Date: Thu, 27 Sep 2018 20:08:42 +0000 (UTC) From: FreeBSD Errata Notices <errata-notices@freebsd.org> To: FreeBSD Errata Notices <errata-notices@freebsd.org> Subject: [FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-18:09.ip Message-ID: <20180927200842.EFA4F14B6E@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
=============================================================================
FreeBSD-EN-18:09.ip Errata Notice
The FreeBSD Project
Topic: IP fragment remediation causes IPv6 fragment
reassembly failure
Category: core
Module: kernel
Announced: 2018-09-27
Credits: Kristof Provost
Affects: FreeBSD 11.1 and FreeBSD 11.2
Corrected: 2018-09-27 18:29:55 UTC (releng/11.2, 11.2-RELEASE-p4)
2018-09-27 18:29:55 UTC (releng/11.1, 11.1-RELEASE-p15)
For general information regarding FreeBSD Errata Notices and Security
Advisories, including descriptions of the fields above, security
branches, and the following sections, please visit
<URL:https://security.FreeBSD.org/>.
I. Background
The recent security advisory titled SA-18:10.ip resolved an issue in the IPv4
and IPv6 fragment reassembly code.
II. Problem Description
As a result of fixing the issue describe in SA-18:10.ip, a regression was
introduced in the IPv6 fragment hashing code which could cause reassembly to
fail.
III. Impact
Received IPv6 packets requiring fragment reassembly may be dropped instead of
properly reassembled and delivered.
IV. Workaround
Disable IPv6 fragment reassembly, using these commands:
% sysctl net.inet6.ip6.maxfrags=0
On systems compiled with VIMAGE, these sysctls will need to be
executed for each VNET.
V. Solution
Perform one of the following:
1) Upgrade your system to a supported FreeBSD stable or release / security
branch (releng) dated after the correction date.
Afterward, reboot the system.
2) To update your system via a binary patch:
Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:
# freebsd-update fetch
# freebsd-update install
Afterward, reboot the system.
3) To update your system via a source code patch:
The following patches have been verified to apply to the applicable
FreeBSD release branches.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
[FreeBSD 11.x]
# fetch https://security.FreeBSD.org/patches/EN-18:09/ip.patch
# fetch https://security.FreeBSD.org/patches/EN-18:09/ip.patch.asc
# gpg --verify ip.patch.asc
b) Apply the patch. Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
c) Recompile your kernel as described in
<URL:https://www.FreeBSD.org/handbook/kernelconfig.html>; and reboot the
system.
VI. Correction details
The following list contains the correction revision numbers for each
affected branch.
Branch/path Revision
- -------------------------------------------------------------------------
releng/11.1/ r338978
releng/11.2/ r338978
- -------------------------------------------------------------------------
To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
Or visit the following URL, replacing NNNNNN with the revision number:
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>;
VII. References
The security advisory that introduced the regression is available at
<URL:https://www.freebsd.org/security/advisories/FreeBSD-SA-18:10.ip.asc>;
<URL:https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=231045>;
The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-EN-18:09.ip.asc>;
-----BEGIN PGP SIGNATURE-----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=1FtK
-----END PGP SIGNATURE-----
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20180927200842.EFA4F14B6E>