| // BUG: soft lockup (2) |
| // https://syzkaller.appspot.com/bug?id=cb561a307af2189d57b6227959c41ed7e53515f2 |
| // 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/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 <stdarg.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <stdlib.h> |
| #include <sys/ioctl.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/uio.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 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(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 (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 MAX_PIDS 32 |
| #define ADDR_MAX_LEN 32 |
| |
| #define LOCAL_MAC "aa:aa:aa:aa:aa:%02hx" |
| #define REMOTE_MAC "bb:bb:bb:bb:bb:%02hx" |
| |
| #define LOCAL_IPV4 "172.20.%d.170" |
| #define REMOTE_IPV4 "172.20.%d.187" |
| |
| #define LOCAL_IPV6 "fe80::%02hxaa" |
| #define REMOTE_IPV6 "fe80::%02hxbb" |
| |
| #define IFF_NAPI 0x0010 |
| #define IFF_NAPI_FRAGS 0x0020 |
| |
| static void initialize_tun(uint64_t pid) |
| { |
| if (pid >= MAX_PIDS) |
| fail("tun: no more than %d executors", MAX_PIDS); |
| int id = pid; |
| |
| 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; |
| } |
| |
| char iface[IFNAMSIZ]; |
| snprintf_check(iface, sizeof(iface), "syz%d", id); |
| |
| struct ifreq ifr; |
| memset(&ifr, 0, sizeof(ifr)); |
| strncpy(ifr.ifr_name, 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; |
| |
| char local_mac[ADDR_MAX_LEN]; |
| snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id); |
| char remote_mac[ADDR_MAX_LEN]; |
| snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id); |
| |
| char local_ipv4[ADDR_MAX_LEN]; |
| snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id); |
| char remote_ipv4[ADDR_MAX_LEN]; |
| snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id); |
| |
| char local_ipv6[ADDR_MAX_LEN]; |
| snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id); |
| char remote_ipv6[ADDR_MAX_LEN]; |
| snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id); |
| |
| execute_command("sysctl -w net.ipv6.conf.%s.accept_dad=0", iface); |
| |
| execute_command("sysctl -w net.ipv6.conf.%s.router_solicitations=0", iface); |
| |
| execute_command("ip link set dev %s address %s", iface, local_mac); |
| execute_command("ip addr add %s/24 dev %s", local_ipv4, iface); |
| execute_command("ip -6 addr add %s/120 dev %s", local_ipv6, iface); |
| execute_command("ip neigh add %s lladdr %s dev %s nud permanent", remote_ipv4, |
| remote_mac, iface); |
| execute_command("ip -6 neigh add %s lladdr %s dev %s nud permanent", |
| remote_ipv6, remote_mac, iface); |
| execute_command("ip link set dev %s up", iface); |
| } |
| |
| static void setup_tun(uint64_t pid, bool enable_tun) |
| { |
| if (enable_tun) |
| initialize_tun(pid); |
| } |
| |
| 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; |
| } |
| } |
| } |
| } |
| |
| #ifndef __NR_mmap |
| #define __NR_mmap 192 |
| #endif |
| #ifndef __NR_openat |
| #define __NR_openat 295 |
| #endif |
| #ifndef __NR_write |
| #define __NR_write 4 |
| #endif |
| #undef __NR_mmap |
| #define __NR_mmap __NR_mmap2 |
| |
| long r[1]; |
| void execute_call(int call) |
| { |
| switch (call) { |
| case 0: |
| syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); |
| break; |
| case 1: |
| memcpy((void*)0x20000000, "/dev/audio", 11); |
| r[0] = syscall(__NR_openat, 0xffffff9c, 0x20000000, 0x202, 0); |
| break; |
| case 2: |
| *(uint8_t*)0x20735ee0 = 0; |
| *(uint8_t*)0x20735ee1 = 0; |
| *(uint8_t*)0x20735ee2 = 0; |
| *(uint8_t*)0x20735ee3 = 0; |
| *(uint32_t*)0x20735ee4 = 0; |
| *(uint32_t*)0x20735ee8 = 0; |
| *(uint8_t*)0x20735eec = 0; |
| *(uint8_t*)0x20735eed = 0; |
| *(uint8_t*)0x20735eee = 0; |
| *(uint8_t*)0x20735eef = 0; |
| *(uint32_t*)0x20735ef0 = 0; |
| *(uint32_t*)0x20735ef4 = 0; |
| *(uint32_t*)0x20735ef8 = 0; |
| syscall(__NR_write, r[0], 0x20735ee0, 0xfffffee4); |
| break; |
| } |
| } |
| |
| void loop() |
| { |
| memset(r, -1, sizeof(r)); |
| execute(3); |
| collide = 1; |
| execute(3); |
| } |
| |
| int main() |
| { |
| setup_tun(0, true); |
| loop(); |
| return 0; |
| } |