From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 013.lax.mailroute.net (013.lax.mailroute.net [199.89.1.16]) (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 459254CCDED; Mon, 31 Aug 2026 16:14:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788192893; cv=none; b=CdljANNH+DKTWqPqum6LZ3XME9zYjSwCNEni7ltT2YE2/tGPZBq8BGwo8oh3xVDdzZnJVrzjy97qdjVrRPIQ3/YHkqKsI1k+C3UfrDKMs+1UgcRkTRRdqiLf3Idr5DigazHlqaYFfLMix77G6WiFQXVkImyZlqH4kWyenJETQ30= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788192893; c=relaxed/simple; bh=QNwcsZjJFVrXdEUCCIjgAGniheS835dXsn4vUs5xqng=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=V+gNqCnXtJQcPHPbA2ZqbFwki+CVRi2ZsRpU8MZoDCeBV/IZb4ShPq3AVFUuf8MPxy+2q3fiC21M96kWFDk1OmnZ7QNFCxyhKgBososgzqSwzvzjOD++3K1SDTbEZZvQcc4AJ1nvnHOJBJLkYYAcqNXCI3I7RbijBuUOTRlsyKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=4q1GZ52I; arc=none smtp.client-ip=199.89.1.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="4q1GZ52I" Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4hYYwp5WLdzlfvps; Mon, 31 Aug 2026 16:14:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1788192882; x=1790784883; bh=QNwcsZjJFVrXdEUCCIjgAGni heS835dXsn4vUs5xqng=; b=4q1GZ52IPMwMCZTI7qns+0qxTqPa80tDzWBakZW8 vh5ZTwqi9nR6cFCFQxzRhGLhzHTAGSmKZYUJ27rk+QkNb+kem+fKCm7oG8htVyuj /5Nj8OjyRZdz4P3B5H5CJgjzlwYcZykNZADke1kIyNKJSU+j363eV+SOEVpteawK rXk5QZmcPj/UwMMI3GgccRJij3GCu2qbUw1o5Z5fTRHJYtdhY2dWQyfsRx2s6M+6 YmqO2AhIU3kol6ENGjFj7Yn4+25H8wDqRHElcRy1aHdotJhsS/xnN06IwOnimkuM pFE7/QbJT3IWe0FqRsDnz/goozangZuvn++9npvefaCzJQ== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id mixfySwKtzaB; Mon, 31 Aug 2026 16:14:42 +0000 (UTC) Received: from [IPV6:2a00:79e0:2ed2:d:a104:ffdc:9983:687c] (unknown [104.135.182.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4hYYwX6WNtzlfvpM; Mon, 31 Aug 2026 16:14:36 +0000 (UTC) Message-ID: Date: Mon, 31 Aug 2026 09:14:35 -0700 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7] loop: Fix NULL pointer dereference in lo_rw_aio() To: Tetsuo Handa , Markus Elfring , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, Alexander Viro , Damien Le Moal , Jens Axboe Cc: linux-kernel@vger.kernel.org, linux-next@vger.kernel.org, lkp@intel.com, oe-lkp@lists.linux.dev, Christian Brauner , Christoph Hellwig , Christoph Hellwig , Hillf Danton , Linus Torvalds , Mark Brown , Oliver Sang , linux-btrfs@vger.kernel.org References: <8dedfc40-9cae-44ff-9960-e0eb1825e963@I-love.SAKURA.ne.jp> <550ff0b4-df39-46d2-9781-c8688df10c93@web.de> <38ad64c1-edc7-431d-8f52-fba572ebf3eb@I-love.SAKURA.ne.jp> <372ca5f6-81a0-4f6c-8f55-ebeeada9f955@acm.org> <27bcb147-bead-4432-8cd0-981489f36228@acm.org> <7e51bca8-218a-40b8-8ff8-fc59671f5add@acm.org> <3bb080d0-4421-4012-8a62-6a2bf165cbd9@I-love.SAKURA.ne.jp> <903a22a2-432c-4e72-bc09-7898becf2f3e@I-love.SAKURA.ne.jp> Content-Language: en-US From: Bart Van Assche In-Reply-To: <903a22a2-432c-4e72-bc09-7898becf2f3e@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/28/26 10:17 PM, Tetsuo Handa wrote: > Calling synchronize_rcu() makes sure that no more queue_work() calls are > made from loop_queue_work() from loop_queue_rq(). Since loop_queue_rq() is > called with RCU read lock, subsequent loop_queue_rq() calls which are made > after synchronize_rcu() returned shall see lo->lo_state != Lo_bound and > return with BLK_STS_IOERR. Please add a comment above the synchronize_rcu() call that explains the purpose of that call. > That is OK. But after you agreed that my patch works as expected. I appreciate your work and agree that this patch takes the right direction. But I would appreciate it if you would take another look at my review comments. Thanks, Bart.