From 13cac15296afe7e42088ecfcd0f1d4b658248c46 Mon Sep 17 00:00:00 2001 From: Lukasz Rymanowski Date: Thu, 14 Aug 2014 09:35:34 +0200 Subject: [PATCH] Bluetooth: Fix ERTM L2CAP resend packet I-Frame which is going to be resend already has FCS field added and set (if it was required). Adding additional FCS field calculated from data + old FCS in resend function is incorrect. This patch fix that. Issue has been found during PTS testing. Signed-off-by: Lukasz Rymanowski Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap_core.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index ebe7454362f0..4a90438d99df 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1968,10 +1968,12 @@ static void l2cap_ertm_resend(struct l2cap_chan *chan) tx_skb->data + L2CAP_HDR_SIZE); } + /* Update FCS */ if (chan->fcs == L2CAP_FCS_CRC16) { - u16 fcs = crc16(0, (u8 *) tx_skb->data, tx_skb->len); - put_unaligned_le16(fcs, skb_put(tx_skb, - L2CAP_FCS_SIZE)); + u16 fcs = crc16(0, (u8 *) tx_skb->data, + tx_skb->len - L2CAP_FCS_SIZE); + put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) - + L2CAP_FCS_SIZE); } l2cap_do_send(chan, tx_skb); -- 2.34.1