Several security issues were fixed in the Linux kernel.
Jann Horn discovered that the OverlayFS and ShiftFS Drivers in the Linux kernel did not properly handle reference counting during memory mapping operations when used in conjunction with AUFS. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-15794)
2 December 2019
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the Linux kernel.
Jann Horn discovered that the OverlayFS and ShiftFS Drivers in the Linux kernel did not properly handle reference counting during memory mapping operations when used in conjunction with AUFS. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-15794)
It was discovered that a buffer overflow existed in the 802.11 Wi-Fi configuration interface for the Linux kernel when handling beacon settings. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-16746)
It was discovered that there was a memory leak in the Advanced Buffer Management functionality of the Netronome NFP4000/NFP6000 NIC Driver in the Linux kernel during certain error scenarios. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2019-19076)
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. 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.