// autogenerated by syzkaller (http://github.com/google/syzkaller) #ifndef __NR_mmap #define __NR_mmap 9 #endif #ifndef __NR_socket #define __NR_socket 41 #endif #ifndef __NR_setsockopt #define __NR_setsockopt 54 #endif #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 const int kFailStatus = 67; const int kErrorStatus = 68; const int kRetryStatus = 69; __attribute__((noreturn)) void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } __attribute__((noreturn)) void fail(const char* msg, ...) { int e = errno; fflush(stdout); 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); } __attribute__((noreturn)) void exitf(const char* msg, ...) { int e = errno; fflush(stdout); va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit(kRetryStatus); } static int flag_debug; void debug(const char* msg, ...) { if (!flag_debug) return; va_list args; va_start(args, msg); vfprintf(stdout, msg, args); va_end(args); fflush(stdout); } __thread int skip_segv; __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)) { debug("SIGSEGV on %p, skipping\n", addr); _longjmp(segv_env, 1); } debug("SIGSEGV on %p, exiting\n", addr); doexit(sig); for (;;) { } } static void install_segv_handler() { struct sigaction sa; 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); \ } #define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1) #define BITMASK_LEN_OFF(type, bf_off, bf_len) \ (type)(BITMASK_LEN(type, (bf_len)) << (bf_off)) #define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len) \ if ((bf_off) == 0 && (bf_len) == 0) { \ *(type*)(addr) = (type)(val); \ } else { \ type new_val = *(type*)(addr); \ new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len)); \ new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off); \ *(type*)(addr) = new_val; \ } static uintptr_t execute_syscall(int nr, uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5, uintptr_t a6, uintptr_t a7, uintptr_t a8) { switch (nr) { default: return syscall(nr, a0, a1, a2, a3, a4, a5); } } static void setup_main_process() { 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); install_segv_handler(); char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } 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 = 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); unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_IO); } static int do_sandbox_none(int executor_pid, bool enable_tun) { int pid = fork(); if (pid) return pid; sandbox_common(); loop(); doexit(1); } long r[10]; void loop() { memset(r, -1, sizeof(r)); r[0] = execute_syscall(__NR_mmap, 0x20000000ul, 0x4000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul, 0, 0, 0); r[1] = execute_syscall(__NR_socket, 0x2ul, 0x80003ul, 0x2ul, 0, 0, 0, 0, 0, 0); NONFAILING(*(uint32_t*)0x20f01000 = (uint32_t)0x0); r[3] = execute_syscall(__NR_setsockopt, r[1], 0x0ul, 0xc8ul, 0x20f01000ul, 0x4ul, 0, 0, 0, 0); NONFAILING(*(uint32_t*)0x20001ff4 = (uint32_t)0xa2090000); NONFAILING(*(uint32_t*)0x20001ff8 = (uint32_t)0x0); NONFAILING(*(uint32_t*)0x20001ffc = (uint32_t)0x9); r[7] = execute_syscall(__NR_setsockopt, r[1], 0x0ul, 0x23ul, 0x20001ff4ul, 0xcul, 0, 0, 0, 0); NONFAILING(*(uint32_t*)0x20000000 = (uint32_t)0x0); r[9] = execute_syscall(__NR_setsockopt, r[1], 0x0ul, 0x5ul, 0x20000000ul, 0x4ul, 0, 0, 0, 0); } int main() { setup_main_process(); int pid = do_sandbox_none(0, false); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }