Re: [PATCH 1/2] Bluetooth: Fix early return from l2cap_chan_del

[Marcel Holtmann <marcel@holtmann.org>]

Hi Mat,

> This fixes a regression from commit
> 2ead70b8390d199ca04cd35311b51f5f3676079e that is present in all
> kernels starting at v3.0.
> 
> When L2CAP information was moved to struct l2cap_chan, a check was
> added to l2cap_chan_del to avoid certain cleanup operations when ERTM
> or streaming mode had not yet been initialized.  The logic in the
> check did not take in to account that chan->conf_state is set to 0 in
> l2cap_chan_ready, so l2cap_chan_del failed to cancel timers and leaked
> memory any time the ERTM queues or lists were not empty.
> 
> This change makes sure that l2cap_chan_del only returns early if
> ERTM initialization was not performed.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  include/net/bluetooth/l2cap.h |    1 +
>  net/bluetooth/l2cap_core.c    |    4 ++--
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> index 1c7d1cd..452fcc4 100644
> --- a/include/net/bluetooth/l2cap.h
> +++ b/include/net/bluetooth/l2cap.h
> @@ -597,6 +597,7 @@ enum {
>  	CONF_EWS_RECV,
>  	CONF_LOC_CONF_PEND,
>  	CONF_REM_CONF_PEND,
> +	CONF_NOT_COMPLETE,
>  };
>  
>  #define L2CAP_CONF_MAX_CONF_REQ 2
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 24f144b..36edd42 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -391,6 +391,7 @@ struct l2cap_chan *l2cap_chan_create(void)
>  	chan->state = BT_OPEN;
>  
>  	atomic_set(&chan->refcnt, 1);
> +	set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
>  
>  	BT_DBG("chan %p", chan);
>  
> @@ -509,8 +510,7 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
>  
>  	release_sock(sk);
>  
> -	if (!(test_bit(CONF_OUTPUT_DONE, &chan->conf_state) &&
> -			test_bit(CONF_INPUT_DONE, &chan->conf_state)))
> +	if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
>  		return;

explain to me how this works? We never clear that bit.

Regards

Marcel