USN-1644-1: Linux kernel vulnerabilities
30 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 - Linux kernel
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. (CVE-2012-0957)
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)
Dave Jones discovered that the Linux kernel’s socket subsystem does not correctly ensure the keepalive action is associated with a stream socket. A local user could exploit this flaw to cause a denial of service (system crash) by creating a raw socket. (CVE-2012-6657)
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). (CVE-2013-0309)
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 versions:
- Ubuntu 12.04 LTS
- linux-image-3.2.0-34-generic - 3.2.0-34.53
- linux-image-3.2.0-34-generic-pae - 3.2.0-34.53
- linux-image-3.2.0-34-highbank - 3.2.0-34.53
- linux-image-3.2.0-34-omap - 3.2.0-34.53
- linux-image-3.2.0-34-powerpc-smp - 3.2.0-34.53
- linux-image-3.2.0-34-powerpc64-smp - 3.2.0-34.53
- linux-image-3.2.0-34-virtual - 3.2.0-34.53
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.