From 876727eabf3f224beb5f9b3bbcec2fb891faa89d Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Sun, 26 May 2013 22:55:03 +0200 Subject: [PATCH] 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 Signed-off-by: Jiri Kosina --- drivers/hid/hid-wiimote-core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) 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 bool valid_ext_handler(const struct wiimod_ops *ops, size_t len) 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 */ -- 2.7.4