From: Johannes Berg <johannes@sipsolutions.net>
Date: Sat, 31 Oct 2009 06:44:08 +0000 (+0100)
Subject: mac80211: fix scan abort sanity checks
X-Git-Tag: firefly_0821_release~9833^2~3968^2~449^2~92
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6d3560d4fc9c5b9fe1a07a63926ea70512c69c32;p=firefly-linux-kernel-4.4.55.git

mac80211: fix scan abort sanity checks

Since sometimes mac80211 queues up a scan request
to only act on it later, it must be allowed to
(internally) cancel a not-yet-running scan, e.g.
when the interface is taken down. This condition
was missing since we always checked only the
local->scanning variable which isn't yet set in
that situation.

Reported-by: Luis R. Rodriguez <mcgrof@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index c46ac01e2a8f..88a9a1be314a 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -288,10 +288,14 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 
 	mutex_lock(&local->scan_mtx);
 
-	if (WARN_ON(!local->scanning)) {
-		mutex_unlock(&local->scan_mtx);
-		return;
-	}
+	/*
+	 * It's ok to abort a not-yet-running scan (that
+	 * we have one at all will be verified by checking
+	 * local->scan_req next), but not to complete it
+	 * successfully.
+	 */
+	if (WARN_ON(!local->scanning && !aborted))
+		aborted = true;
 
 	if (WARN_ON(!local->scan_req)) {
 		mutex_unlock(&local->scan_mtx);