Ubuntu Security Notice USN-1645-1
30th November, 2012
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 12.04 LTS
Several security issues were fixed in the kernel.
- linux-ti-omap4 - Linux kernel for OMAP4
Brad Spengler discovered a flaw in the Linux kernel's uname system call. An
unprivileged user could exploit this flaw to read kernel stack memory.
Dmitry Monakhov reported a race condition flaw the Linux ext4 filesystem
that can expose stale data. An unprivileged user could exploit this flaw to
cause an information leak. (CVE-2012-4508)
Rodrigo Freire discovered a flaw in the Linux kernel's TCP illinois
congestion control algorithm. A local attacker could use this to cause a
denial of service. (CVE-2012-4565)
Mathias Krause discovered a flaw in the Linux kernel's XFRM netlink
interface. A local user with the NET_ADMIN capability could exploit this
flaw to leak the contents of kernel memory. (CVE-2012-6536)
Mathias Krause discovered several errors in the Linux kernel's xfrm_user
implementation. A local attacker could exploit these flaws to examine parts
of kernel memory. (CVE-2012-6537)
Mathias Krause discovered an information leak in the Linux kernel's
xfrm_user copy_to_user_auth function. A local user could exploit this flaw
to examine parts of kernel heap memory. (CVE-2012-6538)
A flaw was discovered in the Linux kernels handling of memory ranges with
PROT_NONE when transparent hugepages are in use. An unprivileged local user
could exploit this flaw to cause a denial of service (crash the system).
Mathias Krause discovered a flaw in xfrm_user in the Linux kernel. A local
attacker with NET_ADMIN capability could potentially exploit this flaw to
escalate privileges. (CVE-2013-1826)
An information leak was discovered in the Linux kernel's /dev/dvb device. A
local user could exploit this flaw to obtain sensitive information from the
kernel's stack memory. (CVE-2013-1928)
The problem can be corrected by updating your system to the following package version:
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.