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>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index c6865f2..99cdee1 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1470,7 +1470,6 @@
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 @@
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);
