[Ksplice][Ubuntu-20.10-Updates] New Ksplice updates for Ubuntu 20.10 Groovy (USN-4910-1)

[Oracle Ksplice]

Synopsis: USN-4910-1 can now be patched using Ksplice
CVEs: CVE-2020-27170 CVE-2020-27171 CVE-2021-20239 CVE-2021-20268 CVE-2021-3178 CVE-2021-3347 CVE-2021-3348

Systems running Ubuntu 20.10 Groovy can now use Ksplice to patch
against the latest Ubuntu Security Notice, USN-4910-1.

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running Ubuntu 20.10
Groovy 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-2021-3348: 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.


* CVE-2021-3178: Path traversal vulnerability in NFSv3 filesystem.

A flaw in the NFSv3 implementation when there is an NFS export of
a subdirectory of a filesystem could lead to a leak of the file handle
for parent directory. A remote attackers could use this flaw to traverse
to other parts of the filesystem and gain more access than expected.


* 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.


* Improved update to 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-2021-20239: Information leak via cgroup BPF filter.

BPF programs running on cgroups can contain addresses provided from
userspace. The BPF code erroneously returns a different error number if
the program attempts to access a valid kernel address. A malicious user
with the CAP_NET_ADMIN permission could exploit this to gain information
about the running kernel.


* CVE-2021-20268: Escalation of privileges in eBPF code verifier.

An out-of-bounds access flaw in the eBPF code verifier could happen when
a user running the eBPF script calls dev_map_init_map or sock_map_alloc.
A local user could use this flaw to cause a denial-of-service or
possibly escalate their privileges.

SUPPORT

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