Scientific Linux Security Update : libvirt on SL6.x i386/x86_64
Medium Nessus Plugin ID 66491
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionIt was found that libvirtd leaked file descriptors when listing all volumes for a particular pool. A remote attacker able to establish a read- only connection to libvirtd could use this flaw to cause libvirtd to consume all available file descriptors, preventing other users from using libvirtd services (such as starting a new guest) until libvirtd is restarted. (CVE-2013-1962)
This update also fixes the following bugs :
- Previously, libvirt made control group (cgroup) requests on files that it should not have. With older kernels, such nonsensical cgroup requests were ignored; however, newer kernels are stricter, resulting in libvirt logging spurious warnings and failures to the libvirtd and audit logs. The audit log failures displayed by the ausearch tool were similar to the following :
root [date] - failed cgroup allow path rw /dev/kqemu
With this update, libvirt no longer attempts the nonsensical cgroup actions, leaving only valid attempts in the libvirtd and audit logs (making it easier to search for real cases of failure).
- Previously, libvirt used the wrong variable when constructing audit messages. This led to invalid audit messages, causing ausearch to format certain entries as having 'path=(null)' instead of the correct path. This could prevent ausearch from locating events related to cgroup device ACL modifications for guests managed by libvirt. With this update, the audit messages are generated correctly, preventing loss of audit coverage.
After installing the updated packages, libvirtd will be restarted automatically.
SolutionUpdate the affected packages.