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FreeBSD Errata Notice FreeBSD-EN-16:12.hv_storvsc

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FreeBSD-EN-16:12.hv_storvsc                                     Errata Notice
                                                          The FreeBSD Project

Topic:          Enable INQUIRY result check only on Windows 10 host systems

Category:       core
Module:         hv_storvsc
Announced:      2016-08-12
Credits:        Microsoft OSTC
Affects:        FreeBSD 10.3
Corrected:      2016-05-25 06:15:26 UTC (stable/10, 10.3-STABLE)
                2016-08-12 04:01:16 UTC (releng/10.3, 10.3-RELEASE-p7)

For general information regarding FreeBSD Errata Notices and Security
Advisories, including descriptions of the fields above, security
branches, and the following sections, please visit

I.   Background

A FreeBSD virtual machine running on Hyper-V uses hv_storvsc(4) to discover,
access, and control block devices.  The SCSI INQUIRY command is used to scan
the disks attached to the virtual machine, and hv_storvsc(4) checks if the
response from the host is valid.

II.  Problem Description

On Windows 8 and earlier systems, the response to the INQUIRY command may
return invalid results.

III. Impact

When a SCSI disk hotplug occurs, some disks may not be visible to the guest
virtual machine despite being present.

IV.  Workaround

No workaround is available however guest machines not running on Hyper-V on
Windows 8 and earlier are unaffected.

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.  After which, reboot the

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
After which, 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.

# fetch
# fetch
# gpg --verify hv_storvsc.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:> and reboot the

VI.  Correction details

The following list contains the correction revision numbers for each
affected branch.

Branch/path                                                      Revision
- -------------------------------------------------------------------------
stable/10/                                                        r300656
releng/10.3/                                                      r303984
- -------------------------------------------------------------------------

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://

Or visit the following URL, replacing NNNNNN with the revision number:


VII. References


The latest revision of this advisory is available at

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