net: bridge: add compile-time assert for cb struct size

make build fail if structure no longer fits into ->cb storage.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br.c b/net/bridge/br.c
index fb57ab6..02c24cf 100644 (file)
--- a/net/bridge/br.c
+++ b/net/bridge/br.c
@@ -190,6 +190,8 @@ static int __init br_init(void)
 {
        int err;
 
+       BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
+
        err = stp_proto_register(&br_stp_proto);
        if (err < 0) {
                pr_err("bridge: can't register sap for STP\n");