diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 5af8800..e4086ec 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -171,7 +171,8 @@
 {
 	char *cp = (char *)p;
 	struct kvec *vec = &rqstp->rq_arg.head[0];
-	return cp - (char*)vec->iov_base <= vec->iov_len;
+	return cp >= (char*)vec->iov_base
+		&& cp <= (char*)vec->iov_base + vec->iov_len;
 }
 
 static inline int