netdev - [PATCH net-next 4/7] net: dsa: free orig skb on rcv if reallocated

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Message-Id: <20170530142131.23568-5-vivien.didelot@savoirfairelinux.com>
Date:   Tue, 30 May 2017 10:21:28 -0400
From:   Vivien Didelot <vivien.didelot@...oirfairelinux.com>
To:     netdev@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, kernel@...oirfairelinux.com,
        "David S. Miller" <davem@...emloft.net>,
        Florian Fainelli <f.fainelli@...il.com>,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...oirfairelinux.com>
Subject: [PATCH net-next 4/7] net: dsa: free orig skb on rcv if reallocated

If the receive function of a tagger reallocated the SKB, the original
SKB is currently not freed. Fix this and free it on both copy or error.

Signed-off-by: Vivien Didelot <vivien.didelot@...oirfairelinux.com>
---
 net/dsa/dsa.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 98173a3f6fd1..0b6f2c7d7d1c 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -209,11 +209,12 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (!skb)
 		return 0;
 
+	/* Receive function may have to reallocate the original SKB */
 	nskb = dst->tag_ops->rcv(skb, dev);
-	if (!nskb) {
+	if (nskb != skb)
 		kfree_skb(skb);
+	if (!nskb)
 		return 0;
-	}
 
 	skb = nskb;
 	skb_push(skb, ETH_HLEN);
-- 
2.13.0