// https://syzkaller.appspot.com/bug?id=7e9fcb0736aaac1fc071ddbbb213f82e9a99df01 // autogenerated by syzkaller (http://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 #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include 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); } static uintptr_t syz_open_procfs(uintptr_t a0, uintptr_t a1) { char buf[128]; memset(buf, 0, sizeof(buf)); if (a0 == 0) { snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1); } else if (a0 == (uintptr_t)-1) { snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1); } else { snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0, (char*)a1); } int fd = open(buf, O_RDWR); if (fd == -1) fd = open(buf, O_RDONLY); return fd; } 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 = 1 << 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); #define CLONE_NEWCGROUP 0x02000000 unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_NEWCGROUP); unshare(CLONE_NEWNET); unshare(CLONE_NEWUTS); unshare(CLONE_SYSVSEM); } static int do_sandbox_none(int executor_pid, bool enable_tun) { unshare(CLONE_NEWPID); int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; sandbox_common(); setup_tun(executor_pid, enable_tun); loop(); doexit(1); } static void test(); void loop() { while (1) { test(); } } long r[28]; void* thr(void* arg) { switch ((long)arg) { case 0: r[0] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); break; case 1: memcpy((void*)0x201c2000, "\x2e\x2f\x66\x69\x6c\x65\x30\x00", 8); r[2] = syscall(__NR_mknod, 0x201c2000ul, 0x1040ul, 0x0ul); break; case 2: memcpy((void*)0x20f8aff8, "\x2e\x2f\x66\x69\x6c\x65\x30\x00", 8); *(uint64_t*)0x20030000 = (uint64_t)0x2085bfa6; *(uint64_t*)0x20030008 = (uint64_t)0x2015effa; *(uint64_t*)0x20030010 = (uint64_t)0x20219ff4; *(uint64_t*)0x20030018 = (uint64_t)0x204ea000; *(uint64_t*)0x20030020 = (uint64_t)0x20e0aff0; *(uint64_t*)0x20030028 = (uint64_t)0x2019f000; *(uint64_t*)0x20030030 = (uint64_t)0x20d8c000; *(uint64_t*)0x20030038 = (uint64_t)0x2072c000; *(uint64_t*)0x20030040 = (uint64_t)0x20ffe000; memcpy((void*)0x2085bfa6, "\x75\x73\x65\x72\x5d\x2a\x6d\x69\x6d\x65\x5f\x74\x79\x70" "\x65\x6d\x64\x35\x73\x75\x6d\x7b\x5d\x74\x72\x75\x73\x74" "\x65\x64\x73\x65\x6c\x69\x6e\x75\x78\x16\x26\x75\x73\x65" "\x72\x73\x65\x63\x75\x72\x69\x74\x79\x2c\x24\x76\x62\x6f" "\x78\x6e\x65\x74\x31\x26\x2b\x5b\x47\x50\x4c\x76\x62\x6f" "\x78\x6e\x65\x74\x31\x6d\x64\x35\x73\x75\x6d\xcf\x65\x74" "\x68\x30\x47\x50\x4c\x00", 90); memcpy((void*)0x2015effa, "\x6c\x6f\x67\x6f\x6e\x00", 6); memcpy((void*)0x20219ff4, "\x65\x6d\x31\x73\x65\x63\x75\x72\x69\x74\x79\x00", 12); memcpy((void*)0x204ea000, "\x63\x70\x75\x73\x65\x74\x7d\x25\x25\x00", 10); memcpy((void*)0x20e0aff0, "\x2f\x64\x65\x76\x2f\x73\x65\x71\x75\x65" "\x6e\x63\x65\x72\x32\x00", 16); memcpy((void*)0x2019f000, "\x21\x7b\x00", 3); memcpy((void*)0x20d8c000, "\x65\x6d\x31\x5b\x2c\x00", 6); memcpy((void*)0x2072c000, "\x40\x73\x65\x63\x75\x72\x69\x74\x79\x2d\x00", 11); memcpy((void*)0x20ffe000, "\x00", 1); r[22] = syscall(__NR_execve, 0x20f8aff8ul, 0x2089d000ul, 0x20030000ul); break; case 3: r[23] = syscall(__NR_pipe2, 0x20c42000ul, 0x0ul); if (r[23] != -1) r[24] = *(uint32_t*)0x20c42004; break; case 4: memcpy((void*)0x20e03ff8, "\x73\x79\x73\x63\x61\x6c\x6c\x00", 8); r[26] = syz_open_procfs(0x0ul, 0x20e03ff8ul); break; case 5: r[27] = syscall(__NR_splice, r[26], 0x0ul, r[24], 0x0ul, 0xa3eaul, 0x0ul); break; } return 0; } void test() { long i; pthread_t th[12]; memset(r, -1, sizeof(r)); for (i = 0; i < 6; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(rand() % 10000); } usleep(rand() % 100000); } int main() { int pid = do_sandbox_none(0, true); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }