Patch "netlink: ensure to loop over all netns in genlmsg_multicast_allns()" has been added to the 4.4-stable tree

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

netlink: ensure to loop over all netns in genlmsg_multicast_allns()

to the 4.4-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:
netlink-ensure-to-loop-over-all-netns-in-genlmsg_multicast_allns.patch
and it can be found in the queue-4.4 subdirectory.

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

From: Nicolas Dichtel <[email protected]>
Date: Tue, 6 Feb 2018 14:48:32 +0100
Subject: netlink: ensure to loop over all netns in genlmsg_multicast_allns()

From: Nicolas Dichtel <[email protected]>

[ Upstream commit cb9f7a9a5c96a773bbc9c70660dc600cfff82f82 ]

Nowadays, nlmsg_multicast() returns only 0 or -ESRCH but this was not the case when commit 134e63756d5f was pushed.
However, there was no reason to stop the loop if a netns does not have listeners.
Returns -ESRCH only if there was no listeners in all netns.

To avoid having the same problem in the future, I didn't take the assumption that nlmsg_multicast() returns only 0 or -ESRCH.

---
 net/netlink/genetlink.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

@@ -1118,6 +1118,7 @@ static int genlmsg_mcast(struct sk_buff
 {
 	struct sk_buff *tmp;
 	struct net *net, *prev = NULL;
+	bool delivered = false;
 	int err;
 
 	for_each_net_rcu(net) {

@@ -1129,14 +1130,21 @@ static int genlmsg_mcast(struct sk_buff
 			}
 			err = nlmsg_multicast(prev->genl_sock, tmp,
 					      portid, group, flags);
-			if (err)
+			if (!err)
+				delivered = true;
+			else if (err != -ESRCH)
 				goto error;
 		}
 
 		prev = net;
 	}
 
-	return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
+	err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
+	if (!err)
+		delivered = true;
+	else if (err != -ESRCH)
+		goto error;
+	return delivered ? 0 : -ESRCH;
  error:
 	kfree_skb(skb);
 	return err;

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

queue-4.4/netlink-ensure-to-loop-over-all-netns-in-genlmsg_multicast_allns.patch