// https://syzkaller.appspot.com/bug?id=cf7393b4bd452eebfbd5ce0a7de3f4db51c46aed // 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 __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #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 __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); } 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); } #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) fail("command '%s' failed: %d", &command[0], rv); } } #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) { unsigned i; const char* devtypes[] = {"ip6gretap", "bridge", "vcan", "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"}; const char* devmasters[] = {"bridge", "bond", "team"}; 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 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 veth0_to_%s up", devmasters[i]); execute_command(0, "ip link set veth1_to_%s up", devmasters[i]); } execute_command(0, "ip link set bridge_slave_0 up"); execute_command(0, "ip link set bridge_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 loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 160 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 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); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; sandbox_common(); if (unshare(CLONE_NEWNET)) { } initialize_netdevices(); loop(); doexit(1); } #ifndef __NR_bpf #define __NR_bpf 321 #endif uint64_t r[1] = {0xffffffffffffffff}; void loop() { long res = 0; NONFAILING(*(uint32_t*)0x20000000 = 0); NONFAILING(*(uint32_t*)0x20000004 = 3); NONFAILING(*(uint64_t*)0x20000008 = 0x20001000); NONFAILING(memcpy((void*)0x20001000, "\x7b\x1a\xf8\xff\x00\x00\x00\x00\x69" "\xa2\xf8\xce\xdd\x2e\x00\x0d\x5c\xc4" "\xb3\xaa\xb4\xff\x00\x00\x00", 25)); NONFAILING(*(uint64_t*)0x20000010 = 0x20000100); NONFAILING(memcpy((void*)0x20000100, "GPL", 4)); NONFAILING(*(uint32_t*)0x20000018 = 0); NONFAILING(*(uint32_t*)0x2000001c = 0); NONFAILING(*(uint64_t*)0x20000020 = 0); NONFAILING(*(uint32_t*)0x20000028 = 0); NONFAILING(*(uint32_t*)0x2000002c = 0); NONFAILING(*(uint8_t*)0x20000030 = 0); NONFAILING(*(uint8_t*)0x20000031 = 0); NONFAILING(*(uint8_t*)0x20000032 = 0); NONFAILING(*(uint8_t*)0x20000033 = 0); NONFAILING(*(uint8_t*)0x20000034 = 0); NONFAILING(*(uint8_t*)0x20000035 = 0); NONFAILING(*(uint8_t*)0x20000036 = 0); NONFAILING(*(uint8_t*)0x20000037 = 0); NONFAILING(*(uint8_t*)0x20000038 = 0); NONFAILING(*(uint8_t*)0x20000039 = 0); NONFAILING(*(uint8_t*)0x2000003a = 0); NONFAILING(*(uint8_t*)0x2000003b = 0); NONFAILING(*(uint8_t*)0x2000003c = 0); NONFAILING(*(uint8_t*)0x2000003d = 0); NONFAILING(*(uint8_t*)0x2000003e = 0); NONFAILING(*(uint8_t*)0x2000003f = 0); NONFAILING(*(uint32_t*)0x20000040 = 0); NONFAILING(*(uint32_t*)0x20000044 = 0); syscall(__NR_bpf, 5, 0x20000000, 0x48); NONFAILING(*(uint32_t*)0x20001000 = 0x10000); NONFAILING(*(uint32_t*)0x20001004 = 4); NONFAILING(*(uint32_t*)0x20001008 = 0x100); NONFAILING(*(uint32_t*)0x2000100c = 0x400); syscall(__NR_setsockopt, -1, 0x84, 0, 0x20001000, 6); res = syscall(__NR_socket, 0x11, 0x80002, 0); if (res != -1) r[0] = res; NONFAILING(*(uint32_t*)0x20788000 = 2); syscall(__NR_setsockopt, r[0], 0x107, 0xa, 0x20788000, 4); NONFAILING(*(uint16_t*)0x20000480 = 0x11); NONFAILING(*(uint16_t*)0x20000482 = htobe16(3)); NONFAILING(*(uint32_t*)0x20000484 = 0); NONFAILING(*(uint16_t*)0x20000488 = 1); NONFAILING(*(uint8_t*)0x2000048a = 0); NONFAILING(*(uint8_t*)0x2000048b = 6); NONFAILING(*(uint8_t*)0x2000048c = 0xaa); NONFAILING(*(uint8_t*)0x2000048d = 0xaa); NONFAILING(*(uint8_t*)0x2000048e = 0xaa); NONFAILING(*(uint8_t*)0x2000048f = 0xaa); NONFAILING(*(uint8_t*)0x20000490 = 0xaa); NONFAILING(*(uint8_t*)0x20000491 = 0xaa); NONFAILING(*(uint8_t*)0x20000492 = 0); NONFAILING(*(uint8_t*)0x20000493 = 0); syscall(__NR_bind, r[0], 0x20000480, 0x14); syscall(__NR_setsockopt, r[0], 0x107, 5, 0x20001000, 0xc5); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); install_segv_handler(); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }