// https://syzkaller.appspot.com/bug?id=ed27ebe0b24ead3266ca693b56de758301d383a2 // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static long syz_open_pts(volatile long a0, volatile long a1) { int ptyno = 0; if (ioctl(a0, TIOCGPTN, &ptyno)) return -1; char buf[128]; sprintf(buf, "/dev/pts/%d", ptyno); return open(buf, a1, 0); } static int inject_fault(int nth) { int fd; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exit(1); char buf[16]; sprintf(buf, "%d", nth + 1); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exit(1); return fd; } static void setup_fault() { static struct { const char* file; const char* val; bool fatal; } files[] = { {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true}, {"/sys/kernel/debug/fail_futex/ignore-private", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false}, {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false}, }; unsigned i; for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].file, files[i].val)) { if (files[i].fatal) exit(1); } } } uint64_t r[3] = {0x0, 0xffffffffffffffff, 0xffffffffffffffff}; int main(void) { syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); setup_fault(); intptr_t res = 0; res = syscall(__NR_getpid); if (res != -1) r[0] = res; syscall(__NR_sched_setscheduler, r[0], 5ul, 0ul); syscall(__NR_sendmsg, -1, 0ul, 0ul); syscall(__NR_perf_event_open, 0ul, 0, -1ul, -1, 0ul); syscall(__NR_socketpair, 1ul, 0ul, 0ul, 0ul); memcpy((void*)0x200001c0, "/dev/ptmx\000", 10); res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x200001c0ul, 0ul, 0ul); if (res != -1) r[1] = res; *(uint32_t*)0x205befdc = 0; *(uint32_t*)0x205befe0 = 0; *(uint32_t*)0x205befe4 = 0; *(uint32_t*)0x205befe8 = 0; *(uint8_t*)0x205befec = 0; memcpy((void*)0x205befed, "\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000", 19); syscall(__NR_ioctl, r[1], 0x40045431ul, 0x205befdcul); res = syz_open_pts(r[1], 1); if (res != -1) r[2] = res; syscall(__NR_fcntl, r[2], 4ul, 0x102800ul); memcpy((void*)0x20000000, "\xd5", 1); inject_fault(2); syscall(__NR_write, r[2], 0x20000000ul, 0xfffffedful); return 0; }