-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                  ESB-2004.0369 -- FreeBSD-SA-04:11.msync
              buffer cache invalidation implementation issues
                                28 May 2004

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:                kernel
Operating System:       FreeBSD
Impact:                 Reduced Security
Access Required:        Existing Account
CVE Names:              CAN-2004-0435

- --------------------------BEGIN INCLUDED TEXT--------------------

- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=============================================================================
FreeBSD-SA-04:11.msync                                      Security Advisory
                                                          The FreeBSD Project

Topic:          buffer cache invalidation implementation issues

Category:       core
Module:         sys
Announced:      2004-05-26
Credits:        Stephan Uphoff <ups@tree.com>
                Matt Dillon <dillon@apollo.backplane.com>
Affects:        All FreeBSD versions prior to the correction date
Corrected:      2004-05-25 22:46:38 UTC (RELENG_4, 4.10-STABLE)
                2004-05-25 23:07:55 UTC (RELENG_5_2, 5.2.1-RELEASE-p8)
                2004-05-22 23:09:19 UTC (RELENG_4_10, 4.10-RELEASE)
                2004-05-25 23:01:21 UTC (RELENG_4_9, 4.9-RELEASE-p9)
                2004-05-25 23:01:19 UTC (RELENG_4_8, 4.8-RELEASE-p22)
CVE Name:       CAN-2004-0435
FreeBSD only:   YES

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

I.   Background

The msync(2) system call is used by applications to request that
modified memory pages are written to permanent storage.

II.  Problem Description

Programming errors in the implementation of the msync(2) system call
involving the MS_INVALIDATE operation lead to cache consistency
problems between the virtual memory system and on-disk contents.

III. Impact

In some situations, a user with read access to a file may be able to
prevent changes to that file from being committed to disk.

IV.  Workaround

There is no workaround.

V.   Solution

Perform one of the following:

1) Upgrade your vulnerable system to 4-STABLE; or to the RELENG_5_2,
RELENG_4_10, RELENG_4_9, or RELENG_4_8 security branch dated after the
correction date.

2) To patch your present system:

The following patches have been verified to apply to FreeBSD 4.8, 4.9,
4.10 and 5.2 systems.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

[FreeBSD 5.2]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:11/msync5.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:11/msync5.patch.asc

[FreeBSD 4.8, 4.9, 4.10]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:11/msync4.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:11/msync4.patch.asc

b) Apply the patch.

# cd /usr/src
# patch < /path/to/patch

c) Recompile your kernel as described in
<URL:http://www.freebsd.org/handbook/kernelconfig.html> and reboot the
system.

VI.  Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

Branch                                                           Revision
  Path
- - -------------------------------------------------------------------------
RELENG_4
  src/sys/ufs/ufs/ufs_readwrite.c                               1.65.2.16
  src/sys/vm/vm_map.c                                          1.187.2.30
RELENG_4_10
  src/sys/ufs/ufs/ufs_readwrite.c                           1.65.2.14.4.1
  src/sys/vm/vm_map.c                                      1.187.2.24.2.4
RELENG_4_9
  src/UPDATING                                             1.73.2.89.2.10
  src/sys/conf/newvers.sh                                  1.44.2.32.2.10
  src/sys/ufs/ufs/ufs_readwrite.c                           1.65.2.14.2.1
  src/sys/vm/vm_map.c                                      1.187.2.23.2.1
RELENG_4_8
  src/UPDATING                                             1.73.2.80.2.25
  src/sys/conf/newvers.sh                                  1.44.2.29.2.23
  src/sys/ufs/ufs/ufs_readwrite.c                           1.65.2.13.2.1
  src/sys/vm/vm_map.c                                      1.187.2.17.2.1
RELENG_5_2
  src/UPDATING                                                 1.282.2.16
  src/sys/conf/newvers.sh                                       1.56.2.15
  src/sys/ufs/ffs/ffs_vnops.c                                   1.119.2.1
  src/sys/vm/vm_object.c                                        1.317.2.1
- - -------------------------------------------------------------------------
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (FreeBSD)

iD8DBQFAtH2pFdaIBMps37IRAmycAJ0cv/iG6NlGBsC1xT4gg/Gx3lF8DwCghfHl
G2wdUNyfvhz0u3kFB9pH41c=
=SK1u
- -----END PGP SIGNATURE-----

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:

        http://www.auscert.org.au/render.html?it=3192

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business 
                hours which are GMT+10:00 (AEST).  On call after hours 
                for member emergencies only.
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iQCVAwUBQLbbhSh9+71yA2DNAQIjMAP+JhoF+dlAZzwJgB3ytfE9/fBHlR/9+um8
rO7Fb/3fG9iKy9saaEdHJvrZTx8wV/ixpsKGtVRLD2aZivh1mV9oNaGcPdLtTvKF
cobEYlPxravGllV45iVjALukEralzCCLwHujUfBreqIyiWDVjE0420XIRUs9x9n3
Dr8wpXSX93A=
=Eeux
-----END PGP SIGNATURE-----