diff options
| author | Kevin Cernekee <cernekee@chromium.org> | 2017-12-06 12:12:27 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-02 20:33:24 +0100 |
| commit | f778ce6faa0d4c8d7a90b7bd11c3db7fb687c8cc (patch) | |
| tree | 44932f0f08d80fa03ebd61c2e520cee8e43eb32a | |
| parent | 373b423038a873bee54c8f42375c4bc438e3059a (diff) | |
netlink: Add netns check on taps
[ 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>
| -rw-r--r-- | net/netlink/af_netlink.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 5fabe68e20dd..48e1608414e6 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -261,6 +261,9 @@ static int __netlink_deliver_tap_skb(struct sk_buff *skb, 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)) |