[El-errata] New Ksplice updates for UEKR4 4.1.12 on OL6 and OL7 (ELSA-2021-9051)

[Errata Announcements for Oracle Linux]

Synopsis: ELSA-2021-9051 can now be patched using Ksplice
CVEs: CVE-2021-26930 CVE-2021-26931 CVE-2021-26932

Users with Oracle Linux Premier Support can now use Ksplice to patch
against the latest Oracle Linux Security Advisory, ELSA-2021-9051.
More information about this errata can be found at
https://linux.oracle.com/errata/ELSA-2021-9051.html

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running UEKR4 4.1.12 on
OL6 and OL7 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-2021-26930, XSA-365: Bad error handing of blkback grant references.

The Xen blkback driver can incorrectly ignore errors when mapping grant
references, potentially reporting a false success, and causing unmapped
memory to be accessed. Hosting a malicious or buggy frontend driver
might result in a denial-of-service on the host.

Orabug: 32492113


* CVE-2021-26931, XSA-362: Mishandling of errors causes DoS of Xen backend.

Several error conditions in the scsi, block, and net Xen backend drivers
incorrectly cause kernel assertion failures. A malicious or buggy Xen
frontend might trigger these conditions, causing a denial-of-service in the
host.

Orabug: 32492105


* CVE-2021-26932, XSA-361: Denial-of-host-service by malicious Xen frontend.

Batched mapping operations can be potentially mishandled by the Linux
Xen backend, resulting in incorrectly reported success or failure of the
operation. Running a malicious or buggy frontend could result in a
denial-of-service on the host.

Orabug: 32492098


* Denial-of-service when retrieving receive flow hash indirection table on Broadcom NetXtreme-C/E interface.

A missing check when retrieving receive flow hash indirection table on a
Broadcom NetXtreme-C/E network interface which is down could lead to
NULL pointer dereference. A local attacker could use this flaw to cause
a denial-of-service.

Orabug: 32466092

SUPPORT

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