diff --git a/ChangeLog b/ChangeLog
index 3f0471d70..a06554857 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -17,6 +17,10 @@
      > fix bz#1948: ssh -f doesn't fork for multiplexed connection.
      > ok dtucker@
      it interacts badly with ControlPersist
+   - djm@cvs.openbsd.org 2011/12/07 05:44:38
+     [auth2.c dh.c packet.c roaming.h roaming_client.c roaming_common.c]
+     fix some harmless and/or unreachable int overflows;
+     reported Xi Wang, ok markus@
 
 20111125
  - OpenBSD CVS Sync
diff --git a/auth2.c b/auth2.c
index c06c95f06..b66bef64c 100644
--- a/auth2.c
+++ b/auth2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2.c,v 1.123 2011/03/10 02:52:57 djm Exp $ */
+/* $OpenBSD: auth2.c,v 1.124 2011/12/07 05:44:38 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -113,7 +113,7 @@ auth2_read_banner(void)
 		close(fd);
 		return (NULL);
 	}
-	if (st.st_size > 1*1024*1024) {
+	if (st.st_size <= 0 || st.st_size > 1*1024*1024) {
 		close(fd);
 		return (NULL);
 	}
diff --git a/dh.c b/dh.c
index b9029d867..d943ca1e1 100644
--- a/dh.c
+++ b/dh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh.c,v 1.48 2009/10/01 11:37:33 grunk Exp $ */
+/* $OpenBSD: dh.c,v 1.49 2011/12/07 05:44:38 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  *
@@ -236,6 +236,8 @@ dh_gen_key(DH *dh, int need)
 {
 	int i, bits_set, tries = 0;
 
+	if (need < 0)
+		fatal("dh_gen_key: need < 0");
 	if (dh->p == NULL)
 		fatal("dh_gen_key: dh->p == NULL");
 	if (need > INT_MAX / 2 || 2 * need >= BN_num_bits(dh->p))
diff --git a/packet.c b/packet.c
index ba9341731..5e82fe753 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.173 2011/05/06 21:14:05 djm Exp $ */
+/* $OpenBSD: packet.c,v 1.174 2011/12/07 05:44:38 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -242,7 +242,7 @@ packet_set_connection(int fd_in, int fd_out)
 void
 packet_set_timeout(int timeout, int count)
 {
-	if (timeout == 0 || count == 0) {
+	if (timeout <= 0 || count <= 0) {
 		active_state->packet_timeout_ms = -1;
 		return;
 	}
diff --git a/roaming.h b/roaming.h
index 6bb94cc39..da069f878 100644
--- a/roaming.h
+++ b/roaming.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: roaming.h,v 1.5 2009/10/24 11:11:58 andreas Exp $ */
+/* $OpenBSD: roaming.h,v 1.6 2011/12/07 05:44:38 djm Exp $ */
 /*
  * Copyright (c) 2004-2009 AppGate Network Security AB
  *
@@ -18,8 +18,9 @@
 #ifndef ROAMING_H
 #define ROAMING_H
 
-#define DEFAULT_ROAMBUF 65536
-#define ROAMING_REQUEST "roaming@appgate.com"
+#define DEFAULT_ROAMBUF	65536
+#define MAX_ROAMBUF	(2*1024*1024) /* XXX arbitrary */
+#define ROAMING_REQUEST	"roaming@appgate.com"
 
 extern int roaming_enabled;
 extern int resume_in_progress;
diff --git a/roaming_client.c b/roaming_client.c
index cea8e7360..48009d781 100644
--- a/roaming_client.c
+++ b/roaming_client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: roaming_client.c,v 1.3 2010/01/18 01:50:27 dtucker Exp $ */
+/* $OpenBSD: roaming_client.c,v 1.4 2011/12/07 05:44:38 djm Exp $ */
 /*
  * Copyright (c) 2004-2009 AppGate Network Security AB
  *
@@ -72,7 +72,7 @@ roaming_reply(int type, u_int32_t seq, void *ctxt)
 	cookie = packet_get_int64();
 	key1 = oldkey1 = packet_get_int64();
 	key2 = oldkey2 = packet_get_int64();
-	set_out_buffer_size(packet_get_int() +  get_snd_buf_size());
+	set_out_buffer_size(packet_get_int() + get_snd_buf_size());
 	roaming_enabled = 1;
 }
 
diff --git a/roaming_common.c b/roaming_common.c
index 9adbe56fc..8d0b6054a 100644
--- a/roaming_common.c
+++ b/roaming_common.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: roaming_common.c,v 1.8 2010/01/12 00:59:29 djm Exp $ */
+/* $OpenBSD: roaming_common.c,v 1.9 2011/12/07 05:44:38 djm Exp $ */
 /*
  * Copyright (c) 2004-2009 AppGate Network Security AB
  *
@@ -75,6 +75,8 @@ get_recv_buf_size()
 void
 set_out_buffer_size(size_t size)
 {
+	if (size == 0 || size > MAX_ROAMBUF)
+		fatal("%s: bad buffer size %lu", __func__, (u_long)size);
 	/*
 	 * The buffer size can only be set once and the buffer will live
 	 * as long as the session lives.