From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f53.google.com (mail-qv1-f53.google.com [209.85.219.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BCB73612CF for ; Wed, 27 May 2026 03:00:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779850860; cv=none; b=dCFSQw4g2hXiTYN1K9Sxyyt1K8eQbWpBy/qloIclIH2Ff90CTElHnatqDIGP7K4ncgjA5nWaZSgAyPlCYf+JoVGLGnAEdnwwOGoOYeTB5+3s13VWTiXTo76roWPUBq1+nLvViw7mNrg6FZBKAXuzjwfvyqoj70GLtQLK0IPZL+8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779850860; c=relaxed/simple; bh=l24Cx1MrKrvp4Q2cUKmT1CDQC1RwyjfAflDdCsjh3ng=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VZV97ZQPifMUC6VDbHBKwg8mE8+srS79wQLXklb6mhh2t6z2YUwGpKyIxfB+1ZIYwjyVeEM9PiXaKUOuuXZvvuUBOQOBfPeUoUlIjH9bHThxGTVJbZqKeVq0eNysyBV+/odOdnTRAaN299eQZ3uLoO5tgSlsEzAEHP19x67AX98= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=otPOjawa; arc=none smtp.client-ip=209.85.219.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="otPOjawa" Received: by mail-qv1-f53.google.com with SMTP id 6a1803df08f44-8b7105dfb35so145627356d6.3 for ; Tue, 26 May 2026 20:00:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1779850858; x=1780455658; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=LW74ifQIEMw9K0LJrVq6jLhT79y6ZRMrtmCmy57465k=; b=otPOjawas0BUAfr7T7mWO/WO2cE9MqQwXaLT1vnDh7uBqVDWlQ2LzgkXovUMs3I5xK hI3emTeseBOhS4+I7/IBi8+P4GZ0RxFZKb/a5WvujLn5k6v/34AmyenTjzCeCdJbg32T mlHQ0xigGqGFb8VGAkB6pHqB0l7XbFEqw+ETuaIqQHKYCvP6DXRofuaFs4/aeANIvPDH de33rYv4z2KOJcLwuM6+TeylcJmBEaD5T08oFieNjlNn494zPrLIe8rGNP/N6tPOtPG5 2WE2mrnc6zEJy8CYtxH4udIJGEDa4kVLTsM7U9McNlfe95D/MytXxo5sO4VPh+4uVCiD eLEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779850858; x=1780455658; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LW74ifQIEMw9K0LJrVq6jLhT79y6ZRMrtmCmy57465k=; b=kcs52TcySrjT/WZCtfwtVobUz+yRCig+jMcZCQzMNMaQL3Bhe/cgPg5fGJkapHi7J5 vbWqfKQl8NXDu8PIO742PWBo+q0ooo7IY6TEW1aRMZJiJ8w/WxQ2VOyjMzZEcZNEh2JZ laJCjWggXwIZtXBokkThGy4YR0oQdeNUkMy31hNE3uCCZgoeP+ZuTdcieVvPy1qSvcGh RqFSIQz/OHoJSQxRxvmIAsa9XGQssQBeXfLW7JuVNknGAZFXGi+G3EQhtwfBpA0UsqFQ qzA2GpLXZMgPnenvFCammyrHuadu03vzj0aa0c+nGaTYMd1X7wT0cOmc4USylnw8pzKt u6iQ== X-Forwarded-Encrypted: i=1; AFNElJ+pEql2t8NyotA9Zbx6ihzYn5eZN4j3aAwljtLwwty/y68rKUTk5sbqXd8Qss61E0aILgrKUEFiZkFg1pA=@vger.kernel.org X-Gm-Message-State: AOJu0YyOe6iacfnISf4Bsnody0KH7ka6eLgcxgthzwAOs9XwmX2G/UMz NaqVdMDt7+nVRbbtMqhuTba2IYYA8suyhLwdGuHUSqSkmwrgS8UiTGf8 X-Gm-Gg: Acq92OHv0ILmWEXGSTRCu0oqCYF6jzT2JjSWzwBeRLN2nihiCnF7P7/ofBbq8zEg8BA 4iBTuQFT2DFIjC0akAf54I7tTuJ+BRzFPXHKOp3a+Qm/kewii9oLbS+eOVTHk59jN/3aaUzCYqz q7YAPlREQCQ1OTl1vTIxjUmmzBNHgOy35FUZFJicrYGxXaMs2FSUqGNr+O+uLPfdtrGuP10SJiH ZNtiVnyfCUz4jcTmYonBELNtrWjxW/Ti5BfMLcZuiX7qoqNsjnCzp3d4ySlemegt71ytJLPzNbJ V+Pfiy/R9wiiGw4sfN2oyocnD+fpoy/JWlq0fI8h54MWfalhEITOnLdxBiXcQxkblQs1cK/0OGx Hot51GADw4WqUip3toTEKupOQ3Zv67g2U9WCu3prpiFZfkqhMPjg4P60dBznck2wzpownoX0XSE ojUU0DN9vlmg2nQPOiLGeB2isZpkMZ17xXC190v+L8fvvqKIr0Qol7HeW5lHQO9luQkMWXCICKR aDFhTYKTk9yTbUEjpWEtA== X-Received: by 2002:a05:6214:5093:b0:8a0:3bd8:5950 with SMTP id 6a1803df08f44-8cc7b5c0bb4mr338124896d6.23.1779850858174; Tue, 26 May 2026 20:00:58 -0700 (PDT) Received: from fedora ([172.245.82.59]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8cc81302a98sm153788216d6.33.2026.05.26.20.00.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2026 20:00:57 -0700 (PDT) Date: Tue, 26 May 2026 22:00:49 -0500 From: Ming Lei To: Tetsuo Handa Cc: Jens Axboe , Bart Van Assche , Christoph Hellwig , Damien Le Moal , linux-block , LKML , Andrew Morton , Linus Torvalds , linux-btrfs@vger.kernel.org, David Sterba , linux-fsdevel@vger.kernel.org, Christian Brauner Subject: Re: [PATCH v3] loop: Fix NULL pointer dereference in lo_rw_aio() Message-ID: References: <94076bc9-2c09-4bb6-8468-b6b8af419cb9@I-love.SAKURA.ne.jp> <1ab8c579-eb76-4227-8a72-6ec819135219@I-love.SAKURA.ne.jp> <1a9f53d4-6f48-4df8-a3d8-2b0e442a163a@I-love.SAKURA.ne.jp> Precedence: bulk X-Mailing-List: linux-kernel@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 Wed, May 27, 2026 at 10:35:56AM +0900, Tetsuo Handa wrote: > On 2026/05/27 10:20, Ming Lei wrote: > >> Of course we should try to figure out the root cause first, but how can we do? > > > > Definitely unexpected write IO(after umount & loop closed) from btrfs is more serious, > > which may cause data loss, so CC btrfs list and maintainer. > > Why do you assume that the culprit is btrfs? > > https://syzkaller.appspot.com/bug?extid=bc273027d5643e48e5b3 indicated that > this similar race is also happening with jfs. I just didn't see the above report on jfs. It doesn't change anything, the same question still stands: unexpected write IO is issued or crosses umount & last closing of loop disk. Thanks, Ming