// https://syzkaller.appspot.com/bug?id=ac3c994dc869f71f2366928dc94a4f6bd01a7438 // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned long long procid; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { 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); } exit(sig); } static void install_segv_handler(void) { 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 sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } static void thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); if (pthread_create(&th, &attr, fn, arg)) exit(1); pthread_attr_destroy(&attr); } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_RELAXED)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } 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) exit(1); if ((size_t)rv >= size) exit(1); } #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) exit(1); } } 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 = 240; if (dup2(tunfd, kTunFd) < 0) exit(1); 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) exit(1); } if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) exit(1); tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0; execute_command(0, "sysctl -w net.ipv6.conf.%s.accept_dad=0", TUN_IFACE); execute_command(0, "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 neigh add %s lladdr %s dev %s nud permanent", REMOTE_IPV4, REMOTE_MAC, TUN_IFACE); execute_command(0, "ip -6 addr add %s/120 dev %s", LOCAL_IPV6, TUN_IFACE); execute_command(0, "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 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) { char netdevsim[16]; sprintf(netdevsim, "netdevsim%d", (int)procid); const char* devtypes[] = {"ip6gretap", "ip6erspan", "bridge", "vcan", "bond", "team", "dummy", "nlmon", "caif", "batadv"}; const char* devmasters[] = {"bridge", "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", "veth0_to_hsr", "veth1_to_hsr", "hsr0", "ip6erspan0", "dummy0", "nlmon0", "vxcan1", "caif0", "batadv0", netdevsim}; unsigned i; 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 vxcan1 type vxcan"); execute_command(0, "ip link add dev %s type netdevsim", netdevsim); 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 bridge_slave_0 up"); execute_command(0, "ip link set bridge_slave_1 up"); execute_command( 0, "ip link add name hsr_slave_0 type veth peer name veth0_to_hsr"); execute_command( 0, "ip link add name hsr_slave_1 type veth peer name veth1_to_hsr"); execute_command( 0, "ip link add dev hsr0 type hsr slave1 hsr_slave_0 slave2 hsr_slave_1"); execute_command(0, "ip link set hsr_slave_0 up"); execute_command(0, "ip link set hsr_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 initialize_netdevices_init(void) { int pid = procid; execute_command(0, "ip link set dev nr%d address bb:bb:bb:bb:bb:00:%02hx", pid, pid); execute_command(0, "ip -4 addr add 172.30.00.%d/24 dev nr%d", pid + 1, pid); execute_command(0, "ip -6 addr add fe88::00:%02hx/120 dev nr%d", pid + 1, pid); execute_command(0, "ip link set dev nr%d up", pid); execute_command(0, "ip link set dev rose%d address bb:bb:bb:01:%02hx", pid, pid); execute_command(0, "ip -4 addr add 172.30.01.%d/24 dev rose%d", pid + 1, pid); execute_command(0, "ip -6 addr add fe88::01:%02hx/120 dev rose%d", pid + 1, pid); } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 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 = 200 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 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); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) { if (!write_file(sysctls[i].name, sysctls[i].value)) { } } } int wait_for_loop(int pid) { if (pid < 0) exit(1); 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); setup_common(); sandbox_common(); initialize_netdevices_init(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); exit(1); } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void loop(void) { int i, call, thread; int collide = 0; again: for (call = 0; call < 1; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); if (collide && (call % 2) == 0) break; event_timedwait(&th->done, 45); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); if (!collide) { collide = 1; goto again; } } void execute_call(int call) { switch (call) { case 0: NONFAILING(*(uint32_t*)0x20940000 = 2); NONFAILING(*(uint32_t*)0x20940004 = 0x70); NONFAILING(*(uint8_t*)0x20940008 = 0x6a); NONFAILING(*(uint8_t*)0x20940009 = 0); NONFAILING(*(uint8_t*)0x2094000a = 0); NONFAILING(*(uint8_t*)0x2094000b = 0); NONFAILING(*(uint32_t*)0x2094000c = 0); NONFAILING(*(uint64_t*)0x20940010 = 5); NONFAILING(*(uint64_t*)0x20940018 = 0x20); NONFAILING(*(uint64_t*)0x20940020 = 0); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 0, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 1, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 2, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 3, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 4, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 5, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 6, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 7, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 8, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 9, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 10, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 11, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 12, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 13, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 14, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 15, 2)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 17, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 18, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 19, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 20, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 21, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 22, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 23, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 24, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 25, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 26, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 27, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 28, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x20940028, 0, 29, 35)); NONFAILING(*(uint32_t*)0x20940030 = 0); NONFAILING(*(uint32_t*)0x20940034 = 0); NONFAILING(*(uint64_t*)0x20940038 = 0); NONFAILING(*(uint64_t*)0x20940040 = 0); NONFAILING(*(uint64_t*)0x20940048 = 0); NONFAILING(*(uint64_t*)0x20940050 = 0); NONFAILING(*(uint32_t*)0x20940058 = 0); NONFAILING(*(uint32_t*)0x2094005c = 0); NONFAILING(*(uint64_t*)0x20940060 = 0); NONFAILING(*(uint32_t*)0x20940068 = 0); NONFAILING(*(uint16_t*)0x2094006c = 0); NONFAILING(*(uint16_t*)0x2094006e = 0); syscall(__NR_perf_event_open, 0x20940000, 0, 0, -1, 0); break; } } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); install_segv_handler(); use_temporary_dir(); do_sandbox_none(); return 0; }