From patchwork Wed Sep 1 16:36:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Stern X-Patchwork-Id: 506174 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95DA1C4320A for ; Wed, 1 Sep 2021 16:36:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E42B6102A for ; Wed, 1 Sep 2021 16:36:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245406AbhIAQg7 (ORCPT ); Wed, 1 Sep 2021 12:36:59 -0400 Received: from netrider.rowland.org ([192.131.102.5]:41383 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S245300AbhIAQg7 (ORCPT ); Wed, 1 Sep 2021 12:36:59 -0400 Received: (qmail 405969 invoked by uid 1000); 1 Sep 2021 12:36:00 -0400 Date: Wed, 1 Sep 2021 12:36:00 -0400 From: Alan Stern To: Benjamin Tissoires , Jiri Kosina Cc: Michal Kubecek , Oleksandr Natalenko , syzkaller-bugs@googlegroups.com, linux-input@vger.kernel.org, Linux USB Mailing List Subject: [PATCH 2/3] HID: usbhid: Fix warning caused by 0-length input reports Message-ID: <20210901163600.GB404634@rowland.harvard.edu> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Syzbot found a warning caused by hid_submit_ctrl() submitting a control request to transfer a 0-length input report: usb 1-1: BOGUS control dir, pipe 80000280 doesn't match bRequestType a1 (The warning message is a little difficult to understand. It means that the control request claims to be for an IN transfer but this contradicts the USB spec, which requires 0-length control transfers always to be in the OUT direction.) Now, a zero-length report isn't good for anything and there's no reason for a device to have one, but the fuzzer likes to pick out these weird edge cases. In the future, perhaps we will decide to reject 0-length reports at probe time. For now, the simplest approach for avoiding these warnings is to pretend that the report actually has length 1. Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+9b57a46bf1801ce2a2ca@syzkaller.appspotmail.com Tested-by: Oleksandr Natalenko Tested-by: Benjamin Tissoires Acked-by: Benjamin Tissoires Cc: stable@vger.kernel.org --- drivers/hid/usbhid/hid-core.c | 1 + 1 file changed, 1 insertion(+) Index: usb-devel/drivers/hid/usbhid/hid-core.c =================================================================== --- usb-devel.orig/drivers/hid/usbhid/hid-core.c +++ usb-devel/drivers/hid/usbhid/hid-core.c @@ -389,6 +389,7 @@ static int hid_submit_ctrl(struct hid_de maxpacket = usb_maxpacket(hid_to_usb_dev(hid), usbhid->urbctrl->pipe, 0); if (maxpacket > 0) { + len += (len == 0); /* Don't allow 0-length reports */ len = DIV_ROUND_UP(len, maxpacket); len *= maxpacket; if (len > usbhid->bufsize)