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===================================================================
RCS file: /ftp/cvs/cvsroot/src/sys/netinet/udp_usrreq.c,v
retrieving revision 1.169
retrieving revision 1.170
diff -u -p -r1.169 -r1.170
--- src/sys/netinet/udp_usrreq.c	2008/04/23 06:09:05	1.169
+++ src/sys/netinet/udp_usrreq.c	2008/04/24 11:38:38	1.170
@@ -1,4 +1,4 @@
-/*	$NetBSD: udp_usrreq.c,v 1.169 2008/04/23 06:09:05 thorpej Exp $	*/
+/*	$NetBSD: udp_usrreq.c,v 1.170 2008/04/24 11:38:38 ad Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.169 2008/04/23 06:09:05 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.170 2008/04/24 11:38:38 ad Exp $");
 
 #include "opt_inet.h"
 #include "opt_ipsec.h"
@@ -1181,9 +1181,11 @@ udp_usrreq(struct socket *so, int req, s
 	s = splsoftnet();
 
 	if (req == PRU_PURGEIF) {
+		mutex_enter(softnet_lock);
 		in_pcbpurgeif0(&udbtable, (struct ifnet *)control);
 		in_purgeif((struct ifnet *)control);
 		in_pcbpurgeif(&udbtable, (struct ifnet *)control);
+		mutex_exit(softnet_lock);
 		splx(s);
 		return (0);
 	}
@@ -1193,7 +1195,9 @@ udp_usrreq(struct socket *so, int req, s
 	if (req != PRU_SEND && req != PRU_SENDOOB && control)
 		panic("udp_usrreq: unexpected control mbuf");
 #endif
-	if (inp == 0 && req != PRU_ATTACH) {
+	if (req == PRU_ATTACH) {
+		sosetlock(so);
+	} else if (inp == 0) {
 		error = EINVAL;
 		goto release;
 	}