linux-kernel - Re: [PATCH] vhost: zero vhost

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Message-ID: <CAGF4SLiZxXcWskZXmGbwO11MnwyMAK_Bpbn0ugZzK6jSMHdiog@mail.gmail.com>
Date:   Thu, 28 Mar 2019 13:08:36 -0400
From:   Vitaly Mayatskih <v.mayatskih@...il.com>
To:     Stefan Hajnoczi <stefanha@...hat.com>
Cc:     Michal Hocko <mhocko@...e.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] vhost: zero vhost_vsock memory on allocation

On Thu, Mar 28, 2019 at 12:36 PM Stefan Hajnoczi <stefanha@...hat.com> wrote:

> vsock->hash is only read if vsock->guest_cid has already been set and
> hence vsock->hash has been initialized too.  I don't see where the
> problem is.
>
> Was your tree missing commit a72b69dc083a931422cc8a5e33841aff7d5312f2
> ("vhost/vsock: fix uninitialized vhost_vsock->guest_cid")?
>
> Are you sure the crash can be reproduced on linux.git/master?

You are right: we hit it on 4.14.91 while the guest_cid fix was
backported in 4.14.93.
Thus not a real issue. Sorry for confusion, vhost is something still new to me.

> Sounds good.  Please send a v2 that also removes the explicit zero
> initialization since it's no longer needed with zalloc.

I changed my mind, all the rest is initialized explicitly, let's keep
it that way.
Will send the patch shortly.

-- 
wbr, Vitaly