[PATCH 3/6] ALSA: serial-u16550: Check card index validity at probe

Takashi Iwai <[email protected]>
Newsgroups org.kernel.vger.linux-sound
Message-ID <[email protected]>
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: <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
---
 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;
-- 
2.55.0
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.