From: Daniel Lezcano <dlezcano@fr.ibm.com>
Date: Tue, 30 Oct 2007 22:38:57 +0000 (-0700)
Subject: [NETNS]: fix net released by rcu callback
X-Git-Tag: v3.12-rc1~24933^2~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=310928d9633b04866a47f07eb43c498b2d82ebcb;p=kernel%2Fkernel-generic.git

[NETNS]: fix net released by rcu callback

When a network namespace reference is held by a network subsystem,
and when this reference is decremented in a rcu update callback, we
must ensure that there is no more outstanding rcu update before
trying to free the network namespace.

In the normal case, the rcu_barrier is called when the network namespace
is exiting in the cleanup_net function.

But when a network namespace creation fails, and the subsystems are
undone (like the cleanup), the rcu_barrier is missing.

This patch adds the missing rcu_barrier.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 6f71db8..662e6ea 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -112,6 +112,8 @@ out_undo:
 		if (ops->exit)
 			ops->exit(net);
 	}
+
+	rcu_barrier();
 	goto out;
 }