| // WARNING in refcount_sub_and_test |
| // https://syzkaller.appspot.com/bug?id=1665547180092fef185a46d5a4ba5b382d77848e |
| // status:fixed |
| // autogenerated by syzkaller (http://github.com/google/syzkaller) |
| |
| #define _GNU_SOURCE |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/capability.h> |
| #include <pthread.h> |
| #include <sched.h> |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/mman.h> |
| #include <sys/mount.h> |
| #include <sys/prctl.h> |
| #include <sys/resource.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/time.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| __attribute__((noreturn)) static void doexit(int status) |
| { |
| volatile unsigned i; |
| syscall(__NR_exit_group, status); |
| for (i = 0;; i++) { |
| } |
| } |
| |
| #include <errno.h> |
| #include <stdarg.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| |
| 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); |
| } |
| |
| #ifndef __NR_sendto |
| #define __NR_sendto 369 |
| #endif |
| #ifndef __NR_mmap |
| #define __NR_mmap 90 |
| #endif |
| #ifndef __NR_socket |
| #define __NR_socket 359 |
| #endif |
| #ifndef __NR_listen |
| #define __NR_listen 363 |
| #endif |
| #ifndef __NR_accept4 |
| #define __NR_accept4 364 |
| #endif |
| #undef __NR_mmap |
| #define __NR_mmap __NR_mmap2 |
| |
| 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; |
| } |