1 files changed, 14 insertions, 1 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 1a32562adf46..bf5bb7dc6abf 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1814,9 +1814,22 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
                         break;
                 }
 
+                l2cap_pi(sk)->mode = opts.mode;
+                switch (l2cap_pi(sk)->mode) {
+                case L2CAP_MODE_BASIC:
+                        break;
+                case L2CAP_MODE_ERTM:
+                case L2CAP_MODE_STREAMING:
+                        if (enable_ertm)
+                                break;
+                        /* fall through */
+                default:
+                        err = -EINVAL;
+                        break;
+                }
+
                 l2cap_pi(sk)->imtu = opts.imtu;
                 l2cap_pi(sk)->omtu = opts.omtu;
-                l2cap_pi(sk)->mode = opts.mode;
                 l2cap_pi(sk)->fcs  = opts.fcs;
                 l2cap_pi(sk)->max_tx = opts.max_tx;
                 l2cap_pi(sk)->tx_win = (__u8)opts.txwin_size;