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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 23 Sep 2013 08:51:23 +0000
From:	Paul Durrant <>
To:	annie li <>
CC:	"" <>,
	"" <>,
	Wei Liu <>,
	David Vrabel <>,
	Ian Campbell <>
Subject: RE: [Xen-devel] [PATCH net-next v2 1/2] xen-netback: add a
 vif-is-connected flag

> -----Original Message-----
> From: annie li []
> Sent: 22 September 2013 03:57
> To: Paul Durrant
> Cc:;; Wei Liu; David Vrabel;
> Ian Campbell
> Subject: Re: [Xen-devel] [PATCH net-next v2 1/2] xen-netback: add a vif-is-
> connected flag
> On 2013-9-20 21:57, Paul Durrant wrote:
> > Having applied my patch to separate vif disconnect and free, I ran into a
> > BUG when testing resume from S3 with a Windows frontend because the
> vif task
> > pointer was not cleared by xenvif_disconnect() and so a double call to this
> > function tries to stop the thread twice.
> Or it is better to do more implements in windows netfront? For example,
> when the windows vm hibernates, disconnect the vif as required by
> netback: connect-> closing-> closed.

S3 != hibernation; that is S4. The backend does not go away when the VM goes into S3 as the domain remains intact. We do go through the correct closing->closed transition on the way down but, because of the way the D3->D0 code in the frontend needs to be generalized, we attempt a second closing->closed transition on the way back up. In the S4 case this ok because we have a fresh backend, but in the S3 case we don't and therefore hit the double-disconnect issue. The fact the backend BUGs in this case clearly shows a vulnerability in the backend and thus that is where the fix needs to be made; the frontend is doing nothing wrong.

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists