[PATCH 3.8 018/152] cfg80211: fix scheduled scan pointer access

[Kamal Mostafa]

3.8.13.14 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.berg at intel.com>

commit 79845c662eeb95c9a180b9bd0d3ad848ee65b94c upstream.

Since rdev->sched_scan_req is dereferenced outside the
lock protecting it, this might be done at the wrong
time, causing crashes. Move the dereference to where
it should be - inside the RTNL locked section.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/wireless/scan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 45f1618..c6390e7 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -166,10 +166,10 @@ void __cfg80211_sched_scan_results(struct work_struct *wk)
 	rdev = container_of(wk, struct cfg80211_registered_device,
 			    sched_scan_results_wk);
 
-	request = rdev->sched_scan_req;
-
 	mutex_lock(&rdev->sched_scan_mtx);
 
+	request = rdev->sched_scan_req;
+
 	/* we don't have sched_scan_req anymore if the scan is stopping */
 	if (request) {
 		if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
-- 
1.8.3.2