[Ksplice][Ubuntu-Oracle-Updates] New Ksplice updates for Ubuntu OCI kernel (USN-4907-1)

[Oracle Ksplice]

Synopsis: USN-4907-1 can now be patched using Ksplice
CVEs: CVE-2018-13095 CVE-2020-27170 CVE-2020-27171 CVE-2020-27825 CVE-2021-3347 CVE-2021-3348

Systems running Ubuntu OCI kernel can now use Ksplice to patch against
the latest Ubuntu Security Notice, USN-4907-1.

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running Ubuntu OCI
kernel 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-2018-13095: Denial-of-service on xfs inode with outsize extent count.

The xfs filesystem fails to properly handle an inode with more extents
than fit in the inode fork. Encountering such a file could cause the xfs
verification code to corrupt memory or cause a denial-of-service.


* CVE-2020-27825: Race condition in kernel tracing buffers causes DoS.

Missing locking around kernel trace buffers could result in
use-after-free when the buffers are resized. A malicious user with trace
permissions might exploit this to cause a denial-of-service or escalate
their privileges.


* CVE-2021-3348: Use-after-free due to bad locking in Network block device.

A missing locking in Network block device could lead to use-after-free
when setting up a device. A local user could use this flaw to cause
a denial-of-service or to execute code.


* Improved fix for CVE-2020-27170, CVE-2020-27171: Information disclosure in BPF verifier.

Multiple flaws in the BPF verifier implementation could result in
incorrect arithmetic operations. A local user could use these flaws
to cause information disclosure.


* CVE-2021-3347: Privilege escalation in the Fast Userspace Mutexes.

A flaw in the Fast Userspace Mutexes implementation could lead to
a use-after-free. A local user could use this flaw to crash the system
or escalate their privileges.

SUPPORT

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