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 7C21042885F; Thu, 16 Jul 2026 14:25:42 +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=1784211943; cv=none; b=JNfoRg/6IE0ahoFane1dFPVZGuLF4lxjMr8Qo9+2cQlvMWnAZ/nKeXC0lXMTYeYzJ6lH5PC0+56pl/QQKLwW+QkhshKfu0uw53EUVElUPw83Cnec55FdKV7kLg0PhIbRYdj3K213OX8L4EP+oxwEHltReeRID/zb2bosDvTGK/Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211943; c=relaxed/simple; bh=4dUqs1hb95fRvear9s9X1KHrqhmxzE5iKvTfMiSqYgY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HHXLJT3c22h3l3H3ck3PSxBC3ZhIW1opJt1CDlo/fSgolOSMnRlQX2yHD6CnJPDFEt/cTWaKcXOXiyzo15/agGbUTsTXPXUXVEeIQ0HTr75Q3sQRyn38EIgSO5gYzJMUNfVQawx6lKHVbovZAHLsIbsdH4iu26nwt300PbE9tpM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UzPLy1rM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UzPLy1rM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0CCE1F000E9; Thu, 16 Jul 2026 14:25:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211942; bh=SdWqpj9BOr6OuX/zVlmX+2ZIC5oYmzzDvBPPitmtoBo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UzPLy1rMXV/F6RkZoX+lftBc8VfJ+W+wyxML5mWngyZvbeFTFCG7gS/iWDqTD0CkF 9muereOGghr/kivB6tJtQ6XuNiBbq63tPoh3Y4lkuV/PoDqxsCex5a7qLoX/4GLmXy LJkOyOO+sVFOXNsWbvc3tqYfftJxShXrlLUZvWb8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Runyu Xiao , Jens Axboe Subject: [PATCH 6.12 137/349] io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item Date: Thu, 16 Jul 2026 15:31:11 +0200 Message-ID: <20260716133036.429714048@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Runyu Xiao commit 29bef9934b2521f787bb15dd1985d4c0d12ae02a upstream. commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early. io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun. Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time. Fixes: 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") Cc: stable@vger.kernel.org Signed-off-by: Runyu Xiao Link: https://patch.msgid.link/20260527172203.2043962-1-runyu.xiao@seu.edu.cn Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/io-wq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/io_uring/io-wq.c +++ b/io_uring/io-wq.c @@ -554,7 +554,6 @@ static void io_worker_handle_work(struct struct io_wq *wq = worker->wq; do { - bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state); struct io_wq_work *work; /* @@ -590,6 +589,7 @@ static void io_worker_handle_work(struct /* handle a whole dependent link */ do { + bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state); struct io_wq_work *next_hashed, *linked; unsigned int hash = io_get_work_hash(work);