From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.126.com (m16.mail.126.com [117.135.210.8]) (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 DBD913368AF; Wed, 20 May 2026 03:20:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779247254; cv=none; b=O5GRvBYh6IJq7B3avjYesxOz28gY0aOHlk1eaSxeUQ+pXJHqEH35PUwGFP4Ms6oaq7MBXkVpB0VD4TkX0EuEps34Znt9FRARPQ3+I+c0Mzd5Kjq6ynIFEk5wC5BnSGVoSiatJibOntjci+uXTxjSyYJ4eIcv4B4b5jgg7D06fog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779247254; c=relaxed/simple; bh=cfYq+SjH+p+YG232F3VRkdb2diPl1oNEJ31m4DeUH6A=; h=Message-ID:Date:From:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type; b=H2koBLQEjVZDgBlNHKHpR9L+jJO4BhcrSS9MNijnEvcjUv3hX3gECWqB8rjAt16GI3PutGx7gVzJ4S1GrXsiWnEefCFr6eW71ZmMFoIF92V9ZR4lMM6DSXgkWbOqNL3VtLUWX/K3fZgYGQbkKw+tq9qQYTR0H1ogaYANw2MAz1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com; spf=pass smtp.mailfrom=126.com; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b=YDVBch3i; arc=none smtp.client-ip=117.135.210.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=126.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b="YDVBch3i" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; bh=XB2OMyDi8b4+Shyxz45cEcm4xV0Vs3VCygezyQF4KrI=; b=YDVBch3i1WQ5MDHiUnSMfwDs6anstozmqJ9h+sSAvBdRaaWdYLmIvAFzVjoH/Z rKZ4pGzSSORfmNU0SVFky0nd7ldRCYlJTq+f9OlcJzW6E0NZa/d6YSpvBNbBSlhG RsM7uLvD1hOj/PHlcrgZU73TkuOT96AsPoFWyY4f7R6N4= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g1-0 (Coremail) with SMTP id _____wDnF9p+KA1qpSx1Bg--.2621S2; Wed, 20 May 2026 11:20:31 +0800 (CST) Message-ID: <6A0D2886.1020707@126.com> Date: Wed, 20 May 2026 11:20:38 +0800 From: Hongling Zeng User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 To: Tetsuo Handa , Ming Lei CC: Hongling Zeng , axboe@kernel.dk, ming.lei@canonical.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] block/loop: Fix NULL pointer dereference in lo_rw_aio() References: <20260519040103.22776-1-zenghongling@kylinos.cn> <6A0BFDE2.5000808@126.com> <6A0C29F6.5080704@126.com> <8f5602c6-52c6-4c96-9c85-892160b1718b@I-love.SAKURA.ne.jp> In-Reply-To: <8f5602c6-52c6-4c96-9c85-892160b1718b@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wDnF9p+KA1qpSx1Bg--.2621S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrKFWDAF18uFWrGw4ruF48JFb_yoWxCrg_CF 409F9xJw1kGr4UWan8CF43ZrZ5t3W5Xry5Jr47ZFy5ZF93JFWayFs3Grn5Z39rXrW7Jrsx AryF9anYkr1agjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU8DEf5UUUUU== X-CM-SenderInfo: x2kr0wpolqwiqxrzqiyswou0bp/xtbBoR8H12oNKH89sAAA3T Thanks, I'll review Tetsuo's analysis to better understand the full scope of the issue. 在 2026年05月19日 20:37, Tetsuo Handa 写道: > On 2026/05/19 20:28, Ming Lei wrote: >>> This means |__loop_clr_fd()|runs while I/O is still active. >>> Regression introduced by: >>> 6050fa4c84cc ("loop: don't hold lo_mutex during __loop_clr_fd()") >> Why do you conclude it is caused by above commit? > Some commit in the merge window for 7.1 broke the loop driver. > Even synchronize_rcu() + drain_workqueue(lo->workqueue) is not sufficient. > Please see a thread at https://lkml.kernel.org/r/d43125ff-cc66-49b7-b16d-1b2650c68c23@I-love.SAKURA.ne.jp .