Patchwork [3.11,162/272] cfg80211: fix scheduled scan pointer access

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Submitter Luis Henriques
Date Dec. 6, 2013, 12:57 p.m.
Message ID <1386334761-25517-163-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/297979/
State New
Headers show

Comments

Luis Henriques - Dec. 6, 2013, 12:57 p.m.
3.11.10.1 -stable review patch.  If anyone has any objections, please let me know.

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

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: Luis Henriques <luis.henriques@canonical.com>
---
 net/wireless/scan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index ae8c186..7811f81 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -254,10 +254,10 @@  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;
-
 	rtnl_lock();
 
+	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) {