syzkaller-repros/linux/b0e069ac9b03eab43b106c22fcc8bd778a7ccfb5.c

// KMSAN: uninit-value in ip_tunnel_xmit (2)
// https://syzkaller.appspot.com/bug?id=b0e069ac9b03eab43b106c22fcc8bd778a7ccfb5
// status:open
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <endian.h>
#include <errno.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 <stdarg.h>
#include <stdbool.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 <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.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 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);
}

#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);
  }
}

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

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);
}

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",
                            "veth0_to_bridge",
                            "veth1_to_bridge",
                            "veth0_to_bond",
                            "veth1_to_bond",
                            "veth0_to_team",
                            "veth1_to_team"};
  const char* devmasters[] = {"bridge", "bond", "team"};

  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(devmasters) / (sizeof(devmasters[0])); i++) {
    execute_command(
        0, "ip link add name %s_slave_0 type veth peer name veth0_to_%s",
        devmasters[i], devmasters[i]);
    execute_command(
        0, "ip link add name %s_slave_1 type veth peer name veth1_to_%s",
        devmasters[i], devmasters[i]);
    execute_command(0, "ip link set %s_slave_0 master %s0", devmasters[i],
                    devmasters[i]);
    execute_command(0, "ip link set %s_slave_1 master %s0", devmasters[i],
                    devmasters[i]);
    execute_command(0, "ip link set veth0_to_%s up", devmasters[i]);
    execute_command(0, "ip link set veth1_to_%s up", devmasters[i]);
  }
  execute_command(0, "ip link set bridge_slave_0 up");
  execute_command(0, "ip link set bridge_slave_1 up");

  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 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 = 160 << 20;
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 8 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 136 << 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)) {
  }
}

int wait_for_loop(int pid)
{
  if (pid < 0)
    fail("sandbox fork failed");
  int status = 0;
  while (waitpid(-1, &status, __WALL) != pid) {
  }
  return WEXITSTATUS(status);
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid != 0)
    return wait_for_loop(pid);

  sandbox_common();
  if (unshare(CLONE_NEWNET)) {
  }
  initialize_netdevices();
  loop();
  doexit(1);
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void loop()
{
  long res = 0;
  res = syscall(__NR_socket, 0x11, 3, 0);
  if (res != -1)
    r[0] = res;
  *(uint64_t*)0x20000600 = 0x20000040;
  *(uint16_t*)0x20000040 = 0x27;
  *(uint32_t*)0x20000044 = 3;
  *(uint32_t*)0x20000048 = 0;
  *(uint32_t*)0x2000004c = 0;
  *(uint32_t*)0x20000608 = 0x80;
  *(uint64_t*)0x20000610 = 0x20000680;
  *(uint64_t*)0x20000618 = 0;
  *(uint64_t*)0x20000620 = 0;
  *(uint64_t*)0x20000628 = 0;
  *(uint32_t*)0x20000630 = 0;
  syscall(__NR_sendmsg, r[0], 0x20000600, 0);
  res = syscall(__NR_socket, 0x10, 3, 0);
  if (res != -1)
    r[1] = res;
  *(uint64_t*)0x20000140 = 0x200000c0;
  *(uint16_t*)0x200000c0 = 0x10;
  *(uint16_t*)0x200000c2 = 0;
  *(uint32_t*)0x200000c4 = 0;
  *(uint32_t*)0x200000c8 = 0;
  *(uint32_t*)0x20000148 = 0xc;
  *(uint64_t*)0x20000150 = 0x20000100;
  *(uint64_t*)0x20000100 = 0x20000180;
  *(uint32_t*)0x20000180 = 0x28;
  *(uint16_t*)0x20000184 = 0x10;
  *(uint16_t*)0x20000186 = 0xba5f;
  *(uint32_t*)0x20000188 = 0;
  *(uint32_t*)0x2000018c = 0;
  *(uint8_t*)0x20000190 = 0;
  *(uint8_t*)0x20000191 = 0;
  *(uint16_t*)0x20000192 = 0;
  *(uint32_t*)0x20000194 = 0;
  *(uint32_t*)0x20000198 = 3;
  *(uint32_t*)0x2000019c = 0;
  *(uint16_t*)0x200001a0 = 8;
  *(uint16_t*)0x200001a2 = 0x1b;
  *(uint32_t*)0x200001a4 = 0;
  *(uint64_t*)0x20000108 = 0x28;
  *(uint64_t*)0x20000158 = 1;
  *(uint64_t*)0x20000160 = 0;
  *(uint64_t*)0x20000168 = 0;
  *(uint32_t*)0x20000170 = 0;
  syscall(__NR_sendmsg, r[1], 0x20000140, 0);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  do_sandbox_none();
  return 0;
}