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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
index 0a04468..49bae3d 100644 (file)
--- a/net/sched/em_meta.c
+++ b/net/sched/em_meta.c
@@ -311,12 +311,15 @@ 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 {
@@ -324,7 +327,7 @@ META_COLLECTOR(var_sk_bound_if)
 
                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();
        }