1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 7c2f03057ddb..a64d6b4dcc16 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -334,10 +334,11 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
                         ret = -EINVAL;
                         goto err_ah;
                 }
-                /* Validate that management class can support RMPP */
+
+                /* Validate that the management class can support RMPP */
                 if (rmpp_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_ADM) {
                         hdr_len = offsetof(struct ib_sa_mad, data);
-                        data_len = length;
+                        data_len = length - hdr_len;
                 } else if ((rmpp_mad->mad_hdr.mgmt_class >= IB_MGMT_CLASS_VENDOR_RANGE2_START) &&
                             (rmpp_mad->mad_hdr.mgmt_class <= IB_MGMT_CLASS_VENDOR_RANGE2_END)) {
                                 hdr_len = offsetof(struct ib_vendor_mad, data);