[3.16.y-ckt stable] Patch "net: ip6mr: fix static mfc/dev leaks on table destruction" has been added to staging queue

[Luis Henriques]

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

    net: ip6mr: fix static mfc/dev leaks on table destruction

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt22.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 658438d663b3aff1a6f841aae9e0de2d783b2fa8 Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Date: Fri, 20 Nov 2015 13:54:20 +0100
Subject: net: ip6mr: fix static mfc/dev leaks on table destruction

commit 4c6980462f32b4f282c5d8e5f7ea8070e2937725 upstream.

Similar to ipv4, when destroying an mrt table the static mfc entries and
the static devices are kept, which leads to devices that can never be
destroyed (because of refcnt taken) and leaked memory. Make sure that
everything is cleaned up on netns destruction.

Fixes: 8229efdaef1e ("netns: ip6mr: enable namespace support in ipv6 multicast forwarding code")
CC: Benjamin Thery <benjamin.thery at bull.net>
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Reviewed-by: Cong Wang <cwang at twopensource.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv6/ip6mr.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 77eede59b617..72f3baee76d9 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -120,7 +120,7 @@ static void mr6_netlink_event(struct mr6_table *mrt, struct mfc6_cache *mfc,
 			      int cmd);
 static int ip6mr_rtm_dumproute(struct sk_buff *skb,
 			       struct netlink_callback *cb);
-static void mroute_clean_tables(struct mr6_table *mrt);
+static void mroute_clean_tables(struct mr6_table *mrt, bool all);
 static void ipmr_expire_process(unsigned long arg);

 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
@@ -337,7 +337,7 @@ static struct mr6_table *ip6mr_new_table(struct net *net, u32 id)
 static void ip6mr_free_table(struct mr6_table *mrt)
 {
 	del_timer(&mrt->ipmr_expire_timer);
-	mroute_clean_tables(mrt);
+	mroute_clean_tables(mrt, true);
 	kfree(mrt);
 }

@@ -1536,7 +1536,7 @@ static int ip6mr_mfc_add(struct net *net, struct mr6_table *mrt,
  *	Close the multicast socket, and clear the vif tables etc
  */

-static void mroute_clean_tables(struct mr6_table *mrt)
+static void mroute_clean_tables(struct mr6_table *mrt, bool all)
 {
 	int i;
 	LIST_HEAD(list);
@@ -1546,8 +1546,9 @@ static void mroute_clean_tables(struct mr6_table *mrt)
 	 *	Shut down all active vif entries
 	 */
 	for (i = 0; i < mrt->maxvif; i++) {
-		if (!(mrt->vif6_table[i].flags & VIFF_STATIC))
-			mif6_delete(mrt, i, &list);
+		if (!all && (mrt->vif6_table[i].flags & VIFF_STATIC))
+			continue;
+		mif6_delete(mrt, i, &list);
 	}
 	unregister_netdevice_many(&list);

@@ -1556,7 +1557,7 @@ static void mroute_clean_tables(struct mr6_table *mrt)
 	 */
 	for (i = 0; i < MFC6_LINES; i++) {
 		list_for_each_entry_safe(c, next, &mrt->mfc6_cache_array[i], list) {
-			if (c->mfc_flags & MFC_STATIC)
+			if (!all && (c->mfc_flags & MFC_STATIC))
 				continue;
 			write_lock_bh(&mrt_lock);
 			list_del(&c->list);
@@ -1619,7 +1620,7 @@ int ip6mr_sk_done(struct sock *sk)
 						     net->ipv6.devconf_all);
 			write_unlock_bh(&mrt_lock);

-			mroute_clean_tables(mrt);
+			mroute_clean_tables(mrt, false);
 			err = 0;
 			break;
 		}