diff -up openssh-5.5p1/channels.c.x11 openssh-5.5p1/channels.c

--- openssh-5.5p1/channels.c.x11	2010-06-30 15:22:45.000000000 +0200

+++ openssh-5.5p1/channels.c	2010-06-30 15:27:42.000000000 +0200

@@ -3332,7 +3332,7 @@ x11_create_display_inet(int x11_display_

 }

 static int

-connect_local_xsocket_path(const char *pathname)

+connect_local_xsocket_path(const char *pathname, int len)

 {

 	int sock;

 	struct sockaddr_un addr;

@@ -3342,7 +3342,11 @@ connect_local_xsocket_path(const char *p

 		error("socket: %.100s", strerror(errno));

 	memset(&addr, 0, sizeof(addr));

 	addr.sun_family = AF_UNIX;

-	strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);

+	if (len <= 0)

+		return -1;

+	if (len > sizeof addr.sun_path)

+		len = sizeof addr.sun_path;

+	memcpy(addr.sun_path, pathname , len);

 	if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)

 		return sock;

 	close(sock);

@@ -3354,8 +3358,18 @@ static int

 connect_local_xsocket(u_int dnr)

 {

 	char buf[1024];

-	snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);

-	return connect_local_xsocket_path(buf);

+	int len;

+#ifdef linux

+	int ret;

+#endif

+	len = snprintf(buf + 1, sizeof (buf) - 1, _PATH_UNIX_X, dnr);

+#ifdef linux

+	/* try abstract socket first */

+	buf[0] = '\0';

+	if ((ret = connect_local_xsocket_path(buf, len + 1)) >= 0)

+		return ret;

+#endif

+	return connect_local_xsocket_path(buf + 1, len);

 }

 int