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authorKevin Cernekee <cernekee@chromium.org>2017-12-06 23:12:27 +0300
committerDavid S. Miller <davem@davemloft.net>2017-12-11 19:58:18 +0300
commit93c647643b48f0131f02e45da3bd367d80443291 (patch)
tree652bb87e4f4be4132684bbf24c6f1437a53119b3 /net
parent2aab6b40b03154a263463a5d992ddd7d122a016a (diff)
downloadlinux-93c647643b48f0131f02e45da3bd367d80443291.tar.xz
netlink: Add netns check on taps
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>
Diffstat (limited to 'net')
-rw-r--r--net/netlink/af_netlink.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index b9e0ee4e22f5..79cc1bf36e4a 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -253,6 +253,9 @@ 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))