This is a note to let you know that I've just added the patch titled net: bridge: clear bridge's private skb space on xmit to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-bridge-clear-bridge-s-private-skb-space-on-xmit.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fd65e5a95d08389444e8591a20538b3edece0e15 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx> Date: Fri, 31 Jul 2020 19:26:16 +0300 Subject: net: bridge: clear bridge's private skb space on xmit From: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx> commit fd65e5a95d08389444e8591a20538b3edece0e15 upstream. 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 <nikolay@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Huang Guobin <huangguobin4@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/bridge/br_device.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -42,6 +42,8 @@ netdev_tx_t br_dev_xmit(struct sk_buff * struct ethhdr *eth; 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)) { Patches currently in stable-queue which might be from nikolay@xxxxxxxxxxxxxxxxxxx are queue-4.19/net-bridge-clear-bridge-s-private-skb-space-on-xmit.patch