_namespace(int executor_pid, bool enable_tun) { real_uid = getuid(); real_gid = getgid(); mprotect(sandbox_stack, 4096, PROT_NONE); return clone( namespace_sandbox_proc, &sandbox_stack[sizeof(sandbox_stack) - 64], CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWUTS | CLONE_NEWNET, NULL); } long r[19]; void* thr(void* arg) { switch ((long)arg) { case 0: r[0] = syscall(__NR_mmap, 0x20000000ul, 0xb50000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); break; case 1: r[1] = syscall(__NR_socket, 0x2ul, 0x1ul, 0x84ul); break; case 2: r[2] = syscall(__NR_listen, r[1], 0x11000000000000c8ul); break; case 3: *(uint32_t*)0x20137ffc = (uint32_t)0x10; r[4] = syscall(__NR_accept4, r[1], 0x20b53ff0ul, 0x20137ffcul, 0x80000ul); break; case 4: r[5] = syscall(__NR_listen, r[1], 0x0ul); break; case 5: memcpy((void*)0x20001f98, "\x37\x55\xce\xcb\x8e\xcf\xa3\x3e\xce\xd6" "\x58\xb4\x6a\x02\x8c\xba\x45\x65\xdf\xf3" "\x3d\xff\x05\x00\x23\x77", 26); *(uint16_t*)0x20944000 = (uint16_t)0x2; *(uint16_t*)0x20944002 = (uint16_t)0x234e; *(uint32_t*)0x20944004 = (uint32_t)0x100007f; *(uint8_t*)0x20944008 = (uint8_t)0x0; *(uint8_t*)0x20944009 = (uint8_t)0x0; *(uint8_t*)0x2094400a = (uint8_t)0x0; *(uint8_t*)0x2094400b = (uint8_t)0x0; *(uint8_t*)0x2094400c = (uint8_t)0x0; *(uint8_t*)0x2094400d = (uint8_t)0x0; *(uint8_t*)0x2094400e = (uint8_t)0x0; *(uint8_t*)0x2094400f = (uint8_t)0x0; r[18] = syscall(__NR_sendto, r[1], 0x20001f98ul, 0x1aul, 0x4ul, 0x20944000ul, 0x10ul); break; } return 0; } void loop() { long i; pthread_t th[12]; memset(r, -1, sizeof(r)); srand(getpid()); for (i = 0; i < 6; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(rand() % 10000); } for (i = 0; i < 6; i++) { pthread_create(&th[6 + i], 0, thr, (void*)i); if (rand() % 2) usleep(rand() % 10000); } usleep(rand() % 100000); } int main() { use_temporary_dir(); int pid = do_sandbox_namespace(0, false); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }