netdev - RE: [PATCH net-next v2] xen-netback: implement dynamic multicast control

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Tue, 2 Feb 2016 11:57:43 +0000
From:	Paul Durrant <Paul.Durrant@...rix.com>
To:	Ian Campbell <Ian.Campbell@...rix.com>,
	Wei Liu <wei.liu2@...rix.com>
CC:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>
Subject: RE: [PATCH net-next v2] xen-netback: implement dynamic multicast
 control

> -----Original Message-----
> From: Ian Campbell [mailto:ian.campbell@...rix.com]
> Sent: 02 February 2016 11:54
> To: Paul Durrant; Wei Liu
> Cc: netdev@...r.kernel.org; xen-devel@...ts.xenproject.org
> Subject: Re: [PATCH net-next v2] xen-netback: implement dynamic multicast
> control
> 
> On Tue, 2016-02-02 at 11:48 +0000, Paul Durrant wrote:
> > > -----Original Message-----
> > > From: Wei Liu [mailto:wei.liu2@...rix.com]
> > > Sent: 02 February 2016 11:47
> > > To: Paul Durrant
> > > Cc: netdev@...r.kernel.org; xen-devel@...ts.xenproject.org; Ian
> > > Campbell;
> > > Wei Liu
> > > Subject: Re: [PATCH net-next v2] xen-netback: implement dynamic
> > > multicast
> > > control
> > >
> > > On Tue, Feb 02, 2016 at 11:31:08AM +0000, Paul Durrant wrote:
> > > [...]
> > > > +static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
> > > > +					 struct xenvif *vif)
> > > > +{
> > > > +	int err = 0;
> > > > +	char *node;
> > > > +	unsigned maxlen = strlen(dev->otherend) +
> > > > +		sizeof("/request-multicast-control");
> > > > +
> > > > +	if (vif->mcast_ctrl_watch.node)
> > > > +		return -EADDRINUSE;
> > > > +
> > >
> > > Sorry if I didn't make myself clear enough. I think EADDRINUSE should
> > > also be logged.
> > >
> >
> > Ok. Not sure how much noise that will cause though.
> 
> If this is a guest trigerable path then don't forget to use the
> ratelimiting printk options....
> 

I *think* it is essentially an error path (i.e should not happen) and the function is only called when connecting backend and frontend, which is fairly well rate-limited by other things, but I'll stick a rate-limit in there just in case.

  Paul

> Ian.