[USN-4911-1] Linux kernel (OEM) vulnerabilities

========================================================================== Ubuntu Security Notice USN-4911-1 April 13, 2021
linux-oem-5.10 vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux-oem-5.10: Linux kernel for OEM systems
Details:
It was discovered that the Nouveau GPU driver in the Linux kernel did not properly handle error conditions in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-25639)
Jan Beulich discovered that the Xen netback backend in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-28038)
It was discovered that the fastrpc driver in the Linux kernel did not prevent user space applications from sending kernel RPC messages. A local attacker could possibly use this to gain elevated privileges. (CVE-2021-28375)
It was discovered that the fuse user space file system implementation in the Linux kernel did not properly handle bad inodes in some situations. A local attacker could possibly use this to cause a denial of service. (CVE-2021-28950)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04 LTS: linux-image-5.10.0-1021-oem 5.10.0-1021.22 linux-image-oem-20.04b 5.10.0.1021.22
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: ubuntu.com/security/notices/USN-4911-1 CVE-2020-25639, CVE-2021-28038, CVE-2021-28375, CVE-2021-28950
Package Information: launchpad.net/ubuntu/+source/linux-oem-5.10/5.10.0-1021.22