Scientific Linux Security Update : qemu-kvm on SL6.x i386/x86_64
Low Nessus Plugin ID 97379
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionSecurity Fix(es) :
- Quick emulator (Qemu) built with the Cirrus CLGD 54xx VGA emulator support is vulnerable to an out-of-bounds access issue. It could occur while copying VGA data via bitblt copy in backward mode. A privileged user inside a guest could use this flaw to crash the Qemu process resulting in DoS or potentially execute arbitrary code on the host with privileges of Qemu process on the host.
- An out-of-bounds read-access flaw was found in the QEMU emulator built with IP checksum routines. The flaw could occur when computing a TCP/UDP packet's checksum, because a QEMU function used the packet's payload length without checking against the data buffer's size. A user inside a guest could use this flaw to crash the QEMU process (denial of service). (CVE-2016-2857)
This update also fixes the following bug :
- Previously, rebooting a guest virtual machine more than 128 times in a short period of time caused the guest to shut down instead of rebooting, because the virtqueue was not cleaned properly. This update ensures that the virtqueue is cleaned more reliably, which prevents the described problem from occurring.
After installing this update, shut down all running virtual machines.
Once all virtual machines have shut down, start them again for this update to take effect.
SolutionUpdate the affected packages.