Red Hat ENTERPRISE LINUX 5.5 - TECHNICAL NOTES Manual page 284

Chapter 1. Package Updates
This update has been rated as having moderate security impact by the Red Hat Security Response
Team.
Xen is an open source virtualization framework. Virtualization allows users to run guest operating
systems in virtual machines on top of a host operating system.
The pyGrub boot loader did not honor the "password" option in the grub.conf file for para-virtualized
guests. Users with access to a guest's console could use this flaw to bypass intended access
restrictions and boot the guest with arbitrary kernel boot options, allowing them to get root privileges
in the guest's operating system. With this update, pyGrub correctly honors the "password" option in
grub.conf for para-virtualized guests.
This update also fixes the following bugs:
* rebooting para-virtualized guests sometimes caused those guests to crash due to a race condition in
the xend node control daemon. This update fixes this race condition so that rebooting guests no longer
potentially causes them to crash and fail to reboot.
* due to a race condition in the xend daemon, a guest could disappear from the list of running guests
following a reboot, even though the guest rebooted successfully and was running. This update fixes
this race condition so that guests always reappear in the guest list following a reboot.
* attempting to use PCI pass-through to para-virtualized guests on certain kernels failed with a
"Function not implemented" error message. As a result, users requiring PCI pass-through on para-
virtualized guests were not able to update the xen packages without also updating the kernel and
thus requiring a reboot. These updated packages enable PCI pass-through for para-virtualized guests
so that users do not need to upgrade the kernel in order to take advantage of PCI pass-through
functionality. (BZ#525149
All Xen users should upgrade to these updated packages, which contain backported patches to
correct these issues. After installing the updated packages, the xend service must be restarted for this
update to take effect.
1.217.4. RHBA-2010:0294: bug fix and enhancement update
The xen packages contain tools for managing the virtual machine monitor in Red Hat Enterprise Linux
Virtualization.
These updated packages fix the following bugs:
• Cause: Fully-virtualized Fedora 10 and newer guests would freeze during the boot sequence. The
guest would repeatedly receive an error similar to the following error:
ata2.00: configured for MWDMA2
ata2: EH complete
ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
ata2.00: cmd a0/00:00:00:00:00/00:00:00:00:00/a0 tag 0
cdb 1e 00 00 00 00 00 00 00
res 41/20:03:00:00:00/00:00:00:00:00/a0 Emask 0x3 (HSM violation)
ata2.00: status: { DRDY ERR -}
ata2: soft resetting link
2152
https://www.redhat.com/security/data/cve/CVE-2009-3525.html
2153
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=525141
2154
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=525143
2155
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=525149
274
(CVE-2009-3525
2155
)
00 00 00 00 00 00 00 00
2152
)
2153
(BZ#525141 )
2154
(BZ#525143 )