From 8742f229b635bf1c1c84a3dfe5e47c814c20b5c8 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Thu, 8 Aug 2013 18:55:32 +0200
Subject: userns: limit the maximum depth of user_namespace->parent chain

Ensure that user_namespace->parent chain can't grow too much.
Currently we use the hardroded 32 as limit.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/user_namespace.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'include/linux/user_namespace.h')

diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index b6b215f13b45..14105c26a836 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -23,6 +23,7 @@ struct user_namespace {
 	struct uid_gid_map	projid_map;
 	atomic_t		count;
 	struct user_namespace	*parent;
+	int			level;
 	kuid_t			owner;
 	kgid_t			group;
 	unsigned int		proc_inum;
-- 
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