HID: core: do not reject devices when they declare too many usages
Some device present proprietary collections with a usage min of 0x00 and
a usage max of 0xffff. hid-core currently reject them while most of the
time this is harmless.
Let's ignore the exceeding usages, and hope for the best.
Reported-by: Simon Wörner <mail@simon-woerner.de>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 157c627..b403fe2 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -427,6 +427,7 @@
{
__u32 data;
unsigned n;
+ __u32 count;
data = item_udata(item);
@@ -490,6 +491,24 @@
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) {
+ /*
+ * We do not warn if the name is not set, we are
+ * actually pre-scanning the device.
+ */
+ if (dev_name(&parser->device->dev))
+ hid_warn(parser->device,
+ "ignoring exceeding usage max\n");
+ data = HID_MAX_USAGES - parser->local.usage_index +
+ parser->local.usage_minimum - 1;
+ if (data <= 0) {
+ hid_err(parser->device,
+ "no more usage index available\n");
+ return -1;
+ }
+ }
+
for (n = parser->local.usage_minimum; n <= data; n++)
if (hid_add_usage(parser, n)) {
dbg_hid("hid_add_usage failed\n");