Re: [PATCH net] net/packet: fix a race in packet_bind() and packet_notifier()
From: David Miller <davem@davemloft.net>
Date: 2017-11-28 14:49:00
From: Eric Dumazet <redacted> Date: Mon, 27 Nov 2017 20:00:52 -0800
quoted hunk ↗ jump to hunk
@@ -368,9 +368,11 @@ static void __unregister_prot_hook(struct sock *sk, bool sync) __sock_put(sk); if (sync) { + po->frozen = 1; spin_unlock(&po->bind_lock); synchronize_net(); spin_lock(&po->bind_lock); + po->frozen = 0; } }
Ugh. Maybe you can just set po->num to zero in the bind code path which causes this problem. That will prevent this situation entirely.