Subject: Re: sctp_close/sk_free: kernel BUG at arch/x86/mm/physaddr.c:18!

From: Fengguang Wu <[email-masked]>
Date: Thu, 6 Sep 2012 06:28:50 +0800

On Wed, Sep 05, 2012 at 06:57:00PM +0200, Eric Dumazet wrote:
> On Wed, 2012-09-05 at 17:40 +0200, Eric Dumazet wrote:
> 
> > Could you test the following patch please ?

It works - no single error for 1000 boots!

btw, the first bad commit has been bisected to 

        commit 8336886f786fdacbc19b719c1f7ea91eb70706d4
        Author: Jerry Chu <[email-masked]>
        Date:   Fri Aug 31 12:29:12 2012 +0000

            tcp: TCP Fast Open Server - support TFO listeners

> > (Not sure why sctp doesnt memset/bzero its whole socket by the way...)
> > 
> > Thanks
> 
> Here is a more complete patch, as there are three potential problems,
> not only one :

Great! I'll start tests for it.

Thanks,
Fengguang

> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index 4f70ef0..845372b 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -149,11 +149,8 @@ void inet_sock_destruct(struct sock *sk)
>  		pr_err("Attempt to release alive inet socket %p\n", sk);
>  		return;
>  	}
> -	if (sk->sk_type == SOCK_STREAM) {
> -		struct fastopen_queue *fastopenq =
> -			inet_csk(sk)->icsk_accept_queue.fastopenq;
> -		kfree(fastopenq);
> -	}
> +	if (sk->sk_protocol == IPPROTO_TCP)
> +		kfree(inet_csk(sk)->icsk_accept_queue.fastopenq);
>  
>  	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
>  	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
> diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
> index 8464b79..f0c5b9c 100644
> --- a/net/ipv4/inet_connection_sock.c
> +++ b/net/ipv4/inet_connection_sock.c
> @@ -314,7 +314,7 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
>  	newsk = req->sk;
>  
>  	sk_acceptq_removed(sk);
> -	if (sk->sk_type == SOCK_STREAM && queue->fastopenq != NULL) {
> +	if (sk->sk_protocol == IPPROTO_TCP && queue->fastopenq != NULL) {
>  		spin_lock_bh(&queue->fastopenq->lock);
>  		if (tcp_rsk(req)->listener) {
>  			/* We are still waiting for the final ACK from 3WHS
> @@ -775,7 +775,7 @@ void inet_csk_listen_stop(struct sock *sk)
>  
>  		percpu_counter_inc(sk->sk_prot->orphan_count);
>  
> -		if (sk->sk_type == SOCK_STREAM && tcp_rsk(req)->listener) {
> +		if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->listener) {
>  			BUG_ON(tcp_sk(child)->fastopen_rsk != req);
>  			BUG_ON(sk != tcp_rsk(req)->listener);
>  
>