[PATCH 3.2 152/199] packet: call fanout_release, while UNREGISTERING a netdev

From: Ben Hutchings
Date: Fri Mar 10 2017 - 07:07:06 EST

3.2.87-rc1 review patch. If anyone has any objections, please let me know.


From: Anoob Soman <anoob.soman@xxxxxxxxxx>

commit 6664498280cf17a59c3e7cf1a931444c02633ed1 upstream.

If a socket has FANOUT sockopt set, a new proto_hook is registered
as part of fanout_add(). When processing a NETDEV_UNREGISTER event in
af_packet, __fanout_unlink is called for all sockets, but prot_hook which was
registered as part of fanout_add is not removed. Call fanout_release, on a
NETDEV_UNREGISTER, which removes prot_hook and removes fanout from the

This fixes BUG_ON(!list_empty(&dev->ptype_specific)) in netdev_run_todo()

Signed-off-by: Anoob Soman <anoob.soman@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
net/packet/af_packet.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3350,6 +3350,7 @@ static int packet_notifier(struct notifi
+ fanout_release(sk);
po->ifindex = -1;
if (po->prot_hook.dev)