USN-2515-2: Linux kernel (Trusty HWE) vulnerabilities regression

4 March 2015

linux-lts-trusty vulnerabilities

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

  • Ubuntu 12.04 LTS

Summary

USN-2515-1 introduced a regression in the Linux kernel.

Software Description

  • linux-lts-trusty - Linux hardware enablement kernel from Trusty

Details

USN-2515-1 fixed vulnerabilities in the Linux kernel. There was an unrelated regression in the use of the virtual counter (CNTVCT) on arm64 architectures. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

A flaw was discovered in the Kernel Virtual Machine’s (KVM) emulation of the SYSTENTER instruction when the guest OS does not initialize the SYSENTER MSRs. A guest OS user could exploit this flaw to cause a denial of service of the guest OS (crash) or potentially gain privileges on the guest OS. (CVE-2015-0239)

Andy Lutomirski discovered an information leak in the Linux kernel’s Thread Local Storage (TLS) implementation allowing users to bypass the espfix to obtain information that could be used to bypass the Address Space Layout Randomization (ASLR) protection mechanism. A local user could exploit this flaw to obtain potentially sensitive information from kernel memory. (CVE-2014-8133)

A restriction bypass was discovered in iptables when conntrack rules are specified and the conntrack protocol handler module is not loaded into the Linux kernel. This flaw can cause the firewall rules on the system to be bypassed when conntrack rules are used. (CVE-2014-8160)

A flaw was discovered with file renaming in the linux kernel. A local user could exploit this flaw to cause a denial of service (deadlock and system hang). (CVE-2014-8559)

A flaw was discovered in how supplemental group memberships are handled in certain namespace scenarios. A local user could exploit this flaw to bypass file permission restrictions. (CVE-2014-8989)

A flaw was discovered in how Thread Local Storage (TLS) is handled by the task switching function in the Linux kernel for x86_64 based machines. A local user could exploit this flaw to bypass the Address Space Layout Radomization (ASLR) protection mechanism. (CVE-2014-9419)

Prasad J Pandit reported a flaw in the rock_continue function of the Linux kernel’s ISO 9660 CDROM file system. A local user could exploit this flaw to cause a denial of service (system crash or hang). (CVE-2014-9420)

A flaw was discovered in the fragment handling of the B.A.T.M.A.N. Advanced Meshing Protocol in the Linux kernel. A remote attacker could exploit this flaw to cause a denial of service (mesh-node system crash) via fragmented packets. (CVE-2014-9428)

A race condition was discovered in the Linux kernel’s key ring. A local user could cause a denial of service (memory corruption or panic) or possibly have unspecified impact via the keyctl commands. (CVE-2014-9529)

A memory leak was discovered in the ISO 9660 CDROM file system when parsing rock ridge ER records. A local user could exploit this flaw to obtain sensitive information from kernel memory via a crafted iso9660 image. (CVE-2014-9584)

A flaw was discovered in the Address Space Layout Randomization (ASLR) of the Virtual Dynamically linked Shared Objects (vDSO) location. This flaw makes it easier for a local user to bypass the ASLR protection mechanism. (CVE-2014-9585)

Dmitry Chernenkov discovered a buffer overflow in eCryptfs’ encrypted file name decoding. A local unprivileged user could exploit this flaw to cause a denial of service (system crash) or potentially gain administrative privileges. (CVE-2014-9683)

Update instructions

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

Ubuntu 12.04 LTS
linux-image-3.13.0-46-generic - 3.13.0-46.77~precise1
linux-image-3.13.0-46-generic-lpae - 3.13.0-46.77~precise1

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