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 43B2035C681; Tue, 21 Jul 2026 21:11:38 +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=1784668300; cv=none; b=P5aU8cLp7zc+n3mZ5PKO0gFF9imCbPlmnWWJvnJEcDcBRNVA183xEDldFO11/8tUWaXarmI0aN5c59UL2ELot8cpeLIpaiPHa1G53ndtqCWlk00lZzbRSMVPLyGyBMcbGSyAqoS4aOljCwEEo9onmOst1hQAEX3mHBQd8h9f1vU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784668300; c=relaxed/simple; bh=Sc1xCOVBvv1MC7opRjWpNQ/+rQuLDCloFlCt2c/dM80=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r9rNxvOzZahRub1o4AVp0+44oUZp3Z9vvKuuXbGhjt/9rPaCrnuWZhLGZeIhOM7rCY2h0zeOjdJg9F/qDBtDKeX3irKtawHbZ4OIjCIhEOmhqmQoz5YDkqiXUL/pD4gvQqzDHKMSLApiJNk3aBuS0WLQcufxjuo6RLQ9B6byCCA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JFKCN7e/; 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="JFKCN7e/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A42211F000E9; Tue, 21 Jul 2026 21:11:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784668298; bh=QcYwqbNgBA47MPw839KwGyg7MSUG5OxBUGRTH6gVvHs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JFKCN7e/eF/CCDAb6GQ1EO/OFzAQLmdBg5Jl8sHgWygPn93NJRE5Ctp5T2w2fJfGB vc/mAuVZIQwNtVHGEarfMFTpRbZF4WeWSmqE5LR7P3sKBCL4BiiEOx3MJiDbH0snJZ zhMk6zphsFf2X/tppjSHj9LCNJ8e1kPsretHehgU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Runyu Xiao , Jens Axboe Subject: [PATCH 6.1 0123/1067] io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item Date: Tue, 21 Jul 2026 17:12:04 +0200 Message-ID: <20260721152427.342716277@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@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 6.1-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; /* @@ -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);