linux-kernel - Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and OOM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <30069778-9509-8112-5089-2eea7b679236@oracle.com>
Date:   Mon, 30 Jan 2017 12:06:34 -0500
From:   Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:     Vineeth Remanan Pillai <vineethp@...zon.com>,
        linux-kernel@...r.kernel.org
Cc:     David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
        Wei Liu <wei.liu2@...rix.com>,
        Paul Durrant <paul.durrant@...rix.com>,
        xen-devel <xen-devel@...ts.xen.org>
Subject: Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and
 OOM

On 01/30/2017 11:47 AM, Vineeth Remanan Pillai wrote:
>
>> 2. It tickles a latent bug during resume where the timer triggers
>> before we re-connect. The trouble is that we now try to dereference
>> queue->rx.sring which is NULL since we disconnect in
>> netfront_resume(). (Curiously, I only observe it with 32-bit guests)
> I think we may hit this bug after removing the timer as well. We call
> RING_PUSH_REQUESTS_AND_CHECK_NOTIFY soon after, which also dereference
> queue->rx.sring.


If the timer is deleted in xennet_disconnect_backend() then why would
anyone be pushing anything to the backend after that?

-boris