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=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=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 01F2CC43215 for ; Wed, 27 Nov 2019 20:36:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD9512158A for ; Wed, 27 Nov 2019 20:36:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574886998; bh=28UcTghOrsaTsVNgqi4hwzYOQG18W8MsP+t0Js06z9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N5FTJMPokW6K6SfRQYNr+rBhG551wHSyDZT/2oIaa5Nl8xaCbIKzEuaPuKfK5pccd EuGe/YBhTrC5NYtYa+300UMLR/LjkPu6DeMSzrUc+wQKN+JcMw4FWXPYKkbp/eI5VP zJThaBOaFaR+IDu+eAqVusLA0vDbNMtIrM7ycwHk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728349AbfK0Ugi (ORCPT ); Wed, 27 Nov 2019 15:36:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:38946 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728287AbfK0Ugg (ORCPT ); Wed, 27 Nov 2019 15:36:36 -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 E63EB2158C; Wed, 27 Nov 2019 20:36:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574886996; bh=28UcTghOrsaTsVNgqi4hwzYOQG18W8MsP+t0Js06z9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SDcw5D/16kmpgSeP2aqr8EouM+oweTJDeNeZrTcelxkLjMkRSgFSu64HtJZMpAcmz G1GKtfchWNdYAirgNaiGCgXMR3NnXx/FcT6jKHgJxQZB2uhV4KvGyGXK5QgOvRnDnk Nk1YnVYNQ+quuzThWxwF5AwCqZBLr1HS7TK0bvbc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikolay Borisov , Lu Fengqi , David Sterba , Sasha Levin Subject: [PATCH 4.4 030/132] btrfs: handle error of get_old_root Date: Wed, 27 Nov 2019 21:30:21 +0100 Message-Id: <20191127202927.521838423@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191127202857.270233486@linuxfoundation.org> References: <20191127202857.270233486@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nikolay Borisov [ Upstream commit 315bed43fea532650933e7bba316a7601d439edf ] In btrfs_search_old_slot get_old_root is always used with the assumption it cannot fail. However, this is not true in rare circumstance it can fail and return null. This will lead to null point dereference when the header is read. Fix this by checking the return value and properly handling NULL by setting ret to -EIO and returning gracefully. Coverity-id: 1087503 Signed-off-by: Nikolay Borisov Reviewed-by: Lu Fengqi Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/ctree.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 51a0409e1b84a..a980b33097701 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2966,6 +2966,10 @@ int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, again: b = get_old_root(root, time_seq); + if (!b) { + ret = -EIO; + goto done; + } level = btrfs_header_level(b); p->locks[level] = BTRFS_READ_LOCK; -- 2.20.1