From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:57104 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756148AbcBSI7Q (ORCPT ); Fri, 19 Feb 2016 03:59:16 -0500 From: Alexander Aring Subject: [PATCH bluetooth-next 2/5] mac802154: fix mac header length check Date: Fri, 19 Feb 2016 09:59:11 +0100 Message-Id: <1455872354-26032-2-git-send-email-aar@pengutronix.de> In-Reply-To: <1455872354-26032-1-git-send-email-aar@pengutronix.de> References: <1455872354-26032-1-git-send-email-aar@pengutronix.de> Sender: linux-wpan-owner@vger.kernel.org List-ID: To: linux-wpan@vger.kernel.org Cc: Alexander Aring I got report about that sometimes the WARN_ON occurs there which should never happen. I came to the conclusion that the mac header is there but inside the headroom of skb. The skb->len information doesn't contain the information about the headroom length and skb->len is lesser than two. We check now if the skb_mac_header pointer is set and the room between mac header pointer and tail pointer. Signed-off-by: Alexander Aring --- include/net/mac802154.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/net/mac802154.h b/include/net/mac802154.h index da574bb..2e3cdd20 100644 --- a/include/net/mac802154.h +++ b/include/net/mac802154.h @@ -247,8 +247,9 @@ struct ieee802154_ops { */ static inline __le16 ieee802154_get_fc_from_skb(const struct sk_buff *skb) { - /* return some invalid fc on failure */ - if (unlikely(skb->len < 2)) { + /* check if we can fc at skb_mac_header of sk buffer */ + if (unlikely(!skb_mac_header_was_set(skb) || + (skb_tail_pointer(skb) - skb_mac_header(skb)) < 2)) { WARN_ON(1); return cpu_to_le16(0); } -- 2.7.1