120 lines
4.2 KiB
Text
120 lines
4.2 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
|
|
Hash: SHA512
|
|
|
|
=============================================================================
|
|
FreeBSD-EN-16:11.vmbus Errata Notice
|
|
The FreeBSD Project
|
|
|
|
Topic: Avoid using spin locks for channel message locks
|
|
|
|
Category: core
|
|
Module: vmbus
|
|
Announced: 2016-08-12
|
|
Credits: Microsoft OSTC
|
|
Affects: FreeBSD 10.3
|
|
Corrected: 2016-06-15 09:52:01 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
|
|
<URL:https://security.FreeBSD.org/>.
|
|
|
|
I. Background
|
|
|
|
The vmbus driver has a global lock hv_vmbus_g_connection.channel_msg_lock,
|
|
whose type is MTX_SPIN. The lock is used to protect concurrent access to the
|
|
global pending message list hv_vmbus_g_connection.channel_msg_anchor.
|
|
|
|
II. Problem Description
|
|
|
|
In some cases, sema_post() is invoked when the spin mutex is held.
|
|
|
|
III. Impact
|
|
|
|
Using sema_post() with a held spin mutex may trigger a system panic.
|
|
|
|
IV. Workaround
|
|
|
|
No workaround is available, however FreeBSD virtual machines not running in
|
|
Hyper-V or Azure are unaffected.
|
|
|
|
V. Solution
|
|
|
|
1) Upgrade your system to a supported FreeBSD stable or release / security
|
|
branch (releng) dated after the correction date. After which, 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
|
|
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 https://security.FreeBSD.org/patches/EN-16:11/vmbus.patch
|
|
# fetch https://security.FreeBSD.org/patches/EN-16:11/vmbus.patch.asc
|
|
# gpg --verify vmbus.patch.asc
|
|
|
|
b) Apply the patch. Execute the following commands as root:
|
|
|
|
# cd /usr/src
|
|
# patch < /path/to/patch
|
|
|
|
<for a kernel bug:>
|
|
|
|
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/ r301925
|
|
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://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 latest revision of this advisory is available at
|
|
<URL:https://security.FreeBSD.org/advisories/FreeBSD-EN-16:11.vmbux.asc>
|
|
-----BEGIN PGP SIGNATURE-----
|
|
|
|
iQIcBAEBCgAGBQJXrUsfAAoJEO1n7NZdz2rnyAgP/3ZQ6JLhVWjdHHQz13XyT32r
|
|
NjhZ5VWdL8ZOd4psbLTmqMh79KT4u/bMZ4RackAcpX2agnpPx8sDQL5kaRNypQuj
|
|
OC+rTyRy4J/TZTeX6OPA+TSwOS/yczdGFhgexk0AuxoqWN3j8yZ/P+DyTC7y5CmD
|
|
8Fc9lcTAyFP/OEwybprWesRsC6wS1hKKhzz32e+i2EONzU5Xk8V3rondLZ2cSC9h
|
|
UaeUqJHCbdIogWt7h0zD3WKbcYEwdTmE6MNFJenjWLaIJQkFxqYUfncK9nePm+v7
|
|
W/QfVhEMuClKJRQRI6hHC+XJU2BxoXVB7uuJxk4rfLYO+TynvJ8w2iAMpf6liQLM
|
|
ChvBsczIDHtha7z1uqMRHouywHgSc/YWXodMrRRbOjDfFFHzsTIE/ZVdAncGqxwQ
|
|
/b7VmBS4kZRG5KP0ip/SHRUR+Ououp79gOkIphsT8ikpQKyHQVfG9FL8desSpE8f
|
|
nTyAWwlbBuIid7PqLcFwlIZuqbx52eMWG3//bZNKnxrx2b9RILNRDbOOrwbD2VHq
|
|
n9mO2EKdEPQg+Fz4omwCcmK2kMhknvotQ9oWUOGFK6i/BqZ6q5PffH4lxTyTS+Jr
|
|
oDxHZ3jmSVFb7bcjCqYwqpvxloOXY3ChgfYvnq3OI8Ry5Y7rnI8sGmKFwgqWcSqE
|
|
KS1LNBSGT1A7/mpgzld7
|
|
=GPUS
|
|
-----END PGP SIGNATURE-----
|