CVE request: linux kernel:fd leak in vhost ioctl VHOST_SET_LOG_FD

[Wade Mealing <wmealing () redhat com>]

Gday,

I'd like to request a CVE for the following issue:

A flaw was found in the way Linux kernel's vhost driver treated userspace
provided log fd while processing VHOST_SET_LOG_FD ioctl command. A
privileged local user with access to the /dev/vhost-net files.  The
provided descriptor would never be released and consume kernel memory.

Usually this /dev/vhost-net file(s) have write access with
root permissions but applications may access it with privileged 
access through libvirt or other virtualisation.

A file descriptor may waste memory for each VHOST_SET_LOG_FD command issued, eventually
wasting available system resources creating a denial of service.

Thanks,

Wade Mealing
Red Hat Product Security

Patch:
https://lkml.org/lkml/2015/8/10/375

Bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=1251839