[alsa-devel] [patch v2] ALSA: rawmidi: fix the get next midi device ioctl
perex at perex.cz
Wed Sep 8 23:29:14 CEST 2010
On Wed, 8 Sep 2010, Takashi Iwai wrote:
> 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 at 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".
Also note that this check changes a bit semantics. All other NEXT_DEVICE
ioctls returns -1 if the value is beyond the last device (meaning no more
devices were found). So the
if (device == SNDRV_RAWMIDI_DEVICES)
device = -1;
check should be
if (device >= SNDRV_RAWMIDI_DEVICES)
device = -1;
... resulting in one line patch.
Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.
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