media: lirc: validate scancode for transmit
Ensure we reject an attempt to transmit invalid scancodes.
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 56b322b..ce8837b 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -776,6 +776,37 @@
EXPORT_SYMBOL_GPL(rc_keydown_notimeout);
/**
+ * rc_validate_scancode() - checks that a scancode is valid for a protocol
+ * @proto: protocol
+ * @scancode: scancode
+ */
+bool rc_validate_scancode(enum rc_proto proto, u32 scancode)
+{
+ switch (proto) {
+ case RC_PROTO_NECX:
+ if ((((scancode >> 16) ^ ~(scancode >> 8)) & 0xff) == 0)
+ return false;
+ break;
+ case RC_PROTO_NEC32:
+ if ((((scancode >> 24) ^ ~(scancode >> 16)) & 0xff) == 0)
+ return false;
+ break;
+ case RC_PROTO_RC6_MCE:
+ if ((scancode & 0xffff0000) != 0x800f0000)
+ return false;
+ break;
+ case RC_PROTO_RC6_6A_32:
+ if ((scancode & 0xffff0000) == 0x800f0000)
+ return false;
+ break;
+ default:
+ break;
+ }
+
+ return true;
+}
+
+/**
* rc_validate_filter() - checks that the scancode and mask are valid and
* provides sensible defaults
* @dev: the struct rc_dev descriptor of the device
@@ -794,26 +825,8 @@
mask = protocols[protocol].scancode_bits;
- switch (protocol) {
- case RC_PROTO_NECX:
- if ((((s >> 16) ^ ~(s >> 8)) & 0xff) == 0)
- return -EINVAL;
- break;
- case RC_PROTO_NEC32:
- if ((((s >> 24) ^ ~(s >> 16)) & 0xff) == 0)
- return -EINVAL;
- break;
- case RC_PROTO_RC6_MCE:
- if ((s & 0xffff0000) != 0x800f0000)
- return -EINVAL;
- break;
- case RC_PROTO_RC6_6A_32:
- if ((s & 0xffff0000) == 0x800f0000)
- return -EINVAL;
- break;
- default:
- break;
- }
+ if (!rc_validate_scancode(protocol, s))
+ return -EINVAL;
filter->data &= mask;
filter->mask &= mask;