While reading the backout-anon-vma diff to compare 2.6.32 with rhel6 anon-vma code, I noticed a regression in vma_adjust.
fix posted on rhkernel-list
Patch(es) available on kernel-2.6.32-31.el6
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.