USN-2420-1: Linux kernel vulnerabilities

24 November 2014

linux vulnerabilities

Releases

Packages

  • linux - Linux kernel

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 a flaw in how the Linux kernel handles
pivot_root when used with a chroot directory. A local user could exploit
this flaw to cause a denial of service (mount-tree loop). (CVE-2014-7970)

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

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.

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.