From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri,  8 May 2020 14:34:32 +0200
Message-Id: <20200508123144.177646487@linuxfoundation.org>
In-Reply-To: <20200508123124.574959822@linuxfoundation.org>
References: <20200508123124.574959822@linuxfoundation.org>
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Subject: [Bridge] [PATCH 4.4 281/312] net: bridge: dont increment tx_dropped
	in br_do_proxy_arp
To: linux-kernel@vger.kernel.org
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Roopa Prabhu <roopa@cumulusnetworks.com>, bridge@lists.linux-foundation.org, stable@vger.kernel.org, Kyeyoon Park <kyeyoonp@codeaurora.org>, "David S. Miller" <davem@davemloft.net>

From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

commit 85a3d4a9356b595d5440c3f1bf07ee7cecca1567 upstream.

pskb_may_pull may fail due to various reasons (e.g. alloc failure), but the
skb isn't changed/dropped and processing continues so we shouldn't
increment tx_dropped.

CC: Kyeyoon Park <kyeyoonp@codeaurora.org>
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: Stephen Hemminger <stephen@networkplumber.org>
CC: bridge@lists.linux-foundation.org
Fixes: 958501163ddd ("bridge: Add support for IEEE 802.11 Proxy ARP")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/bridge/br_input.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -78,13 +78,10 @@ static void br_do_proxy_arp(struct sk_bu
 
 	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
 
-	if (dev->flags & IFF_NOARP)
+	if ((dev->flags & IFF_NOARP) ||
+	    !pskb_may_pull(skb, arp_hdr_len(dev)))
 		return;
 
-	if (!pskb_may_pull(skb, arp_hdr_len(dev))) {
-		dev->stats.tx_dropped++;
-		return;
-	}
 	parp = arp_hdr(skb);
 
 	if (parp->ar_pro != htons(ETH_P_IP) ||