From nobody Fri Oct 17 10:31:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 556ABC4332F for ; Wed, 19 Oct 2022 08:42:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231158AbiJSImJ (ORCPT ); Wed, 19 Oct 2022 04:42:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230408AbiJSIku (ORCPT ); Wed, 19 Oct 2022 04:40:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1939680F7D; Wed, 19 Oct 2022 01:39:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 86E12B822D1; Wed, 19 Oct 2022 08:39:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE511C433D7; Wed, 19 Oct 2022 08:39:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666168747; bh=jBoTbudxBixvFylnCwkGubpi1p23EEKMHTLT51gJ8yc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wrffrh7X06cksoPcc86hWA3se0axooEjBP8G1e6B0cXxnbQBoMrKbKURE2UTyWdMJ AH1vIvL5p5hU16p32zzCTkcDPCyved0+6RyXAUVF5jjDzdwyjZR1HeFTUYLBM7tXTh XZ8LCWr3+gqgRtYXO8YsTOD3Ve6KjY+U048cT24w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Aring , David Teigland Subject: [PATCH 6.0 041/862] fs: dlm: fix race between test_bit() and queue_work() Date: Wed, 19 Oct 2022 10:22:08 +0200 Message-Id: <20221019083251.817711321@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Alexander Aring commit eef6ec9bf390e836a6c4029f3620fe49528aa1fe upstream. This patch fixes a race by using ls_cb_mutex around the bit operations and conditional code blocks for LSFL_CB_DELAY. The function dlm_callback_stop() expects to stop all callbacks and flush all currently queued onces. The set_bit() is not enough because there can still be queue_work() after the workqueue was flushed. To avoid queue_work() after set_bit(), surround both by ls_cb_mutex. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman --- fs/dlm/ast.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/dlm/ast.c +++ b/fs/dlm/ast.c @@ -200,13 +200,13 @@ void dlm_add_cb(struct dlm_lkb *lkb, uin if (!prev_seq) { kref_get(&lkb->lkb_ref); =20 + mutex_lock(&ls->ls_cb_mutex); if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) { - mutex_lock(&ls->ls_cb_mutex); list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay); - mutex_unlock(&ls->ls_cb_mutex); } else { queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work); } + mutex_unlock(&ls->ls_cb_mutex); } out: mutex_unlock(&lkb->lkb_cb_mutex); @@ -288,7 +288,9 @@ void dlm_callback_stop(struct dlm_ls *ls =20 void dlm_callback_suspend(struct dlm_ls *ls) { + mutex_lock(&ls->ls_cb_mutex); set_bit(LSFL_CB_DELAY, &ls->ls_flags); + mutex_unlock(&ls->ls_cb_mutex); =20 if (ls->ls_callback_wq) flush_workqueue(ls->ls_callback_wq);