// https://syzkaller.appspot.com/bug?id=6dcd14a729df98f989c7b76d254226ae67084efd // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #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 #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 uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; NONFAILING(strncpy(buf, (char*)a0, sizeof(buf))); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } static void test(); void loop() { while (1) { test(); } } struct thread_t { int created, running, call; pthread_t th; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (running) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } #ifndef __NR_writev #define __NR_writev 146 #endif #ifndef __NR_read #define __NR_read 3 #endif #ifndef __NR_mmap #define __NR_mmap 192 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 long r[1]; uint64_t procid; void execute_call(int call) { switch (call) { case 0: syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); break; case 1: NONFAILING(memcpy((void*)0x20012ff7, "/dev/sg#", 9)); r[0] = syz_open_dev(0x20012ff7, 0, 2); break; case 2: NONFAILING(*(uint32_t*)0x20028fe0 = 0x20033fcb); NONFAILING(*(uint32_t*)0x20028fe4 = 0x35); NONFAILING(*(uint32_t*)0x20028fe8 = 0x2001c000); NONFAILING(*(uint32_t*)0x20028fec = 0); NONFAILING(memcpy((void*)0x20033fcb, "\xcf\x45\x0e\x6d\x0c\xd5\xff\x03\x00\x00\x00\x00\x00\x00" "\x6b\xb8\x30\x95\x9d\x07\x6d\x1e\xf7\xf6\x7d\x67\x2a\x01" "\x00\x00\x00\x50\xf0\x84\xc4\xea\x94\x89\xb7\x1a\x9f\x75" "\x99\xb0\xec\x91\x04\xb8\x8f\xbe\xe3\xe5\xfe", 53)); syscall(__NR_writev, r[0], 0x20028fe0, 2); break; case 3: syscall(__NR_read, r[0], 0x2022b000, 0); break; } } void test() { memset(r, -1, sizeof(r)); execute(4); } int main() { 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; }