From 9a65064abdf82934e0ed4744125f9f466f421f57 Mon Sep 17 00:00:00 2001
From: Dedy Lansky <dlansky@codeaurora.org>
Date: Thu, 23 Aug 2018 14:47:07 +0300
Subject: [PATCH] wil6210: drop Rx multicast packets that are looped-back to STA
Git-commit: 9a65064abdf82934e0ed4744125f9f466f421f57
Patch-mainline: v4.20-rc1
References: bsc#1111666

Delivering a looped-back multicast packet to network stack can cause
higher layer protocols to fail like for example IPv6 DAD.
In STA mode, upon receiving Rx multicast packet, check if the source
MAC address is equal to our own MAC address and if so drop the packet.

Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/ath/wil6210/txrx.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index 6a7943e487fb..e7b003b38f45 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -765,7 +765,14 @@ void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
 		return;
 	}
 
-	if (wdev->iftype == NL80211_IFTYPE_AP && !vif->ap_isolate) {
+	if (wdev->iftype == NL80211_IFTYPE_STATION) {
+		if (mcast && ether_addr_equal(eth->h_source, ndev->dev_addr)) {
+			/* mcast packet looped back to us */
+			rc = GRO_DROP;
+			dev_kfree_skb(skb);
+			goto stats;
+		}
+	} else if (wdev->iftype == NL80211_IFTYPE_AP && !vif->ap_isolate) {
 		if (mcast) {
 			/* send multicast frames both to higher layers in
 			 * local net stack and back to the wireless medium
-- 
2.16.4