Bluetooth: Close L2CAP channel on invalid ReqSeq
Signed-off-by: João Paulo Rechi Vita <jprvita@profusion.mobi>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 478def7..31514d8 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -3772,7 +3772,7 @@
struct sock *sk;
struct l2cap_pinfo *pi;
u16 control, len;
- u8 tx_seq;
+ u8 tx_seq, req_seq, next_tx_seq_offset, req_seq_offset;
sk = l2cap_get_chan_by_scid(&conn->chan_list, cid);
if (!sk) {
@@ -3823,6 +3823,22 @@
if (l2cap_check_fcs(pi, skb))
goto drop;
+ req_seq = __get_reqseq(control);
+ req_seq_offset = (req_seq - pi->expected_ack_seq) % 64;
+ if (req_seq_offset < 0)
+ req_seq_offset += 64;
+
+ next_tx_seq_offset =
+ (pi->next_tx_seq - pi->expected_ack_seq) % 64;
+ if (next_tx_seq_offset < 0)
+ next_tx_seq_offset += 64;
+
+ /* check for invalid req-seq */
+ if (req_seq_offset > next_tx_seq_offset) {
+ l2cap_send_disconn_req(pi->conn, sk);
+ goto drop;
+ }
+
if (__is_iframe(control)) {
if (len < 4)
goto drop;