From nobody Fri Dec 19 15:46:22 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 BB832C433FE for ; Sat, 22 Oct 2022 07:41:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231231AbiJVHl4 (ORCPT ); Sat, 22 Oct 2022 03:41:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230519AbiJVHl3 (ORCPT ); Sat, 22 Oct 2022 03:41:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C97002D762; Sat, 22 Oct 2022 00:39:26 -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 1BADAB82DB2; Sat, 22 Oct 2022 07:37:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BC9AC433D6; Sat, 22 Oct 2022 07:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666424219; bh=jBoTbudxBixvFylnCwkGubpi1p23EEKMHTLT51gJ8yc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TZV78V4vEcacLNqVOteInxngf0sBchFvD3o6EC965Uq5kPflbJFWVWB/gdBnhrTIG lxnzjkFaddwXFWYRLS0jKUzx0X7gyIRiWfw243xy+tdse1ebRxIcPfG7YIJ/2Si0yK kNlGnOKRDk1lOueTEoiszkwzdskaWLFA4PnkZKzw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Aring , David Teigland Subject: [PATCH 5.19 036/717] fs: dlm: fix race between test_bit() and queue_work() Date: Sat, 22 Oct 2022 09:18:35 +0200 Message-Id: <20221022072421.521048689@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221022072415.034382448@linuxfoundation.org> References: <20221022072415.034382448@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);