[PATCH 3.10 139/173] cfg80211: fix scheduled scan pointer access

Greg Kroah-Hartman
2013-12-02T20:38:43Z

From: Johannes Berg <johannes.berg@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@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/wireless/scan.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -253,10 +253,10 @@ void __cfg80211_sched_scan_results(struc
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) {