USN-3381-2: Linux kernel (Trusty HWE) vulnerabilities

Ubuntu Security Notice USN-3381-2

7th August, 2017

linux-lts-trusty vulnerabilities

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

  • Ubuntu 12.04 LTS

Summary

Several security issues were fixed in the Linux kernel.

Software description

  • linux-lts-trusty - Linux hardware enablement kernel from Trusty for Precise ESM

Details

USN-3381-1 fixed vulnerabilities in the Linux kernel for Ubuntu 14.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 14.04 LTS for Ubuntu
12.04 ESM.

Peter Pi discovered that the colormap handling for frame buffer devices in
the Linux kernel contained an integer overflow. A local attacker could use
this to disclose sensitive information (kernel memory). (CVE-2016-8405)

It was discovered that the Linux kernel did not properly restrict
RLIMIT_STACK size. A local attacker could use this in conjunction with
another vulnerability to possibly execute arbitrary code.
(CVE-2017-1000365)

It was discovered that SELinux in the Linux kernel did not properly handle
empty writes to /proc/pid/attr. A local attacker could use this to cause a
denial of service (system crash). (CVE-2017-2618)

石磊 discovered that the RxRPC Kerberos 5 ticket handling code in the
Linux kernel did not properly verify metadata. A remote attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-7482)

Update instructions

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

Ubuntu 12.04 LTS:
linux-image-3.13.0-126-generic-lpae 3.13.0-126.175~precise1
linux-image-generic-lpae-lts-trusty 3.13.0.126.117
linux-image-3.13.0-126-generic 3.13.0-126.175~precise1
linux-image-generic-lts-trusty 3.13.0.126.117

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.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

CVE-2016-8405, CVE-2017-1000365, CVE-2017-2618, CVE-2017-7482