[Bluetooth] Disconnect when encryption gets disabled

The Bluetooth specification allows to enable or disable the encryption
of an ACL link at any time by either the peer or the remote device. If
a L2CAP or RFCOMM connection requested an encrypted link, they will now
disconnect that link if the encryption gets disabled. Higher protocols
that don't care about encryption (like SDP) are not affected.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 2e3abdfbd69d..252264062f59 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -2197,7 +2197,7 @@ static int l2cap_auth_cfm(struct hci_conn *hcon, u8 status)
         return 0;
 }
 
-static int l2cap_encrypt_cfm(struct hci_conn *hcon, u8 status)
+static int l2cap_encrypt_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 {
         struct l2cap_chan_list *l;
         struct l2cap_conn *conn = hcon->l2cap_data;
@@ -2215,8 +2215,19 @@ static int l2cap_encrypt_cfm(struct hci_conn *hcon, u8 status)
         read_lock(&l->lock);
 
         for (sk = l->head; sk; sk = l2cap_pi(sk)->next_c) {
+                struct l2cap_pinfo *pi = l2cap_pi(sk);
+
                 bh_lock_sock(sk);
 
+                if ((pi->link_mode & (L2CAP_LM_ENCRYPT | L2CAP_LM_SECURE)) &&
+                                        (sk->sk_state == BT_CONNECTED ||
+                                                sk->sk_state == BT_CONFIG) &&
+                                                !status && encrypt == 0x00) {
+                        __l2cap_sock_close(sk, ECONNREFUSED);
+                        bh_unlock_sock(sk);
+                        continue;
+                }
+
                 if (sk->sk_state != BT_CONNECT2) {
                         bh_unlock_sock(sk);
                         continue;