9.3 - USN-2631-1

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

- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description: - linux: Linux kernel

Details:

Jan Beulich discovered the Xen virtual machine subsystem of the Linux kernel did not properly restrict access to PCI command registers. A local guest user could exploit this flaw to cause a denial of service (host crash). (CVE-2015-2150)

A privilege escalation was discovered in the fork syscall via the int80 entry on 64 bit kernels with 32 bit emulation support. An unprivileged local attacker could exploit this flaw to increase their privileges on the system. (CVE-2015-2830)

A memory corruption issue was discovered in AES decryption when using the Intel AES-NI accelerated code path. A remote attacker could exploit this flaw to cause a denial of service (system crash) or potentially escalate privileges on Intel base machines with AEC-GCM mode IPSec security association. (CVE-2015-3331)

Wen Xu discovered a use-after-free flaw in the Linux kernel's ipv4 ping support. A local user could exploit this flaw to cause a denial of service (system crash) or gain administrative privileges on the system. (CVE-2015-3636)

Carl H Lunde discovered missing sanity checks in the the Linux kernel's UDF file system (CONFIG_UDF_FS). A local attack could exploit this flaw to cause a denial of service (system crash) by using a corrupted filesystem image. (CVE-2015-4167)

Update instructions:

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

Ubuntu 12.04 LTS:
linux-image-3.2.0-85-generic 3.2.0-85.122
linux-image-3.2.0-85-generic-pae 3.2.0-85.122
linux-image-3.2.0-85-highbank 3.2.0-85.122
linux-image-3.2.0-85-omap 3.2.0-85.122
linux-image-3.2.0-85-powerpc-smp 3.2.0-85.122
linux-image-3.2.0-85-powerpc64-smp 3.2.0-85.122
linux-image-3.2.0-85-virtual 3.2.0-85.122

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:
http://www.ubuntu.com/usn/usn-2631-1
CVE-2015-2150, CVE-2015-2830, CVE-2015-3331, CVE-2015-3636,
CVE-2015-4167

Package Information:
https://launchpad.net/ubuntu/+source/linux/3.2.0-85.122