Bluetooth: L2CAP: Add missing checks for invalid LE DCID

When receiving a connect response we should make sure that the DCID is
within the valid range and that we don't already have another channel
allocated for the same DCID.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index fdb7989e29976742a6617b7c54b87c7562aa5a06..66e8b6ee19a525d8cc54032843934b0fedb11dc7 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -5250,7 +5250,9 @@ static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
        credits = __le16_to_cpu(rsp->credits);
        result  = __le16_to_cpu(rsp->result);
 
-       if (result == L2CAP_CR_SUCCESS && (mtu < 23 || mps < 23))
+       if (result == L2CAP_CR_SUCCESS && (mtu < 23 || mps < 23 ||
+                                          dcid < L2CAP_CID_DYN_START ||
+                                          dcid > L2CAP_CID_LE_DYN_END))
                return -EPROTO;
 
        BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
@@ -5270,6 +5272,11 @@ static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
 
        switch (result) {
        case L2CAP_CR_SUCCESS:
+               if (__l2cap_get_chan_by_dcid(conn, dcid)) {
+                       err = -EBADSLT;
+                       break;
+               }
+
                chan->ident = 0;
                chan->dcid = dcid;
                chan->omtu = mtu;