—–BEGIN PGP SIGNED MESSAGE—–
Hash: SHA512

=============================================================================
FreeBSD-SA-16:19.sendmsg Security Advisory
The FreeBSD Project

Topic: Incorrect argument handling in sendmsg(2)

Category: core
Module: kernel
Announced: 2016-05-17
Credits: CTurt and the HardenedBSD team
Affects: FreeBSD 10.x
Corrected: 2016-05-17 22:30:43 UTC (stable/10, 10.3-STABLE)
2016-05-17 22:28:27 UTC (releng/10.3, 10.3-RELEASE-p3)
2016-05-17 22:28:20 UTC (releng/10.2, 10.2-RELEASE-p17)
2016-05-17 22:28:11 UTC (releng/10.1, 10.1-RELEASE-p34)
CVE Name: CVE-2016-1887

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.

I. Background

The sendmsg(2) system call allows to send data to a socket. The data
may be accompanied by optional ancillary data.

II. Problem Description

Incorrect argument handling in the socket code allows malicious local
user to overwrite large portion of the kernel memory.

III. Impact

Malicious local user may crash kernel or execute arbitrary code in the kernel,
potentially gaining superuser privileges.

IV. Workaround

No workaround is available.

V. Solution

Perform one of the following:

1) Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.

Reboot is required.

2) To update your vulnerable 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

Reboot is required.

3) To update your vulnerable 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.

# fetch https://security.FreeBSD.org/patches/SA-16:19/sendmsg.patch
# fetch https://security.FreeBSD.org/patches/SA-16:19/sendmsg.patch.asc
# gpg –verify sendmsg.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
– ————————————————————————-
stable/10/ r300093
releng/10.1/ r300085
releng/10.2/ r300086
releng/10.3/ r300087
– ————————————————————————-

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

<URL:http://cturt.github.io/sendmsg.html>
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-1887>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:19.sendmsg.asc>
—–BEGIN PGP SIGNATURE—–
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=wuhi
—–END PGP SIGNATURE—–
_______________________________________________
freebsd-security-notifications@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-security-notifications
To unsubscribe, send any mail to “freebsd-security-notifications-unsubscribe@freebsd.org”