USN-2691-1: Linux kernel vulnerabilities
28 July 2015
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 15.04
Several security issues were fixed in the kernel.
- linux - Linux kernel
Andy Lutomirski discovered a flaw in the Linux kernel’s handling of nested NMIs (non-maskable interrupts). An unprivileged local user could exploit this flaw to cause a denial of service (system crash) or potentially escalate their privileges. (CVE-2015-3290)
Colin King discovered a flaw in the add_key function of the Linux kernel’s keyring subsystem. A local user could exploit this flaw to cause a denial of service (memory exhaustion). (CVE-2015-1333)
Andy Lutomirski discovered a flaw that allows user to cause the Linux kernel to ignore some NMIs (non-maskable interrupts). A local unprivileged user could exploit this flaw to potentially cause the system to miss important NMIs resulting in unspecified effects. (CVE-2015-3291)
Andy Lutomirski and Petr Matousek discovered that an NMI (non-maskable interrupt) that interrupts userspace and encounters an IRET fault is incorrectly handled by the Linux kernel. An unprivileged local user could exploit this flaw to cause a denial of service (kernel OOPs), corruption, or potentially escalate privileges on the system. (CVE-2015-5157)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 15.04
- linux-image-3.19.0-25-generic - 3.19.0-25.26
- linux-image-3.19.0-25-generic-lpae - 3.19.0-25.26
- linux-image-3.19.0-25-lowlatency - 3.19.0-25.26
- linux-image-3.19.0-25-powerpc-e500mc - 3.19.0-25.26
- linux-image-3.19.0-25-powerpc-smp - 3.19.0-25.26
- linux-image-3.19.0-25-powerpc64-emb - 3.19.0-25.26
- linux-image-3.19.0-25-powerpc64-smp - 3.19.0-25.26
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.