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: http://ift.tt/17VXqjU.

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

References

http://ift.tt/1TGaq3N

from Ubuntu Security Notices http://ift.tt/1TGapwI