From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Hughes Subject: Re: x25: possible skb leak on bad facilities Date: Mon, 07 Feb 2011 10:25:29 +0100 Message-ID: <4D4FBA89.606@Calva.COM> References: <20110131130826.GC16804@shadowen.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Andrew Hendry , "David S. Miller" , linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Tim Gardner To: Andy Whitcroft Return-path: In-Reply-To: <20110131130826.GC16804@shadowen.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 31/01/11 14:08, Andy Whitcroft wrote: > Looking at the changes introduced in the commit below, we seem to > introduce an skb leak when a packet with bad facilities are present: > > commit a6331d6f9a4298173b413cf99a40cc86a9d92c37 > Author: andrew hendry > Date: Wed Nov 3 12:54:53 2010 +0000 > > memory corruption in X.25 facilities parsing > > If I am understanding things correctly then we trigger a -1 return to > the main packet dispatch loop, this being non-zero implies that we have > requeued the skb and it should not be freed. As it was not requeued, > I believe the skb is no longer referenced and then is leaked. > > Perhaps someone better aquainted with this code could review my analysis > in the patch leader below. If accurate I believe we need the patch below > to resolve this. If it is not then I suspect a comment is required on > the -1 return. > > Thoughts? > Sadly, after nearly 30 years (1982-2010) we've just closed our last X.25 line so I can no longer test this. Sorry.