// https://syzkaller.appspot.com/bug?id=05ab204e25c2b557d4cf71d523e7857e7f2ee220 // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #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 #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 use_temporary_dir() { 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 execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; unsigned long long procid; void execute_one() { long res = 0; res = syscall(__NR_pipe2, 0x20000100, 0); if (res != -1) { NONFAILING(r[0] = *(uint32_t*)0x20000100); NONFAILING(r[1] = *(uint32_t*)0x20000104); } NONFAILING(memcpy((void*)0x20000340, "./file0", 8)); syscall(__NR_open, 0x20000340, 0x42, 0); NONFAILING(memcpy((void*)0x200000c0, "./file0", 8)); NONFAILING(memcpy((void*)0x20000180, "9p", 3)); NONFAILING(memcpy((void*)0x200001c0, "trans=fd,", 9)); NONFAILING(memcpy((void*)0x200001c9, "rfdno", 5)); NONFAILING(*(uint8_t*)0x200001ce = 0x3d); NONFAILING(sprintf((char*)0x200001cf, "0x%016llx", (long long)r[0])); NONFAILING(*(uint8_t*)0x200001e1 = 0x2c); NONFAILING(memcpy((void*)0x200001e2, "wfdno", 5)); NONFAILING(*(uint8_t*)0x200001e7 = 0x3d); NONFAILING(sprintf((char*)0x200001e8, "0x%016llx", (long long)r[1])); NONFAILING(*(uint8_t*)0x200001fa = 0x2c); NONFAILING(*(uint8_t*)0x200001fb = 0); syscall(__NR_mount, 0, 0x200000c0, 0x20000180, 0, 0x200001c0); syscall(__NR_fstat, r[0], 0x20000480); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); char* cwd = get_current_dir_name(); for (procid = 0; procid < 8; procid++) { if (fork() == 0) { install_segv_handler(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); loop(); } } } sleep(1000000); return 0; }