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Ubuntu Security Notice USN-1704-2
February 01, 2013

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

- Ubuntu 12.04 LTS

Summary:

USN-1704-1 introduced a regression in the Linux kernel.

Software Description:
- linux-lts-quantal: Linux hardware enablement kernel from Quantal

Details:

USN-1704-1 fixed vulnerabilities in the Linux kernel. Due to an unrelated
regression inotify/fanotify stopped working after upgrading. This update
fixes the problem.

We apologize for the inconvenience.

Original advisory 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-3.5.0-23-generic    3.5.0-23.35~precise1

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.

References:
  http://www.ubuntu.com/usn/usn-1704-2
  http://www.ubuntu.com/usn/usn-1704-1
  https://launchpad.net/bugs/1101666

Package Information:
  https://launchpad.net/ubuntu/+source/linux-lts-quantal/3.5.0-23.35~precise1