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HID: core: fix validation of report id 0

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Some drivers use the first HID report in the list instead of using an
index. In these cases, validation uses ID 0, which was supposed to mean
"first known report". This fixes the problem, which was causing at least
the lgff family of devices to stop working since hid_validate_values
was being called with ID 0, but the devices used single numbered IDs
for their reports:

0x05, 0x01,         /*  Usage Page (Desktop),                   */
0x09, 0x05,         /*  Usage (Gamepad),                        */
0xA1, 0x01,         /*  Collection (Application),               */
0xA1, 0x02,         /*      Collection (Logical),               */
0x85, 0x01,         /*          Report ID (1),                  */
...

Cc: stable@vger.kernel.org
Reported-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Kees Cook 2014-04-17 13:22:09 -07:00 committed by Jiri Kosina
parent 825747bb85
commit 1b15d2e5b8
1 changed files with 11 additions and 1 deletions
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10
drivers/hid/hid-core.c
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@ -842,7 +842,17 @@ struct hid_report *hid_validate_values(struct hid_device *hid,
* ->numbered being checked, which may not always be the case when * ->numbered being checked, which may not always be the case when
* drivers go to access report values. * drivers go to access report values.
*/ */
if (id == 0) {
/*
* Validating on id 0 means we should examine the first
* report in the list.
*/
report = list_entry(
hid->report_enum[type].report_list.next,
struct hid_report, list);
} else {
report = hid->report_enum[type].report_id_hash[id]; report = hid->report_enum[type].report_id_hash[id];
}
if (!report) { if (!report) {
hid_err(hid, "missing %s %u\n", hid_report_names[type], id); hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
return NULL; return NULL;