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HID: core: do not reject devices when they declare too many usages

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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>
This commit is contained in:
Benjamin Tissoires 2015-07-24 12:02:22 -04:00 committed by Jiri Kosina
parent 3eb4351af4
commit ba53219809
1 changed files with 19 additions and 0 deletions
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19
drivers/hid/hid-core.c
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@ -427,6 +427,7 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
{
__u32 data;
unsigned n;
__u32 count;
data = item_udata(item);
@ -490,6 +491,24 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
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");