Index: sys/kern/uipc_mqueue.c
===================================================================
--- sys/kern/uipc_mqueue.c
+++ sys/kern/uipc_mqueue.c
@@ -869,7 +869,7 @@
 	if (dvp->v_type != VDIR)
 		return (ENOTDIR);
 
-	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
+	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
 	if (error)
 		return (error);
 
Index: sys/kern/vfs_lookup.c
===================================================================
--- sys/kern/vfs_lookup.c
+++ sys/kern/vfs_lookup.c
@@ -317,6 +317,7 @@
 	cnp = &ndp->ni_cnd;
 	td = cnp->cn_thread;
 	p = td->td_proc;
+	ASSERT_CN_THREAD(&ndp->ni_cnd);
 	ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_thread->td_ucred;
 	KASSERT(cnp->cn_cred && p, ("namei: bad cred/proc"));
 	KASSERT((cnp->cn_nameiop & (~OPMASK)) == 0,
@@ -385,8 +386,7 @@
 	ndp->ni_loopcnt = 0;
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_NAMEI)) {
-		KASSERT(cnp->cn_thread == curthread,
-		    ("namei not using curthread"));
+		ASSERT_CN_THREAD(cnp);
 		ktrnamei(cnp->cn_pnbuf);
 	}
 #endif
@@ -895,6 +895,7 @@
 unionlookup:
 #ifdef MAC
 	if ((cnp->cn_flags & NOMACCHECK) == 0) {
+		ASSERT_CN_THREAD(cnp);
 		error = mac_vnode_check_lookup(cnp->cn_thread->td_ucred, dp,
 		    cnp);
 		if (error)
Index: sys/kern/vfs_subr.c
===================================================================
--- sys/kern/vfs_subr.c
+++ sys/kern/vfs_subr.c
@@ -4632,7 +4632,16 @@
 	if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
 		vfs_badlock("is not exclusive locked but should be", str, vp);
 }
+
 #endif /* DEBUG_VFS_LOCKS */
+
+void
+assert_cn_thread(struct componentname *cnp)
+{
+
+	KASSERT(cnp->cn_thread == curthread,
+	    ("cn_thread %p != curthread %p", cnp->cn_thread, curthread));
+}
 
 void
 vop_rename_fail(struct vop_rename_args *ap)