[PATCH 5/6] ALSA: mts64: Check card index validity at probe

Although mts64 driver has a check of the given devptr->id value, it
doesn't check for a negative id, which is often given as "none" or
such value when bound via sysfs.  This may lead to OOB access for
index[] and other parameters.

Add a sanity check for the card index and warn/correct it if it's a
value out of the range.

Cc: <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
---
 sound/drivers/mts64.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/drivers/mts64.c b/sound/drivers/mts64.c
index 36e9eab204ca..cefaa00b83e7 100644
--- a/sound/drivers/mts64.c
+++ b/sound/drivers/mts64.c
@@ -900,6 +900,12 @@ static int snd_mts64_probe(struct platform_device *pdev)
 	p = platform_get_drvdata(pdev);
 	platform_set_drvdata(pdev, NULL);
 
+	if (dev < 0) {
+		dev_warn(&pdev->dev,
+			 "Invalid card index %d, using default 0\n", dev);
+		dev = 0;
+	}
+
 	if (dev >= SNDRV_CARDS)
 		return -ENODEV;
 	if (!enable[dev]) 
-- 
2.55.0