From: Joe Perches <joe@perches.com>
Date: Thu, 03 Dec 2015 20:24:06 +0000
Subject: Re: use-after-free in sctp_do_sm
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To: Jason Baron <jbaron@akamai.com>, Aaron Conole <aconole@redhat.com>, Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>, syzkaller <syzkaller@googlegroups.com>, Vladislav Yasevich <vyasevich@gmail.com>, linux-sctp@vger.kernel.org, netdev <netdev@vger.kernel.org>, Kostya Serebryany <kcc@google.com>, Alexander Potapenko <glider@google.com>, Sasha Levin <sasha.levin@oracle.com>

On Thu, 2015-12-03 at 15:10 -0500, Jason Baron wrote:
> On 12/03/2015 03:03 PM, Joe Perches wrote:
> > On Thu, 2015-12-03 at 14:32 -0500, Jason Baron wrote:
> > > On 12/03/2015 01:52 PM, Aaron Conole wrote:
> > > > I think that as a minimum, the following patch should be evaluted,
> > > > but am unsure to whom I should submit it (after I test):
> > []
> > > Agreed - the intention here is certainly to have no side effects. It
> > > looks like 'no_printk()' is used in quite a few other places that wou=
ld
> > > benefit from this change. So we probably want a generic
> > > 'really_no_printk()' macro.
> >=20
> > https://lkml.org/lkml/2012/6/17/231
>=20
> I don't see this in the tree.

It never got applied.

> Also maybe we should just convert
> no_printk() to do what your 'eliminated_printk()'.

Some of them at least.

> So we can convert all users with this change?

I don't think so, I think there are some
function evaluation/side effects that are
required. =A0I believe some do hardware I/O.

It'd be good to at least isolate them.

I'm not sure how to find them via some
automated tool/mechanism though.

I asked Julia Lawall about it once in this
thread:  https://lkml.org/lkml/2014/12/3/696