cfg80211: fix scheduled scan pointer access

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>

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index fd99ea495b7e68cd9e5265542a6aa059d0ac7760..81019ee3ddc8c8a71955322d193238962edc05b4 100644 (file)
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -253,10 +253,10 @@ 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) {