[3.16.y-ckt stable] Patch "netfilter: nf_log: wait for rcu grace after logger unregistration" has been added to staging queue

[Kamal Mostafa]

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

    netfilter: nf_log: wait for rcu grace after logger unregistration

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 3.19.8-ckt9.

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.
-Kamal

------

>From 3b77298bc6f8aa584708334babbcb2eedeae00b6 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo at netfilter.org>
Date: Thu, 17 Sep 2015 13:37:00 +0200
Subject: netfilter: nf_log: wait for rcu grace after logger unregistration

commit ad5001cc7cdf9aaee5eb213fdee657e4a3c94776 upstream.

The nf_log_unregister() function needs to call synchronize_rcu() to make sure
that the objects are not dereferenced anymore on module removal.

Fixes: 5962815a6a56 ("netfilter: nf_log: use an array of loggers instead of list")
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/netfilter/nf_log.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 43c926c..7ea79a2 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -113,6 +113,7 @@ void nf_log_unregister(struct nf_logger *logger)
 	for (i = 0; i < NFPROTO_NUMPROTO; i++)
 		RCU_INIT_POINTER(loggers[i][logger->type], NULL);
 	mutex_unlock(&nf_log_mutex);
+	synchronize_rcu();
 }
 EXPORT_SYMBOL(nf_log_unregister);

--
1.9.1