From cab0936aac8aa907c6bb814c2cf26385478f254b Mon Sep 17 00:00:00 2001
From: Ian Kent <raven@themaw.net>
Date: Thu, 1 May 2008 04:35:07 -0700
Subject: [PATCH] autofs4: check for invalid dentry in getpath

Catch invalid dentry when calculating its path.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/autofs4/waitq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 1fe28e4754..75e5955c3f 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -171,7 +171,7 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
 	for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
 		len += tmp->d_name.len + 1;
 
-	if (--len > NAME_MAX) {
+	if (!len || --len > NAME_MAX) {
 		spin_unlock(&dcache_lock);
 		return 0;
 	}
-- 
2.39.5