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Ubuntu Security Notice USN-1704-1
January 22, 2013

linux-lts-quantal - Linux kernel hardware enablement from Quantal vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux-lts-quantal: Linux kernel LTS from Quantal

Details:

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)

Jon Howell reported a flaw in the Linux kernel's KVM (Kernel-based virtual
machine) subsystem's handling of the XSAVE feature. On hosts, using qemu
userspace, without the XSAVE feature an unprivileged local attacker could
exploit this flaw to crash the system. (CVE-2012-4461)

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)

A flaw was discovered in the Linux kernel's handling of script execution
when module loading is enabled. A local attacker could exploit this flaw to
cause a leak of kernel stack contents. (CVE-2012-4530)

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)

A flaw was discovered in the Linux kernel's handling of new hot-plugged
memory. An unprivileged local user could exploit this flaw to cause a
denial of service by crashing the system. (CVE-2012-5517)

Florian Weimer discovered that hypervkvpd, which is distributed in the
Linux kernel, was not correctly validating source addresses of netlink
packets. An untrusted local user can cause a denial of service by causing
hypervkvpd to exit. (CVE-2012-5532)

Update instructions:

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

Ubuntu 12.04 LTS:
  linux-image-3.5.0-22-generic    3.5.0-22.34~precise1

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

References:
  https://www.ubuntu.com/usn/usn-1704-1
  CVE-2012-0957, CVE-2012-4461, CVE-2012-4508, CVE-2012-4530,
  CVE-2012-4565, CVE-2012-5517, CVE-2012-5532

Package Information:
  https://launchpad.net/ubuntu/+source/linux-lts-quantal/3.5.0-22.34~precise1