syzkaller-repros/linux/4c40c60c221b5f2b725757965b30a72ab909cc13.c

// KASAN: slab-out-of-bounds Write in perf_callchain_user
// https://syzkaller.appspot.com/bug?id=4c40c60c221b5f2b725757965b30a72ab909cc13
// status:fixed
// 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/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 <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.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);
}

#define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1)

#define BITMASK_LEN_OFF(type, bf_off, bf_len)                                  \
  (type)(BITMASK_LEN(type, (bf_len)) << (bf_off))

#define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len)                      \
  if ((bf_off) == 0 && (bf_len) == 0) {                                        \
    *(type*)(addr) = (type)(val);                                              \
  } else {                                                                     \
    type new_val = *(type*)(addr);                                             \
    new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len));                     \
    new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off);          \
    *(type*)(addr) = new_val;                                                  \
  }

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);
  va_end(args);
  rv = system(command);
  if (rv) {
    if (panic)
      fail("command '%s' failed: %d", &command[0], rv);
  }
}

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", "team"};
  const char* devnames[] = {
      "lo",      "sit0",    "bridge0",  "vcan0",   "tunl0",   "gre0",
      "gretap0", "ip_vti0", "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0",
      "erspan0", "bond0",   "veth0",    "veth1",   "team0"};

  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 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]);
  }
  execute_command(0,
                  "ip link add name bond_slave type veth peer name team_slave");
  execute_command(0, "ip link set bond_slave master bond0");
  execute_command(0, "ip link set team_slave master team0");
}

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();
  }
}

void execute_one()
{
  NONFAILING(*(uint32_t*)0x2025c000 = 2);
  NONFAILING(*(uint32_t*)0x2025c004 = 0x70);
  NONFAILING(*(uint8_t*)0x2025c008 = 0xe3);
  NONFAILING(*(uint8_t*)0x2025c009 = 0);
  NONFAILING(*(uint8_t*)0x2025c00a = 0);
  NONFAILING(*(uint8_t*)0x2025c00b = 0);
  NONFAILING(*(uint32_t*)0x2025c00c = 0);
  NONFAILING(*(uint64_t*)0x2025c010 = 1);
  NONFAILING(*(uint64_t*)0x2025c018 = 0x2020);
  NONFAILING(*(uint64_t*)0x2025c020 = 0);
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 0, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 1, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 2, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 3, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 4, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 5, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 6, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 7, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 8, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 9, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 10, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 11, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 12, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 13, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 14, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 15, 2));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 17, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 18, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 19, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 20, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 21, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 22, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 23, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 24, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 25, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 26, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 27, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 28, 1));
  NONFAILING(STORE_BY_BITMASK(uint64_t, 0x2025c028, 0, 29, 35));
  NONFAILING(*(uint32_t*)0x2025c030 = 0);
  NONFAILING(*(uint32_t*)0x2025c034 = 0);
  NONFAILING(*(uint64_t*)0x2025c038 = 0x20389000);
  NONFAILING(*(uint64_t*)0x2025c040 = 0);
  NONFAILING(*(uint64_t*)0x2025c048 = 0);
  NONFAILING(*(uint64_t*)0x2025c050 = 0);
  NONFAILING(*(uint32_t*)0x2025c058 = 0);
  NONFAILING(*(uint32_t*)0x2025c05c = 0);
  NONFAILING(*(uint64_t*)0x2025c060 = 0);
  NONFAILING(*(uint32_t*)0x2025c068 = 0);
  NONFAILING(*(uint16_t*)0x2025c06c = 0x401);
  NONFAILING(*(uint16_t*)0x2025c06e = 0);
  syscall(__NR_perf_event_open, 0x2025c000, -1, 0, -1, 0);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  install_segv_handler();
  char* cwd = get_current_dir_name();
  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) {
    }
  }
}