From 81e03f638dd47c27f06bbd85acb5869589db2364 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Fri, 31 Jul 2020 19:26:16 +0300 Subject: [PATCH] net: bridge: clear bridge's private skb space on xmit [ Upstream commit fd65e5a95d08389444e8591a20538b3edece0e15 ] 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: 821f1b21cabb ("bridge: add new BR_NEIGH_SUPPRESS port flag to suppress arp and nd flood") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/bridge/br_device.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index f085b1648e66..501f77f0f480 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -35,6 +35,8 @@ 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)) {