From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 28 Jul 2022 14:25:16 +0000 (+0300)
Subject: wifi: mac80211: potential NULL dereference in ieee80211_tx_control_port()
X-Git-Tag: v6.0-rc4~25^2~27^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=55f0a4894484e8d6ddf662f5aebbf3b4cb028541;p=users%2Fdwmw2%2Flinux.git

wifi: mac80211: potential NULL dereference in ieee80211_tx_control_port()

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>
Link: https://lore.kernel.org/r/YuKcTAyO94YOy0Bu@kili
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 594bd70ee641a..bf7fe6cd9dfca 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -5900,7 +5900,7 @@ 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();