media: rc: ensure we do not read out of bounds
If rc_validate_filter() is called for CEC or XMP, then we would read
beyond the end of the array.
Suggested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index f306e67..7aaf28b 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -733,7 +733,7 @@ EXPORT_SYMBOL_GPL(rc_keydown_notimeout);
static int rc_validate_filter(struct rc_dev *dev,
struct rc_scancode_filter *filter)
{
- static u32 masks[] = {
+ static const u32 masks[] = {
[RC_TYPE_RC5] = 0x1f7f,
[RC_TYPE_RC5X_20] = 0x1f7f3f,
[RC_TYPE_RC5_SZ] = 0x2fff,
@@ -757,6 +757,9 @@ static int rc_validate_filter(struct rc_dev *dev,
u32 s = filter->data;
enum rc_type protocol = dev->wakeup_protocol;
+ if (protocol >= ARRAY_SIZE(masks))
+ return -EINVAL;
+
switch (protocol) {
case RC_TYPE_NECX:
if ((((s >> 16) ^ ~(s >> 8)) & 0xff) == 0)