bridge: ignore bogus STP config packets
If the message_age is already greater than the max_age, then the
BPDU is bogus. Linux won't generate BPDU, but conformance tester
or buggy implementation might.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index 289646e..b69232b 100644
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -210,6 +210,17 @@
bpdu.hello_time = br_get_ticks(buf+28);
bpdu.forward_delay = br_get_ticks(buf+30);
+ if (bpdu.message_age > bpdu.max_age) {
+ if (net_ratelimit())
+ br_notice(p->br,
+ "port %u config from %pM"
+ " (message_age %ul > max_age %ul)\n",
+ p->port_no,
+ eth_hdr(skb)->h_source,
+ bpdu.message_age, bpdu.max_age);
+ goto out;
+ }
+
br_received_config_bpdu(p, &bpdu);
}