Re: [patch v2] ALSA: rawmidi: fix the get next midi device ioctl

[Takashi Iwai <tiwai@suse.de>]

At Wed, 8 Sep 2010 21:36:41 +0200,
Dan Carpenter wrote:
> 
> If we pass in a device which is higher than SNDRV_RAWMIDI_DEVICES then
> this function just returns device + 1 which isn't helpful.  I've
> modified it to return -EINVAL instead.
> 
> Also Smatch complains because the "device + 1" could be an integer
> overflow.  It's harmless, but we may as well silence the warning.
> 
> Signed-off-by: Dan Carpenter <error27@gmail.com>
> ---
> V2:  In the first version I made negative values return -EINVAL
> 
> diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
> index eb68326..1633bac 100644
> --- a/sound/core/rawmidi.c
> +++ b/sound/core/rawmidi.c
> @@ -829,6 +829,8 @@ static int snd_rawmidi_control_ioctl(struct snd_card *card,
>  		
>  		if (get_user(device, (int __user *)argp))
>  			return -EFAULT;
> +		if (device > SNDRV_RAWMIDI_DEVICES)
> +			return -EINVAL;

This should be "device >= SNDRV_RAWMIDI_DEVICES".


Takashi

>  		mutex_lock(&register_mutex);
>  		device = device < 0 ? 0 : device + 1;
>  		while (device < SNDRV_RAWMIDI_DEVICES) {
>