==========================================================================
Ubuntu Security Notice USN-6044-1
April 26, 2023

linux, linux-aws, linux-aws-5.15, linux-azure, linux-gke, linux-gke-5.15,
linux-gkeop, linux-hwe-5.15, linux-ibm, linux-lowlatency,
linux-lowlatency-hwe-5.15, linux-oracle, linux-oracle-5.15 vulnerabilities
==========================================================================

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

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

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-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gke: Linux kernel for Google Container Engine (GKE) systems
- linux-gkeop: Linux kernel for Google Container Engine (GKE) systems
- linux-ibm: Linux kernel for IBM cloud systems
- linux-lowlatency: Linux low latency kernel
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-aws-5.15: Linux kernel for Amazon Web Services (AWS) systems
- linux-gke-5.15: Linux kernel for Google Container Engine (GKE) systems
- linux-hwe-5.15: Linux hardware enablement (HWE) kernel
- linux-lowlatency-hwe-5.15: Linux low latency kernel
- linux-oracle-5.15: Linux kernel for Oracle Cloud systems

Details:

It was discovered that the Traffic-Control Index (TCINDEX) implementation
in the Linux kernel did not properly perform filter deactivation in some
situations. A local attacker could possibly use this to gain elevated
privileges. Please note that with the fix for this CVE, kernel support for
the TCINDEX classifier has been removed. (CVE-2023-1829)

It was discovered that a race condition existed in the io_uring subsystem
in 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-2023-1872)

Update instructions:

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

Ubuntu 22.04 LTS:
   linux-image-5.15.0-1019-gkeop   5.15.0-1019.24
   linux-image-5.15.0-1029-ibm     5.15.0-1029.32
   linux-image-5.15.0-1032-gke     5.15.0-1032.37
   linux-image-5.15.0-1034-oracle  5.15.0-1034.40
   linux-image-5.15.0-1035-aws     5.15.0-1035.39
   linux-image-5.15.0-1037-azure   5.15.0-1037.44
   linux-image-5.15.0-71-generic   5.15.0-71.78
   linux-image-5.15.0-71-generic-64k  5.15.0-71.78
   linux-image-5.15.0-71-generic-lpae  5.15.0-71.78
   linux-image-5.15.0-71-lowlatency  5.15.0-71.78
   linux-image-5.15.0-71-lowlatency-64k  5.15.0-71.78
   linux-image-aws-lts-22.04       5.15.0.1035.34
   linux-image-azure               5.15.0.1037.33
   linux-image-azure-lts-22.04     5.15.0.1037.33
   linux-image-generic             5.15.0.71.69
   linux-image-generic-64k         5.15.0.71.69
   linux-image-generic-lpae        5.15.0.71.69
   linux-image-gke                 5.15.0.1032.31
   linux-image-gke-5.15            5.15.0.1032.31
   linux-image-gkeop               5.15.0.1019.18
   linux-image-gkeop-5.15          5.15.0.1019.18
   linux-image-ibm                 5.15.0.1029.25
   linux-image-lowlatency          5.15.0.71.76
   linux-image-lowlatency-64k      5.15.0.71.76
   linux-image-oracle              5.15.0.1034.29
   linux-image-virtual             5.15.0.71.69

Ubuntu 20.04 LTS:
   linux-image-5.15.0-1032-gke     5.15.0-1032.37~20.04.1
   linux-image-5.15.0-1034-oracle  5.15.0-1034.40~20.04.1
   linux-image-5.15.0-1035-aws     5.15.0-1035.39~20.04.1
   linux-image-5.15.0-71-generic   5.15.0-71.78~20.04.1
   linux-image-5.15.0-71-generic-64k  5.15.0-71.78~20.04.1
   linux-image-5.15.0-71-generic-lpae  5.15.0-71.78~20.04.1
   linux-image-5.15.0-71-lowlatency  5.15.0-71.78~20.04.1
   linux-image-5.15.0-71-lowlatency-64k  5.15.0-71.78~20.04.1
   linux-image-aws                 5.15.0.1035.39~20.04.24
   linux-image-generic-64k-hwe-20.04  5.15.0.71.78~20.04.32
   linux-image-generic-hwe-20.04   5.15.0.71.78~20.04.32
   linux-image-generic-lpae-hwe-20.04  5.15.0.71.78~20.04.32
   linux-image-gke-5.15            5.15.0.1032.37~20.04.1
   linux-image-lowlatency-64k-hwe-20.04  5.15.0.71.78~20.04.29
   linux-image-lowlatency-hwe-20.04  5.15.0.71.78~20.04.29
   linux-image-oem-20.04           5.15.0.71.78~20.04.32
   linux-image-oem-20.04b          5.15.0.71.78~20.04.32
   linux-image-oem-20.04c          5.15.0.71.78~20.04.32
   linux-image-oem-20.04d          5.15.0.71.78~20.04.32
   linux-image-oracle              5.15.0.1034.40~20.04.1
   linux-image-virtual-hwe-20.04   5.15.0.71.78~20.04.32

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-6044-1
   CVE-2023-1829, CVE-2023-1872

Package Information:
   https://launchpad.net/ubuntu/+source/linux/5.15.0-71.78
   https://launchpad.net/ubuntu/+source/linux-aws/5.15.0-1035.39
   https://launchpad.net/ubuntu/+source/linux-azure/5.15.0-1037.44
   https://launchpad.net/ubuntu/+source/linux-gke/5.15.0-1032.37
   https://launchpad.net/ubuntu/+source/linux-gkeop/5.15.0-1019.24
   https://launchpad.net/ubuntu/+source/linux-ibm/5.15.0-1029.32
   https://launchpad.net/ubuntu/+source/linux-lowlatency/5.15.0-71.78
   https://launchpad.net/ubuntu/+source/linux-oracle/5.15.0-1034.40
   https://launchpad.net/ubuntu/+source/linux-aws-5.15/5.15.0-1035.39~20.04.1
   https://launchpad.net/ubuntu/+source/linux-gke-5.15/5.15.0-1032.37~20.04.1
   https://launchpad.net/ubuntu/+source/linux-hwe-5.15/5.15.0-71.78~20.04.1
 
https://launchpad.net/ubuntu/+source/linux-lowlatency-hwe-5.15/5.15.0-71.78~20.04.1
 
https://launchpad.net/ubuntu/+source/linux-oracle-5.15/5.15.0-1034.40~20.04.1