From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 3 Jul 2024 12:10:01 +0200
Subject: [PATCH] wifi: mac80211: clear vif drv_priv after calling
 remove_interface

Avoid reusing stale driver data when an interface is brought down and up
again. In order to avoid having to duplicate the memset in every single
driver, do it here.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -693,8 +693,12 @@ static void ieee80211_do_stop(struct iee
 
 		fallthrough;
 	default:
-		if (going_down)
-			drv_remove_interface(local, sdata);
+		if (!going_down)
+			break;
+		drv_remove_interface(local, sdata);
+
+		/* Clear private driver data to prevent reuse */
+		memset(sdata->vif.drv_priv, 0, local->hw.vif_data_size);
 	}
 
 	ieee80211_recalc_ps(local);