Fix panic when we attempt to mess with "." but have a flags mismatch

so unveil_check_final returns an error - in this case we can't
just VOP_UNLOCK the parent we have to know we are dealing with "."
found by anton@ - thanks

diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c
index efda601..5a93a8b 100644 (file)
--- a/sys/kern/vfs_lookup.c
+++ b/sys/kern/vfs_lookup.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vfs_lookup.c,v 1.72 2018/07/30 00:16:59 beck Exp $    */
+/*     $OpenBSD: vfs_lookup.c,v 1.73 2018/08/02 04:41:47 beck Exp $    */
 /*     $NetBSD: vfs_lookup.c,v 1.17 1996/02/09 19:00:59 christos Exp $ */
 
 /*
@@ -227,7 +227,8 @@ fail:
                        if ((error = unveil_check_final(p, ndp))) {
                                pool_put(&namei_pool, cnp->cn_pnbuf);
                                if ((cnp->cn_flags & LOCKPARENT) &&
-                                   (cnp->cn_flags & ISLASTCN))
+                                   (cnp->cn_flags & ISLASTCN) &&
+                                   (ndp->ni_vp != ndp->ni_dvp))
                                        VOP_UNLOCK(ndp->ni_dvp);
                                if (ndp->ni_vp) {
                                        if ((cnp->cn_flags & LOCKLEAF))