USN-2644-2: Linux kernel (Utopic HWE) regression

Ubuntu Security Notice USN-2644-2

21st June, 2015

linux-lts-utopic regression

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

  • Ubuntu 14.04 LTS

Summary

The system could be made to crash under certain conditions.

Software description

  • linux-lts-utopic
    – Linux hardware enablement kernel from Utopic

Details

The Fix for CVE-2015-1328 introduced a regression into the Linux kernel’s
overlayfs file system. The removal of a directory that only exists on the
lower layer results in a kernel panic.

We apologize for the inconvenience.

Original advisory details:

Philip Pettersson discovered a privilege escalation when using overlayfs
mounts inside of user namespaces. A local user could exploit this flaw to
gain administrative privileges on the system.

Update instructions

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

Ubuntu 14.04 LTS:
linux-image-3.16.0-41-powerpc-smp

3.16.0-41.57~14.04.1
linux-image-3.16.0-41-powerpc64-smp

3.16.0-41.57~14.04.1
linux-image-3.16.0-41-generic

3.16.0-41.57~14.04.1
linux-image-3.16.0-41-powerpc-e500mc

3.16.0-41.57~14.04.1
linux-image-3.16.0-41-generic-lpae

3.16.0-41.57~14.04.1
linux-image-3.16.0-41-lowlatency

3.16.0-41.57~14.04.1
linux-image-3.16.0-41-powerpc64-emb

3.16.0-41.57~14.04.1

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.

References

http://bugs.launchpad.net/bugs/1465998

Leave a Reply