==========================================================================
Ubuntu Security Notice USN-5791-3
January 10, 2023

linux-azure-5.4, linux-azure-fde vulnerabilities
==========================================================================

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

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-azure-fde: Linux kernel for Microsoft Azure CVM cloud systems
- linux-azure-5.4: Linux kernel for Microsoft Azure cloud systems

Details:

It was discovered that a race condition existed in the Android Binder IPC
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-2022-20421)

David Leadbeater discovered that the netfilter IRC protocol tracking
implementation in the Linux Kernel incorrectly handled certain message
payloads in some situations. A remote attacker could possibly use this to
cause a denial of service or bypass firewall filtering. (CVE-2022-2663)

It was discovered that the Intel 740 frame buffer driver in the Linux
kernel contained a divide by zero vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2022-3061)

It was discovered that the sound subsystem in the Linux kernel contained a
race condition in some situations. A local attacker could use this to cause
a denial of service (system crash). (CVE-2022-3303)

Gwnaun Jung discovered that the SFB packet scheduling implementation in the
Linux kernel contained 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-2022-3586)

It was discovered that the NILFS2 file system implementation in the Linux
kernel did not properly deallocate memory in certain error conditions. An
attacker could use this to cause a denial of service (memory exhaustion).
(CVE-2022-3646)

Hyunwoo Kim discovered that an integer overflow vulnerability existed in
the PXA3xx graphics driver in the Linux kernel. A local attacker could
possibly use this to cause a denial of service (system crash).
(CVE-2022-39842)

It was discovered that a race condition existed in the EFI capsule loader
driver 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-2022-40307)

Zheng Wang and Zhuorao Yang discovered that the RealTek RTL8712U wireless
driver in the Linux kernel contained 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-2022-4095)

It was discovered that the USB monitoring (usbmon) component in the Linux
kernel did not properly set permissions on memory mapped in to user space
processes. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2022-43750)

Update instructions:

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

Ubuntu 20.04 LTS:
   linux-image-5.4.0-1100-azure-fde  5.4.0-1100.106+cvm1.1
   linux-image-azure-fde           5.4.0.1100.106+cvm1.35

Ubuntu 18.04 LTS:
   linux-image-5.4.0-1100-azure    5.4.0-1100.106~18.04.1
   linux-image-azure               5.4.0.1100.73

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-5791-3
   https://ubuntu.com/security/notices/USN-5791-1
   CVE-2022-20421, CVE-2022-2663, CVE-2022-3061, CVE-2022-3303,
   CVE-2022-3586, CVE-2022-3646, CVE-2022-39842, CVE-2022-40307,
   CVE-2022-4095, CVE-2022-43750

Package Information:
   https://launchpad.net/ubuntu/+source/linux-azure-fde/5.4.0-1100.106+cvm1.1
   https://launchpad.net/ubuntu/+source/linux-azure-5.4/5.4.0-1100.106~18.04.1