[3.11.y.z extended stable] Patch "mac80211: fix potential use-after-free" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    mac80211: fix potential use-after-free

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From d704a39f9ff9ea3b801217c0de86090e0c99304d Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Tue, 4 Mar 2014 11:43:28 +0100
Subject: mac80211: fix potential use-after-free

commit d2722f8b87fb172ff2f31d3a2816b31d58678d40 upstream.

The bss struct might be freed in ieee80211_rx_bss_put(),
so we shouldn't use it afterwards.

Fixes: 817cee7675237 ("mac80211: track AP's beacon rate and give it to the driver")
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/mac80211/mlme.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index a83d76a..06f71fb 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2871,8 +2871,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 					channel);
 	if (bss) {
-		ieee80211_rx_bss_put(local, bss);
 		sdata->vif.bss_conf.beacon_rate = bss->beacon_rate;
+		ieee80211_rx_bss_put(local, bss);
 	}
 }

--
1.9.1