4.9 - USN-2843-3

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 15.10

Summary:

Several security issues were fixed in the kernel.

Software Description: - linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

郭永刚 discovered that the ppp implementation in the Linux kernel did not ensure that certain slot numbers are valid. A local attacker with the privilege to call ioctl() on /dev/ppp could cause a denial of service (system crash). (CVE-2015-7799)

Dmitry Vyukov discovered that the Linux kernel's keyring handler attempted to garbage collect incompletely instantiated keys. A local unprivileged attacker could use this to cause a denial of service (system crash). (CVE-2015-7872)

It was discovered that the virtual video osd test driver in the Linux kernel did not properly initialize data structures. A local attacker could use this to obtain sensitive information from the kernel. (CVE-2015-7884)

It was discovered that the driver for Digi Neo and ClassicBoard devices did not properly initialize data structures. A local attacker could use this to obtain sensitive information from the kernel. (CVE-2015-7885)

Update instructions:

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

Ubuntu 15.10:
linux-image-4.2.0-1016-raspi2 4.2.0-1016.23

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-2843-3
http://www.ubuntu.com/usn/usn-2843-1
CVE-2015-7799, CVE-2015-7872, CVE-2015-7884, CVE-2015-7885

Package Information:
https://launchpad.net/ubuntu/+source/linux-raspi2/4.2.0-1016.23