--- x/net/bluetooth/l2cap_sock.c
+++ y/net/bluetooth/l2cap_sock.c
@@ -960,7 +960,7 @@ static int l2cap_sock_setsockopt(struct
 			break;
 		}
 
-		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
+		if (optlen < sizeof(u32) || copy_from_sockptr(&opt, optval, sizeof(u32))) {
 			err = -EFAULT;
 			break;
 		}