CentOS 5 : kvm (CESA-2010:0627)
Medium Nessus Plugin ID 48910
SynopsisThe remote CentOS host is missing one or more security updates.
DescriptionUpdated kvm packages that fix three security issues and multiple bugs are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.
KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for the standard Red Hat Enterprise Linux kernel.
It was found that QEMU-KVM on the host did not validate all pointers provided from a guest system's QXL graphics card driver. A privileged guest user could use this flaw to cause the host to dereference an invalid pointer, causing the guest to crash (denial of service) or, possibly, resulting in the privileged guest user escalating their privileges on the host. (CVE-2010-0431)
A flaw was found in QEMU-KVM, allowing the guest some control over the index used to access the callback array during sub-page MMIO initialization. A privileged guest user could use this flaw to crash the guest (denial of service) or, possibly, escalate their privileges on the host. (CVE-2010-2784)
A NULL pointer dereference flaw was found when the host system had a processor with the Intel VT-x extension enabled. A privileged guest user could use this flaw to trick the host into emulating a certain instruction, which could crash the host (denial of service).
This update also fixes the following bugs :
* running a 'qemu-img' check on a faulty virtual machine image ended with a segmentation fault. With this update, the segmentation fault no longer occurs when running the 'qemu-img' check. (BZ#610342)
* when attempting to transfer a file between two guests that were joined in the same virtual LAN (VLAN), the receiving guest unexpectedly quit. With this update, the transfer completes successfully. (BZ#610343)
* installation of a system was occasionally failing in KVM. This was caused by KVM using wrong permissions for large guest pages. With this update, the installation completes successfully. (BZ#616796)
* previously, the migration process would fail for a virtual machine because the virtual machine could not map all the memory. This was caused by a conflict that was initiated when a virtual machine was initially run and then migrated right away. With this update, the conflict no longer occurs and the migration process no longer fails.
* using a thinly provisioned VirtIO disk on iSCSI storage and performing a 'qemu-img' check during an 'e_no_space' event returned cluster errors. With this update, the errors no longer appear.
All KVM users should upgrade to these updated packages, which contain backported patches to resolve these issues. Note: The procedure in the Solution section must be performed before this update will take effect.
SolutionUpdate the affected kvm packages.