From patchwork Fri Feb 21 07:42:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230706 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CFCCFC35640 for ; Fri, 21 Feb 2020 08:39:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B49420578 for ; Fri, 21 Feb 2020 08:39:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582274360; bh=1Nd3uqmzSwlrm6Jrm/B7yAgszo+KDV79jFfoLkxUOLE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=10VPPhxDuvLHKW8HQQZfTyJCbqIwbFrh8+ZmJ5sHS9GIijZMxTELaJ+orJQPZ6ltl Xyutb1jHhkp37rZTkjvkkILZ2GNDtw655Lyd9S1Z7MWgLHolWNXjQK/z0wvpZF99b9 +i+CDsWHYH2x/lCHcTtVPtDzAIuYF/hMr3JT3OAQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731161AbgBUIBQ (ORCPT ); Fri, 21 Feb 2020 03:01:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:33520 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730863AbgBUIBP (ORCPT ); Fri, 21 Feb 2020 03:01:15 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4C6DE206ED; Fri, 21 Feb 2020 08:01:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582272074; bh=1Nd3uqmzSwlrm6Jrm/B7yAgszo+KDV79jFfoLkxUOLE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=whL5EsWrliUqkS911cWmrwrNrRfTyNzjlKrNQgDo3YgXd3JArjOPlkZnfv8xks1st vxypPtIp04oR788/Q0mSlj8+AfM9XdSnJiarOLn/WDnEVKxn5J9OeRDGvTzI6LU1hU E8UrWHwZTQlbCpYQ1IqpOPJq6/8S4dx50sXRV2Ko= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Coly Li , Jens Axboe , Sasha Levin Subject: [PATCH 5.5 399/399] bcache: properly initialize path and err in register_bcache() Date: Fri, 21 Feb 2020 08:42:04 +0100 Message-Id: <20200221072438.575910308@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072402.315346745@linuxfoundation.org> References: <20200221072402.315346745@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Coly Li [ Upstream commit 29cda393bcaad160c4bf3676ddd99855adafc72f ] Patch "bcache: rework error unwinding in register_bcache" from Christoph Hellwig changes the local variables 'path' and 'err' in undefined initial state. If the code in register_bcache() jumps to label 'out:' or 'out_module_put:' by goto, these two variables might be reference with undefined value by the following line, out_module_put: module_put(THIS_MODULE); out: pr_info("error %s: %s", path, err); return ret; Therefore this patch initializes these two local variables properly in register_bcache() to avoid such issue. Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/md/bcache/super.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 05cb94664efee..3b3724285d907 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2376,18 +2376,20 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, const char *buffer, size_t size) { const char *err; - char *path; + char *path = NULL; struct cache_sb *sb; struct block_device *bdev = NULL; struct page *sb_page; ssize_t ret; ret = -EBUSY; + err = "failed to reference bcache module"; if (!try_module_get(THIS_MODULE)) goto out; /* For latest state of bcache_is_reboot */ smp_mb(); + err = "bcache is in reboot"; if (bcache_is_reboot) goto out_module_put;