From: Jiri Kosina <jkosina@suse.cz>
Date: Tue, 5 Jan 2010 10:45:52 +0000 (+0100)
Subject: HID: fix parsing of local delimiter with size 0
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=722612cd51cf1b574c89dff57cc5dbedf1f645bb;p=linux-beck.git

HID: fix parsing of local delimiter with size 0

Acording to HID standard 1.11, value 0 allows for size being 0.
Local delimiter tag has has 0 one of the possible values.

Therefore we need to handle this case properly, to be fully compliant
with the specification.

Reported-by: Marcin Tolysz <tolysz@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
---

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 6462c923805f..a4b496c68259 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -387,7 +387,8 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 	__u32 data;
 	unsigned n;
 
-	if (item->size == 0) {
+	/* Local delimiter could have value 0, which allows size to be 0 */
+	if (item->size == 0 && item->tag != HID_LOCAL_ITEM_TAG_DELIMITER) {
 		dbg_hid("item data expected for local item\n");
 		return -1;
 	}