From patchwork Mon Sep 21 19:12:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Dewar X-Patchwork-Id: 11790769 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F20B759D for ; Mon, 21 Sep 2020 19:13:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D393B216C4 for ; Mon, 21 Sep 2020 19:13:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bnj1JHq7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727423AbgIUTNX (ORCPT ); Mon, 21 Sep 2020 15:13:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726810AbgIUTNX (ORCPT ); Mon, 21 Sep 2020 15:13:23 -0400 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACE05C061755; Mon, 21 Sep 2020 12:13:22 -0700 (PDT) Received: by mail-wr1-x441.google.com with SMTP id z4so13978613wrr.4; Mon, 21 Sep 2020 12:13:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=aPi1IscOmPCDTsGEXayQqIEZk0OLwEPpIOImWgP4cnQ=; b=bnj1JHq7CcAGVKoKWOfIh+tsUynbNk25F6tBjfR2b7ExNP9P3sPNDyyFOlV53LMkcU OtcZyoh+5k+zdWgFqCZLq1hlEP7T6vNBO5eCAksb9FzrElsiEViZ2yB5VL0f684DDq7b ARsRJf05ILNP9eqxtEGyRcc8a6fX+O3/xyaAHoR5BjAU+ScuqXK8Ekjs1RDTkSz5Utke 785ruqM/npzdW3xwJ6BS+eriz2YIM+AiE8N75ICc+S9mwHvLz6qwkKb1Gua5QJ1R0vgh y3Y+USuwmL3DfmA0KzQYDSpmev9MDtGa/fEeGcCCQBI4U2OQFnHEOz1hlz8CLDc2bQqP XO9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=aPi1IscOmPCDTsGEXayQqIEZk0OLwEPpIOImWgP4cnQ=; b=o+JDlkWsBjGB/RItsqMsIXoaWULccm/mDOEcyc8S3LC7aa1h3ei4wvrOLzKCJRfUZK K5wdnvH1CCG8acXlYdynEppKNSHzFatKSdW872+MBBrbriarIMC4BXxzmARlSA9hI5P/ tNWvrhMEAa1g+Iws+WKjOnPkZUhA+hhTBOctS6n6lxsO8J+vLoTO3D7smZYwlLOXzoZO OuI757U94Ba6Z7Ab3ptfIwKOePWCDkhFwEr5CfdAjsaMd5H1uPzF1uccZ52SbroxyQaY x1KbAFhEjniGdtWAt2Av9vHo0JzJr5N82B3ygMXMtjTjeINPjcVAfHS4PMA8cqfw3Fn2 X5Kg== X-Gm-Message-State: AOAM532bnop/6OC4RhV5bqXik7MtJQL8c+QwytZ4l1eWeXDby25eLgqO dZEPX4H7eo5j6FnFz0eX00w= X-Google-Smtp-Source: ABdhPJxvfPxZM/4oUFnZ0MvIM9LiFCHrzJweXb63DAr++LmDEgMfMhW3R4OIuoyfgW8omvxEmzXGHA== X-Received: by 2002:adf:fe43:: with SMTP id m3mr1282186wrs.19.1600715601388; Mon, 21 Sep 2020 12:13:21 -0700 (PDT) Received: from localhost.localdomain (cpc83661-brig20-2-0-cust443.3-3.cable.virginm.net. [82.28.105.188]) by smtp.gmail.com with ESMTPSA id z83sm874068wmb.4.2020.09.21.12.13.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Sep 2020 12:13:20 -0700 (PDT) From: Alex Dewar X-Google-Original-From: Alex Dewar Cc: Alex Dewar , Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] btrfs: Fix potential null pointer deref Date: Mon, 21 Sep 2020 20:12:44 +0100 Message-Id: <20200921191243.27833-1-a.dewar@sussex.ac.uk> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org In btrfs_destroy_inode(), the variable root may be NULL, but the check for this takes place after its value has already been dereferenced to access its fs_info member. Move the dereference operation to later in the function. Fixes: a6dbd429d8dd ("Btrfs: fix panic when trying to destroy a newly allocated") Addresses-Coverity: CID 1497103: Null pointer dereferences (REVERSE_INULL) Signed-off-by: Alex Dewar Reviewed-by: Josef Bacik --- fs/btrfs/inode.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a5dae53c1e27..8f230b7bfe65 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8648,7 +8648,6 @@ void btrfs_destroy_inode(struct inode *vfs_inode) struct btrfs_ordered_extent *ordered; struct btrfs_inode *inode = BTRFS_I(vfs_inode); struct btrfs_root *root = inode->root; - struct btrfs_fs_info *fs_info = root->fs_info; WARN_ON(!hlist_empty(&vfs_inode->i_dentry)); WARN_ON(vfs_inode->i_data.nrpages); @@ -8673,7 +8672,7 @@ void btrfs_destroy_inode(struct inode *vfs_inode) if (!ordered) break; else { - btrfs_err(fs_info, + btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", ordered->file_offset, ordered->num_bytes); btrfs_remove_ordered_extent(inode, ordered);