Clients since 2.6.18 DO NOT need any patches.
PATCH SERIES FOR SERVER KERNELS:
-2.6-rhel6.series 2.6.32-431.23.3.el6
-3.0-sles11sp3.series 3.0.101-0.31
+2.6-rhel6.series 2.6.32-431.29.2.el6 (RHEL 6.5)
+2.6-rhel6.series 2.6.32-504.23.4.el6 (RHEL 6.6)
+3.10-rhel7.series 3.10.0-229.4.2.el7 (RHEL 7.1)
+3.0-sles11sp3.series 3.0.101-0.47.52 (SLES11 SP3)
See lustre/ChangeLog for supported client kernel versions.