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>
This commit is contained in:
Sean Young 2017-08-07 09:21:29 -04:00 committed by Mauro Carvalho Chehab
parent 86fe1ac0d5
commit 2168b416c8
1 changed files with 4 additions and 1 deletions

View File

@ -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)