// https://syzkaller.appspot.com/bug?id=d461cd8556a66a8b30c99c6e5af52ee1c6c3a2f7 // 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 #include #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 exitf(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(kRetryStatus); } static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* uctx) { 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); } doexit(sig); for (;;) { } } static void install_segv_handler() { 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 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 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 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) { close(fd); return false; } close(fd); return true; } static int inject_fault(int nth) { int fd; char buf[16]; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exitf("failed to open /proc/thread-self/fail-nth"); sprintf(buf, "%d", nth + 1); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exitf("failed to write /proc/thread-self/fail-nth"); return fd; } void loop() { syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); NONFAILING(*(uint32_t*)0x20b8cf88 = (uint32_t)0x2); NONFAILING(*(uint32_t*)0x20b8cf8c = (uint32_t)0x78); NONFAILING(*(uint8_t*)0x20b8cf90 = (uint8_t)0xe3); NONFAILING(*(uint8_t*)0x20b8cf91 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x20b8cf92 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x20b8cf93 = (uint8_t)0x0); NONFAILING(*(uint32_t*)0x20b8cf94 = (uint32_t)0x0); NONFAILING(*(uint64_t*)0x20b8cf98 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfa0 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfa8 = (uint64_t)0x0); NONFAILING(*(uint8_t*)0x20b8cfb0 = (uint8_t)0x80000040fe); NONFAILING(*(uint8_t*)0x20b8cfb1 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x20b8cfb2 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x20b8cfb3 = (uint8_t)0x0); NONFAILING(*(uint32_t*)0x20b8cfb4 = (uint32_t)0x0); NONFAILING(*(uint32_t*)0x20b8cfb8 = (uint32_t)0x0); NONFAILING(*(uint32_t*)0x20b8cfbc = (uint32_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfc0 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfc8 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfd0 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfd8 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x20b8cfe0 = (uint64_t)0x0); NONFAILING(*(uint32_t*)0x20b8cfe8 = (uint32_t)0x0); NONFAILING(*(uint64_t*)0x20b8cff0 = (uint64_t)0x0); NONFAILING(*(uint32_t*)0x20b8cff8 = (uint32_t)0x0); NONFAILING(*(uint16_t*)0x20b8cffc = (uint16_t)0x0); NONFAILING(*(uint16_t*)0x20b8cffe = (uint16_t)0x0); syscall(__NR_perf_event_open, 0x20b8cf88ul, 0x0ul, 0x0ul, 0xfffffffffffffffful, 0x0ul); NONFAILING(*(uint64_t*)0x202e2000 = (uint64_t)0x0); NONFAILING(*(uint16_t*)0x202e2008 = (uint16_t)0x2); NONFAILING(*(uint16_t*)0x202e200a = (uint16_t)0x204e); NONFAILING(*(uint8_t*)0x202e200c = (uint8_t)0xac); NONFAILING(*(uint8_t*)0x202e200d = (uint8_t)0x14); NONFAILING(*(uint8_t*)0x202e200e = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e200f = (uint8_t)0xbb); NONFAILING(*(uint8_t*)0x202e2010 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2011 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2012 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2013 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2014 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2015 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2016 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2017 = (uint8_t)0x0); NONFAILING(*(uint16_t*)0x202e2018 = (uint16_t)0x2); NONFAILING(*(uint16_t*)0x202e201a = (uint16_t)0x204e); NONFAILING(*(uint8_t*)0x202e201c = (uint8_t)0xac); NONFAILING(*(uint8_t*)0x202e201d = (uint8_t)0x14); NONFAILING(*(uint8_t*)0x202e201e = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e201f = (uint8_t)0xaa); NONFAILING(*(uint8_t*)0x202e2020 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2021 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2022 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2023 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2024 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2025 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2026 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2027 = (uint8_t)0x0); NONFAILING(*(uint16_t*)0x202e2028 = (uint16_t)0x2); NONFAILING(*(uint16_t*)0x202e202a = (uint16_t)0x204e); NONFAILING(*(uint32_t*)0x202e202c = (uint32_t)0x100007f); NONFAILING(*(uint8_t*)0x202e2030 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2031 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2032 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2033 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2034 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2035 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2036 = (uint8_t)0x0); NONFAILING(*(uint8_t*)0x202e2037 = (uint8_t)0x0); NONFAILING(*(uint16_t*)0x202e2038 = (uint16_t)0x0); NONFAILING(*(uint16_t*)0x202e203a = (uint16_t)0x0); NONFAILING(*(uint64_t*)0x202e2040 = (uint64_t)0x0); NONFAILING(*(uint64_t*)0x202e2048 = (uint64_t)0x0); NONFAILING(*(uint16_t*)0x202e2050 = (uint16_t)0x0); NONFAILING(*(uint64_t*)0x202e2058 = (uint64_t)0x20000000); NONFAILING(*(uint64_t*)0x202e2060 = (uint64_t)0x12d); NONFAILING(*(uint64_t*)0x202e2068 = (uint64_t)0x2); NONFAILING(*(uint16_t*)0x202e2070 = (uint16_t)0x2); syscall(__NR_ioctl, 0xfffffffffffffffful, 0x890bul, 0x202e2000ul); NONFAILING(memcpy((void*)0x20e06ff8, "./file0", 8)); syscall(__NR_open, 0x20e06ff8ul, 0x80040ul, 0x0ul); NONFAILING(memcpy((void*)0x20b85ff8, "./file0", 8)); NONFAILING(memcpy((void*)0x202b9000, "./file0", 8)); NONFAILING(memcpy((void*)0x20f9effa, "tmpfs", 6)); write_file("/sys/kernel/debug/failslab/ignore-gfp-wait", "N"); write_file("/sys/kernel/debug/fail_futex/ignore-private", "N"); inject_fault(14); syscall(__NR_mount, 0x20b85ff8ul, 0x202b9000ul, 0x20f9effaul, 0x0ul, 0x207caf71ul); } int main() { install_segv_handler(); int pid = do_sandbox_none(0, true); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }