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 80F99388364 for ; Mon, 20 Apr 2026 08:36:24 +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=1776674184; cv=none; b=IixNbl1dtKw1xsQFCX/wDCRR9M4/5aJu3uBiRIZPHEs8I7ZfQRODl3c2wuaoFCnQ2DBPmocpzxU9w+TNDWlrjzpK/F2eHF959L8e0LPAWkHcviL3oyIgZ80DqUYchDAmMKXjuEIngywxMmf5DvwWp2WUYvfqFwHMnjWqbQKEEeo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776674184; c=relaxed/simple; bh=ZjSMC1+rQxb7tT18VaXKCGLg1fOlc/Ds+iviih6AekI=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=UyB7yKL23VwBcS995NJx/CRpjjR0o+80q+Opk8uHFpnwkQEnsjg5qKhbqvEvaER9SR+eSGi28zfqo09C4XvmsZifrZ4iwAjD2Ep0D+4eFLJqjcphZjzs2F0iwdYcwGTl2A0yQH2aarmxX9RXiE/HgzXN6WoHl6C1KugW8zuwkFM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OyNb3JVH; 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="OyNb3JVH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 775BFC19425; Mon, 20 Apr 2026 08:36:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776674184; bh=ZjSMC1+rQxb7tT18VaXKCGLg1fOlc/Ds+iviih6AekI=; h=Date:Subject:To:References:From:In-Reply-To:From; b=OyNb3JVH+N9z/VikAd0HqfX471mryIlcQzZylQwIHFI65x6mhe+7d+nG1yxGi/fuf 5c/DE8PeTOXC+JWdmg7y404PGdBuitmEf7920+6jRYRW2Y7wWvokr7u3Q5Nx5Fmqp+ LmMXQJzGZG6LUxWlaXkudra28vhaCjJ4cNuUU4/+7fEPWe7mBZi5VeDOeehMIklUqJ JrZkqmYZqbv8he/E7QJ/7NiXc/A9e8+eaUyNt/iULeaNH/AEOBicAcnAPi0BZl1Ot/ WuyCAXJ2pPPNqvmfBUXtqWXZ2gaEcKzEQbzvtXAAAeWWdmuCtUr6eFmNyUbCNjGAXU F7OkKfzODkn3Q== Message-ID: Date: Mon, 20 Apr 2026 10:36:20 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [mm?] KCSAN: data-race in mas_wr_store_entry / mtree_range_walk (2) Content-Language: en-US To: "Liam R. Howlett" , syzbot , akpm@linux-foundation.org, jannh@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, pfalcato@suse.de, syzkaller-bugs@googlegroups.com References: <69e1f975.050a0220.1de265.0009.GAE@google.com> From: "Vlastimil Babka (SUSE)" In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/18/26 01:50, Liam R. Howlett wrote: > * syzbot [260417 05:12]: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: 1d51b370a0f8 Merge tag 'jfs-7.1' of github.com:kleikamp/li.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=117dc4ce580000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=7f207c4b1fbf85a3 >> dashboard link: https://syzkaller.appspot.com/bug?extid=38a879f4a73497f2dfef >> compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 >> >> Unfortunately, I don't have any reproducer for this issue yet. > > ... and you won't. This will work unless we tear aligned unsigned long > writes/reads. Note I think the reproducer here means code that will trigger that KCSAN alert deterministically (as opposed to fuzzing), not something that would depend on whether the alert is pointing to a "real" problem.