Commit fd65e5a9 authored Jul 31, 2020 by Nikolay Aleksandrov Committed by David S. Miller Aug 03, 2020

net: bridge: clear bridge's private skb space on xmit

We need to clear all of the bridge private skb variables as they can be
stale due to the packet being recirculated through the stack and then
transmitted through the bridge device. Similar memset is already done on
bridge's input. We've seen cases where proxyarp_replied was 1 on routed
multicast packets transmitted through the bridge to ports with neigh
suppress which were getting dropped. Same thing can in theory happen with
the port isolation bit as well.

Fixes: 821f1b21 ("bridge: add new BR_NEIGH_SUPPRESS port flag to suppress arp and nd flood")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent ae79dbf6

net/bridge/br_device.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,8 @@ netdev_tx_t br_dev_xmit(struct sk_buff skb, struct net_device dev)
		const unsigned char *dest;
		u16 vid = 0;

		memset(skb->cb, 0, sizeof(struct br_input_skb_cb));

		rcu_read_lock();
		nf_ops = rcu_dereference(nf_br_ops);
		if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {

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