USN-1246-1: Linux kernel vulnerabilities

25 October 2011

linux vulnerabilities

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

  • Ubuntu 11.04

Summary

Several security issues were fixed in the kernel.

Software Description

  • linux - Linux kernel

Details

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service. (CVE-2011-2213)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

It was discovered that the EXT4 filesystem contained multiple off-by-one flaws. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2695)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service. (CVE-2011-2928)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence number generation. An attacker could use this flaw to possibly predict sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191)

Update instructions

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

Ubuntu 11.04
linux-image-2.6.38-12-generic - 2.6.38-12.51
linux-image-2.6.38-12-generic-pae - 2.6.38-12.51
linux-image-2.6.38-12-omap - 2.6.38-12.51
linux-image-2.6.38-12-powerpc - 2.6.38-12.51
linux-image-2.6.38-12-powerpc-smp - 2.6.38-12.51
linux-image-2.6.38-12-powerpc64-smp - 2.6.38-12.51
linux-image-2.6.38-12-server - 2.6.38-12.51
linux-image-2.6.38-12-versatile - 2.6.38-12.51
linux-image-2.6.38-12-virtual - 2.6.38-12.51

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