mac80211: fix sta_info_destroy(NULL)

sta_info_destroy(NULL) should be valid, but currently isn't because
the argument is dereferenced before the NULL check. There are no
users that currently pass in NULL, i.e. all check before calling the
function, but I want to change that.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f708367092d1b1ba6e674a1c2311718a5489368b..2a5a2f067bae044815cd5c1e91152b7b516261fe 100644 (file)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -129,16 +129,18 @@ struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx,
 
 void sta_info_destroy(struct sta_info *sta)
 {
-       struct ieee80211_local *local = sta->local;
+       struct ieee80211_local *local;
        struct sk_buff *skb;
        int i;
        DECLARE_MAC_BUF(mbuf);
 
+       ASSERT_RTNL();
+       might_sleep();
+
        if (!sta)
                return;
 
-       ASSERT_RTNL();
-       might_sleep();
+       local = sta->local;
 
        rate_control_remove_sta_debugfs(sta);
        ieee80211_sta_debugfs_remove(sta);