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Date:   Thu, 28 Jul 2022 17:25:16 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     linux-wireless@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH] wifi: mac80211: potential NULL dereference in
 ieee80211_tx_control_port()
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The ieee80211_lookup_ra_sta() function will sometimes set "sta" to NULL
so add this NULL check to prevent an Oops.

Fixes: 9dd1953846c7 ("wifi: nl80211/mac80211: clarify link ID in control port TX")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 net/mac80211/tx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 45df9932d0ba..fd7e7dd66efc 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -5899,7 +5899,7 @@ int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
 		 * for MLO STA, the SA should be the AP MLD address, but
 		 * the link ID has been selected already
 		 */
-		if (sta->sta.mlo)
+		if (sta && sta->sta.mlo)
 			memcpy(ehdr->h_source, sdata->vif.addr, ETH_ALEN);
 	}
 	rcu_read_unlock();
-- 
2.35.1