From f7dcecb92ed192ff5fcf842918fb1aaea84b5bdd Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 6 Aug 2026 17:32:19 +0200 Subject: [PATCH] ALSA: mpu401: Check card index validity at probe mpu401 driver blindly trusts that the given devptr->id value is within the proper card index range at probe. It's OK for the devices the driver itself creates at the module probe time, but if the device is bound manually via sysfs interface, this could be -1 as "none", and this leads 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: stable@vger.kernel.org Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20260806153227.1460166-3-tiwai@suse.de --- sound/drivers/mpu401/mpu401.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/sound/drivers/mpu401/mpu401.c b/sound/drivers/mpu401/mpu401.c index c217c427bf1e..b93291ad067a 100644 --- a/sound/drivers/mpu401/mpu401.c +++ b/sound/drivers/mpu401/mpu401.c @@ -89,6 +89,12 @@ static int snd_mpu401_probe(struct platform_device *devptr) int err; struct snd_card *card; + if (dev < 0 || dev >= SNDRV_CARDS) { + dev_warn(&devptr->dev, + "Invalid card index %d, using default 0\n", dev); + dev = 0; + } + if (port[dev] == SNDRV_AUTO_PORT) { dev_err(&devptr->dev, "specify port\n"); return -EINVAL;