diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index c7c6e8b8344d..20668760daa0 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -348,6 +348,10 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src, size_t size = min(ksize, usize); size_t rest = max(ksize, usize) - size; + /* Double check if ksize is larger than a known object size. */ + if (WARN_ON_ONCE(ksize > __builtin_object_size(dst, 1))) + return -E2BIG; + /* Deal with trailing bytes. */ if (usize < ksize) { memset(dst + size, 0, rest);