1. Ubuntu Security Notices
  2. USN-2421-1

USN-2421-1: Linux kernel vulnerabilities

Publication date

25 November 2014

Overview

Several security issues were fixed in the kernel.

Releases

Packages

Details

A flaw was discovered in how the Linux kernel’s KVM (Kernel Virtual
Machine) subsystem handles the CR4 control register at VM entry on Intel
processors. A local host OS user can exploit this to cause a denial of
service (kill arbitrary processes, or system disruption) by leveraging
/dev/kvm access. (CVE-2014-3690)

Don Bailey discovered a flaw in the LZO decompress algorithm used by the
Linux kernel. An attacker could exploit this flaw to cause a denial of
service (memory corruption or OOPS). (CVE-2014-4608)

Andy Lutomirski discovered that the Linux kernel was not checking the
CAP_SYS_ADMIN when remounting filesystems to read-only. A local user could
exploit this flaw to cause a denial of service (loss of writability).
(CVE-2014-7975)

A flaw was discovered in how the Linux kernel’s KVM (Kernel Virtual
Machine) subsystem handles the CR4 control register at VM entry on Intel
processors. A local host OS user can exploit this to cause a denial of
service (kill arbitrary processes, or system disruption) by leveraging
/dev/kvm access. (CVE-2014-3690)

Don Bailey discovered a flaw in the LZO decompress algorithm used by the
Linux kernel. An attacker could exploit this flaw to cause a denial of
service (memory corruption or OOPS). (CVE-2014-4608)

Andy Lutomirski discovered that the Linux kernel was not checking the
CAP_SYS_ADMIN when remounting filesystems to read-only. A local user could
exploit this flaw to cause a denial of service (loss of writability).
(CVE-2014-7975)

Update instructions

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

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
14.10 utopic linux-image-3.16.0-25-powerpc-smp –  3.16.0-25.33
linux-image-3.16.0-25-powerpc-e500mc –  3.16.0-25.33
linux-image-3.16.0-25-generic-lpae –  3.16.0-25.33
linux-image-3.16.0-25-generic –  3.16.0-25.33
linux-image-3.16.0-25-powerpc64-smp –  3.16.0-25.33
linux-image-3.16.0-25-lowlatency –  3.16.0-25.33
linux-image-3.16.0-25-powerpc64-emb –  3.16.0-25.33

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References

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