From: Arik Nemtsov <arik@wizery.com>
Date: Sun, 3 Jun 2012 20:32:32 +0000 (+0300)
Subject: mac80211: fix non RCU-safe sta_list manipulation
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=794454ce72a298de6f4536ade597bdcc7dcde7c7;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

mac80211: fix non RCU-safe sta_list manipulation

sta_info_cleanup locks the sta_list using rcu_read_lock however
the delete operation isn't rcu safe. A race between sta_info_cleanup
timer being called and a STA being removed can occur which leads
to a panic while traversing sta_list. Fix this by switching to the
RCU-safe versions.

Cc: stable@vger.kernel.org
Reported-by: Eyal Shapira <eyal@wizery.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f5b1638fbf80..de455f8bbb91 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -378,7 +378,7 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
 	/* make the station visible */
 	sta_info_hash_add(local, sta);
 
-	list_add(&sta->list, &local->sta_list);
+	list_add_rcu(&sta->list, &local->sta_list);
 
 	set_sta_flag(sta, WLAN_STA_INSERTED);
 
@@ -688,7 +688,7 @@ int __must_check __sta_info_destroy(struct sta_info *sta)
 	if (ret)
 		return ret;
 
-	list_del(&sta->list);
+	list_del_rcu(&sta->list);
 
 	mutex_lock(&local->key_mtx);
 	for (i = 0; i < NUM_DEFAULT_KEYS; i++)