===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/server-client.c,v
retrieving revision 1.300
retrieving revision 1.301
diff -u -r1.300 -r1.301
--- src/usr.bin/tmux/server-client.c	2019/12/12 11:39:56	1.300
+++ src/usr.bin/tmux/server-client.c	2019/12/16 15:48:50	1.301
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.300 2019/12/12 11:39:56 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.301 2019/12/16 15:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2024,10 +2024,10 @@
 	struct msg_read_data	*msg = imsg->data;
 	size_t			 msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
 	struct client_file	 find, *cf;
-	void			*bdata = msg->data;
-	size_t			 bsize = msg->size;
+	void			*bdata = msg + 1;
+	size_t			 bsize = msglen - sizeof *msg;
 
-	if (msglen != sizeof *msg)
+	if (msglen < sizeof *msg)
 		fatalx("bad MSG_READ_DATA size");
 	find.stream = msg->stream;
 	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL)