From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5694A4A4844; Mon, 31 Aug 2026 14:58:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788188340; cv=none; b=RNEs+k9uqjTH/gtNjsDeAtszBQJNyQytooWzmvX9T5BBcJgnydBf8fnTLadsIU+z/GtUY4YnWEz4jYIbELtML3Fgm+/7hHSGNFIyaNNw19O8lajyHexAdVI2lPYOX+9uxQQvp0tymaPbqO4FNBpnC6OO/p7IunmfZFZprwDEUo8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788188340; c=relaxed/simple; bh=APbP3/wimRJr2gE1cSIRP3gDJwEHcvRTK6fLaUrVbFU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=T8GQNtzC2CjhIJIPR5RIans1uj3BwQ+JLrzvx6RIzoUR4SXXogVsCu+VlImfGo70c8Q3TVxi5Y0RN93DCygYcnIAwt5keX0G9iQl6E926ob+qi+3jIYhSk29JItiKuAZDrCqC+9fLD23oSRqx5Mw7c+DBEM3/wQIPWiRfVk+Nfk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IwIigDYm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IwIigDYm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECE6B1F000E9; Mon, 31 Aug 2026 14:58:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788188339; bh=14bNFPNL5UxWNXFU6JP1TsTgUvqSn2B1NpHtXK6Gc8s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=IwIigDYmUFKcMyWnc48szI2N9Wf1Wh4eaJ2qeAnCArP5eyhm2WCJ1oHo6dgjvWvpF ayof/nBOv9fNGf3nv2yv01Z9SGx9EN2VB0EpgMiwFHPHe6oRCsqpBBeYHEnvOtramz D6+zHiFBVVUhrR7tUcHwrtKLP8C8USlKJCW6eslv2z1Mp+Wg7rBqmKekbpgG723oIr eRfL3UY11/lHkRl3UqYojjcvXTKKJsOk5pmrINmccWd5G17LJf09iDEIvbY4To1J5H l8kIhYmmNOV6nBxWslm/20cnKSzObV3L2Lej3GvhDx0B8a4TR9fnJi2baBUJyU+vCn fhq3hd98Ch23g== Date: Mon, 31 Aug 2026 08:58:57 -0600 From: Keith Busch To: Bart Van Assche Cc: syzbot , axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Christoph Hellwig Subject: Re: [syzbot] [block?] BUG: corrupted list in blk_mq_request_bypass_insert Message-ID: References: <6a926eaf.1d9ded08.62e62.0102.GAE@google.com> <2cf45e85-176a-4209-86ad-8f389a9a4282@acm.org> Precedence: bulk X-Mailing-List: linux-block@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: <2cf45e85-176a-4209-86ad-8f389a9a4282@acm.org> On Sat, Aug 29, 2026 at 05:16:00PM -0700, Bart Van Assche wrote: > On 8/28/26 10:31 PM, syzbot wrote: > > kernel BUG at lib/list_debug.c:34! > > Call trace: > > __list_add_valid_or_report+0x144/0x148 lib/list_debug.c:32 (P) > > __list_add_valid include/linux/list.h:96 [inline] > > __list_add include/linux/list.h:158 [inline] > > list_add_tail include/linux/list.h:191 [inline] > > blk_mq_request_bypass_insert+0x130/0x1cc block/blk-mq.c:2551 > > blk_mq_requeue_work+0x3a4/0x52c block/blk-mq.c:1560 > > process_one_work kernel/workqueue.c:3322 [inline] > > process_scheduled_works+0x788/0x10b8 kernel/workqueue.c:3405 > > worker_thread+0x798/0xbd0 kernel/workqueue.c:3486 > > kthread+0x304/0x3d4 kernel/kthread.c:436 > > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838 > > If my AI assistant got it right the root cause of this issue is as > follows (I haven't tried to verify this): > * Concurrent calls of nvme_reset_work() and blk_mq_requeue_work(). > * nvme_decide_disposition() does not check NVME_REQ_CANCELLED for > non-multipath requests and returns RETRY instead of COMPLETE. We want to be able to retry eligible commands that were caught in the crossfire of a controller reset.