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Message-ID: <096c5828-2b86-d689-e1cb-ba7de8abbf6f@kvaser.com>
Date:   Sat, 28 May 2022 09:34:53 +0200
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From:   Jimmy Assarsson <extja@kvaser.com>
Subject: Re: [PATCH 02/12] can: kvaser_usb: Fix use of uninitialized
 completion
To:     Anssi Hannula <anssi.hannula@bitwise.fi>
Cc:     linux-can@vger.kernel.org, Marc Kleine-Budde <mkl@pengutronix.de>,
        linux-kernel@vger.kernel.org
References: <20220516134748.3724796-1-anssi.hannula@bitwise.fi>
 <20220516134748.3724796-3-anssi.hannula@bitwise.fi>
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On 5/16/22 15:47, Anssi Hannula wrote:
> flush_comp is initialized when CMD_FLUSH_QUEUE is sent to the device and
> completed when the device sends CMD_FLUSH_QUEUE_RESP.
> 
> This causes completion of uninitialized completion if the device sends
> CMD_FLUSH_QUEUE_RESP before CMD_FLUSH_QUEUE is ever sent (e.g. as a
> response to a flush by a previously bound driver, or a misbehaving
> device).
> 
> Fix that by initializing flush_comp in kvaser_usb_init_one() like the
> other completions.
> 
> This issue is only triggerable after RX URBs have been set up, i.e. the
> interface has been opened at least once.
> 
> Fixes: aec5fb2268b7 ("can: kvaser_usb: Add support for Kvaser USB hydra family")
> Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>

Looks good to me.
Tested-by: Jimmy Assarsson <extja@kvaser.com>


> ---
>   drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c  | 1 +
>   drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 2 +-
>   2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> index e67658b53d02..47bff40c36b6 100644
> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> @@ -673,6 +673,7 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev,
>   	init_usb_anchor(&priv->tx_submitted);
>   	init_completion(&priv->start_comp);
>   	init_completion(&priv->stop_comp);
> +	init_completion(&priv->flush_comp);
>   	priv->can.ctrlmode_supported = 0;
>   
>   	priv->dev = dev;
> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
> index a26823c5b62a..4e90a4b7f95a 100644
> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
> @@ -1910,7 +1910,7 @@ static int kvaser_usb_hydra_flush_queue(struct kvaser_usb_net_priv *priv)
>   {
>   	int err;
>   
> -	init_completion(&priv->flush_comp);
> +	reinit_completion(&priv->flush_comp);
>   
>   	err = kvaser_usb_hydra_send_simple_cmd(priv->dev, CMD_FLUSH_QUEUE,
>   					       priv->channel);