Patch "ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock" has been added to the 4.9-stable tree

Patch "ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipv6-addrconf-avoid-addrconf_disable_change-using-rcu-read-side-lock.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Feb  1 08:50:24 CET 2017
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Date: Thu, 19 Jan 2017 16:26:21 +0800
Subject: ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock

From: Kefeng Wang <wangkefeng.wang@huawei.com>


[ Upstream commit 03e4deff4987f79c34112c5ba4eb195d4f9382b0 ]

Just like commit 4acd4945cd1e ("ipv6: addrconf: Avoid calling
netdevice notifiers with RCU read-side lock"), it is unnecessary
to make addrconf_disable_change() use RCU iteration over the
netdev list, since it already holds the RTNL lock, or we may meet
Illegal context switch in RCU read-side critical section.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv6/addrconf.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5515,8 +5515,7 @@ static void addrconf_disable_change(stru
 	struct net_device *dev;
 	struct inet6_dev *idev;
 
-	rcu_read_lock();
-	for_each_netdev_rcu(net, dev) {
+	for_each_netdev(net, dev) {
 		idev = __in6_dev_get(dev);
 		if (idev) {
 			int changed = (!idev->cnf.disable_ipv6) ^ (!newf);
@@ -5525,7 +5524,6 @@ static void addrconf_disable_change(stru
 				dev_disable_change(idev);
 		}
 	}
-	rcu_read_unlock();
 }
 
 static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)


Patches currently in stable-queue which might be from wangkefeng.wang@huawei.com are

queue-4.9/ipv6-addrconf-avoid-addrconf_disable_change-using-rcu-read-side-lock.patch