[El-errata] New Ksplice updates for UEKR6 5.4.17 on OL7 and OL8 (ELSA-2022-9709)

[Errata Announcements for Oracle Linux]

Synopsis: ELSA-2022-9709 can now be patched using Ksplice
CVEs: CVE-2021-4034 CVE-2022-1966 CVE-2022-2153 CVE-2022-23816 CVE-2022-32250 CVE-2022-32981

Users with Oracle Linux Premier Support can now use Ksplice to patch
against the latest Oracle Linux Security Advisory, ELSA-2022-9709.
More information about this errata can be found at
https://linux.oracle.com/errata/ELSA-2022-9709.html

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running UEKR6 5.4.17 on
OL7 and OL8 install these updates.

On systems that have "autoinstall = yes" in /etc/uptrack/uptrack.conf,
these updates will be installed automatically and you do not need to
take any action.

Alternatively, you can install these updates by running:

# /usr/sbin/uptrack-upgrade -y


DESCRIPTION

* CVE-2022-1966, CVE-2022-32250: Code execution in Netfilter due to use-after-free.

A flaw in nftables API of the Netfilter subsystem when removing stateful
expressions could result in a use-after-free. A local user could use
this flaw to cause a denial-of-service or execute arbitrary code.


* CVE-2021-4034: Prevent empty argument list when executing processes.

Incorrect input validation in the pkexec program (part of Polkit) allows
any local user to become root.


* Improved update to CVE-2022-2153: Denial-of-service in Kernel-based Virtual Machine.

A logic flaw in Kernel-based Virtual Machine in some cases when KVM
initializes a vCPU without creating APIC could result in NULL pointer
dereference. A local user could use this flaw for a denial-of-service.

Orabug: 34323859


* Note: Oracle has determined that CVE-2022-32981 is not applicable.

Oracle has determined that CVE-2022-32981 is not applicable to x86 or
aarch64. Applying the patch has no resulting changes in the generated
object files.


* CVE-2022-23816: Information leak on x86 CPUs (Retbleed).

This is a partial mitigation to prevent guests from training the branch
predictor of the host on AMD CPUs by issuing an IBPB to clear architectural
buffers on vmexit events.  It is default disabled, and can be enabled by:

  echo 1 | sudo tee /sys/kernel/debug/x86/ibpb_vmexit_enabled

SUPPORT

Ksplice support is available at ksplice-support_ww at oracle.com.