oss-security - Xen Security Advisory 424 v1 (CVE-2022-42328,CVE-2022-42329) - Guests can trigger deadlock in Linux netback driver

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <E1p2ZhW-0005Xe-FG@xenbits.xenproject.org>
Date: Tue, 06 Dec 2022 15:17:42 +0000
From: Xen.org security team <security@....org>
To: xen-announce@...ts.xen.org, xen-devel@...ts.xen.org,
 xen-users@...ts.xen.org, oss-security@...ts.openwall.com
CC: Xen.org security team <security-team-members@....org>
Subject: Xen Security Advisory 424 v1 (CVE-2022-42328,CVE-2022-42329) -
 Guests can trigger deadlock in Linux netback driver

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

     Xen Security Advisory CVE-2022-42328,CVE-2022-42329 / XSA-424

          Guests can trigger deadlock in Linux netback driver

ISSUE DESCRIPTION
=================

The patch for XSA-392 introduced another issue which might result in
a deadlock when trying to free the SKB of a packet dropped due to
the XSA-392 handling (CVE-2022-42328).

Additionally when dropping packages for other reasons the same
deadlock could occur in case of netpoll being active for the interface
the xen-netback driver is connected to (CVE-2022-42329).

IMPACT
======

A malicious guest could cause Denial of Service (DoS) of the host via
the paravirtualized network interface.

VULNERABLE SYSTEMS
==================

All systems using the Linux kernel based network backend xen-netback
are vulnerable.

MITIGATION
==========

Using another PV network backend (e.g. the qemu based "qnic" backend)
will mitigate the problem.

Using a dedicated network driver domain per guest will mitigate the
problem.

NOTE REGARDING LACK OF EMBARGO
==============================

This issue was discussed in public already.

RESOLUTION
==========

Applying the attached patch resolves this issue.

xsa424-linux.patch     Linux 6.0, 6.1-rc

$ sha256sum xsa424*
89db7cad9694f498c4ac450356932fb69fb514162e07aea0343776effa821fc8  xsa424-linux.patch
$

-----BEGIN PGP SIGNATURE-----

iQFABAEBCAAqFiEEI+MiLBRfRHX6gGCng/4UyVfoK9kFAmOPXKYMHHBncEB4ZW4u
b3JnAAoJEIP+FMlX6CvZ30IH/1GZwPXXAqMjN3d1n7BotiDLfmDiNp8e92wvQvmh
cXgsBtvTZ+oDzI7J+Xr/42c4IN41s34fWl0hmNbdrw4lwrOSoj0rnCP73Bn22oUT
jbv3bmFOHytCs5crvVrA4S7dCNcdpoEmfOoSaz1cBPhMecotlgTQo7M2Cagv3O9a
a9fR+KGMk9EBDGdo2wBJyEcD9ApASPEV+LJgLoTOuYFIStCO/+TTBfJx5H7T/vgK
Dqxsq1nULCSBc5Z5wrmtF49G3asBrAbPTkRhpyp9giXU+UV0QNJclnc+IJPdLIOe
jISAvpHQ3Fkb7Q25jaBg+c0bf9KzT3ekBOaf1RofgA84Jg0=
=4J/5
-----END PGP SIGNATURE-----

Download attachment "xsa424-linux.patch" of type "application/octet-stream" (3524 bytes)

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.