HID: wiimote: discard invalid EXT data reports
If an extension device isn't initialized properly, or during hardware
initialization, a device might send extension data which is all 0xff.
This is ambigious because this is also a valid normal data report. But
it is impossible, under normal conditions, to trigger valid reports with
all 0xff. Hence, we can safely ignore them.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-wiimote-core.c b/drivers/hid/hid-wiimote-core.c
index ea00030..e0ac84b 100644
--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -1276,11 +1276,19 @@
static void handler_ext(struct wiimote_data *wdata, const __u8 *payload,
size_t len)
{
+ static const __u8 invalid[21] = { 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff };
const __u8 *iter, *mods;
const struct wiimod_ops *ops;
bool is_mp;
- if (len < 6)
+ if (len > 21)
+ len = 21;
+ if (len < 6 || !memcmp(payload, invalid, len))
return;
/* if MP is active, track MP slot hotplugging */