From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756565Ab2KNFzM (ORCPT ); Wed, 14 Nov 2012 00:55:12 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55280 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756470Ab2KNFvJ (ORCPT ); Wed, 14 Nov 2012 00:51:09 -0500 Message-Id: <20121114053938.038709059@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Wed, 14 Nov 2012 05:40:03 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Johannes Berg Subject: [ 30/82] mac80211: check management frame header length In-Reply-To: <20121114053933.726869752@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg commit 4a4f1a5808c8bb0b72a4f6e5904c53fb8c9cd966 upstream. Due to pskb_may_pull() checking the skb length, all non-management frames are checked on input whether their 802.11 header is fully present. Also add that check for management frames and remove a check that is now duplicate. This prevents accessing skb data beyond the frame end. Signed-off-by: Johannes Berg Signed-off-by: Ben Hutchings --- net/mac80211/rx.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1457,7 +1457,6 @@ ieee80211_rx_h_defragment(struct ieee802 frag = sc & IEEE80211_SCTL_FRAG; if (likely((!ieee80211_has_morefrags(fc) && frag == 0) || - (rx->skb)->len < 24 || is_multicast_ether_addr(hdr->addr1))) { /* not fragmented */ goto out; @@ -2875,10 +2874,15 @@ static void __ieee80211_rx_handle_packet test_bit(SCAN_OFF_CHANNEL, &local->scanning))) status->rx_flags |= IEEE80211_RX_IN_SCAN; - if (ieee80211_is_mgmt(fc)) - err = skb_linearize(skb); - else + if (ieee80211_is_mgmt(fc)) { + /* drop frame if too short for header */ + if (skb->len < ieee80211_hdrlen(fc)) + err = -ENOBUFS; + else + err = skb_linearize(skb); + } else { err = !pskb_may_pull(skb, ieee80211_hdrlen(fc)); + } if (err) { dev_kfree_skb(skb);