Bug 628828 - Fix hot-unplug handling of virtio-console ports
Summary: Fix hot-unplug handling of virtio-console ports
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.6
Hardware: All
OS: Linux
low
medium
Target Milestone: rc
: ---
Assignee: Amit Shah
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On: 628805
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-08-31 06:44 UTC by Amit Shah
Modified: 2013-01-09 23:04 UTC (History)
10 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 628805
Environment:
Last Closed: 2011-01-13 21:14:08 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2011:0017 0 normal SHIPPED_LIVE Important: Red Hat Enterprise Linux 5.6 kernel security and bug fix update 2011-01-13 10:37:42 UTC

Comment 1 RHEL Program Management 2010-09-22 15:29:15 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 2 Amit Shah 2010-09-23 03:39:09 UTC
The current version of virtio-console doesn't handle hot-unplug properly: it
leads to accessing memory outside the driver's memory area and can cause guest
kernel panics.

There are a few ways to trigger this, one of them:

1. Open a virtio-console port in the guest (eg /dev/vport0p1)
2. Block the port on read (eg cat /dev/vport0p1 with host chardev connected)
3. Hot-unplug the port (using the device_del command for the qemu monitor)
4. Close the port in the guest

Patches are queued for inclusion upstream.

Note that by default only root is allowed to open a virtio-console port, so
this can't be triggered by an unprivileged user in the default setup.

Comment 4 Jarod Wilson 2010-10-14 14:03:06 UTC
in kernel-2.6.18-227.el5
You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.

Comment 7 errata-xmlrpc 2011-01-13 21:14:08 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0017.html


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