USN-1704-2: Linux kernel (Quantal HWE) regression
1 February 2013
linux-lts-quantal - Linux kernel hardware enablement from Quantal regression
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 12.04 LTS
USN-1704-1 introduced a regression in the Linux kernel.
- linux-lts-quantal - Linux hardware enablement kernel from Quantal
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)
The problem can be corrected by updating your system to the following package versions:
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.