net_sched: em_meta: add READ_ONCE() in var_sk_bound_if()

sk->sk_bound_dev_if can change under us, use READ_ONCE() annotation. Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
wafgo · May 16, 2022 · 70f87de · 70f87de
1 parent d2c1356
commit 70f87de
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
@@ -311,20 +311,23 @@ META_COLLECTOR(int_sk_bound_if)
 
 META_COLLECTOR(var_sk_bound_if)
 {
+	int bound_dev_if;
+
 	if (skip_nonlocal(skb)) {
 		*err = -1;
 		return;
 	}
 
-	if (skb->sk->sk_bound_dev_if == 0) {
+	bound_dev_if = READ_ONCE(skb->sk->sk_bound_dev_if);
+	if (bound_dev_if == 0) {
 		dst->value = (unsigned long) "any";
 		dst->len = 3;
 	} else {
 		struct net_device *dev;
 
 		rcu_read_lock();
 		dev = dev_get_by_index_rcu(sock_net(skb->sk),
-					   skb->sk->sk_bound_dev_if);
+					   bound_dev_if);
 		*err = var_dev(dev, dst);
 		rcu_read_unlock();
 	}