tcp: Fix data-races around sysctl_tcp_syncookies.

[linux-2.6-microblaze.git] / net / ipv4 / syncookies.c

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index b387c48..9b234b4 100644 (file)
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -340,7 +340,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
        struct flowi4 fl4;
        u32 tsoff = 0;
 
-       if (!sock_net(sk)->ipv4.sysctl_tcp_syncookies || !th->ack || th->rst)
+       if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
+           !th->ack || th->rst)
                goto out;
 
        if (tcp_synq_no_recent_overflow(sk))