USN-2910-2: Linux kernel (Vivid HWE) regression

Ubuntu Security Notice USN-2910-2

27th February, 2016

linux-lts-vivid regression

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

• Ubuntu 14.04 LTS

Summary

USN-2910-1 introduced a regression in the Ubuntu 15.04 Linux kernel backported to Ubuntu 14.04 LTS.

Software description

• linux-lts-vivid - Linux hardware enablement kernel from Vivid for Trusty

Details

USN-2910-1 fixed vulnerabilities in the Ubuntu 15.04 Linux kernel
backported to Ubuntu 14.04 LTS. An incorrect locking fix caused a
regression that broke graphics displays for Ubuntu 14.04 LTS guests
running the Ubuntu 15.04 backport kernel within VMWare virtual
machines. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

halfdog discovered that OverlayFS, when mounting on top of a FUSE mount,
incorrectly propagated file attributes, including setuid. A local
unprivileged attacker could use this to gain privileges. (CVE-2016-1576)

halfdog discovered that OverlayFS in the Linux kernel incorrectly
propagated security sensitive extended attributes, such as POSIX ACLs. A
local unprivileged attacker could use this to gain privileges.
(CVE-2016-1575)

It was discovered that the Linux kernel keyring subsystem contained a race
between read and revoke operations. A local attacker could use this to
cause a denial of service (system crash). (CVE-2015-7550)

郭永刚 discovered that the Linux kernel networking implementation did
not validate protocol identifiers for certain protocol families, A local
attacker could use this to cause a denial of service (system crash) or
possibly gain administrative privileges. (CVE-2015-8543)

Dmitry Vyukov discovered that the pptp implementation in the Linux kernel
did not verify an address length when setting up a socket. A local attacker
could use this to craft an application that exposed sensitive information
from kernel memory. (CVE-2015-8569)

David Miller discovered that the Bluetooth implementation in the Linux
kernel did not properly validate the socket address length for Synchronous
Connection-Oriented (SCO) sockets. A local attacker could use this to
expose sensitive information. (CVE-2015-8575)

It was discovered that the Linux kernel's Filesystem in Userspace (FUSE)
implementation did not handle initial zero length segments properly. A
local attacker could use this to cause a denial of service (unkillable
task). (CVE-2015-8785)

Update instructions

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

Ubuntu 14.04 LTS:

linux-image-3.19.0-51-generic-lpae 3.19.0-51.58~14.04.1

linux-image-3.19.0-51-lowlatency 3.19.0-51.58~14.04.1

linux-image-3.19.0-51-generic 3.19.0-51.58~14.04.1

linux-image-3.19.0-51-powerpc-e500mc 3.19.0-51.58~14.04.1

linux-image-3.19.0-51-powerpc64-smp 3.19.0-51.58~14.04.1

linux-image-3.19.0-51-powerpc64-emb 3.19.0-51.58~14.04.1

linux-image-3.19.0-51-powerpc-smp 3.19.0-51.58~14.04.1

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

LP: 1548587