Clients since 2.6.18 DO NOT need any patches.
PATCH SERIES FOR SERVER KERNELS:
-2.6-rhel6.series 2.6.32-431.29.2.el6 (RHEL 6.5)
-2.6-rhel6.series 2.6.32-504.30.3.el6 (RHEL 6.6)
-2.6-rhel6.series 2.6.32-573.26.1.el6 (RHEL 6.7)
-2.6-rhel6.8.series 2.6.32-642.11.1.el6 (RHEL 6.8)
-3.10-rhel7.series 3.10.0-514.2.2.el7 (RHEL 7.3)
-3.0-sles11sp3.series 3.0.101-0.47.71 (SLES11 SP3)
-3.0-sles11sp3.series 3.0.101-80 (SLES11 SP4)
-3.12-sles12.series 3.12.62-60.64.8 (SLES12 SP1)
+3.10-rhel7.6.series 3.10.0-957.27.2.el7 (RHEL 7.6)
+3.10-rhel7.7.series 3.10.0-1062.18.1.el7 (RHEL 7.7)
+3.10-rhel7.8.series 3.10.0-1127.19.1.el7 (RHEL 7.8)
+3.10-rhel7.9.series 3.10.0-1160.6.1.el7 (RHEL 7.9)
+4.18-rhel8.series 4.18.0-80.11.2.el8 (RHEL 8.0)
+4.18-rhel8.1.series 4.18.0-147.8.1.el8 (RHEL 8.1)
+4.18-rhel8.2.series 4.18.0-193.28.1.el8 (RHEL 8.2)
+4.18-rhel8.3.series 4.18.0-240.1.1.el8 (RHEL 8.3)
See lustre/ChangeLog for supported client kernel versions.