This bug has been copied from bug #720551 and has been proposed to be backported to 5.7 z-stream (EUS).
in kernel-2.6.18-274.1.1.el5 linux-2.6-fs-xfs-handle-null-mount-struct-in-error-reports.patch
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Under some circumstances, error reports within the XFS file system could dereference a NULL pointer cause kernel panic. This update fixes the NULL pointer dereference, and kernel panic no longer occurs
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-2011-1212.html