commit aadc42fe5b33eda0b42c8bcdf65f3e9644af8982
Author: Mikolaj Golub <trociny@freebsd.org>
Date:   Sat Feb 18 21:17:35 2012 +0200

    unp_connect() may use a shared lock on the vnode to fetch the socket.
    
    Suggested by:	jhb
    Reviewed by:	jhb, kib, rwatson

diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index 0504d63..5eb3066 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1273,8 +1273,8 @@ unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	UNP_PCB_UNLOCK(unp);
 
 	sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
-	NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf,
-	    td);
+	NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKSHARED | LOCKLEAF,
+	    UIO_SYSSPACE, buf, td);
 	error = namei(&nd);
 	if (error)
 		vp = NULL;