// https://syzkaller.appspot.com/bug?id=0d259373da8be7356652213543e1efc254a5abf0 // 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 #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 exitf(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(kRetryStatus); } static uint64_t current_time_ms() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } 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); #define CLONE_NEWCGROUP 0x02000000 unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_NEWCGROUP); unshare(CLONE_NEWNET); unshare(CLONE_NEWUTS); unshare(CLONE_SYSVSEM); } 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) { int pid; real_uid = getuid(); real_gid = getgid(); mprotect(sandbox_stack, 4096, PROT_NONE); pid = clone(namespace_sandbox_proc, &sandbox_stack[sizeof(sandbox_stack) - 64], CLONE_NEWUSER | CLONE_NEWPID, NULL); if (pid < 0) fail("sandbox clone failed"); return pid; } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting"); } exitf("opendir(%s) failed", dir); } 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)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } } static void test(); void loop() { int iter; for (iter = 0;; iter++) { char cwdbuf[256]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); test(); doexit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(-1, &status, __WALL | WNOHANG); if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } } remove_dir(cwdbuf); } } long r[3]; void* thr(void* arg) { switch ((long)arg) { case 0: syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); break; case 1: memcpy((void*)0x20e37000, "/dev/kvm", 9); r[0] = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20e37000ul, 0x0ul, 0x0ul); break; case 2: r[1] = syscall(__NR_ioctl, r[0], 0xae01ul, 0x0ul); break; case 3: r[2] = syscall(__NR_ioctl, r[1], 0xae41ul, 0x0ul); break; case 4: *(uint64_t*)0x2099afd0 = (uint64_t)0x2000; *(uint32_t*)0x2099afd8 = (uint32_t)0x6000; *(uint16_t*)0x2099afdc = (uint16_t)0xa; *(uint8_t*)0x2099afde = (uint8_t)0x11; *(uint8_t*)0x2099afdf = (uint8_t)0xff; *(uint8_t*)0x2099afe0 = (uint8_t)0x5e3fc9f4; *(uint8_t*)0x2099afe1 = (uint8_t)0x1; *(uint8_t*)0x2099afe2 = (uint8_t)0x81; *(uint8_t*)0x2099afe3 = (uint8_t)0x0; *(uint8_t*)0x2099afe4 = (uint8_t)0x6; *(uint8_t*)0x2099afe5 = (uint8_t)0x4; *(uint8_t*)0x2099afe6 = (uint8_t)0x101; *(uint8_t*)0x2099afe7 = (uint8_t)0x0; *(uint64_t*)0x2099afe8 = (uint64_t)0xf000; *(uint32_t*)0x2099aff0 = (uint32_t)0xd000; *(uint16_t*)0x2099aff4 = (uint16_t)0x0; *(uint8_t*)0x2099aff6 = (uint8_t)0x7; *(uint8_t*)0x2099aff7 = (uint8_t)0x1000; *(uint8_t*)0x2099aff8 = (uint8_t)0x1205; *(uint8_t*)0x2099aff9 = (uint8_t)0x3; *(uint8_t*)0x2099affa = (uint8_t)0x80000000; *(uint8_t*)0x2099affb = (uint8_t)0xb27; *(uint8_t*)0x2099affc = (uint8_t)0x5; *(uint8_t*)0x2099affd = (uint8_t)0x9; *(uint8_t*)0x2099affe = (uint8_t)0x0; *(uint8_t*)0x2099afff = (uint8_t)0x0; *(uint64_t*)0x2099b000 = (uint64_t)0x3000; *(uint32_t*)0x2099b008 = (uint32_t)0x0; *(uint16_t*)0x2099b00c = (uint16_t)0xf; *(uint8_t*)0x2099b00e = (uint8_t)0x80000000; *(uint8_t*)0x2099b00f = (uint8_t)0x1ff; *(uint8_t*)0x2099b010 = (uint8_t)0x7ff; *(uint8_t*)0x2099b011 = (uint8_t)0x1; *(uint8_t*)0x2099b012 = (uint8_t)0x7; *(uint8_t*)0x2099b013 = (uint8_t)0xf84; *(uint8_t*)0x2099b014 = (uint8_t)0x1ff; *(uint8_t*)0x2099b015 = (uint8_t)0x2; *(uint8_t*)0x2099b016 = (uint8_t)0x1000; *(uint8_t*)0x2099b017 = (uint8_t)0x0; *(uint64_t*)0x2099b018 = (uint64_t)0x3000; *(uint32_t*)0x2099b020 = (uint32_t)0x10000; *(uint16_t*)0x2099b024 = (uint16_t)0x8; *(uint8_t*)0x2099b026 = (uint8_t)0x1; *(uint8_t*)0x2099b027 = (uint8_t)0x7; *(uint8_t*)0x2099b028 = (uint8_t)0x9de1; *(uint8_t*)0x2099b029 = (uint8_t)0xffffffffffffffc1; *(uint8_t*)0x2099b02a = (uint8_t)0x7; *(uint8_t*)0x2099b02b = (uint8_t)0x7fff; *(uint8_t*)0x2099b02c = (uint8_t)0x9; *(uint8_t*)0x2099b02d = (uint8_t)0x1; *(uint8_t*)0x2099b02e = (uint8_t)0x89fd; *(uint8_t*)0x2099b02f = (uint8_t)0x0; *(uint64_t*)0x2099b030 = (uint64_t)0x2; *(uint32_t*)0x2099b038 = (uint32_t)0x1000; *(uint16_t*)0x2099b03c = (uint16_t)0x86ef34c8e8fc3ca8; *(uint8_t*)0x2099b03e = (uint8_t)0xdc33; *(uint8_t*)0x2099b03f = (uint8_t)0xffffffff; *(uint8_t*)0x2099b040 = (uint8_t)0xae13; *(uint8_t*)0x2099b041 = (uint8_t)0x100000000; *(uint8_t*)0x2099b042 = (uint8_t)0x10000; *(uint8_t*)0x2099b043 = (uint8_t)0x5; *(uint8_t*)0x2099b044 = (uint8_t)0xfff; *(uint8_t*)0x2099b045 = (uint8_t)0x4; *(uint8_t*)0x2099b046 = (uint8_t)0x7; *(uint8_t*)0x2099b047 = (uint8_t)0x0; *(uint64_t*)0x2099b048 = (uint64_t)0x100000; *(uint32_t*)0x2099b050 = (uint32_t)0xd004; *(uint16_t*)0x2099b054 = (uint16_t)0x4; *(uint8_t*)0x2099b056 = (uint8_t)0x3; *(uint8_t*)0x2099b057 = (uint8_t)0x4; *(uint8_t*)0x2099b058 = (uint8_t)0x1; *(uint8_t*)0x2099b059 = (uint8_t)0xfffffffffffffb53; *(uint8_t*)0x2099b05a = (uint8_t)0x9b; *(uint8_t*)0x2099b05b = (uint8_t)0x1; *(uint8_t*)0x2099b05c = (uint8_t)0x2; *(uint8_t*)0x2099b05d = (uint8_t)0x3; *(uint8_t*)0x2099b05e = (uint8_t)0x2; *(uint8_t*)0x2099b05f = (uint8_t)0x0; *(uint64_t*)0x2099b060 = (uint64_t)0x6001; *(uint32_t*)0x2099b068 = (uint32_t)0xd000; *(uint16_t*)0x2099b06c = (uint16_t)0x0; *(uint8_t*)0x2099b06e = (uint8_t)0x64d; *(uint8_t*)0x2099b06f = (uint8_t)0x9; *(uint8_t*)0x2099b070 = (uint8_t)0xba70; *(uint8_t*)0x2099b071 = (uint8_t)0xfff; *(uint8_t*)0x2099b072 = (uint8_t)0x1000; *(uint8_t*)0x2099b073 = (uint8_t)0x22; *(uint8_t*)0x2099b074 = (uint8_t)0x88e; *(uint8_t*)0x2099b075 = (uint8_t)0x91; *(uint8_t*)0x2099b076 = (uint8_t)0x8; *(uint8_t*)0x2099b077 = (uint8_t)0x0; *(uint64_t*)0x2099b078 = (uint64_t)0x0; *(uint32_t*)0x2099b080 = (uint32_t)0xf002; *(uint16_t*)0x2099b084 = (uint16_t)0x19; *(uint8_t*)0x2099b086 = (uint8_t)0x4; *(uint8_t*)0x2099b087 = (uint8_t)0x5; *(uint8_t*)0x2099b088 = (uint8_t)0x3; *(uint8_t*)0x2099b089 = (uint8_t)0x0; *(uint8_t*)0x2099b08a = (uint8_t)0x7; *(uint8_t*)0x2099b08b = (uint8_t)0x8; *(uint8_t*)0x2099b08c = (uint8_t)0x8; *(uint8_t*)0x2099b08d = (uint8_t)0x9; *(uint8_t*)0x2099b08e = (uint8_t)0x100; *(uint8_t*)0x2099b08f = (uint8_t)0x0; *(uint64_t*)0x2099b090 = (uint64_t)0x3000; *(uint16_t*)0x2099b098 = (uint16_t)0xf000; *(uint16_t*)0x2099b09a = (uint16_t)0x0; *(uint16_t*)0x2099b09c = (uint16_t)0x0; *(uint16_t*)0x2099b09e = (uint16_t)0x0; *(uint64_t*)0x2099b0a0 = (uint64_t)0x2000; *(uint16_t*)0x2099b0a8 = (uint16_t)0x3000; *(uint16_t*)0x2099b0aa = (uint16_t)0x0; *(uint16_t*)0x2099b0ac = (uint16_t)0x0; *(uint16_t*)0x2099b0ae = (uint16_t)0x0; *(uint64_t*)0x2099b0b0 = (uint64_t)0x1; *(uint64_t*)0x2099b0b8 = (uint64_t)0x0; *(uint64_t*)0x2099b0c0 = (uint64_t)0x10d000; *(uint64_t*)0x2099b0c8 = (uint64_t)0x100000; *(uint64_t*)0x2099b0d0 = (uint64_t)0x2; *(uint64_t*)0x2099b0d8 = (uint64_t)0x100; *(uint64_t*)0x2099b0e0 = (uint64_t)0x7002; *(uint64_t*)0x2099b0e8 = (uint64_t)0x2; *(uint64_t*)0x2099b0f0 = (uint64_t)0x8; *(uint64_t*)0x2099b0f8 = (uint64_t)0x2; *(uint64_t*)0x2099b100 = (uint64_t)0x80000001; syscall(__NR_ioctl, r[2], 0x4138ae84ul, 0x2099afd0ul); break; } return 0; } void test() { long i; pthread_t th[10]; memset(r, -1, sizeof(r)); srand(getpid()); for (i = 0; i < 5; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(rand() % 10000); } for (i = 0; i < 5; i++) { pthread_create(&th[5 + i], 0, thr, (void*)i); if (rand() % 2) usleep(rand() % 10000); } usleep(rand() % 100000); } int main() { int i; for (i = 0; i < 8; i++) { if (fork() == 0) { use_temporary_dir(); int pid = do_sandbox_namespace(i, false); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; } } sleep(1000000); return 0; }