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Commit 9eba9353 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: fix a lockdep issue in tcp_fastopen_reset_cipher() 



icsk_accept_queue.fastopenq.lock is only fully initialized at listen()
time.

LOCKDEP is not happy if we attempt a spin_lock_bh() on it, because
of missing annotation. (Although kernel runs just fine)

Lets use net->ipv4.tcp_fastopen_ctx_lock to protect ctx access.

Fixes: 1fba70e5 ("tcp: socket option to set TCP fast open key")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: default avatarChristoph Paasch <cpaasch@apple.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8c01c4f8

net/ipv4/tcp_fastopen.c

+3 −5
Original line number Diff line number Diff line
@@ -92,20 +92,18 @@ error: kfree(ctx); 
	memcpy(ctx->key, key, len);





	spin_lock(&net->ipv4.tcp_fastopen_ctx_lock);

	if (sk) {

		q = &inet_csk(sk)->icsk_accept_queue.fastopenq;

		spin_lock_bh(&q->lock);

		octx = rcu_dereference_protected(q->ctx,

						 lockdep_is_held(&q->lock));

			lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));

		rcu_assign_pointer(q->ctx, ctx);

		spin_unlock_bh(&q->lock);

	} else {

		spin_lock(&net->ipv4.tcp_fastopen_ctx_lock);

		octx = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx,

			lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));

		rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, ctx);

		spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock);

	}

	spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock);



	if (octx)

		call_rcu(&octx->rcu, tcp_fastopen_ctx_free);