1 files changed, 78 insertions, 14 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a306493e2e97..2d089d3954e3 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -196,16 +196,37 @@ static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 }
 
 /*
+ * Concatenate usage which defines 16 bits or less with the
+ * currently defined usage page to form a 32 bit usage
+ */
+
+static void complete_usage(struct hid_parser *parser, unsigned int index)
+{
+	parser->local.usage[index] &= 0xFFFF;
+	parser->local.usage[index] |=
+		(parser->global.usage_page & 0xFFFF) << 16;
+}
+
+/*
  * Add a usage to the temporary parser table.
  */
 
-static int hid_add_usage(struct hid_parser *parser, unsigned usage)
+static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 {
 	if (parser->local.usage_index >= HID_MAX_USAGES) {
 		hid_err(parser->device, "usage index exceeded\n");
 		return -1;
 	}
 	parser->local.usage[parser->local.usage_index] = usage;
+
+	/*
+	 * If Usage item only includes usage id, concatenate it with
+	 * currently defined usage page
+	 */
+	if (size <= 2)
+		complete_usage(parser, parser->local.usage_index);
+
+	parser->local.usage_size[parser->local.usage_index] = size;
 	parser->local.collection_index[parser->local.usage_index] =
 		parser->collection_stack_ptr ?
 		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
@@ -247,6 +268,12 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
 	offset = report->size;
 	report->size += parser->global.report_size * parser->global.report_count;
 
+	/* Total size check: Allow for possible report index byte */
+	if (report->size > (HID_MAX_BUFFER_SIZE - 1) << 3) {
+		hid_err(parser->device, "report is too long\n");
+		return -1;
+	}
+
 	if (!parser->local.usage_index) /* Ignore padding fields */
 		return 0;
 
@@ -462,10 +489,7 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 			return 0;
 		}
 
-		if (item->size <= 2)
-			data = (parser->global.usage_page << 16) + data;
-
-		return hid_add_usage(parser, data);
+		return hid_add_usage(parser, data, item->size);
 
 	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 
@@ -474,9 +498,6 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 			return 0;
 		}
 
-		if (item->size <= 2)
-			data = (parser->global.usage_page << 16) + data;
-
 		parser->local.usage_minimum = data;
 		return 0;
 
@@ -487,9 +508,6 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 			return 0;
 		}
 
-		if (item->size <= 2)
-			data = (parser->global.usage_page << 16) + data;
-
 		count = data - parser->local.usage_minimum;
 		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 			/*
@@ -509,7 +527,7 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 		}
 
 		for (n = parser->local.usage_minimum; n <= data; n++)
-			if (hid_add_usage(parser, n)) {
+			if (hid_add_usage(parser, n, item->size)) {
 				dbg_hid("hid_add_usage failed\n");
 				return -1;
 			}
@@ -524,6 +542,41 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 }
 
 /*
+ * Concatenate Usage Pages into Usages where relevant:
+ * As per specification, 6.2.2.8: "When the parser encounters a main item it
+ * concatenates the last declared Usage Page with a Usage to form a complete
+ * usage value."
+ */
+
+static void hid_concatenate_last_usage_page(struct hid_parser *parser)
+{
+	int i;
+	unsigned int usage_page;
+	unsigned int current_page;
+
+	if (!parser->local.usage_index)
+		return;
+
+	usage_page = parser->global.usage_page;
+
+	/*
+	 * Concatenate usage page again only if last declared Usage Page
+	 * has not been already used in previous usages concatenation
+	 */
+	for (i = parser->local.usage_index - 1; i >= 0; i--) {
+		if (parser->local.usage_size[i] > 2)
+			/* Ignore extended usages */
+			continue;
+
+		current_page = parser->local.usage[i] >> 16;
+		if (current_page == usage_page)
+			break;
+
+		complete_usage(parser, i);
+	}
+}
+
+/*
  * Process a main item.
  */
 
@@ -532,6 +585,8 @@ static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 	__u32 data;
 	int ret;
 
+	hid_concatenate_last_usage_page(parser);
+
 	data = item_udata(item);
 
 	switch (item->tag) {
@@ -711,6 +766,10 @@ static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 	    parser->global.report_size == 8)
 		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
+
+	if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
+	    parser->global.report_size == 8)
+		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 }
 
 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
@@ -741,6 +800,8 @@ static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 	__u32 data;
 	int i;
 
+	hid_concatenate_last_usage_page(parser);
+
 	data = item_udata(item);
 
 	switch (item->tag) {
@@ -967,6 +1028,7 @@ int hid_open_report(struct hid_device *device)
 	__u8 *start;
 	__u8 *buf;
 	__u8 *end;
+	__u8 *next;
 	int ret;
 	static int (*dispatch_type[])(struct hid_parser *parser,
 				      struct hid_item *item) = {
@@ -1020,7 +1082,8 @@ int hid_open_report(struct hid_device *device)
 	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
 
 	ret = -EINVAL;
-	while ((start = fetch_item(start, end, &item)) != NULL) {
+	while ((next = fetch_item(start, end, &item)) != NULL) {
+		start = next;
 
 		if (item.format != HID_ITEM_FORMAT_SHORT) {
 			hid_err(device, "unexpected long global item\n");
@@ -1049,7 +1112,8 @@ int hid_open_report(struct hid_device *device)
 		}
 	}
 
-	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
+	hid_err(device, "item fetching failed at offset %u/%u\n",
+		size - (unsigned int)(end - start), size);
 err:
 	vfree(parser);
 	hid_close_report(device);