[3.13.y-ckt stable] Patch "net/ipv6: Correct PIM6 mrt_lock handling" has been added to staging queue

[Kamal Mostafa]

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

    net/ipv6: Correct PIM6 mrt_lock handling

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt29.

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

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From f4eceb1655b688da4c86a2da734b9b0a854b5dc8 Mon Sep 17 00:00:00 2001
From: Richard Laing <richard.laing at alliedtelesis.co.nz>
Date: Thu, 3 Sep 2015 13:52:31 +1200
Subject: net/ipv6: Correct PIM6 mrt_lock handling

[ Upstream commit 25b4a44c19c83d98e8c0807a7ede07c1f28eab8b ]

In the IPv6 multicast routing code the mrt_lock was not being released
correctly in the MFC iterator, as a result adding or deleting a MIF would
cause a hang because the mrt_lock could not be acquired.

This fix is a copy of the code for the IPv4 case and ensures that the lock
is released correctly.

Signed-off-by: Richard Laing <richard.laing at alliedtelesis.co.nz>
Acked-by: Cong Wang <cwang at twopensource.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv6/ip6mr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 8737400..821d8df 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -552,7 +552,7 @@ static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)

 	if (it->cache == &mrt->mfc6_unres_queue)
 		spin_unlock_bh(&mfc_unres_lock);
-	else if (it->cache == mrt->mfc6_cache_array)
+	else if (it->cache == &mrt->mfc6_cache_array[it->ct])
 		read_unlock(&mrt_lock);
 }

--
1.9.1