[ 23/66] mac80211: check management frame header length
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2012-11-15 04:37:32
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3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg <redacted> 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 <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/mac80211/rx.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c@@ -1430,7 +1430,6 @@ 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;
@@ -2867,10 +2866,15 @@ static void __ieee80211_rx_handle_packet 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);