syzkaller-repros/linux/d2a4c274c88159193d771cfdfd67bd7ca71b3868.c

// INFO: task hung in bit_wait_io
// https://syzkaller.appspot.com/bug?id=d2a4c274c88159193d771cfdfd67bd7ca71b3868
// status:open
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/net.h>
#include <netinet/in.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdio.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}
#include <stdint.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 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 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;
    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);
  }
}

struct ipt_getinfo {
  char name[32];
  unsigned int valid_hooks;
  unsigned int hook_entry[5];
  unsigned int underflow[5];
  unsigned int num_entries;
  unsigned int size;
};

struct ipt_get_entries {
  char name[32];
  unsigned int size;
  void* entrytable[1024 / sizeof(void*)];
};

struct xt_counters {
  uint64_t pcnt, bcnt;
};

struct ipt_replace {
  char name[32];
  unsigned int valid_hooks;
  unsigned int num_entries;
  unsigned int size;
  unsigned int hook_entry[5];
  unsigned int underflow[5];
  unsigned int num_counters;
  struct xt_counters* counters;
  char entrytable[1024];
};

struct ipt_table_desc {
  const char* name;
  struct ipt_getinfo info;
  struct ipt_get_entries entries;
  struct ipt_replace replace;
  struct xt_counters counters[10];
};

static struct ipt_table_desc ipv4_tables[] = {
    {.name = "filter"}, {.name = "nat"},      {.name = "mangle"},
    {.name = "raw"},    {.name = "security"},
};

#define IPT_BASE_CTL 64
#define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
#define IPT_SO_GET_INFO (IPT_BASE_CTL)
#define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)

static void checkpoint_net_namespace(void)
{
  socklen_t optlen;
  unsigned i;
  int fd;

  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1)
    fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
  for (i = 0; i < sizeof(ipv4_tables) / sizeof(ipv4_tables[0]); i++) {
    struct ipt_table_desc* table = &ipv4_tables[i];
    strcpy(table->info.name, table->name);
    strcpy(table->entries.name, table->name);
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->info);
    if (getsockopt(fd, SOL_IP, IPT_SO_GET_INFO, &table->info, &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      fail("getsockopt(IPT_SO_GET_INFO)");
    }
    if (table->info.size > sizeof(table->entries.entrytable))
      fail("table size is too large: %u", table->info.size);
    if (table->info.num_entries >
        sizeof(table->counters) / sizeof(table->counters[0]))
      fail("too many counters: %u", table->info.num_entries);
    table->entries.size = table->info.size;
    optlen = sizeof(table->entries) - sizeof(table->entries.entrytable) +
             table->info.size;
    if (getsockopt(fd, SOL_IP, IPT_SO_GET_ENTRIES, &table->entries, &optlen))
      fail("getsockopt(IPT_SO_GET_ENTRIES)");
    table->replace.valid_hooks = table->info.valid_hooks;
    table->replace.num_entries = table->info.num_entries;
    table->replace.counters = table->counters;
    table->replace.size = table->info.size;
    memcpy(table->replace.hook_entry, table->info.hook_entry,
           sizeof(table->replace.hook_entry));
    memcpy(table->replace.underflow, table->info.underflow,
           sizeof(table->replace.underflow));
    memcpy(table->replace.entrytable, table->entries.entrytable,
           table->info.size);
  }
  close(fd);
}

static void reset_net_namespace(void)
{
  struct ipt_get_entries entries;
  struct ipt_getinfo info;
  socklen_t optlen;
  unsigned i;
  int fd;

  memset(&info, 0, sizeof(info));
  memset(&entries, 0, sizeof(entries));
  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1)
    fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
  for (i = 0; i < sizeof(ipv4_tables) / sizeof(ipv4_tables[0]); i++) {
    struct ipt_table_desc* table = &ipv4_tables[i];
    if (table->info.valid_hooks == 0)
      continue;
    strcpy(info.name, table->name);
    optlen = sizeof(info);
    if (getsockopt(fd, SOL_IP, IPT_SO_GET_INFO, &info, &optlen))
      fail("getsockopt(IPT_SO_GET_INFO)");
    if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
      strcpy(entries.name, table->name);
      entries.size = table->info.size;
      optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
      if (getsockopt(fd, SOL_IP, IPT_SO_GET_ENTRIES, &entries, &optlen))
        fail("getsockopt(IPT_SO_GET_ENTRIES)");
      if (memcmp(&table->entries, &entries, optlen) == 0)
        continue;
    }
    table->replace.num_counters = info.num_entries;
    optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
             table->replace.size;
    if (setsockopt(fd, SOL_IP, IPT_SO_SET_REPLACE, &table->replace, optlen))
      fail("setsockopt(IPT_SO_SET_REPLACE)");
  }
  close(fd);
}

static void test();

void loop()
{
  int iter;
  checkpoint_net_namespace();
  for (iter = 0;; iter++) {
    int pid = fork();
    if (pid < 0)
      fail("loop fork failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      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;
      }
    }
    reset_net_namespace();
  }
}

long r[1];
void test()
{
  memset(r, -1, sizeof(r));
  syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0);
  memcpy((void*)0x20933ff3, "/dev/binder#", 13);
  r[0] = syz_open_dev(0x20933ff3, 0, 0x800000000000);
  memcpy((void*)0x20008ff3, "/dev/binder#", 13);
  syz_open_dev(0x20008ff3, 0, 0x20000);
  syscall(__NR_ioctl, r[0], 0x40046207, 0);
  *(uint64_t*)0x20007000 = 0x14;
  *(uint64_t*)0x20007008 = 0;
  *(uint64_t*)0x20007010 = 0x2000c000;
  *(uint64_t*)0x20007018 = 0;
  *(uint64_t*)0x20007020 = 0;
  *(uint64_t*)0x20007028 = 0x20001fff;
  *(uint32_t*)0x2000c000 = 0x40486311;
  *(uint64_t*)0x2000c004 = 0;
  *(uint64_t*)0x2000c00c = 0;
  syscall(__NR_ioctl, r[0], 0xc0306201, 0x20007000);
  syscall(__NR_socket, 0x10, 3, 0x15);
}

int main()
{
  for (;;) {
    loop();
  }
}