Re: [PATCH 1/1] comedi: ni_usb6501: fix transfer-buffer overflows

[Greg Kroah-Hartman]

On Tue, Jun 07, 2022 at 07:18:02PM +0800, Xiaohui Zhang wrote:
> Similar to the handling of vmk80xx_alloc_usb_buffers in commit
> a23461c47482("comedi: vmk80xx: fix transfer-buffer overflows"),
> we thought a patch might be needed here as well.
> 
> The driver uses endpoint-sized USB transfer buffers but up until
> recently had no sanity checks on the sizes.
> 
> Signed-off-by: Xiaohui Zhang <xiaohuizhang@xxxxxxxxxx>
> ---
>  drivers/comedi/drivers/ni_usb6501.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/comedi/drivers/ni_usb6501.c b/drivers/comedi/drivers/ni_usb6501.c
> index 0dd9edf7bced..8303bfc305c5 100644
> --- a/drivers/comedi/drivers/ni_usb6501.c
> +++ b/drivers/comedi/drivers/ni_usb6501.c
> @@ -90,6 +90,7 @@
>  #include <linux/comedi/comedi_usb.h>
>  
>  #define	NI6501_TIMEOUT	1000
> +#define MIN_BUF_SIZE	64
>  
>  /* Port request packets */
>  static const u8 READ_PORT_REQUEST[]	= {0x00, 0x01, 0x00, 0x10,
> @@ -459,12 +460,12 @@ static int ni6501_alloc_usb_buffers(struct comedi_device *dev)
>  	struct ni6501_private *devpriv = dev->private;
>  	size_t size;
>  
> -	size = usb_endpoint_maxp(devpriv->ep_rx);
> +	size = max(usb_endpoint_maxp(devpriv->ep_rx), MIN_BUF_SIZE);
>  	devpriv->usb_rx_buf = kzalloc(size, GFP_KERNEL);
>  	if (!devpriv->usb_rx_buf)
>  		return -ENOMEM;
>  
> -	size = usb_endpoint_maxp(devpriv->ep_tx);
> +	size = max(usb_endpoint_maxp(devpriv->ep_tx), MIN_BUF_SIZE);
>  	devpriv->usb_tx_buf = kzalloc(size, GFP_KERNEL);
>  	if (!devpriv->usb_tx_buf)
>  		return -ENOMEM;
> -- 
> 2.17.1
> 

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.

You are receiving this message because of the following common error(s)
as indicated below:

- You did not specify a description of why the patch is needed, or
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  Please read the section entitled "The canonical patch format" in the
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If you wish to discuss this problem further, or you have questions about
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Greg will reply once he has dug out from the pending patches received
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thanks,

greg k-h's patch email bot