Re: [PATCH v2] ALSA: line6: Improve line6_read/write_data() interfaces

[Takashi Iwai <tiwai@suse.de>]

At Wed, 11 Feb 2015 06:03:31 -0600,
Chris Rorvick wrote:
> 
> The address cannot be negative so make it unsigned.  Also, an unsigned
> int is always sufficient for the length, so no need to overdo it with a
> size_t.  Finally, add in range checks to see if the values passed in
> actually fit where they are used.
> 
> Signed-off-by: Chris Rorvick <chris@rorvick.com>
> ---
> This was dropped from an earlier series ("Cleanup reads/writes to Line 6
> device memory".)  This version leaves the arguements wide (within reason)
> and does range checking.
> 
> Regards,
> 
> Chris
> 
>  sound/usb/line6/driver.c | 14 ++++++++++----
>  sound/usb/line6/driver.h |  8 ++++----
>  2 files changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c
> index 99b63a7..4f82b57 100644
> --- a/sound/usb/line6/driver.c
> +++ b/sound/usb/line6/driver.c
> @@ -302,14 +302,17 @@ static void line6_data_received(struct urb *urb)
>  /*
>  	Read data from device.
>  */
> -int line6_read_data(struct usb_line6 *line6, int address, void *data,
> -		    size_t datalen)
> +int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
> +		    unsigned datalen)
>  {
>  	struct usb_device *usbdev = line6->usbdev;
>  	int ret;
>  	unsigned char len;
>  	unsigned count;
>  
> +	if (address > 0xffff || datalen > 0xff)
> +		return EINVAL;

-EINVAL.


Takashi

>  	/* query the serial number: */
>  	ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67,
>  			      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
> @@ -370,14 +373,17 @@ EXPORT_SYMBOL_GPL(line6_read_data);
>  /*
>  	Write data to device.
>  */
> -int line6_write_data(struct usb_line6 *line6, int address, void *data,
> -		     size_t datalen)
> +int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
> +		     unsigned datalen)
>  {
>  	struct usb_device *usbdev = line6->usbdev;
>  	int ret;
>  	unsigned char status;
>  	int count;
>  
> +	if (address > 0xffff || datalen > 0xffff)
> +		return EINVAL;
> +
>  	ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67,
>  			      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
>  			      0x0022, address, data, datalen,
> diff --git a/sound/usb/line6/driver.h b/sound/usb/line6/driver.h
> index 5d20294..7da643e 100644
> --- a/sound/usb/line6/driver.h
> +++ b/sound/usb/line6/driver.h
> @@ -147,8 +147,8 @@ struct usb_line6 {
>  
>  extern char *line6_alloc_sysex_buffer(struct usb_line6 *line6, int code1,
>  				      int code2, int size);
> -extern int line6_read_data(struct usb_line6 *line6, int address, void *data,
> -			   size_t datalen);
> +extern int line6_read_data(struct usb_line6 *line6, unsigned address,
> +			   void *data, unsigned datalen);
>  extern int line6_read_serial_number(struct usb_line6 *line6,
>  				    u32 *serial_number);
>  extern int line6_send_raw_message_async(struct usb_line6 *line6,
> @@ -161,8 +161,8 @@ extern void line6_start_timer(struct timer_list *timer, unsigned long msecs,
>  			      void (*function)(unsigned long),
>  			      unsigned long data);
>  extern int line6_version_request_async(struct usb_line6 *line6);
> -extern int line6_write_data(struct usb_line6 *line6, int address, void *data,
> -			    size_t datalen);
> +extern int line6_write_data(struct usb_line6 *line6, unsigned address,
> +			    void *data, unsigned datalen);
>  
>  int line6_probe(struct usb_interface *interface,
>  		const struct usb_device_id *id,
> -- 
> 2.1.0
>