SUNRPC: Use xdr_stream to encode Reply verifier in svcauth_unix_accept()

Done as part of hardening the server-side RPC header encoding path.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index b24d6c7..e3981e1 100644 (file)
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -894,7 +894,6 @@ struct auth_ops svcauth_tls = {
 static int
 svcauth_unix_accept(struct svc_rqst *rqstp)
 {
-       struct kvec     *resv = &rqstp->rq_res.head[0];
        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
        struct svc_cred *cred = &rqstp->rq_cred;
        struct user_namespace *userns;
@@ -956,12 +955,12 @@ svcauth_unix_accept(struct svc_rqst *rqstp)
                return SVC_DENIED;
        }
 
-       /* Put NULL verifier */
-       svc_putnl(resv, RPC_AUTH_NULL);
-       svc_putnl(resv, 0);
+       svcxdr_init_encode(rqstp);
+       if (xdr_stream_encode_opaque_auth(&rqstp->rq_res_stream,
+                                         RPC_AUTH_NULL, NULL, 0) < 0)
+               return SVC_CLOSE;
 
        rqstp->rq_cred.cr_flavor = RPC_AUTH_UNIX;
-       svcxdr_init_encode(rqstp);
        return SVC_OK;
 
 badcred: