diff options
| author | Nikolay Aleksandrov <nikolay@cumulusnetworks.com> | 2020-02-24 19:46:22 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-24 22:11:19 +0300 |
| commit | 823d81b0fa2cd83a640734e74caee338b5d3c093 (patch) | |
| tree | ca6ce51db8e585d6cb80c1bfe3f1358f64cc5237 /net | |
| parent | e4686c2d08ea1a45c262af5269c2aa6b977b85e2 (diff) | |
| download | linux-823d81b0fa2cd83a640734e74caee338b5d3c093.tar.xz | |
net: bridge: fix stale eth hdr pointer in br_dev_xmit
In br_dev_xmit() we perform vlan filtering in br_allowed_ingress() but
if the packet has the vlan header inside (e.g. bridge with disabled
tx-vlan-offload) then the vlan filtering code will use skb_vlan_untag()
to extract the vid before filtering which in turn calls pskb_may_pull()
and we may end up with a stale eth pointer. Moreover the cached eth header
pointer will generally be wrong after that operation. Remove the eth header
caching and just use eth_hdr() directly, the compiler does the right thing
and calculates it only once so we don't lose anything.
Fixes: 057658cb33fb ("bridge: suppress arp pkts on BR_NEIGH_SUPPRESS ports")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bridge/br_device.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index dc3d2c1dd9d5..0e3dbc5f3c34 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -34,7 +34,6 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) const struct nf_br_ops *nf_ops; u8 state = BR_STATE_FORWARDING; const unsigned char *dest; - struct ethhdr *eth; u16 vid = 0; rcu_read_lock(); @@ -54,15 +53,14 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) BR_INPUT_SKB_CB(skb)->frag_max_size = 0; skb_reset_mac_header(skb); - eth = eth_hdr(skb); skb_pull(skb, ETH_HLEN); if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid, &state)) goto out; if (IS_ENABLED(CONFIG_INET) && - (eth->h_proto == htons(ETH_P_ARP) || - eth->h_proto == htons(ETH_P_RARP)) && + (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) || + eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) && br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) { br_do_proxy_suppress_arp(skb, br, vid, NULL); } else if (IS_ENABLED(CONFIG_IPV6) && |