Re: [PATCH 3/5] vhost: support upto 509 memory regions

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Jun 17, 2015 at 03:20:44PM +0200, Paolo Bonzini wrote:
> 
> 
> On 17/06/2015 15:13, Michael S. Tsirkin wrote:
> > > > Considering userspace can be malicious, I guess yes.
> > > I don't think it's a valid concern in this case,
> > > setting limit back from 509 to 64 will not help here in any way,
> > > userspace still can create as many vhost instances as it needs
> > > to consume memory it desires.
> > 
> > Not really since vhost char device isn't world-accessible.
> > It's typically opened by a priveledged tool, the fd is
> > then passed to an unpriveledged userspace, or permissions dropped.
> 
> Then what's the concern anyway?
> 
> Paolo

Each fd now ties up 16K of kernel memory.  It didn't use to, so
priveledged tool could safely give the unpriveledged userspace
a ton of these fds.

-- 
MST
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux