Re: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use

From: Michael S. Tsirkin
Date: Tue Mar 08 2022 - 06:07:40 EST


On Tue, Mar 08, 2022 at 08:01:32AM +0000, Lee Jones wrote:
> On Mon, 07 Mar 2022, Michael S. Tsirkin wrote:
>
> > On Mon, Mar 07, 2022 at 07:17:57PM +0000, Lee Jones wrote:
> > > vhost_vsock_handle_tx_kick() already holds the mutex during its call
> > > to vhost_get_vq_desc(). All we have to do here is take the same lock
> > > during virtqueue clean-up and we mitigate the reported issues.
> >
> > Pls just basically copy the code comment here. this is just confuses.
> >
> > > Also WARN() as a precautionary measure. The purpose of this is to
> > > capture possible future race conditions which may pop up over time.
> > >
> > > Link: https://syzkaller.appspot.com/bug?extid=279432d30d825e63ba00
> >
> > And this is a bug we already fixed, right?
>
> Well, this was the bug I set out to fix.
>
> I didn't know your patch was in flight at the time.
>
> > > Cc: <stable@xxxxxxxxxxxxxxx>
> > > Reported-by: syzbot+adc3cb32385586bec859@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > not really applicable anymore ...
>
> I can remove these if it helps.

yes let's do that pls.

> --
> Lee Jones [李琼斯]
> Principal Technical Lead - Developer Services
> Linaro.org │ Open source software for Arm SoCs
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