[IPSEC]: Move state lock into x->type->input

This patch releases the lock on the state before calling
x->type->input.  It also adds the lock to the spots where they're
currently needed.

Most of those places (all except mip6) are expected to disappear with
async crypto.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index a989d29..d76803a 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -169,6 +169,8 @@
 		if (ip_clear_mutable_options(iph, &dummy))
 			goto out;
 	}
+
+	spin_lock(&x->lock);
 	{
 		u8 auth_data[MAX_AH_AUTH_LEN];
 
@@ -176,12 +178,16 @@
 		skb_push(skb, ihl);
 		err = ah_mac_digest(ahp, skb, ah->auth_data);
 		if (err)
-			goto out;
-		if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len)) {
+			goto unlock;
+		if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len))
 			err = -EBADMSG;
-			goto out;
-		}
 	}
+unlock:
+	spin_unlock(&x->lock);
+
+	if (err)
+		goto out;
+
 	skb->network_header += ah_hlen;
 	memcpy(skb_network_header(skb), work_buf, ihl);
 	skb->transport_header = skb->network_header;