From nobody Tue Dec 16 11:42:55 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 2E609C32773 for ; Fri, 19 Aug 2022 16:21:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352411AbiHSQUr (ORCPT ); Fri, 19 Aug 2022 12:20:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352352AbiHSQQY (ORCPT ); Fri, 19 Aug 2022 12:16:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 877C3100F3B; Fri, 19 Aug 2022 08:59:31 -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 dfw.source.kernel.org (Postfix) with ESMTPS id F2EEC6177D; Fri, 19 Aug 2022 15:59:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3682C433C1; Fri, 19 Aug 2022 15:59:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660924769; bh=plkBKwiOcI2hGfmIj8K2S+MNH4ueJp+UZYExWInq59s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ihrjKw5BXmZasCMpjGGgqHk5BI5DeIDmNZeYgYi9DUcVDfD+oqA6lkkyLVseAUC/h 9eCBI2sEMIlBIS/n/udHtpb8c1tfPISDRlYVKezeFTk+r6vardfRmCAFp+zbqzFfSO /mjr7GqrvZwNapo6RgrGUuTAzqHab63WRr6m7J1A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Duoming Zhou , Miquel Raynal , Sasha Levin Subject: [PATCH 5.10 275/545] mtd: sm_ftl: Fix deadlock caused by cancel_work_sync in sm_release Date: Fri, 19 Aug 2022 17:40:45 +0200 Message-Id: <20220819153841.641794646@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819153829.135562864@linuxfoundation.org> References: <20220819153829.135562864@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: Duoming Zhou [ Upstream commit a61528d997619a518ee8c51cf0ef0513021afaff ] There is a deadlock between sm_release and sm_cache_flush_work which is a work item. The cancel_work_sync in sm_release will not return until sm_cache_flush_work is finished. If we hold mutex_lock and use cancel_work_sync to wait the work item to finish, the work item also requires mutex_lock. As a result, the sm_release will be blocked forever. The race condition is shown below: (Thread 1) | (Thread 2) sm_release | mutex_lock(&ftl->mutex) | sm_cache_flush_work | mutex_lock(&ftl->mutex) cancel_work_sync | ... This patch moves del_timer_sync and cancel_work_sync out of mutex_lock in order to mitigate deadlock. Fixes: 7d17c02a01a1 ("mtd: Add new SmartMedia/xD FTL") Signed-off-by: Duoming Zhou Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220524044841.10517-1-duoming@zju.= edu.cn Signed-off-by: Sasha Levin --- drivers/mtd/sm_ftl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c index b9f272408c4d..2fedae67c07c 100644 --- a/drivers/mtd/sm_ftl.c +++ b/drivers/mtd/sm_ftl.c @@ -1098,9 +1098,9 @@ static void sm_release(struct mtd_blktrans_dev *dev) { struct sm_ftl *ftl =3D dev->priv; =20 - mutex_lock(&ftl->mutex); del_timer_sync(&ftl->timer); cancel_work_sync(&ftl->flush_work); + mutex_lock(&ftl->mutex); sm_cache_flush(ftl); mutex_unlock(&ftl->mutex); } --=20 2.35.1