Index: sys/compat/linux/linux_socket.c
===================================================================
--- sys/compat/linux/linux_socket.c	(revision 225884)
+++ sys/compat/linux/linux_socket.c	(working copy)
@@ -96,14 +96,13 @@ static int
 do_sa_get(struct sockaddr **sap, const struct osockaddr *osa, int *osalen,
     struct malloc_type *mtype)
 {
-	int error=0, bdom;
 	struct sockaddr *sa;
 	struct osockaddr *kosa;
-	int alloclen;
 #ifdef INET6
+	struct sockaddr_in6 *sin6;
 	int oldv6size;
-	struct sockaddr_in6 *sin6;
 #endif
+	int alloclen, bdom, error, hdrlen, pathlen;
 
 	if (*osalen < 2 || *osalen > UCHAR_MAX || !osa)
 		return (EINVAL);
@@ -133,6 +132,17 @@ do_sa_get(struct sockaddr **sap, const struct osoc
 		goto out;
 	}
 
+	if (bdom == AF_LOCAL) {
+		hdrlen = offsetof(struct sockaddr_un, sun_path);
+		if (alloclen > hdrlen) {
+			pathlen = sizeof(struct sockaddr_un) - hdrlen;
+			alloclen = strnlen(kosa->sa_data, pathlen);
+			if (alloclen == pathlen)
+				log(LOG_DEBUG, "long sockaddr_un truncated\n");
+			alloclen += hdrlen;
+		}
+	}
+
 #ifdef INET6
 	/*
 	 * Older Linux IPv6 code uses obsolete RFC2133 struct sockaddr_in6,
@@ -696,13 +706,26 @@ static int
 linux_bind(struct thread *td, struct linux_bind_args *args)
 {
 	struct sockaddr *sa;
-	int error;
+	int error, pathlen;
 
 	error = linux_getsockaddr(&sa, PTRIN(args->name),
 	    args->namelen);
 	if (error)
 		return (error);
 
+	/*
+	 * XXX Anonymous Unix domain socket not supported.
+	 */
+	if (sa->sa_family == AF_LOCAL) {
+		pathlen = sa->sa_len - offsetof(struct sockaddr_un, sun_path);
+		if (pathlen <= 0) {
+			free(sa, M_SONAME);
+			if (pathlen == 0)
+				return (0);
+			return (EINVAL);
+		}
+	}
+
 	error = kern_bind(td, args->s, sa);
 	free(sa, M_SONAME);
 	if (error == EADDRNOTAVAIL && args->namelen != sizeof(struct sockaddr_in))
@@ -723,13 +746,26 @@ linux_connect(struct thread *td, struct linux_conn
 	struct socket *so;
 	struct sockaddr *sa;
 	u_int fflag;
-	int error;
+	int error, pathlen;
 
 	error = linux_getsockaddr(&sa, (struct osockaddr *)PTRIN(args->name),
 	    args->namelen);
 	if (error)
 		return (error);
 
+	/*
+	 * XXX Anonymous Unix domain socket not supported.
+	 */
+	if (sa->sa_family == AF_LOCAL) {
+		pathlen = sa->sa_len - offsetof(struct sockaddr_un, sun_path);
+		if (pathlen <= 0) {
+			free(sa, M_SONAME);
+			if (pathlen == 0)
+				return (ENOENT);
+			return (EINVAL);
+		}
+	}
+
 	error = kern_connect(td, args->s, sa);
 	free(sa, M_SONAME);
 	if (error != EISCONN)
Index: sys/conf/files
===================================================================
--- sys/conf/files	(revision 225884)
+++ sys/conf/files	(working copy)
@@ -2548,6 +2548,7 @@ libkern/strlcpy.c		standard
 libkern/strlen.c		standard
 libkern/strncmp.c		standard
 libkern/strncpy.c		standard
+libkern/strnlen.c		standard
 libkern/strsep.c		standard
 libkern/strspn.c		standard
 libkern/strstr.c		standard
Index: sys/libkern/strnlen.c
===================================================================
--- sys/libkern/strnlen.c	(revision 225884)
+++ sys/libkern/strnlen.c	(working copy)
@@ -0,0 +1,42 @@
+/*-
+ * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/libkern.h>
+
+size_t
+strnlen(const char *s, size_t maxlen)
+{
+	size_t len;
+
+	for (len = 0; len < maxlen; len++, s++) {
+		if (!*s)
+			break;
+	}
+	return (len);
+}
Index: sys/sys/libkern.h
===================================================================
--- sys/sys/libkern.h	(revision 225884)
+++ sys/sys/libkern.h	(working copy)
@@ -116,6 +116,7 @@ size_t	 strlen(const char *);
 int	 strncasecmp(const char *, const char *, size_t);
 int	 strncmp(const char *, const char *, size_t);
 char	*strncpy(char * __restrict, const char * __restrict, size_t);
+size_t	 strnlen(const char *, size_t);
 char	*strsep(char **, const char *delim);
 size_t	 strspn(const char *, const char *);
 char	*strstr(const char *, const char *);