From mboxrd@z Thu Jan 1 00:00:00 1970 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 4E642C4332F for ; Tue, 7 Nov 2023 12:50:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234739AbjKGMuD (ORCPT ); Tue, 7 Nov 2023 07:50:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233877AbjKGM2b (ORCPT ); Tue, 7 Nov 2023 07:28:31 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36208262F5; Tue, 7 Nov 2023 04:19:43 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA7E1C43391; Tue, 7 Nov 2023 12:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699359569; bh=g22D1Atd4dAcFgs25qXekSdfdiW5ufji0kSmh6Hwzlc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VrkICrvKa0rBzvlI9YGovDbtvD/R0oDNlXe1LcLnLTdg8iBuodrDk8e5/6cDmklW4 a/KRu0K3ER+aHfBao3yubAMU5f/Adzz8A3bwcXv1dsNnZjmGOV0cO4uVgY6JM8oeos fGPyFdFGH0B60+nrVR3K77/dfAVW80h3XFjkvrQ+K9aPOH4CATY514hFrqa8MIGJOX CPOWgC1Tr3abklRlMXbBhxEjBPmLfFPmtDd1RNGzOc1lG2JeLRUSNZCyprOjtW5ZX4 SN2TOdICAW2YfA29EOYY3rsRO8QJqdsgtls0ttiizfoF5qitIp3ocUlT7WhfSfT/5w GN9JLN+F69fJg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yu Kuai , Song Liu , Sasha Levin , linux-raid@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 08/40] md: don't rely on 'mddev->pers' to be set in mddev_suspend() Date: Tue, 7 Nov 2023 07:16:10 -0500 Message-ID: <20231107121837.3759358-8-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231107121837.3759358-1-sashal@kernel.org> References: <20231107121837.3759358-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yu Kuai [ Upstream commit b721e7885eb242aa2459ee66bb42ceef1bcf0f0c ] 'active_io' used to be initialized while the array is running, and 'mddev->pers' is set while the array is running as well. Hence caller must hold 'reconfig_mutex' and guarantee 'mddev->pers' is set before calling mddev_suspend(). Now that 'active_io' is initialized when mddev is allocated, such restriction doesn't exist anymore. In the meantime, follow up patches will refactor mddev_suspend(), hence add checking for 'mddev->pers' to prevent null-ptr-deref. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230825030956.1527023-4-yukuai1@huaweicloud.com Signed-off-by: Sasha Levin --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index a104a025084dc..9247e55c7eafc 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -449,7 +449,7 @@ void mddev_suspend(struct mddev *mddev) set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags); percpu_ref_kill(&mddev->active_io); - if (mddev->pers->prepare_suspend) + if (mddev->pers && mddev->pers->prepare_suspend) mddev->pers->prepare_suspend(mddev); wait_event(mddev->sb_wait, percpu_ref_is_zero(&mddev->active_io)); -- 2.42.0