6.1 - USN-2777-1

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description: - linux-lts-utopic: Linux hardware enablement kernel from Utopic

Details:

It was discovered that virtio networking in the Linux kernel did not handle fragments correctly, leading to kernel memory corruption. A remote attacker could use this to cause a denial of service (system crash) or possibly execute code with administrative privileges. (CVE-2015-5156)

Benjamin Randazzo discovered an information leak in the md (multiple device) driver when the bitmap_info.file is disabled. A local privileged attacker could use this to obtain sensitive information from the kernel. (CVE-2015-5697)

Marc-André Lureau discovered that the vhost driver did not properly release the userspace provided log file descriptor. A privileged attacker could use this to cause a denial of service (resource exhaustion). (CVE-2015-6252)

It was discovered that the Reliable Datagram Sockets (RDS) implementation in the Linux kernel did not verify sockets were properly bound before attempting to send a message, which could cause a NULL pointer dereference. An attacker could use this to cause a denial of service (system crash). (CVE-2015-6937)

Ben Hutchings discovered that the Advanced Union Filesystem (aufs) for the Linux kernel did not correctly handle references of memory mapped files from an aufs mount. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2015-7312)

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 14.04 LTS:
linux-image-3.16.0-51-generic 3.16.0-51.69~14.04.1
linux-image-3.16.0-51-generic-lpae 3.16.0-51.69~14.04.1
linux-image-3.16.0-51-lowlatency 3.16.0-51.69~14.04.1
linux-image-3.16.0-51-powerpc-e500mc 3.16.0-51.69~14.04.1
linux-image-3.16.0-51-powerpc-smp 3.16.0-51.69~14.04.1
linux-image-3.16.0-51-powerpc64-emb 3.16.0-51.69~14.04.1
linux-image-3.16.0-51-powerpc64-smp 3.16.0-51.69~14.04.1

After a standard system update you need to reboot your computer to make all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. If you use linux-restricted-modules, you have to update that package as well to get modules which work with the new kernel version. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-server, linux-powerpc), a standard system upgrade will automatically perform this as well.

References:
http://www.ubuntu.com/usn/usn-2777-1
CVE-2015-5156, CVE-2015-5697, CVE-2015-6252, CVE-2015-6937,
CVE-2015-7312

Package Information:
https://launchpad.net/ubuntu/+source/linux-lts-utopic/3.16.0-51.69~14.04.1