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 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

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-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Mar 8 06:55:02 PST 2018

From: Nicolas Dichtel nicolas.dichtel@6wind.com Date: Tue, 6 Feb 2018 14:48:32 +0100 Subject: netlink: ensure to loop over all netns in genlmsg_multicast_allns()

From: Nicolas Dichtel nicolas.dichtel@6wind.com

[ 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.

Fixes: 134e63756d5f ("genetlink: make netns aware") CC: Johannes Berg johannes.berg@intel.com Signed-off-by: Nicolas Dichtel nicolas.dichtel@6wind.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/genetlink.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)

--- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1103,6 +1103,7 @@ 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) { @@ -1114,14 +1115,21 @@ 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 nicolas.dichtel@6wind.com are

queue-4.9/netlink-ensure-to-loop-over-all-netns-in-genlmsg_multicast_allns.patch