1. Ubuntu Security Notices
  2. USN-1699-2

USN-1699-2: Linux kernel regression

Publication date

1 February 2013

Overview

USN-1699-1 introduced a regression in the Linux kernel.

Releases

Packages

Details

USN-1699-1 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:

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

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)

Florian Weimer discovered that hypervkvpd, which is distributed in the
Linux kernel, was not correctly validating source...

USN-1699-1 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:

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

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)

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

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

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
12.10 quantal linux-image-3.5.0-23-highbank –  3.5.0-23.35
linux-image-3.5.0-23-powerpc-smp –  3.5.0-23.35
linux-image-3.5.0-23-omap –  3.5.0-23.35
linux-image-3.5.0-23-generic –  3.5.0-23.35
linux-image-3.5.0-23-powerpc64-smp –  3.5.0-23.35

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References

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