USN-1944-1: Linux kernel vulnerabilities
6 September 2013
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 12.10
Several security issues were fixed in the kernel.
- linux - Linux kernel
A denial of service flaw was discovered in the Btrfs file system in the Linux kernel. A local user could cause a denial of service by creating a large number of files with names that have the same CRC32 hash value. (CVE-2012-5374)
A denial of service flaw was discovered in the Btrfs file system in the Linux kernel. A local user could cause a denial of service (prevent file creation) for a victim, by creating a file with a specific CRC32C hash value in a directory important to the victim. (CVE-2012-5375)
Vasily Kulikov discovered a flaw in the Linux Kernel’s perf tool that allows for privilege escalation. A local user could exploit this flaw to run commands as root when using the perf tool. (CVE-2013-1060)
A flaw was discovered in the Xen subsystem of the Linux kernel when it provides read-only access to a disk that supports TRIM or SCSI UNMAP to a guest OS. A privileged user in the guest OS could exploit this flaw to destroy data on the disk, even though the guest OS should not be able to write to the disk. (CVE-2013-2140)
A flaw was discovered in the Linux kernel when an IPv6 socket is used to connect to an IPv4 destination. An unprivileged local user could exploit this flaw to cause a denial of service (system crash). (CVE-2013-2232)
An information leak was discovered in the IPSec key_socket implementation in the Linux kernel. An local user could exploit this flaw to examine potentially sensitive information in kernel memory. (CVE-2013-2234)
Hannes Frederic Sowa discovered a flaw in setsockopt UDP_CORK option in the Linux kernel’s IPv6 stack. A local user could exploit this flaw to cause a denial of service (system crash). (CVE-2013-4162)
Hannes Frederic Sowa discovered a flaw in the IPv6 subsystem of the Linux kernel when the IPV6_MTU setsockopt option has been specified in combination with the UDP_CORK option. A local user could exploit this flaw to cause a denial of service (system crash). (CVE-2013-4163)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 12.10
- linux-image-3.5.0-40-generic - 3.5.0-40.62
- linux-image-3.5.0-40-highbank - 3.5.0-40.62
- linux-image-3.5.0-40-omap - 3.5.0-40.62
- linux-image-3.5.0-40-powerpc-smp - 3.5.0-40.62
- linux-image-3.5.0-40-powerpc64-smp - 3.5.0-40.62
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.