Re: x25: possible skb leak on bad facilities

From: John Hughes
Date: Mon Feb 07 2011 - 04:31:09 EST


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<andrew.hendry@xxxxxxxxx>
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.
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