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authorBenjamin Tissoires <benjamin.tissoires@redhat.com>2015-07-24 12:02:22 -0400
committerJiri Kosina <jkosina@suse.com>2015-07-27 14:41:30 +0200
commitba53219809f4b3a08f21600a0f3b675620d518bc (patch)
treec2fe0808f9918180d534a085f5591d5374032669 /drivers/hid/hid-core.c
parent3eb4351af42bd8b6de20daab07b204a85c35248f (diff)
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>
Diffstat (limited to 'drivers/hid/hid-core.c')
-rw-r--r--drivers/hid/hid-core.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 157c62775053..b403fe2c5cbe 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -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");