USN-2777-1: Linux kernel (Utopic HWE) vulnerabilities

Ubuntu Security Notice USN-2777-1

19th October, 2015

linux-lts-utopic vulnerabilities

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 version:

Ubuntu 14.04 LTS:
linux-image-3.16.0-51-generic-lpae

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-generic

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-powerpc64-emb

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-powerpc64-smp

3.16.0-51.69~14.04.1

To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.

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

CVE-2015-5156,

CVE-2015-5697,

CVE-2015-6252,

CVE-2015-6937,

CVE-2015-7312

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