From 4a4f1a5808c8bb0b72a4f6e5904c53fb8c9cd966 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 26 Oct 2012 00:33:36 +0200 Subject: mac80211: check management frame header length 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. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index c6865f2f47f8..99cdee16e31b 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1470,7 +1470,6 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) 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; @@ -2915,10 +2914,15 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc)) local->dot11ReceivedFragmentCount++; - 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); -- cgit v1.2.3-58-ga151