kernel: backport fix for initializing skb->cb in the bridge code to 5.4

This commit is contained in:
lean 2022-03-16 01:40:05 +08:00
parent 3bd126860b
commit a96390e2e7
2 changed files with 30 additions and 2 deletions

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@ -0,0 +1,28 @@
From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Fri, 31 Jul 2020 19:26:16 +0300
Subject: [PATCH] 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: 821f1b21cabb ("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>
---
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -36,6 +36,8 @@ 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)) {

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@ -20,7 +20,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
#include <linux/uaccess.h>
#include "br_private.h"
@@ -382,6 +386,28 @@ static const struct ethtool_ops br_ethto
@@ -384,6 +388,28 @@ static const struct ethtool_ops br_ethto
.get_link = ethtool_op_get_link,
};
@ -49,7 +49,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
static const struct net_device_ops br_netdev_ops = {
.ndo_open = br_dev_open,
.ndo_stop = br_dev_stop,
@@ -410,6 +436,9 @@ static const struct net_device_ops br_ne
@@ -412,6 +438,9 @@ static const struct net_device_ops br_ne
.ndo_bridge_setlink = br_setlink,
.ndo_bridge_dellink = br_dellink,
.ndo_features_check = passthru_features_check,