[PATCH] ALSA: core: Validate device type for dynamic minors

[PATCH] ALSA: core: Validate device type for dynamic minors

[Sreeraj S Kurup]

Reject unsupported device types when allocating dynamic minors.

This prevents invalid device types from being registered and
avoids unnecessarily consuming available minor numbers.

Return -EINVAL for unsupported device types.

Signed-off-by: Sreeraj S Kurup <sreekuttan2156239@gmail.com>
---
 sound/core/sound.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sound/core/sound.c b/sound/core/sound.c
index 24f40763a20c..32637c40df05 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -184,6 +184,18 @@ static int snd_find_free_minor(int type, struct snd_card *card, int dev)
 	if (type == SNDRV_DEVICE_TYPE_TIMER)
 		return SNDRV_MINOR_TIMER;
 
+	switch (type) {
+	case SNDRV_DEVICE_TYPE_CONTROL:
+	case SNDRV_DEVICE_TYPE_HWDEP:
+	case SNDRV_DEVICE_TYPE_RAWMIDI:
+	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
+	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
+	case SNDRV_DEVICE_TYPE_COMPRESS:
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
 		/* skip static minors still used for module auto loading */
 		if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
-- 
2.55.0

Re: [PATCH] ALSA: core: Validate device type for dynamic minors

[Takashi Iwai]

On Wed, 04 Nov 2026 16:52:05 +0100,
Sreeraj S Kurup wrote:
> 
> Reject unsupported device types when allocating dynamic minors.
> 
> This prevents invalid device types from being registered and
> avoids unnecessarily consuming available minor numbers.
> 
> Return -EINVAL for unsupported device types.
> 
> Signed-off-by: Sreeraj S Kurup <sreekuttan2156239@gmail.com>

As it's no urgent fix, I applied to for-next branch now.


thanks,

Takashi

Re: [PATCH] ALSA: core: Validate device type for dynamic minors

[Sreeraj S Kurup]

Hi,

Thanks for applying the patch!

Best regards,
Sreeraj