[USN-5484-1] Linux kernel vulnerabilities


========================================================================== Ubuntu Security Notice USN-5484-1 June 16, 2022
linux vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 14.04 ESM
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux: Linux kernel
Details:
It was discovered that the Linux kernel did not properly restrict access to the kernel debugger when booted in secure boot environments. A privileged attacker could use this to bypass UEFI Secure Boot restrictions. (CVE-2022-21499)
It was discovered that a race condition existed in the network scheduling subsystem of the Linux kernel, 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-2021-39713)
It was discovered that some Intel processors did not completely perform cleanup actions on multi-core shared buffers. A local attacker could possibly use this to expose sensitive information. (CVE-2022-21123)
It was discovered that some Intel processors did not completely perform cleanup actions on microarchitectural fill buffers. A local attacker could possibly use this to expose sensitive information. (CVE-2022-21125)
It was discovered that some Intel processors did not properly perform cleanup during specific special register write operations. A local attacker could possibly use this to expose sensitive information. (CVE-2022-21166)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 14.04 ESM: linux-image-3.13.0-190-generic 3.13.0-190.241 linux-image-3.13.0-190-lowlatency 3.13.0-190.241 linux-image-generic 3.13.0.190.199 linux-image-lowlatency 3.13.0.190.199 linux-image-server 3.13.0.190.199 linux-image-virtual 3.13.0.190.199
Please note that fully mitigating processor vulnerabilities requires corresponding processor microcode/firmware updates.
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-5484-1 CVE-2021-39713, CVE-2022-21123, CVE-2022-21125, CVE-2022-21166, CVE-2022-21499