From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH] HID: core: fix validation of report id 0 Date: Thu, 17 Apr 2014 13:22:09 -0700 Message-ID: <20140417202209.GA30268@www.outflux.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from smtp.outflux.net ([198.145.64.163]:57195 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750814AbaDQUWX (ORCPT ); Thu, 17 Apr 2014 16:22:23 -0400 Content-Disposition: inline Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Jiri Kosina , Benjamin Tissoires , Simon Wood , linux-input@vger.kernel.org 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), */ ... Reported-by: Simon Wood Signed-off-by: Kees Cook Cc: stable@vger.kernel.org --- drivers/hid/hid-core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 9e8064205bc7..07ce28175168 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -839,7 +839,17 @@ struct hid_report *hid_validate_values(struct hid_device *hid, * ->numbered being checked, which may not always be the case when * drivers go to access report values. */ - report = hid->report_enum[type].report_id_hash[id]; + 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]; + } if (!report) { hid_err(hid, "missing %s %u\n", hid_report_names[type], id); return NULL; -- 1.7.9.5 -- Kees Cook Chrome OS Security