diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 2d786b8..16e71d0 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1261,13 +1261,13 @@
 	xdr->buf = buf;
 	xdr->iov = head;
 	xdr->p   = head->iov_base + head->iov_len;
-	xdr->end = head->iov_base + PAGE_SIZE - 2 * RPC_MAX_AUTH_SIZE;
+	xdr->end = head->iov_base + PAGE_SIZE - rqstp->rq_auth_slack;
 	/* Tail and page_len should be zero at this point: */
 	buf->len = buf->head[0].iov_len;
 	xdr->scratch.iov_len = 0;
 	xdr->page_ptr = buf->pages;
 	buf->buflen = PAGE_SIZE * (1 + rqstp->rq_page_end - buf->pages)
-		- 2 * RPC_MAX_AUTH_SIZE;
+		- rqstp->rq_auth_slack;
 }
 
 /*
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 62b882d..d0a016a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2288,7 +2288,7 @@
 			session->se_fchannel.maxresp_sz;
 	status = (seq->cachethis) ? nfserr_rep_too_big_to_cache :
 				    nfserr_rep_too_big;
-	if (xdr_restrict_buflen(xdr, buflen - 2 * RPC_MAX_AUTH_SIZE))
+	if (xdr_restrict_buflen(xdr, buflen - rqstp->rq_auth_slack))
 		goto out_put_session;
 	svc_reserve(rqstp, buflen);
 
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 3e347a1..470fe89 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1611,7 +1611,8 @@
 	DECODE_HEAD;
 	struct nfsd4_op *op;
 	bool cachethis = false;
-	int max_reply = 2 * RPC_MAX_AUTH_SIZE + 8; /* opcnt, status */
+	int auth_slack= argp->rqstp->rq_auth_slack;
+	int max_reply = auth_slack + 8; /* opcnt, status */
 	int readcount = 0;
 	int readbytes = 0;
 	int i;
@@ -1677,7 +1678,7 @@
 	svc_reserve(argp->rqstp, max_reply + readbytes);
 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
 
-	if (readcount > 1 || max_reply > PAGE_SIZE - 2*RPC_MAX_AUTH_SIZE)
+	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
 		argp->rqstp->rq_splice_ok = false;
 
 	DECODE_TAIL;