syzkaller-repros/linux/233a27e0c6c9f5e9ef06eceeaf119522d2c83265.c

// KASAN: alloca-out-of-bounds Read in unwind_next_frame
// https://syzkaller.appspot.com/bug?id=233a27e0c6c9f5e9ef06eceeaf119522d2c83265
// status:invalid
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <net/if_arp.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/uio.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 <setjmp.h>
#include <signal.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 __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* uctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _longjmp(segv_env, 1);
  }
  doexit(sig);
}

static void install_segv_handler()
{
  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 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 vsnprintf_check(char* str, size_t size, const char* format,
                            va_list args)
{
  int rv;

  rv = vsnprintf(str, size, format, args);
  if (rv < 0)
    fail("tun: snprintf failed");
  if ((size_t)rv >= size)
    fail("tun: string '%s...' doesn't fit into buffer", str);
}

static void snprintf_check(char* str, size_t size, const char* format, ...)
{
  va_list args;

  va_start(args, format);
  vsnprintf_check(str, size, format, args);
  va_end(args);
}

#define COMMAND_MAX_LEN 128
#define PATH_PREFIX                                                            \
  "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin "
#define PATH_PREFIX_LEN (sizeof(PATH_PREFIX) - 1)

static void execute_command(bool panic, const char* format, ...)
{
  va_list args;
  char command[PATH_PREFIX_LEN + COMMAND_MAX_LEN];
  int rv;

  va_start(args, format);
  memcpy(command, PATH_PREFIX, PATH_PREFIX_LEN);
  vsnprintf_check(command + PATH_PREFIX_LEN, COMMAND_MAX_LEN, format, args);
  rv = system(command);
  if (panic && rv != 0)
    fail("tun: command \"%s\" failed with code %d", &command[0], rv);

  va_end(args);
}

static int tunfd = -1;
static int tun_frags_enabled;

#define SYZ_TUN_MAX_PACKET_SIZE 1000

#define TUN_IFACE "syz_tun"

#define LOCAL_MAC "aa:aa:aa:aa:aa:aa"
#define REMOTE_MAC "aa:aa:aa:aa:aa:bb"

#define LOCAL_IPV4 "172.20.20.170"
#define REMOTE_IPV4 "172.20.20.187"

#define LOCAL_IPV6 "fe80::aa"
#define REMOTE_IPV6 "fe80::bb"

#define IFF_NAPI 0x0010
#define IFF_NAPI_FRAGS 0x0020

static void initialize_tun(void)
{
  tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
  if (tunfd == -1) {
    printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n");
    printf("otherwise fuzzing or reproducing might not work as intended\n");
    return;
  }
  const int kTunFd = 252;
  if (dup2(tunfd, kTunFd) < 0)
    fail("dup2(tunfd, kTunFd) failed");
  close(tunfd);
  tunfd = kTunFd;

  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, TUN_IFACE, IFNAMSIZ);
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS;
  if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) {
    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
    if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0)
      fail("tun: ioctl(TUNSETIFF) failed");
  }
  if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0)
    fail("tun: ioctl(TUNGETIFF) failed");
  tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0;

  execute_command(1, "sysctl -w net.ipv6.conf.%s.accept_dad=0", TUN_IFACE);

  execute_command(1, "sysctl -w net.ipv6.conf.%s.router_solicitations=0",
                  TUN_IFACE);

  execute_command(1, "ip link set dev %s address %s", TUN_IFACE, LOCAL_MAC);
  execute_command(1, "ip addr add %s/24 dev %s", LOCAL_IPV4, TUN_IFACE);
  execute_command(1, "ip -6 addr add %s/120 dev %s", LOCAL_IPV6, TUN_IFACE);
  execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent",
                  REMOTE_IPV4, REMOTE_MAC, TUN_IFACE);
  execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent",
                  REMOTE_IPV6, REMOTE_MAC, TUN_IFACE);
  execute_command(1, "ip link set dev %s up", TUN_IFACE);
}

#define DEV_IPV4 "172.20.20.%d"
#define DEV_IPV6 "fe80::%02hx"
#define DEV_MAC "aa:aa:aa:aa:aa:%02hx"

static void initialize_netdevices(void)
{
  unsigned i;
  const char* devtypes[] = {"ip6gretap", "bridge", "vcan", "bond", "veth"};
  const char* devnames[] = {"lo",       "sit0",    "bridge0", "vcan0",
                            "tunl0",    "gre0",    "gretap0", "ip_vti0",
                            "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0",
                            "erspan0",  "bond0",   "veth0",   "veth1"};

  for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++)
    execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]);
  execute_command(0, "ip link add dev veth1 type veth");
  for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) {
    char addr[32];
    snprintf_check(addr, sizeof(addr), DEV_IPV4, i + 10);
    execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_IPV6, i + 10);
    execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_MAC, i + 10);
    execute_command(0, "ip link set dev %s address %s", devnames[i], addr);
    execute_command(0, "ip link set dev %s up", devnames[i]);
  }
}

static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    NONFAILING(strncpy(buf, (char*)a0, sizeof(buf)));
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

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 = 32 << 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);

  if (unshare(CLONE_NEWNS)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid < 0)
    fail("sandbox fork failed");
  if (pid)
    return pid;

  sandbox_common();
  if (unshare(CLONE_NEWNET)) {
  }
  initialize_tun();
  initialize_netdevices();

  loop();
  doexit(1);
}

static void execute_one();
extern unsigned long long procid;

void loop()
{
  while (1) {
    execute_one();
  }
}

struct thread_t {
  int created, running, call;
  pthread_t th;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;
static int collide;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
      syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
    syscall(SYS_futex, &th->running, FUTEX_WAKE);
  }
  return 0;
}

static void execute(int num_calls)
{
  int call, thread;
  running = 0;
  for (call = 0; call < num_calls; call++) {
    for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setstacksize(&attr, 128 << 10);
        pthread_create(&th->th, &attr, thr, th);
      }
      if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
        th->call = call;
        __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
        __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
        syscall(SYS_futex, &th->running, FUTEX_WAKE);
        if (collide && call % 2)
          break;
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[5] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff,
                 0xffffffffffffffff, 0x0};
unsigned long long procid;
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    NONFAILING(memcpy((void*)0x200003c0, "./file0", 8));
    syscall(__NR_truncate, 0x200003c0, 0xff);
    break;
  case 1:
    NONFAILING(memcpy((void*)0x20000480, "/dev/snd/seq", 13));
    syz_open_dev(0x20000480, 0, 0);
    break;
  case 2:
    syscall(__NR_socket, 0x10, 3, 0xf);
    break;
  case 3:
    NONFAILING(memcpy((void*)0x200002c0, "/dev/vcsa#", 11));
    res = syz_open_dev(0x200002c0, 0xfffffffffffffffd, 0x2000);
    if (res != -1)
      r[0] = res;
    break;
  case 4:
    NONFAILING(memcpy((void*)0x20000280, "/dev/sequencer", 15));
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000280, 0, 0);
    if (res != -1)
      r[1] = res;
    break;
  case 5:
    NONFAILING(
        memcpy((void*)0x20000b40,
               "\x49\x44\x4c\x45\x54\x49\x4d\x45\x52\x00\x00\x00\x00\x00\x00"
               "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
               29));
    NONFAILING(*(uint8_t*)0x20000b5d = 0);
    NONFAILING(*(uint32_t*)0x20000b80 = 0x1e);
    syscall(__NR_getsockopt, r[1], 0x29, 0x45, 0x20000b40, 0x20000b80);
    break;
  case 6:
    NONFAILING(*(uint32_t*)0x20000240 = 2);
    NONFAILING(memcpy(
        (void*)0x20000244,
        "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
        16));
    NONFAILING(*(uint32_t*)0x20000254 = 0);
    syscall(__NR_setsockopt, -1, 0, 0x48b, 0x20000240, 0x18);
    break;
  case 7:
    NONFAILING(memcpy((void*)0x20000380, "/dev/net/tun", 13));
    syz_open_dev(0x20000380, 0, 0x60441);
    break;
  case 8:
    NONFAILING(memcpy((void*)0x200000c0, "./file0", 8));
    NONFAILING(memcpy((void*)0x20000140, "trusted.syz", 12));
    NONFAILING(memcpy((void*)0x20000440, "/dev/sequencer", 15));
    syscall(__NR_lsetxattr, 0x200000c0, 0x20000140, 0x20000440, 0xf, 0);
    break;
  case 9:
    syscall(__NR_accept, -1, 0, 0);
    break;
  case 10:
    NONFAILING(memcpy((void*)0x20003800, "/dev/loop-control", 18));
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20003800, 0, 0);
    if (res != -1)
      r[2] = res;
    break;
  case 11:
    NONFAILING(memcpy((void*)0x20000080, "/dev/dsp", 9));
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000080, 0x101000, 0);
    if (res != -1)
      r[3] = res;
    break;
  case 12:
    NONFAILING(*(uint32_t*)0x200005c0 = 0x29);
    NONFAILING(*(uint32_t*)0x200005c4 = 3);
    NONFAILING(*(uint32_t*)0x200005c8 = 0);
    NONFAILING(*(uint32_t*)0x200005cc = 0);
    NONFAILING(*(uint32_t*)0x200005d0 = 0xad1c);
    NONFAILING(*(uint32_t*)0x200005d4 = 0x3ff);
    NONFAILING(*(uint8_t*)0x200005d8 = 0);
    NONFAILING(*(uint8_t*)0x200005d9 = 0);
    NONFAILING(*(uint8_t*)0x200005da = 0);
    NONFAILING(*(uint8_t*)0x200005db = 0);
    NONFAILING(*(uint8_t*)0x200005dc = 0);
    NONFAILING(*(uint8_t*)0x200005dd = 0);
    NONFAILING(*(uint8_t*)0x200005de = 0);
    NONFAILING(*(uint8_t*)0x200005df = 0);
    NONFAILING(*(uint8_t*)0x200005e0 = 0);
    NONFAILING(*(uint8_t*)0x200005e1 = 0);
    NONFAILING(*(uint8_t*)0x200005e2 = 0);
    NONFAILING(*(uint8_t*)0x200005e3 = 0);
    NONFAILING(*(uint8_t*)0x200005e4 = 0);
    NONFAILING(*(uint8_t*)0x200005e5 = 0);
    NONFAILING(*(uint8_t*)0x200005e6 = 0);
    NONFAILING(*(uint8_t*)0x200005e7 = 0);
    NONFAILING(*(uint8_t*)0x200005e8 = 0);
    NONFAILING(*(uint8_t*)0x200005e9 = 0);
    NONFAILING(*(uint8_t*)0x200005ea = 0);
    NONFAILING(*(uint8_t*)0x200005eb = 0);
    NONFAILING(*(uint8_t*)0x200005ec = 0);
    NONFAILING(*(uint8_t*)0x200005ed = 0);
    NONFAILING(*(uint8_t*)0x200005ee = 0);
    NONFAILING(*(uint8_t*)0x200005ef = 0);
    NONFAILING(*(uint8_t*)0x200005f0 = 0);
    NONFAILING(*(uint8_t*)0x200005f1 = 0);
    NONFAILING(*(uint8_t*)0x200005f2 = 0);
    NONFAILING(*(uint8_t*)0x200005f3 = 0);
    NONFAILING(*(uint8_t*)0x200005f4 = 0);
    NONFAILING(*(uint8_t*)0x200005f5 = 0);
    NONFAILING(*(uint8_t*)0x200005f6 = 0);
    NONFAILING(*(uint8_t*)0x200005f7 = 0);
    NONFAILING(*(uint8_t*)0x200005f8 = 0);
    NONFAILING(*(uint8_t*)0x200005f9 = 0);
    NONFAILING(*(uint8_t*)0x200005fa = 0);
    NONFAILING(*(uint8_t*)0x200005fb = 0);
    NONFAILING(*(uint8_t*)0x200005fc = 0);
    NONFAILING(*(uint8_t*)0x200005fd = 0);
    NONFAILING(*(uint8_t*)0x200005fe = 0);
    NONFAILING(*(uint8_t*)0x200005ff = 0);
    NONFAILING(*(uint8_t*)0x20000600 = 0);
    NONFAILING(*(uint8_t*)0x20000601 = 0);
    NONFAILING(*(uint8_t*)0x20000602 = 0);
    NONFAILING(*(uint8_t*)0x20000603 = 0);
    NONFAILING(*(uint8_t*)0x20000604 = 0);
    NONFAILING(*(uint8_t*)0x20000605 = 0);
    NONFAILING(*(uint8_t*)0x20000606 = 0);
    NONFAILING(*(uint8_t*)0x20000607 = 0);
    NONFAILING(*(uint8_t*)0x20000608 = 0);
    NONFAILING(*(uint8_t*)0x20000609 = 0);
    NONFAILING(*(uint8_t*)0x2000060a = 0);
    NONFAILING(*(uint8_t*)0x2000060b = 0);
    NONFAILING(*(uint8_t*)0x2000060c = 0);
    NONFAILING(*(uint8_t*)0x2000060d = 0);
    NONFAILING(*(uint8_t*)0x2000060e = 0);
    NONFAILING(*(uint8_t*)0x2000060f = 0);
    NONFAILING(*(uint8_t*)0x20000610 = 0);
    NONFAILING(*(uint8_t*)0x20000611 = 0);
    NONFAILING(*(uint8_t*)0x20000612 = 0);
    NONFAILING(*(uint8_t*)0x20000613 = 0);
    NONFAILING(*(uint8_t*)0x20000614 = 0);
    NONFAILING(*(uint8_t*)0x20000615 = 0);
    NONFAILING(*(uint8_t*)0x20000616 = 0);
    NONFAILING(*(uint8_t*)0x20000617 = 0);
    syscall(__NR_ioctl, r[3], 0xc058534b, 0x200005c0);
    break;
  case 13:
    syscall(__NR_restart_syscall);
    break;
  case 14:
    res = syscall(__NR_ioctl, r[2], 0x4c82);
    if (res != -1)
      r[4] = res;
    break;
  case 15:
    NONFAILING(memcpy((void*)0x20000680, "./file0", 8));
    syscall(__NR_umount2, 0x20000680, 0xf);
    break;
  case 16:
    syscall(__NR_ioctl, r[2], 0x4c81, r[4]);
    break;
  case 17:
    NONFAILING(
        memcpy((void*)0x20000300,
               "\x61\x68\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
               "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
               29));
    NONFAILING(*(uint8_t*)0x2000031d = 0);
    NONFAILING(*(uint32_t*)0x20000340 = 0x1e);
    syscall(__NR_getsockopt, r[1], 0x29, 0x45, 0x20000300, 0x20000340);
    break;
  case 18:
    syscall(__NR_ioctl, r[3], 0x400454ce, 0);
    break;
  case 19:
    NONFAILING(*(uint32_t*)0x20000180 = 8);
    syscall(__NR_setsockopt, r[0], 0x10c, 0, 0x20000180, 4);
    break;
  }
}

void execute_one()
{
  execute(20);
  collide = 1;
  execute(20);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  char* cwd = get_current_dir_name();
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      install_segv_handler();
      for (;;) {
        if (chdir(cwd))
          fail("failed to chdir");
        use_temporary_dir();
        int pid = do_sandbox_none();
        int status = 0;
        while (waitpid(pid, &status, __WALL) != pid) {
        }
      }
    }
  }
  sleep(1000000);
  return 0;
}