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FreeBSD Security Advisory FreeBSD-SA-19:16.bhyve

Posted on 24 July 2019
FreeBSD security notificat

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

Topic: Bhyve out-of-bounds read in XHCI device

Category: core
Module: bhyve
Announced: 2019-07-24
Credits: Reno Robert
Affects: All supported versions of FreeBSD.
Corrected: 2019-07-23 17:48:37 UTC (stable/12, 12.0-STABLE)
2019-07-24 12:56:06 UTC (releng/12.0, 12.0-RELEASE-p8)
2019-07-23 17:48:37 UTC (stable/11, 11.2-STABLE)
2019-07-24 12:56:06 UTC (releng/11.2, 11.2-RELEASE-p12)
2019-07-24 12:56:06 UTC (releng/11.3, 11.3-RELEASE-p1)
CVE Name: CVE-2019-5604

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

bhyve(8) is a hypervisor that supports running a variety of virtual
machines (guests). bhyve includes an emulated XHCI device.

II. Problem Description

The pci_xhci_device_doorbell() function does not validate the 'epid' and
'streamid' provided by the guest, leading to an out-of-bounds read.

III. Impact

A misbehaving bhyve guest could crash the system or access memory that
it should not be able to.

IV. Workaround

No workaround is available, however systems not using bhyve(8) for
virtualization are not vulnerable.

V. Solution

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

No reboot is required. Rather the bhyve(8) process for vulnerable virtual
machines should be restarted.

Perform one of the following:

1) 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

Restart any bhyve virtual machines or reboot the system.

2) 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-19:16/bhyve.patch
# fetch https://security.FreeBSD.org/patches/SA-19:16/bhyve.patch.asc
# gpg --verify bhyve.patch.asc

b) Apply the patch. Execute the following commands as root:

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

c) Recompile the operating system using buildworld and installworld as
described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>.

Restart any bhyve virtual machines, or reboot the system.

VI. Correction details

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

Branch/path Revision
- -------------------------------------------------------------------------
stable/12/ r350246
releng/12.0/ r350285
stable/11/ r350247
releng/11.2/ r350285
releng/11.3/ r350285
- -------------------------------------------------------------------------

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:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5604>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-19:16.bhyve.asc>

 

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