Patch "ipv6: Don't call with rt6_uncached_list_flush_dev" has been added to the 4.2-stable tree

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

ipv6: Don't call with rt6_uncached_list_flush_dev

to the 4.2-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-don-t-call-with-rt6_uncached_list_flush_dev.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Eric W. Biederman" <[email protected]>
Date: Mon, 12 Oct 2015 11:02:08 -0500
Subject: ipv6: Don't call with rt6_uncached_list_flush_dev

From: "Eric W. Biederman" <[email protected]>

[ Upstream commit e332bc67cf5e5e5b71a1aec9750d0791aac65183 ]

As originally written rt6_uncached_list_flush_dev makes no sense when called with dev == NULL as it attempts to flush all uncached routes regardless of network namespace when dev == NULL. Which is simply incorrect behavior.

Furthermore at the point rt6_ifdown is called with dev == NULL no more network devices exist in the network namespace so even if the code in rt6_uncached_list_flush_dev were to attempt something sensible it would be meaningless.

Therefore remove support in rt6_uncached_list_flush_dev for handling network devices where dev == NULL, and only call rt6_uncached_list_flush_dev
when rt6_ifdown is called with a network device.

---
 net/ipv6/route.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

@@ -139,6 +139,9 @@ static void rt6_uncached_list_flush_dev(
 	struct net_device *loopback_dev = net->loopback_dev;
 	int cpu;
 
+	if (dev == loopback_dev)
+		return;
+
 	for_each_possible_cpu(cpu) {
 		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 		struct rt6_info *rt;

@@ -148,14 +151,12 @@ static void rt6_uncached_list_flush_dev(
 			struct inet6_dev *rt_idev = rt->rt6i_idev;
 			struct net_device *rt_dev = rt->dst.dev;
 
-			if (rt_idev && (rt_idev->dev == dev || !dev) &&
-			    rt_idev->dev != loopback_dev) {
+			if (rt_idev->dev == dev) {
 				rt->rt6i_idev = in6_dev_get(loopback_dev);
 				in6_dev_put(rt_idev);
 			}
 
-			if (rt_dev && (rt_dev == dev || !dev) &&
-			    rt_dev != loopback_dev) {
+			if (rt_dev == dev) {
 				rt->dst.dev = loopback_dev;
 				dev_hold(rt->dst.dev);
 				dev_put(rt_dev);

@@ -2577,7 +2578,8 @@ void rt6_ifdown(struct net *net, struct
 
 	fib6_clean_all(net, fib6_ifdown, &adn);
 	icmp6_clean_all(fib6_ifdown, &adn);
-	rt6_uncached_list_flush_dev(net, dev);
+	if (dev)
+		rt6_uncached_list_flush_dev(net, dev);
 }
 
 struct rt6_mtu_change_arg {

Patches currently in stable-queue which might be from [email protected] are

queue-4.2/ipv6-don-t-call-with-rt6_uncached_list_flush_dev.patch