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 <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2012-10-26 00:33:36 +02:00
parent 7dd111e8ee
commit 4a4f1a5808
1 changed files with 8 additions and 4 deletions
net/mac80211

View File

@ -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);