From b515498f5bb5f38fc0e390b4ff7d00b6077de127 Mon Sep 17 00:00:00 2001
From: "Serge E. Hallyn" <serge@hallyn.com>
Date: Wed, 23 Mar 2011 16:43:23 -0700
Subject: userns: add a user namespace owner of ipc ns

Changelog:
	Feb 15: Don't set new ipc->user_ns if we didn't create a new
		ipc_ns.
	Feb 23: Move extern declaration to ipc_namespace.h, and group
		fwd declarations at top.

Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 ipc/msgutil.c   | 1 +
 ipc/namespace.c | 9 +++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

(limited to 'ipc')

diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index f095ee268833..8b5ce5d3f3ef 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -32,6 +32,7 @@ struct ipc_namespace init_ipc_ns = {
 	.mq_msg_max      = DFLT_MSGMAX,
 	.mq_msgsize_max  = DFLT_MSGSIZEMAX,
 #endif
+	.user_ns = &init_user_ns,
 };
 
 atomic_t nr_ipc_ns = ATOMIC_INIT(1);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index a1094ff0befa..aa1889962693 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -11,10 +11,11 @@
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/mount.h>
+#include <linux/user_namespace.h>
 
 #include "util.h"
 
-static struct ipc_namespace *create_ipc_ns(void)
+static struct ipc_namespace *create_ipc_ns(struct ipc_namespace *old_ns)
 {
 	struct ipc_namespace *ns;
 	int err;
@@ -43,6 +44,9 @@ static struct ipc_namespace *create_ipc_ns(void)
 	ipcns_notify(IPCNS_CREATED);
 	register_ipcns_notifier(ns);
 
+	ns->user_ns = old_ns->user_ns;
+	get_user_ns(ns->user_ns);
+
 	return ns;
 }
 
@@ -50,7 +54,7 @@ struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
 {
 	if (!(flags & CLONE_NEWIPC))
 		return get_ipc_ns(ns);
-	return create_ipc_ns();
+	return create_ipc_ns(ns);
 }
 
 /*
@@ -105,6 +109,7 @@ static void free_ipc_ns(struct ipc_namespace *ns)
 	 * order to have a correct value when recomputing msgmni.
 	 */
 	ipcns_notify(IPCNS_REMOVED);
+	put_user_ns(ns->user_ns);
 }
 
 /*
-- 
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