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

netlink: Add netns check on taps

to the 4.4-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-add-netns-check-on-taps.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 stable@vger.kernel.org know about it.

From foo@baz Sun Dec 31 11:20:35 CET 2017

From: Kevin Cernekee cernekee@chromium.org Date: Wed, 6 Dec 2017 12:12:27 -0800 Subject: netlink: Add netns check on taps

From: Kevin Cernekee cernekee@chromium.org

[ Upstream commit 93c647643b48f0131f02e45da3bd367d80443291 ]

Currently, a nlmon link inside a child namespace can observe systemwide netlink activity. Filter the traffic so that nlmon can only sniff netlink messages from its own netns.

Test case:

vpnns -- bash -c "ip link add nlmon0 type nlmon; \ ip link set nlmon0 up; \ tcpdump -i nlmon0 -q -w /tmp/nlmon.pcap -U" & sudo ip xfrm state add src 10.1.1.1 dst 10.1.1.2 proto esp \ spi 0x1 mode transport \ auth sha1 0x6162633132330000000000000000000000000000 \ enc aes 0x00000000000000000000000000000000 grep --binary abc123 /tmp/nlmon.pcap

Signed-off-by: Kevin Cernekee cernekee@chromium.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/af_netlink.c | 3 +++ 1 file changed, 3 insertions(+)

--- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -261,6 +261,9 @@ static int __netlink_deliver_tap_skb(str struct sock *sk = skb->sk; int ret = -ENOMEM;

+ if (!net_eq(dev_net(dev), sock_net(sk))) + return 0; + dev_hold(dev);

if (is_vmalloc_addr(skb->head))

Patches currently in stable-queue which might be from cernekee@chromium.org are

queue-4.4/net-igmp-use-correct-source-address-on-igmpv3-reports.patch queue-4.4/netlink-add-netns-check-on-taps.patch