Re: [Qemu-devel] [PATCH 1/2] 9pfs: fix information leak in xattr read

[Li Qiang]

Yes, I think the limit to apply to xattr size in 9pfs is the same as the
Linux xattr size limit, I will try to find this limit.

Thanks.

On 2016-10-13 4:49 GMT+08:00 Eric Blake <address@hidden> wrote:

> On 10/12/2016 08:23 AM, Greg Kurz wrote:
> >
> > But in fact, I'm afraid we have a more serious problem here... size
> > comes from the guest and could cause g_malloc() to abort if QEMU has
> > reached some RLIMIT... we need to call g_try_malloc0() and return
> > ENOMEM if the allocation fails.
>
> Even if it does not cause an ENOMEM failure right away, the guest can
> also use this to chew up lots of host resources. It may also be worth
> putting a reasonable cap at the maximum the guest can allocate, rather
> than just trying to malloc every possible size.
>
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>
>