USN-2516-2: Linux kernel vulnerability regression

28 February 2015

USN-2516-1 introduced a regression in the Linux kernel.

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Releases

Packages

Details

USN-2516-1 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)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 14.04

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

Join the discussion

Need help with your security needs?

Ubuntu Pro provides up to ten-year security coverage for over 23,000 open-source packages within the Ubuntu Main and Universe repositories.

Talk to an expert to find out what would work best for you

Further reading