[USN-5465-1] Linux kernel vulnerabilities


========================================================================== Ubuntu Security Notice USN-5465-1 June 08, 2022
linux, linux-aws, linux-kvm, linux-lts-xenial vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 16.04 ESM – Ubuntu 14.04 ESM
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux: Linux kernel – linux-aws: Linux kernel for Amazon Web Services (AWS) systems – linux-kvm: Linux kernel for cloud environments – linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty
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)
Aaron Adams discovered that the netfilter subsystem in the Linux kernel did not properly handle the removal of stateful expressions in some situations, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2022-1966)
Jann Horn discovered that the Linux kernel did not properly enforce seccomp restrictions in some situations. A local attacker could use this to bypass intended seccomp sandbox restrictions. (CVE-2022-30594)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 16.04 ESM: linux-image-4.4.0-1108-kvm 4.4.0-1108.118 linux-image-4.4.0-1143-aws 4.4.0-1143.158 linux-image-4.4.0-227-generic 4.4.0-227.261 linux-image-4.4.0-227-lowlatency 4.4.0-227.261 linux-image-aws 4.4.0.1143.147 linux-image-generic 4.4.0.227.233 linux-image-kvm 4.4.0.1108.105 linux-image-lowlatency 4.4.0.227.233 linux-image-virtual 4.4.0.227.233
Ubuntu 14.04 ESM: linux-image-4.4.0-1107-aws 4.4.0-1107.113 linux-image-4.4.0-227-generic 4.4.0-227.261~14.04.1 linux-image-4.4.0-227-lowlatency 4.4.0-227.261~14.04.1 linux-image-aws 4.4.0.1107.104 linux-image-generic-lts-xenial 4.4.0.227.197 linux-image-lowlatency-lts-xenial 4.4.0.227.197 linux-image-virtual-lts-xenial 4.4.0.227.197
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-5465-1 CVE-2022-1966, CVE-2022-21499, CVE-2022-30594