From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED60921423A; Tue, 14 Jan 2025 23:42:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736898127; cv=none; b=OxcH3ClBRz0VPCAYOl528ygyb/wWiFpwfWdnxvp0obEYClrHAxqZy39RpZLO4BGXWtjERobHXAO9xiNUsUQtHkH4ftVa1xpGXeEU/6ns2IYiV3aF5SOyk0T+Mls88CIHkRU2jFHjZhYpaMc/PXy2xq0JPeUjYt5zQemCFeZcK5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736898127; c=relaxed/simple; bh=3VQN+rVY5l/jVo7a/1PQvpOAy9GDidt+UUiHtyuciRc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MPosqYAsTVWSlffDNbsI5vD40RnhnKyuNlwX0pg6LeonaWRqonH7GFqr3x/pUkYZe5+sn7ljXwve0QTxEPIrYU2n2++5gSjwmhSD73NnrakcbF0IdLk9EibydcKdbVBSprYR6VqGAHJ44nAgwsiSkl+CsOAU5ERlTLlkdslrQO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KtLWGYac; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KtLWGYac" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56F90C4CEDD; Tue, 14 Jan 2025 23:42:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736898126; bh=3VQN+rVY5l/jVo7a/1PQvpOAy9GDidt+UUiHtyuciRc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KtLWGYacIEX7HkKK83Y2BJbcASsKkmiV5iZ5luqEjjoX6js/koGLNdeeCaKBbbM3s bxzDS+tEt3FS27RQL+1JWtGo/5JgzN8ZCfROQhC+w1AxF3EwDEPueGZhjI8i1Px8rL sXyY1wE7rTkPHz6bkf//6pc/c0XRRTR00s7vDlfQIsPDt9GikdOqA/lLDpVTrJ39JF qUc3Xab2ZtH7StICwAwPA3TAoJgmAXxAiB21COA0EIzfiof0FvrRC7fYFHytsz7NDd q+ADCjgk+mtVi4Rrw+FQOTkHlqleWIwpcwSuqYy8mC9Qzc+7A0PnOdldSnjDotLTHs nE+RJ9wjTE8cg== Date: Tue, 14 Jan 2025 15:42:05 -0800 From: "Darrick J. Wong" To: Dmitry Vyukov Cc: Matthew Wilcox , Christian Brauner , Kun Hu , Andrey Konovalov , jack@suse.cz, jlayton@redhat.com, tytso@mit.edu, adilger.kernel@dilger.ca, david@fromorbit.com, bfields@redhat.com, viro@zeniv.linux.org.uk, christian.brauner@ubuntu.com, hch@lst.de, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Bug: INFO_ task hung in lock_two_nondirectories Message-ID: <20250114234205.GA3557553@frogsfrogsfrogs> References: <42BD15B5-3C6C-437E-BF52-E22E6F200513@m.fudan.edu.cn> <20250113-herzhaft-desolat-e4d191b82bdf@brauner> <20250113180830.GM6156@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jan 14, 2025 at 09:59:08AM +0100, Dmitry Vyukov wrote: > On Mon, 13 Jan 2025 at 19:08, Darrick J. Wong wrote: > > > > On Mon, Jan 13, 2025 at 04:19:01PM +0000, Matthew Wilcox wrote: > > > On Mon, Jan 13, 2025 at 03:38:57PM +0100, Christian Brauner wrote: > > > > On Sun, Jan 12, 2025 at 06:00:24PM +0800, Kun Hu wrote: > > > > > Hello, > > > > > > > > > > When using our customized fuzzer tool to fuzz the latest Linux kernel, the following crash (43s) > > > > > was triggered. > > > > > > > > I think we need to come to an agreement at LSFMM or somewhere else that > > > > we will by default ingore but reports from non-syzbot fuzzers. Because > > > > we're all wasting time on them. > > > > No need to wait until LSFMM, I already agree with the premise of > > deprioritizing/ignoring piles of reports that come in all at once with > > very little analysis, an IOCCC-esque reproducer, and no effort on the > > part of the reporter to do *anything* about the bug. > > +1 > > It would be good to publish it somewhere on kernel.org (Documentation/ > or people.kernel.org). > We could include the link to our guidelines for external reporters > (where we ask to not test old kernels, reporting dups, not including > essential info, and other silly things): > https://github.com/google/syzkaller/blob/master/docs/linux/reporting_kernel_bugs.mdThere /me reads, wonders if "Do NOT mimic syzbot reports" is behind why everyone claims they have a "custom fuzzer" and proceed to leak the letters s, y, and z in the report. :P > is unfortunately no way to make people read all docs on the internet > beforehand, but at least it's handy to have a link to an existing doc > to give to people. Good idea, we probably ought to have a kernel document setting out our general policies about automated bug finders and linking to the known good ones. BTW, if one got handed a syzbot report, is there an easy way to ask your dashboard if it already knows about that report? --D > > While the Google syzbot dashboard has improved remarkably since 2018, > > particularly in the past couple of years, thanks to the people who did > > that! It's nice that I can fire off patches at the bot and it'll test > > them. That said, I don't perceive Google management to be funding much > > of anyone to solve the problems that their fuzzer uncovers. > > > > This is to say nothing of the people who are coyly running their own > > instances of syzbot sans dashboard and expecting me to download random > > crap from Google Drive. Hell no, I don't do that kind of thing in 2025. > > > > > I think it needs to be broader than that to also include "AI generated > > > bug reports" (while not excluding AI-translated bug reports); see > > > > > > https://daniel.haxx.se/blog/2024/01/02/the-i-in-llm-stands-for-intelligence/ > > > > > > so really, any "automated bug report" system is out of bounds unless > > > previously arranged with the developers who it's supposed to be helping. > > > > Agree. That's been my stance since syzbot first emerged in 2017-18. > > > > > We need to write that down somewhere in Documentation/process/ so we > > > can point misguided people at it. > > > > > > We should also talk about how some parts of the kernel are basically > > > unmaintained and unused, and that automated testing should be focused > > > on parts of the kernel that are actually used. A report about being > > > able to crash a stock configuration of ext4 is more useful than being > > > able to crash an unusual configuration of ufs. > > > > Or maybe we should try to make fuse + iouring fast enough that we can > > kick all these old legacy drivers out to userspace. ;) > > > > > Distinguishing between warnings, BUG()s and actual crashes would also > > > be a useful thing to put in this document. > > > > Yes. And also state that panic_on_warn=1 is a signal that you wanted > > fail(over) fast mode. > > > > --D