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=-7.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 C24E5C43219 for ; Tue, 30 Apr 2019 15:40:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92D5321734 for ; Tue, 30 Apr 2019 15:40:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kroah.com header.i=@kroah.com header.b="FqYKtQqQ"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="YLbWNhEb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726065AbfD3PkK (ORCPT ); Tue, 30 Apr 2019 11:40:10 -0400 Received: from wout1-smtp.messagingengine.com ([64.147.123.24]:55205 "EHLO wout1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725906AbfD3PkK (ORCPT ); Tue, 30 Apr 2019 11:40:10 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id 0C4D779C; Tue, 30 Apr 2019 11:40:08 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Tue, 30 Apr 2019 11:40:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=im7oD5qEY2zhcFnJGGzg2Qlw0IY OGi07CNykA7KpG74=; b=FqYKtQqQ/6eMcn2BKplv+JRDlcoyz5PdmBzSx8kHGGV TF/E0rvdRiXSvZ1LjFYqIaifS4nWequszxQ2L4qk/wIDPwEQb+AYRqlrM/2xmSDt ZvT2VxgA9SNG/jO6cv30eTgkfmmwL9Y+sLRd2tEIcQ+ObDqGJ06T4kBoKMm6NhsV /JbmhqNc05AyI555wr5Hg03CQGSL2qb8YaUjN8VhYtIV/VcKrpDncyB6u0/B/T39 0M4T0HBXCf0ZNdSLxBO+aJEBuLdoqLB1g1jUcrdkarFyIV7TONwK9qy105Qzw4TI v1OS40C63GDmXkJD+CzgbZfnnc/pl6F89on2UBMrnLw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=im7oD5 qEY2zhcFnJGGzg2Qlw0IYOGi07CNykA7KpG74=; b=YLbWNhEbJPL9tS44Iiaqwm WN8qZEOw+YA2mOuVFiPzPwwLa/8OA4waAm9i0UT4ziFZatywspiJRMhHRSesxv5Z g4LSLSLwHlw+uTAQo/tHpmApdH3sUtpJuogCgySe8nl7fP1iQbM71287e5EUjYyd SNPKs24e78+mmAk0uENriafIg4kQvum5s+j2XSp1U7mJuFLb2Za2rraS9KjVJy5P j0fbtQtptk0wpjLdsjoqxnhCd4uXQP0J6KZD+1LjhTtcvTobA6C9lX/mgt5VuMPe Hipnd9yEbTHoeIN3cWlsVmjbC/ZyBa1tZm8lVTNusfCkd+t6pB/WssufnbmC0IKg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddrieehgdefvdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenog fuuhhsphgvtghtffhomhgrihhnucdlgeelmdenucfjughrpeffhffvuffkfhggtggujggf sehttdertddtredvnecuhfhrohhmpefirhgvghcumffjuceoghhrvghgsehkrhhorghhrd gtohhmqeenucffohhmrghinhepghhithhhuhgsrdgtohhmpdhgohhordhglhdprghpphhs phhothdrtghomhenucfkphepkeefrdekiedrkeelrddutdejnecurfgrrhgrmhepmhgrih hlfhhrohhmpehgrhgvgheskhhrohgrhhdrtghomhenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 32D37E4176; Tue, 30 Apr 2019 11:40:06 -0400 (EDT) Date: Tue, 30 Apr 2019 17:40:00 +0200 From: Greg KH To: Andrey Konovalov Cc: Alan Stern , syzbot , LKML , USB list , syzkaller-bugs Subject: Re: WARNING: Support for this device (Terratec Grabster AV400) is experimental. Message-ID: <20190430154000.GB23459@kroah.com> References: <0000000000004101370587c052fb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, Apr 30, 2019 at 05:14:28PM +0200, Andrey Konovalov wrote: > On Tue, Apr 30, 2019 at 5:00 PM Alan Stern wrote: > > > > On Tue, 30 Apr 2019, syzbot wrote: > > > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver > > > git tree: https://github.com/google/kasan.git usb-fuzzer > > > console output: https://syzkaller.appspot.com/x/log.txt?x=141ca62d200000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=af8f8d2ac0d39b0ed3a0 > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1405bedd200000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ce3bbb200000 > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+af8f8d2ac0d39b0ed3a0@syzkaller.appspotmail.com > > > > > > usb 1-1: New USB device found, idVendor=0ccd, idProduct=0039, bcdDevice= > > > d.3c > > > usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 > > > usb 1-1: config 0 descriptor?? > > > pvrusb2: Hardware description: Terratec Grabster AV400 > > > pvrusb2: ********** > > > pvrusb2: WARNING: Support for this device (Terratec Grabster AV400) is > > > experimental. > > > pvrusb2: Important functionality might not be entirely working. > > > pvrusb2: Please consider contacting the driver author to help with further > > > stabilization of the driver. > > > pvrusb2: ********** > > > > > > > > > --- > > > This bug is generated by a bot. It may contain errors. > > > See https://goo.gl/tpsmEJ for more information about syzbot. > > > syzbot engineers can be reached at syzkaller@googlegroups.com. > > > > This does seem like a bug in syzbot. Why does it think this pr_info() > > output indicates a crash? Is it fooled by the capitalized "WARNING" at > > the start of one of the lines? > > Well, as of [1] WARN*() should only be used to indicate a kernel bug. > Normally, WARN*() prints a line that start with a warning, which is > followed by a stack trace. Unfortunately the stack trace is not always > present (kernel memory is badly corrupted, console deadlocked, etc.), > so syzbot detects the "WARNING:" line as a beginning of a WARN*() > reported bug. In this case the driver does something like > `pr_info("WARNING: ...", ...)`, which confuses syzbot. I'd say it's > the kernel that needs to be changed here to use some other kind of > prefix for printing warning messages. > > [1] https://github.com/torvalds/linux/commit/96c6a32ccb55a366054fd82cc63523bb7f7493d3 Ok, we can change these to "Warning" then. Want to send a patch? thanks, greg k-h