[USN-4884-1] Linux kernel (OEM) vulnerabilities

========================================================================== Ubuntu Security Notice USN-4884-1 March 20, 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:
Loris Reiff discovered that the BPF implementation in the Linux kernel did not properly validate attributes in the getsockopt BPF hook. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-20194)
It was discovered that the priority inheritance futex implementation in the Linux kernel contained a race condition, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3347)
It was discovered that the network block device (nbd) driver in the Linux kernel contained a use-after-free vulnerability during device setup. A local attacker with access to the nbd device could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3348)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04 LTS: linux-image-5.10.0-1017-oem 5.10.0-1017.18 linux-image-oem-20.04b 5.10.0.1017.18
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-4884-1 CVE-2021-20194, CVE-2021-3347, CVE-2021-3348
Package Information: launchpad.net/ubuntu/+source/linux-oem-5.10/5.10.0-1017.18