SUNRPC: Ensure get_rpccred() and put_rpccred() can take NULL arguments

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

include/linux/sunrpc/auth.h

@@ -202,7 +202,8 @@ char *			rpcauth_stringify_acceptor(struct rpc_cred *);
 static inline
 struct rpc_cred *	get_rpccred(struct rpc_cred *cred)
 {
-	atomic_inc(&cred->cr_count);
+	if (cred != NULL)
+		atomic_inc(&cred->cr_count);
 	return cred;
 }
 

net/sunrpc/auth.c

@@ -703,8 +703,7 @@ rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 		new = rpcauth_bind_new_cred(task, lookupflags);
 	if (IS_ERR(new))
 		return PTR_ERR(new);
-	if (req->rq_cred != NULL)
-		put_rpccred(req->rq_cred);
+	put_rpccred(req->rq_cred);
 	req->rq_cred = new;
 	return 0;
 }
@@ -712,6 +711,8 @@ rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 void
 put_rpccred(struct rpc_cred *cred)
 {
+	if (cred == NULL)
+		return;
 	/* Fast path for unhashed credentials */
 	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
 		if (atomic_dec_and_test(&cred->cr_count))