wifi: cfg80211: reject auth/assoc to AP with our address

If the AP uses our own address as its MLD address or BSSID, then
clearly something's wrong. Reject such connections so we don't
try and fail later.

Reported-by: syzbot+2676771ed06a6df166ad@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/mlme.c

@@ -281,6 +281,11 @@ int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
 	    ether_addr_equal(req->bss->bssid, wdev->u.client.connected_addr))
 		return -EALREADY;
 
+	if (ether_addr_equal(req->bss->bssid, dev->dev_addr) ||
+	    (req->link_id >= 0 &&
+	     ether_addr_equal(req->ap_mld_addr, dev->dev_addr)))
+		return -EINVAL;
+
 	return rdev_auth(rdev, dev, req);
 }
 
@@ -335,6 +340,9 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 			if (req->links[i].bss == req->links[j].bss)
 				return -EINVAL;
 		}
+
+		if (ether_addr_equal(req->links[i].bss->bssid, dev->dev_addr))
+			return -EINVAL;
 	}
 
 	if (wdev->connected &&
@@ -342,6 +350,11 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 	     !ether_addr_equal(wdev->u.client.connected_addr, req->prev_bssid)))
 		return -EALREADY;
 
+	if ((req->bss && ether_addr_equal(req->bss->bssid, dev->dev_addr)) ||
+	    (req->link_id >= 0 &&
+	     ether_addr_equal(req->ap_mld_addr, dev->dev_addr)))
+		return -EINVAL;
+
 	cfg80211_oper_and_ht_capa(&req->ht_capa_mask,
 				  rdev->wiphy.ht_capa_mod_mask);
 	cfg80211_oper_and_vht_capa(&req->vht_capa_mask,