// https://syzkaller.appspot.com/bug?id=96b7862f6d05608efbb9c0832b2fa6d404cb264a // 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 __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 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 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)) { } loop(); doexit(1); } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } 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 int collide; 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); if (collide && call % 2) break; 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; } } } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { long res; switch (call) { case 0: NONFAILING(memcpy((void*)0x20000440, "/dev/vhost-vsock", 17)); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000440, 2, 0); if (res != -1) r[0] = res; break; case 1: NONFAILING(*(uint64_t*)0x202d7000 = 0x20989fff); syscall(__NR_ioctl, r[0], 0xaf01, 0x202d7000); break; case 2: syscall(__NR_ioctl, r[0], 0x4008af03, 0x20000240); break; case 3: NONFAILING(memcpy((void*)0x200002c0, "/dev/dsp#", 10)); res = syz_open_dev(0x200002c0, 6, 0x80300); if (res != -1) r[1] = res; break; case 4: NONFAILING(*(uint32_t*)0x20000400 = 0xe8); syscall(__NR_getsockopt, r[1], 0x29, 0x23, 0x20000300, 0x20000400); break; case 5: NONFAILING(*(uint32_t*)0x20df5fd8 = 0); NONFAILING(*(uint32_t*)0x20df5fdc = 0); NONFAILING(*(uint64_t*)0x20df5fe0 = 0x203acf97); NONFAILING(*(uint64_t*)0x20df5fe8 = 0x20bf6000); NONFAILING(*(uint64_t*)0x20df5ff0 = 0x2017d000); NONFAILING(*(uint64_t*)0x20df5ff8 = 0); syscall(__NR_ioctl, r[0], 0x4028af11, 0x20df5fd8); break; case 6: NONFAILING(*(uint32_t*)0x20cef000 = 1); NONFAILING(*(uint32_t*)0x20cef004 = 0); NONFAILING(*(uint64_t*)0x20cef008 = 0x2062a000); NONFAILING(*(uint64_t*)0x20cef010 = 0x20aac000); NONFAILING(*(uint64_t*)0x20cef018 = 0x202fdf52); NONFAILING(*(uint64_t*)0x20cef020 = 0); syscall(__NR_ioctl, r[0], 0x4028af11, 0x20cef000); break; case 7: NONFAILING(*(uint32_t*)0x20f82ffc = 1); syscall(__NR_ioctl, r[0], 0x4004af61, 0x20f82ffc); break; case 8: NONFAILING(*(uint32_t*)0x20000200 = 0); NONFAILING(*(uint32_t*)0x20000204 = 1); NONFAILING(*(uint64_t*)0x20000208 = 0x20000000); NONFAILING(*(uint64_t*)0x20000210 = 0x20000100); NONFAILING(*(uint64_t*)0x20000218 = 0x20000140); NONFAILING(*(uint64_t*)0x20000220 = 0xfdfdffff00000000); syscall(__NR_ioctl, r[0], 0x4028af11, 0x20000200); break; } } void execute_one() { execute(9); collide = 1; execute(9); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); install_segv_handler(); for (;;) { int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } }