[Ksplice][Ubuntu-Oracle-Updates] New Ksplice updates for Ubuntu OCI kernel (USN-4426-1)

[Oracle Ksplice]

Synopsis: USN-4426-1 can now be patched using Ksplice
CVEs: CVE-2019-20908 CVE-2020-10757 CVE-2020-11935 CVE-2020-15780

Systems running Ubuntu OCI kernel can now use Ksplice to patch against
the latest Ubuntu Security Notice, USN-4426-1.

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-2020-10757: Flaw in DAX page mapping allows privilege escalation.

A flaw in the kernel handling for remapping huge pages mishandles pages
mapped for the DAX (direct userspace access) subsystem. A user with
access to DAX-mapped storage could exploit this to escalate their
privileges.


* CVE-2020-15780: SecureBoot bypass through ACPI table loading.

A missing check that the kernel is not locked down when loading ACPI tables
from userspace can allow the root user to escape SecureBoot or a kernel
lock down.


* CVE-2019-20908: Incorrect permissions ACPI variable can allow SecureBoot bypass.

Incorrect access permissions for the EFI SSDT ACPI variable could be used by
attackers to bypass lockdown or SecureBoot restrictions.


* CVE-2020-11935: Denial-of-service attack with aufs inode reference counts.

A logic error in the aufs dentry_open function could result in invalid
reference counts, leading to a kernel BUG().  An attacker could potentially
exploit this to cause a denial-of-service attack.

SUPPORT

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