From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423407AbeE1LHU (ORCPT ); Mon, 28 May 2018 07:07:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:53922 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423376AbeE1LHM (ORCPT ); Mon, 28 May 2018 07:07:12 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikolay Borisov , Liu Bo , David Sterba , Sasha Levin Subject: [PATCH 4.16 072/272] Btrfs: fix NULL pointer dereference in log_dir_items Date: Mon, 28 May 2018 12:01:45 +0200 Message-Id: <20180528100246.982508244@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180528100240.256525891@linuxfoundation.org> References: <20180528100240.256525891@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liu Bo [ Upstream commit 80c0b4210a963e31529e15bf90519708ec947596 ] 0, 1 and <0 can be returned by btrfs_next_leaf(), and when <0 is returned, path->nodes[0] could be NULL, log_dir_items lacks such a check for <0 and we may run into a null pointer dereference panic. Fixes: e02119d5a7b4 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") Reviewed-by: Nikolay Borisov Signed-off-by: Liu Bo Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/tree-log.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3548,8 +3548,11 @@ static noinline int log_dir_items(struct * from this directory and from this transaction */ ret = btrfs_next_leaf(root, path); - if (ret == 1) { - last_offset = (u64)-1; + if (ret) { + if (ret == 1) + last_offset = (u64)-1; + else + err = ret; goto done; } btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);