Return-Path: From: Lukasz Rymanowski To: linux-bluetooth@vger.kernel.org Cc: Lukasz Rymanowski Subject: [PATCH v2] Bluetooth: Fix ERTM L2CAP resend packet Date: Thu, 14 Aug 2014 09:35:34 +0200 Message-Id: <1408001734-23910-1-git-send-email-lukasz.rymanowski@tieto.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: 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 --- 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 ebe7454..43e2d74 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); -- 1.8.4