Re: [PATCH v3] can: usb: etas_es58x: Fix RX buffer leak on URB resubmit failure

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Jul 06, 2026 at 09:46:01AM +0800, Guangshuo Li wrote:
> es58x_read_bulk_callback() resubmits the RX URB after processing a
> received packet. If the resubmit succeeds, the URB remains anchored and
> will be handled by the normal RX path or by teardown.
> 
> However, if usb_submit_urb() fails, the callback unanchors the URB and
> then returns directly. This skips the existing free_urb path, so the
> coherent transfer buffer allocated with usb_alloc_coherent() is not
> released.
> 
> Reuse the existing free_urb path after a resubmit failure so that the RX
> coherent buffer is freed before leaving the callback.
> 
> Fixes: 5eaad4f76826 ("can: usb: etas_es58x: correctly anchor the urb in the read bulk callback")
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> Reviewed-by: Vincent Mailhol <mailhol@kernel.org>
> ---
> v3:
>   - Regenerate the patch against the correct base so it removes the
>   original return statement instead of the v1-added goto.
>   - Add the missing changelog. No functional change intended.
> 
> v2:
>   - Remove the redundant goto and let the error path fall through to
>     free_urb, as suggested by Vincent Mailhol.
>   - Add Vincent's Reviewed-by tag
> 
>  drivers/net/can/usb/etas_es58x/es58x_core.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
> index b259f6109808..e1724ae79c5a 100644
> --- a/drivers/net/can/usb/etas_es58x/es58x_core.c
> +++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
> @@ -1476,7 +1476,6 @@ static void es58x_read_bulk_callback(struct urb *urb)
>  		dev_err_ratelimited(dev,
>  				    "Failed resubmitting read bulk urb: %pe\n",
>  				    ERR_PTR(ret));
> -	return;
>  
>   free_urb:
>  	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> -- 
> 2.43.0
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

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