==========================================================================
Ubuntu Security Notice USN-6454-1
October 26, 2023

linux, linux-lowlatency vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 23.10

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux: Linux kernel
- linux-lowlatency: Linux low latency kernel

Details:

Kyle Zeng discovered that the netfilter subsystem in the Linux kernel
contained a race condition in IP set operations in certain situations. A
local attacker could use this to cause a denial of service (system crash).
(CVE-2023-42756)

Alex Birnberg discovered that the netfilter subsystem in the Linux kernel
did not properly validate register length, leading to an out-of- bounds
write vulnerability. A local attacker could possibly use this to cause a
denial of service (system crash). (CVE-2023-4881)

It was discovered that the Quick Fair Queueing scheduler implementation in
the Linux kernel did not properly handle network packets in certain
conditions, 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-2023-4921)

Kevin Rich discovered that the netfilter subsystem in the Linux kernel did
not properly handle removal of rules from chain bindings in certain
circumstances, leading to a use-after-free vulnerability. A local attacker
could possibly use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2023-5197)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 23.10:
   linux-image-6.5.0-10-generic    6.5.0-10.10
   linux-image-6.5.0-10-generic-64k  6.5.0-10.10
   linux-image-6.5.0-10-lowlatency  6.5.0-10.10.1
   linux-image-6.5.0-10-lowlatency-64k  6.5.0-10.10.1
   linux-image-generic             6.5.0.10.12
   linux-image-generic-64k         6.5.0.10.12
   linux-image-generic-lpae        6.5.0.10.12
   linux-image-kvm                 6.5.0.10.12
   linux-image-lowlatency          6.5.0.10.10.10
   linux-image-lowlatency-64k      6.5.0.10.10.10
   linux-image-virtual             6.5.0.10.12

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:
   https://ubuntu.com/security/notices/USN-6454-1
   CVE-2023-42756, CVE-2023-4881, CVE-2023-4921, CVE-2023-5197

Package Information:
   https://launchpad.net/ubuntu/+source/linux/6.5.0-10.10
   https://launchpad.net/ubuntu/+source/linux-lowlatency/6.5.0-10.10.1