From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thadeu Lima de Souza Cascardo Subject: [PATCH 1/2] xfrm6: call kfree_skb when skb is toobig Date: Thu, 30 Aug 2018 09:58:16 -0300 Message-ID: <20180830125817.4567-1-cascardo@canonical.com> Cc: yoshfuji@linux-ipv6.org, kuznet@ms2.inr.ac.ru, davem@davemloft.net, herbert@gondor.apana.org.au, steffen.klassert@secunet.com, eyal.birger@gmail.com To: netdev@vger.kernel.org Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:37486 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728638AbeH3RAb (ORCPT ); Thu, 30 Aug 2018 13:00:31 -0400 Sender: netdev-owner@vger.kernel.org List-ID: After commit d6990976af7c5d8f55903bfb4289b6fb030bf754 ("vti6: fix PMTU caching and reporting on xmit"), some too big skbs might be potentially passed down to __xfrm6_output, causing it to fail to transmit but not free the skb, causing a leak of skb, and consequentially a leak of dst references. After running pmtu.sh, that shows as failure to unregister devices in a namespace: [ 311.397671] unregister_netdevice: waiting for veth_b to become free. Usage count = 1 The fix is to call kfree_skb in case of transmit failures. Signed-off-by: Thadeu Lima de Souza Cascardo --- net/ipv6/xfrm6_output.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c index 5959ce9620eb..6a74080005cf 100644 --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -170,9 +170,11 @@ static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb) if (toobig && xfrm6_local_dontfrag(skb)) { xfrm6_local_rxpmtu(skb, mtu); + kfree_skb(skb); return -EMSGSIZE; } else if (!skb->ignore_df && toobig && skb->sk) { xfrm_local_error(skb, mtu); + kfree_skb(skb); return -EMSGSIZE; } -- 2.17.1