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 DE72145A28F; Tue, 21 Jul 2026 21:57:46 +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=1784671068; cv=none; b=vAb6H2ahaDZQFj1KbvcTl+0yzptlhCbpBJDwTInIzVtN/wSi/h3+X2b2AcBTvT7M0szHCGwrCa09KL+EZGJkdIOuorQWHMIA76w91oMkqi0+6SCJWSPIwL5EXkbA5SYUOsny6/tSNdIXT+fNjX+ithh0Tesn9ccOpHIc2W1tGrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784671068; c=relaxed/simple; bh=1r34K53Wx32hHlpA5rNtFJJdFK/BL7hRn17vXRlGR8c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dhoOKCPEDM4oqnlbPnjAPTH90Pplk8wn55bQdugbG52Pz1PSD4Bl+yqNahUN3hDOItfv1iVBtI+JMDnALC7F92L5GnjLuyM5ceENpym/a6SexhLR60OZTBes+qrK9q+e73AsoQA2BZ+7yzYtmmXMqaP7Uwk4ax9lQqQ0NpCHVFk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Bc8yvnQn; 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="Bc8yvnQn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E704B1F000E9; Tue, 21 Jul 2026 21:57:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784671066; bh=sAwHE+/HoMNScTF1wXSHAB7/xbHv41veGN8GtsBLJp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Bc8yvnQnjmwJ/GW8+GNIImuqvJiLzqo0LBcU9kaoAsbmsqhfqp2LWU759l+KjnS6L 9x2ZPfC2qip3A9phI13kaQh6+/u/IqHDZsQXTMW/JweO0OV2Ev63O4QbfX2XLxxCSS WsXMX0wzg+ubYAq/DXqoccLOOIm2e1KHpumU7NLs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Runyu Xiao , Jens Axboe Subject: [PATCH 5.15 106/843] io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item Date: Tue, 21 Jul 2026 17:15:41 +0200 Message-ID: <20260721152408.387515981@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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 5.15-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 @@ -556,7 +556,6 @@ static void io_worker_handle_work(struct struct io_wq *wq = wqe->wq; do { - bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state); struct io_wq_work *work; get_next: /* @@ -578,6 +577,7 @@ get_next: /* 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);