From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 87301C388F7 for ; Sat, 7 Nov 2020 08:22:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CF2F2151B for ; Sat, 7 Nov 2020 08:22:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604737332; bh=CkbprsLnaQeBBm6DUnL6INt3t6GokDjSX4nOC4dcFLA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=u+DpqbuouEGA7vKOemMytssl+U8WQrNESuQtXlQL9s9bbvjLaGe4pk2CZx19Kzt8n 1uynJvMGuO97YKilzYWDiezfjSfbvfSdGmxSWDkZMXxTpYnD88e1BKuTGzPmL7wuoX WyFuR2NEvF5xUXKZpn9PqS9VIzlS8L48allkH6PM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728302AbgKGIWL (ORCPT ); Sat, 7 Nov 2020 03:22:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:46732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727833AbgKGIWK (ORCPT ); Sat, 7 Nov 2020 03:22:10 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9DC50208E4; Sat, 7 Nov 2020 08:22:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604737330; bh=CkbprsLnaQeBBm6DUnL6INt3t6GokDjSX4nOC4dcFLA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WNID+V9NRHfr44zwSVrr+mO/v5e+giuAfKqMgQ/LtJSX3R/HDPlgV6lqW8xG5Hbe2 28fVsWz4pfUvCdHpSVFM7cbEzEkPFOnjwsv/biK2xEIzpdK4mpMrmOyYoPc1yUmi2v 3hq9EAcqvxDhv2Pw+IcNpc5iR2589AlzUhvL6gl8= Date: Sat, 7 Nov 2020 09:22:06 +0100 From: Greg KH To: Eric Biggers Cc: syzbot , andreyknvl@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, rafael@kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: WARNING in input_register_device Message-ID: <20201107082206.GA19079@kroah.com> References: <000000000000872b5405b36f8e31@google.com> <20201106140336.GA3319902@kroah.com> <20201106170314.GA845@sol.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201106170314.GA845@sol.localdomain> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 06, 2020 at 09:03:14AM -0800, Eric Biggers wrote: > On Fri, Nov 06, 2020 at 03:03:36PM +0100, Greg KH wrote: > > On Fri, Nov 06, 2020 at 04:43:17AM -0800, syzbot wrote: > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 9e39aef3 usb: misc: brcmstb-usb-pinmap: Make sync_all_pins.. > > > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > > > console output: https://syzkaller.appspot.com/x/log.txt?x=145ffa8a500000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=a05f5efbb00b1465 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=92340f7b2b4789907fdb > > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=172ae7a8500000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13b24746500000 > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > Reported-by: syzbot+92340f7b2b4789907fdb@syzkaller.appspotmail.com > > > > > > microsoft 0003:045E:07DA.0001: unknown main item tag 0x0 > > > HID 045e:07da: Invalid code 65791 type 1 > > > ------------[ cut here ]------------ > > > init_uevent_argv: buffer size too small > > > WARNING: CPU: 0 PID: 5 at lib/kobject_uevent.c:259 init_uevent_argv lib/kobject_uevent.c:259 [inline] > > > WARNING: CPU: 0 PID: 5 at lib/kobject_uevent.c:259 kobject_uevent_env+0x1640/0x1680 lib/kobject_uevent.c:608 > > > > You gave it a device with a buffer that was "too small", and it rejected > > it. > > > > Which, aside from the huge warning message, is to be expected, so I > > don't think this is really a bug here. > > > > The purpose of WARN is for reporting recoverable kernel bugs. So a reachable > WARN is a bug. Either it is reporting one, or the bug is that the use of WARN > is wrong. In the past, as you know, we have thought that hardware issues like this are a "recoverable bug but someone better do something about it". Now that we can fake hardware devices so easily, it's probably better to just knock this down to a dev_warn() and keep on moving. If I get a chance, I'll write up a patch today, but anyone else should feel free to also do it. thanks, greg k-h