[3.19.y-ckt stable] Patch "fou: clean up socket with kfree_rcu" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    fou: clean up socket with kfree_rcu

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt13.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From be98a7b2442241b9747ba493fc3a418d4cd6da7f Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes at stressinduktion.org>
Date: Tue, 15 Dec 2015 21:01:53 +0100
Subject: fou: clean up socket with kfree_rcu

[ Upstream commit 3036facbb7be3a169e35be3b271162b0fa564a2d ]

fou->udp_offloads is managed by RCU. As it is actually included inside
the fou sockets, we cannot let the memory go out of scope before a grace
period. We either can synchronize_rcu or switch over to kfree_rcu to
manage the sockets. kfree_rcu seems appropriate as it is used by vxlan
and geneve.

Fixes: 23461551c00628c ("fou: Support for foo-over-udp RX path")
Cc: Tom Herbert <tom at herbertland.com>
Signed-off-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv4/fou.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index b986298..970718e 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -25,6 +25,7 @@ struct fou {
 	u16 port;
 	struct udp_offload udp_offloads;
 	struct list_head list;
+	struct rcu_head rcu;
 };

 struct fou_cfg {
@@ -418,7 +419,7 @@ static void fou_release(struct fou *fou)

 	sock_release(sock);

-	kfree(fou);
+	kfree_rcu(fou, rcu);
 }

 static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
--
1.9.1