7.2 - USN-3208-1

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

- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description: - linux: Linux kernel - linux-snapdragon: Linux kernel for Snapdragon Processors

Details:

It was discovered that the generic SCSI block layer in the Linux kernel did not properly restrict write operations in certain situations. A local attacker could use this to cause a denial of service (system crash) or possibly gain administrative privileges. (CVE-2016-10088)

CAI Qian discovered that the sysctl implementation in the Linux kernel did not properly perform reference counting in some situations. An unprivileged attacker could use this to cause a denial of service (system hang). (CVE-2016-9191)

Jim Mattson discovered that the KVM implementation in the Linux kernel mismanages the #BP and #OF exceptions. A local attacker in a guest virtual machine could use this to cause a denial of service (guest OS crash). (CVE-2016-9588)

Andy Lutomirski and Willy Tarreau discovered that the KVM implementation in the Linux kernel did not properly emulate instructions on the SS segment register. A local attacker in a guest virtual machine could use this to cause a denial of service (guest OS crash) or possibly gain administrative privileges in the guest OS. (CVE-2017-2583)

Dmitry Vyukov discovered that the KVM implementation in the Linux kernel improperly emulated certain instructions. A local attacker could use this to obtain sensitive information (kernel memory). (CVE-2017-2584)

It was discovered that the KLSI KL5KUSB105 serial-to-USB device driver in the Linux kernel did not properly initialize memory related to logging. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2017-5549)

Andrey Konovalov discovered a use-after-free vulnerability in the DCCP implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly gain administrative privileges. (CVE-2017-6074)

Update instructions:

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

Ubuntu 16.04 LTS:
linux-image-4.4.0-1048-snapdragon 4.4.0-1048.52
linux-image-4.4.0-64-generic 4.4.0-64.85
linux-image-4.4.0-64-generic-lpae 4.4.0-64.85
linux-image-4.4.0-64-lowlatency 4.4.0-64.85
linux-image-4.4.0-64-powerpc-e500mc 4.4.0-64.85
linux-image-4.4.0-64-powerpc-smp 4.4.0-64.85
linux-image-4.4.0-64-powerpc64-emb 4.4.0-64.85
linux-image-4.4.0-64-powerpc64-smp 4.4.0-64.85
linux-image-generic 4.4.0.64.68
linux-image-generic-lpae 4.4.0.64.68
linux-image-lowlatency 4.4.0.64.68
linux-image-powerpc-e500mc 4.4.0.64.68
linux-image-powerpc-smp 4.4.0.64.68
linux-image-powerpc64-emb 4.4.0.64.68
linux-image-powerpc64-smp 4.4.0.64.68
linux-image-snapdragon 4.4.0.1048.40

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. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.

References:
http://www.ubuntu.com/usn/usn-3208-1
CVE-2016-10088, CVE-2016-9191, CVE-2016-9588, CVE-2017-2583,
CVE-2017-2584, CVE-2017-5549, CVE-2017-6074

Package Information:
https://launchpad.net/ubuntu/+source/linux/4.4.0-64.85
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1048.52