This is a note to let you know that I've just added the patch titled
mac80211: fix use-after-free in defragmentation
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mac80211-fix-use-after-free-in-defragmentation.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b8fff407a180286aa683d543d878d98d9fc57b13 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@xxxxxxxxx>
Date: Mon, 3 Nov 2014 13:57:46 +0100
Subject: mac80211: fix use-after-free in defragmentation
From: Johannes Berg <johannes.berg@xxxxxxxxx>
commit b8fff407a180286aa683d543d878d98d9fc57b13 upstream.
Upon receiving the last fragment, all but the first fragment
are freed, but the multicast check for statistics at the end
of the function refers to the current skb (the last fragment)
causing a use-after-free bug.
Since multicast frames cannot be fragmented and we check for
this early in the function, just modify that check to also
do the accounting to fix the issue.
Reported-by: Yosef Khyal <yosefx.khyal@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mac80211/rx.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1585,11 +1585,14 @@ ieee80211_rx_h_defragment(struct ieee802
sc = le16_to_cpu(hdr->seq_ctrl);
frag = sc & IEEE80211_SCTL_FRAG;
- if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
- is_multicast_ether_addr(hdr->addr1))) {
- /* not fragmented */
+ if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
+ goto out;
+
+ if (is_multicast_ether_addr(hdr->addr1)) {
+ rx->local->dot11MulticastReceivedFrameCount++;
goto out;
}
+
I802_DEBUG_INC(rx->local->rx_handlers_fragments);
if (skb_linearize(rx->skb))
@@ -1682,10 +1685,7 @@ ieee80211_rx_h_defragment(struct ieee802
out:
if (rx->sta)
rx->sta->rx_packets++;
- if (is_multicast_ether_addr(hdr->addr1))
- rx->local->dot11MulticastReceivedFrameCount++;
- else
- ieee80211_led_rx(rx->local);
+ ieee80211_led_rx(rx->local);
return RX_CONTINUE;
}
Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are
queue-3.10/mac80211-fix-use-after-free-in-defragmentation.patch
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