Make sure we don't count looking at .. as a component

as a descending match.
Noticed by Stuart Cassoff <3d0g@bell.net>

diff --git a/sys/kern/kern_unveil.c b/sys/kern/kern_unveil.c
index e906505..3d8ef46 100644 (file)
--- a/sys/kern/kern_unveil.c
+++ b/sys/kern/kern_unveil.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_unveil.c,v 1.4 2018/07/20 07:28:36 beck Exp $    */
+/*     $OpenBSD: kern_unveil.c,v 1.5 2018/07/29 22:53:39 beck Exp $    */
 
 /*
  * Copyright (c) 2017-2018 Bob Beck <beck@openbsd.org>
@@ -591,6 +591,7 @@ unveil_check_component(struct proc *p, struct nameidata *ni, struct vnode *dp )
 
        if (ni->ni_pledge != PLEDGE_UNVEIL) {
                if ((ni->ni_cnd.cn_flags & BYPASSUNVEIL) == 0 &&
+                   ! (ni->ni_cnd.cn_flags & ISDOTDOT) &&
                    (uv = unveil_lookup(dp, p)) != NULL) {
                        /* if directory flags match, it's a match */
                        if (unveil_flagmatch(ni, uv->uv_flags)) {