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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 A7A69C43603 for ; Sat, 7 Dec 2019 22:29:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C1AC24670 for ; Sat, 7 Dec 2019 22:29:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=fau.de header.i=@fau.de header.b="O+A0xdQX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726427AbfLGW3r (ORCPT ); Sat, 7 Dec 2019 17:29:47 -0500 Received: from mx-rz-3.rrze.uni-erlangen.de ([131.188.11.22]:47579 "EHLO mx-rz-3.rrze.uni-erlangen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725847AbfLGW3r (ORCPT ); Sat, 7 Dec 2019 17:29:47 -0500 X-Greylist: delayed 321 seconds by postgrey-1.27 at vger.kernel.org; Sat, 07 Dec 2019 17:29:46 EST Received: from mx-rz-smart.rrze.uni-erlangen.de (mx-rz-smart.rrze.uni-erlangen.de [IPv6:2001:638:a000:1025::1e]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by mx-rz-3.rrze.uni-erlangen.de (Postfix) with ESMTPS id 47VkXL0dYcz20Yn; Sat, 7 Dec 2019 23:24:34 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fau.de; s=fau-2013; t=1575757474; bh=S8KC8+rjd9jYzf2BGy5fukUD+/i6Mak7uynOyY8j3ys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:To:CC: Subject; b=O+A0xdQXU2zDPz0jAf21Oo+W9wddh8z2GO7rPabNC4pvLNfaF4/TnKCiog0Bj2eWa DYCNzQXDvqrJhbf3cQtDzqyGUv0RcvbK0oFh4OV2NpFYH+Zh0qk6ct1U0ydSOrXKia gg+zPN4bGHzGqkI9yGSmvQT+VTvmwDWuQn4v+tXZ6rg8esb7/7tqkf7wNwS1e0hLii CkRKfDjeD48JZMaF2rt4w4XuOhSFjB8KQCVM+oWUAAJ4clHqiXyMwgsA3QmPL2vWXh H0HTpwvIuHZI3ZmOYqtWRe2LqCzH3o3oyuDqlzurPH+SGFcvuy66Vrvkd/sGF0iIh6 gelUKumRIFvtQ== X-Virus-Scanned: amavisd-new at boeck4.rrze.uni-erlangen.de (RRZE) X-RRZE-Flag: Not-Spam X-RRZE-Submit-IP: 131.188.22.146 Received: from localhost.localdomain (firewall.henke.stw.uni-erlangen.de [131.188.22.146]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: U2FsdGVkX19WIVfm9a1gWO38tbJ7T5+TTACM/Uql3CU=) by smtp-auth.uni-erlangen.de (Postfix) with ESMTPSA id 47VkXH32G0z20Xm; Sat, 7 Dec 2019 23:24:31 +0100 (CET) From: Sebastian To: clm@fb.com Cc: josef@toxicpanda.com, dsterba@suse.com, linux-btrfs@vger.kernel.org, linux-kernel@i4.cs.fau.de, Sebastian Scherbel , Ole Wiedemann Subject: [PATCH 2/2] btrfs: Move dereference behind null check in check volumes Date: Sat, 7 Dec 2019 23:18:18 +0100 Message-Id: <20191207221818.3641-3-sebastian.scherbel@fau.de> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191207221818.3641-1-sebastian.scherbel@fau.de> References: <20191207221818.3641-1-sebastian.scherbel@fau.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Sebastian Scherbel Regarding Bug 205003, point 2 The struct "tgtdev" is currently dereferenced before being checked for null later on. This patch moves the derefernce after the null check to avoid a possible null pointer dereference. Furthermore WARN_ON is replaced by BUG_ON to prevent the subsequent dereference of the null pointer. Signed-off-by: Sebastian Scherbel Co-developed-by: Ole Wiedemann Signed-off-by: Ole Wiedemann --- fs/btrfs/volumes.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index d8e5560db285..12015f60f50d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2128,9 +2128,11 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev) void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev) { - struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices; + struct btrfs_fs_devices *fs_devices; + + BUG_ON(!tgtdev); + fs_devices = tgtdev->fs_info->fs_devices; - WARN_ON(!tgtdev); mutex_lock(&fs_devices->device_list_mutex); btrfs_sysfs_rm_device_link(fs_devices, tgtdev); -- 2.20.1