1 files changed, 15 insertions, 0 deletions

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index b81e790ef9f4..1d9ac4ac818a 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1315,6 +1315,14 @@ svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
         inpages = resbuf->pages;
         /* XXX: Would be better to write some xdr helper functions for
          * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
+
+        /*
+         * If there is currently tail data, make sure there is
+         * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
+         * the page, and move the current tail data such that
+         * there is RPC_MAX_AUTH_SIZE slack space available in
+         * both the head and tail.
+         */
         if (resbuf->tail[0].iov_base) {
                 BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
                                                         + PAGE_SIZE);
@@ -1327,6 +1335,13 @@ svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
                         resbuf->tail[0].iov_len);
                 resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
         }
+        /*
+         * If there is no current tail data, make sure there is
+         * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
+         * allotted page, and set up tail information such that there
+         * is RPC_MAX_AUTH_SIZE slack space available in both the
+         * head and tail.
+         */
         if (resbuf->tail[0].iov_base == NULL) {
                 if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
                         return -ENOMEM;