[PATCH 4.4 099/158] net: bridge: stp: dont cache eth dest pointer before skb pull

Greg Kroah-Hartman
2019-08-02T09:39:24Z

From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

[ Upstream commit 2446a68ae6a8cee6d480e2f5b52f5007c7c41312 ]

Don't cache eth dest pointer before calling pskb_may_pull.

Fixes: cf0f02d04a83 ("[BRIDGE]: use llc for receiving STP packets")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/br_stp_bpdu.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -147,7 +147,6 @@ void br_send_tcn_bpdu(struct net_bridge_
void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
struct net_device *dev)
{
- const unsigned char *dest = eth_hdr(skb)->h_dest;
struct net_bridge_port *p;
struct net_bridge *br;
const unsigned char *buf;
@@ -176,7 +175,7 @@ void br_stp_rcv(const struct stp_proto *
if (p->state == BR_STATE_DISABLED)
goto out;

- if (!ether_addr_equal(dest, br->group_addr))
+ if (!ether_addr_equal(eth_hdr(skb)->h_dest, br->group_addr))
goto out;

if (p->flags & BR_BPDU_GUARD) {