From e0fb960b227fcdebe22e4f26c9486d60943c0424 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 6 Aug 2026 17:32:20 +0200 Subject: [PATCH] ALSA: serial-u16550: Check card index validity at probe serial-u16550 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/20260806153227.1460166-4-tiwai@suse.de --- sound/drivers/serial-u16550.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/sound/drivers/serial-u16550.c b/sound/drivers/serial-u16550.c index 3c28961091b1..cc9c325df910 100644 --- a/sound/drivers/serial-u16550.c +++ b/sound/drivers/serial-u16550.c @@ -846,6 +846,12 @@ static int snd_serial_probe(struct platform_device *devptr) int err; int dev = devptr->id; + if (dev < 0 || dev >= SNDRV_CARDS) { + dev_warn(&devptr->dev, + "Invalid card index %d, using default 0\n", dev); + dev = 0; + } + switch (adaptor[dev]) { case SNDRV_SERIAL_SOUNDCANVAS: ins[dev] = 1;