There have been a number of questions regarding problem with starting X 
after the recent security update.  This email is an attempt to summarize 
the situation, provide insight, demonstrate the process as a whole, and 
clear up some confusion with the solution.

Solution:

It is believed that anyone who runs 'yum clean all; yum update' at this 
time will have the problem fixed.



Praise for the SL community from Pat and Connie:

The community immediately started working together to get this resolved. 
  The attitude expressed by the 20+ emails on the list was generally 
wonderful.  Helpful details were given, explanations were provided to 
people of all sorts of skill sets - in general people started pitching 
in and being wonderfully helpful.  People mostly provided fixes or 
troubleshooting information.

Thanks for that, it means a lot witnessing how helpful everyone on the 
list can be in times like this!


Cause:

At the root of the problem was the security update for xorg-x11-server 
published on July 9th.  The problem was caused by a change in the module 
ABI for loading xorg drivers that happened in SL6.2.  That change was a 
bugfix and not a security update, so it was not pushed out to earlier 
releases.  The security update for xorg-x11-server uses the new ABI. The 
package, however, does not force the use of these newer drivers though 
any rpm dependency tools - such as requires, conflicts, or obsoletes. 
Thus the xorg-x11-drv update can be installed without incident, even 
though it will not work as expected.  Our usual dependency resolution 
process is unable to locate and report dependencies that are not listed 
by the package.  The change in the ABI happened with SL6.2, but none of 
the xorg packages were security errata at that time.  So, we didn't 
catch the problem then as we didn't have to integrate the 6.2 ABI with 
the 6.1 ABI.


On the period in testing:

The xorg-x11-server package was in the sl-testing repository for 12 days 
before the date of release.
I received a few reports from people who tested the packages while they 
were in testing.  It appears that those testers were on 6.2 and thus 
didn't run into the incompatibility problem.  There were no problems 
reported with this package during the testing window.
I tested these packages.  My test system was SL6.2 and uses the ERRepo 
nvidia kmod.  So I did not encounter any problems.


Details on the solution:

Several packages that were present in SL6.2 have been placed in the 
security tree for SL6.1 and SL6.0.[1]  They have been working on 6.2 for 
some time now, and I have many reports of things working as expected for 
people using them. SL6.0-SL6.2 have also received some driver updates 
that will be present in SL6.3.  It is believed that this is exactly what 
upstream has done for their release.


Forward looking resolution:

A bug has been filed with upstream to have the 'conflicts' section 
updated.  The upstream bug number is 840078.  If the fix listed there is 
placed in the next version of this rpm by upstream the problem should 
not reoccur.


Answers to common questions:

Q: Who was affected?
A: Anyone who was running Scientific Linux 6.0 or 6.1 and dependent on 
the xorg-x11-drv provided drivers for running the X server.

Q: Why didn't you just automatically include all the drivers?
A: We provide the older point releases as an attempt to provide a 
reasonably unchanging platform.  Many of our users have their 
applications certified with very specific versions of things.  When 
putting new security packages in older releases our approach is simply, 
"If nothing forces me to add this package I wont add it."  Nothing in 
the package itself said that these drivers were required for 
functionality.  Furthermore, with SL6.2 the x11-xorg-drv-* packages 
provided with the initial release seem to work just fine with this new 
xorg-x11-server package.  This is part of the upstream attempt to 
preserve a consistent ABI.  Usually when the ABI changes this is noted 
in either a 'requires' section or a 'conflicts' section.

Q: Shouldn't I just get new drivers every time there is a new X?
A: Not necessarily.  For example, with SL6.1 the wacom and xgi drivers 
were identical to the SL6.0 packages.  Upstream didn't update them for 
that release.  And with 6.3 the only updated drivers are currently for 
ati, intel, mga, and wacom.  If they didn't rebuild it there shouldn't 
be a need for us to rebuild it.

Q: Can you just make it your policy to release X drivers every time 
there is a new X?
A: If this is something you need, I would encourage you to instead move 
to the 6x release.  As we are trying to keep the releases as unchanging 
as possible while remaining secure.  Adding non-security packages only 
happens to resolve dependency issues.

Q: Some of these packages are from February, aren't they too old?
A: No, the packages from February are those that came with SL6.2.  They 
have been working for a while with the updated xorg ABI.  The packages 
are 'new' to 6.1 and 6.0, but have been around since February as a part 
of the SL6.2 tree.

Q: Why did it take 3 days to fix?
A: Many of the early problem reports required additional research. 
Several of the people reporting problems are many hours off from the 
people working with them to get more information.  Additionally, several 
users were quick to discover moving to 6.2 corrected the issue.  This 
was wonderful, however, many people simply moved to SL6.2 rather than 
installing the packages posted to testing.  This makes sense as SL6.2 
was available instantly, while the testing packages were being assembled 
and having their dependencies checked.  This is not a criticism of that 
solution.  However, getting independent verification that the packages 
in testing actually fixed the problem was a priority before they got 
pushed out.  If they had compounded the issue rather than resolving it, 
the additional problems would have further made a mess of things.  Once 
reports came in from two community members that the packages in testing 
fixed the issue, they were pushed.




[1]
list of 6.2 packages published to 6.0 and 6.1

i386:
xorg-x11-drivers-7.3-13.3.el6.i686.rpm
xorg-x11-drv-acecad-1.5.0-3.el6.i686.rpm
xorg-x11-drv-aiptek-1.4.1-2.el6.i686.rpm
xorg-x11-drv-apm-1.2.3-2.el6.i686.rpm
xorg-x11-drv-ast-0.91.10-1.el6.i686.rpm
xorg-x11-drv-cirrus-1.3.2-2.el6.i686.rpm
xorg-x11-drv-dummy-0.3.4-1.el6.i686.rpm
xorg-x11-drv-elographics-1.3.0-2.el6.i686.rpm
xorg-x11-drv-evdev-2.6.0-2.el6.i686.rpm
xorg-x11-drv-evdev-devel-2.6.0-2.el6.i686.rpm
xorg-x11-drv-fbdev-0.4.2-2.el6.i686.rpm
xorg-x11-drv-fpit-1.4.0-2.el6.i686.rpm
xorg-x11-drv-geode-2.11.12-1.el6.i686.rpm
xorg-x11-drv-glint-1.2.5-1.el6.i686.rpm
xorg-x11-drv-hyperpen-1.4.1-2.el6.i686.rpm
xorg-x11-drv-i128-1.3.4-1.el6.i686.rpm
xorg-x11-drv-i740-1.3.2-2.el6.i686.rpm
xorg-x11-drv-keyboard-1.6.0-1.el6.i686.rpm
xorg-x11-drv-mach64-6.9.0-1.el6.i686.rpm
xorg-x11-drv-mouse-1.7.0-4.el6.i686.rpm
xorg-x11-drv-mutouch-1.3.0-2.el6.i686.rpm
xorg-x11-drv-neomagic-1.2.5-1.el6.i686.rpm
xorg-x11-drv-nouveau-0.0.16-13.20110719gitde9d1ba.el6.i686.rpm
xorg-x11-drv-nv-2.1.18-2.el6.i686.rpm
xorg-x11-drv-openchrome-0.2.904-4.el6.i686.rpm
xorg-x11-drv-openchrome-devel-0.2.904-4.el6.i686.rpm
xorg-x11-drv-penmount-1.5.0-2.el6.i686.rpm
xorg-x11-drv-qxl-0.0.14-13.el6_2.i686.rpm
xorg-x11-drv-r128-6.8.1-3.el6.i686.rpm
xorg-x11-drv-rendition-4.2.4-1.el6.i686.rpm
xorg-x11-drv-s3virge-1.10.4-2.el6.i686.rpm
xorg-x11-drv-savage-2.3.2-1.el6.i686.rpm
xorg-x11-drv-siliconmotion-1.7.5-1.el6.i686.rpm
xorg-x11-drv-sis-0.10.3-1.el6.i686.rpm
xorg-x11-drv-sisusb-0.9.4-1.el6.i686.rpm
xorg-x11-drv-synaptics-1.4.1-3.el6.i686.rpm
xorg-x11-drv-synaptics-devel-1.4.1-3.el6.i686.rpm
xorg-x11-drv-tdfx-1.4.3-2.el6.i686.rpm
xorg-x11-drv-trident-1.3.4-1.el6.i686.rpm
xorg-x11-drv-v4l-0.2.0-4.el6.i686.rpm
xorg-x11-drv-vesa-2.3.0-2.el6.i686.rpm
xorg-x11-drv-vmmouse-12.7.0-1.el6.i686.rpm
xorg-x11-drv-vmware-11.0.3-1.el6.i686.rpm
xorg-x11-drv-void-1.4.0-1.el6.i686.rpm
xorg-x11-drv-voodoo-1.2.4-1.el6.i686.rpm
xorg-x11-drv-xgi-1.6.0-11.el6.i686.rpm

x86_64:
xorg-x11-drv-acecad-1.5.0-3.el6.x86_64.rpm
xorg-x11-drv-aiptek-1.4.1-2.el6.x86_64.rpm
xorg-x11-drv-apm-1.2.3-2.el6.x86_64.rpm
xorg-x11-drv-ast-0.91.10-1.el6.x86_64.rpm
xorg-x11-drv-cirrus-1.3.2-2.el6.x86_64.rpm
xorg-x11-drv-dummy-0.3.4-1.el6.x86_64.rpm
xorg-x11-drv-elographics-1.3.0-2.el6.x86_64.rpm
xorg-x11-drv-evdev-2.6.0-2.el6.x86_64.rpm
xorg-x11-drv-evdev-devel-2.6.0-2.el6.i686.rpm
xorg-x11-drv-evdev-devel-2.6.0-2.el6.x86_64.rpm
xorg-x11-drv-fbdev-0.4.2-2.el6.x86_64.rpm
xorg-x11-drv-fpit-1.4.0-2.el6.x86_64.rpm
xorg-x11-drv-glint-1.2.5-1.el6.x86_64.rpm
xorg-x11-drv-hyperpen-1.4.1-2.el6.x86_64.rpm
xorg-x11-drv-i128-1.3.4-1.el6.x86_64.rpm
xorg-x11-drv-i740-1.3.2-2.el6.x86_64.rpm
xorg-x11-drv-keyboard-1.6.0-1.el6.x86_64.rpm
xorg-x11-drv-mach64-6.9.0-1.el6.x86_64.rpm
xorg-x11-drv-mouse-1.7.0-4.el6.x86_64.rpm
xorg-x11-drv-mutouch-1.3.0-2.el6.x86_64.rpm
xorg-x11-drv-nouveau-0.0.16-13.20110719gitde9d1ba.el6.x86_64.rpm
xorg-x11-drv-nv-2.1.18-2.el6.x86_64.rpm
xorg-x11-drv-openchrome-0.2.904-4.el6.i686.rpm
xorg-x11-drv-openchrome-0.2.904-4.el6.x86_64.rpm
xorg-x11-drv-openchrome-devel-0.2.904-4.el6.i686.rpm
xorg-x11-drv-openchrome-devel-0.2.904-4.el6.x86_64.rpm
xorg-x11-drv-penmount-1.5.0-2.el6.x86_64.rpm
xorg-x11-drv-qxl-0.0.14-13.el6_2.x86_64.rpm
xorg-x11-drv-r128-6.8.1-3.el6.x86_64.rpm
xorg-x11-drv-rendition-4.2.4-1.el6.x86_64.rpm
xorg-x11-drv-s3virge-1.10.4-2.el6.x86_64.rpm
xorg-x11-drv-savage-2.3.2-1.el6.x86_64.rpm
xorg-x11-drv-siliconmotion-1.7.5-1.el6.x86_64.rpm
xorg-x11-drv-sis-0.10.3-1.el6.x86_64.rpm
xorg-x11-drv-sisusb-0.9.4-1.el6.x86_64.rpm
xorg-x11-drv-synaptics-1.4.1-3.el6.x86_64.rpm
xorg-x11-drv-synaptics-devel-1.4.1-3.el6.i686.rpm
xorg-x11-drv-synaptics-devel-1.4.1-3.el6.x86_64.rpm
xorg-x11-drv-tdfx-1.4.3-2.el6.x86_64.rpm
xorg-x11-drv-trident-1.3.4-1.el6.x86_64.rpm
xorg-x11-drv-v4l-0.2.0-4.el6.x86_64.rpm
xorg-x11-drv-vesa-2.3.0-2.el6.x86_64.rpm
xorg-x11-drv-vmmouse-12.7.0-1.el6.x86_64.rpm
xorg-x11-drv-vmware-11.0.3-1.el6.x86_64.rpm
xorg-x11-drv-void-1.4.0-1.el6.x86_64.rpm
xorg-x11-drv-voodoo-1.2.4-1.el6.x86_64.rpm
xorg-x11-drv-xgi-1.6.0-11.el6.x86_64.rpm