From: Johannes Berg <johannes.berg@xxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
net/mac80211/rx.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
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 @@ 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);
--
1.7.10.4
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