NLM: Fix svcxdr_encode_owner()

Dai Ngo reports that, since the XDR overhaul, the NLM server crashes
when the TEST procedure wants to return NLM_DENIED. There is a bug
in svcxdr_encode_owner() that none of our standard test cases found.

Replace the open-coded function with a call to an appropriate
pre-fabricated XDR helper.

Reported-by: Dai Ngo <Dai.Ngo@oracle.com>
Fixes: 416b00459088 ("lockd: Common NLM XDR helpers")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/lockd/svcxdr.h b/fs/lockd/svcxdr.h
index c69a0bb76c940f400004bb660c2d94974628efc8..4f1a451da5ba23794903bb34697dfa9197993580 100644 (file)
--- a/fs/lockd/svcxdr.h
+++ b/fs/lockd/svcxdr.h
@@ -134,18 +134,9 @@ svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj)
 static inline bool
 svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj)
 {
-       unsigned int quadlen = XDR_QUADLEN(obj->len);
-       __be32 *p;
-
-       if (xdr_stream_encode_u32(xdr, obj->len) < 0)
-               return false;
-       p = xdr_reserve_space(xdr, obj->len);
-       if (!p)
+       if (obj->len > XDR_MAX_NETOBJ)
                return false;
-       p[quadlen - 1] = 0;     /* XDR pad */
-       memcpy(p, obj->data, obj->len);
-
-       return true;
+       return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0;
 }
 
 #endif /* _LOCKD_SVCXDR_H_ */