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 9A88BC432C0 for ; Wed, 27 Nov 2019 20:47:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 733AE21844 for ; Wed, 27 Nov 2019 20:47:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574887642; bh=phxjke+MdZknIuPKAZ3hQGzWF9cgS8GpyWlJh7zQ7/8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JxXtkUvSAt/Fs2JUd4cZkIUqGeSxMLqhgQRriGAd2F6MJ2Y8nNkB4N0inHyyWIVqt vLDQMh74rQo69yDIEwx+L68rtni2Idfv6syxYjDlWXMX+FSGIaeF0oyGqZwL4X7Y0z f/jPHINM4X9TksMg9sT48c+TpxuQEMdcDnfK7IhA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729237AbfK0UrV (ORCPT ); Wed, 27 Nov 2019 15:47:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:59854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729972AbfK0UrN (ORCPT ); Wed, 27 Nov 2019 15:47:13 -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 2DC6421826; Wed, 27 Nov 2019 20:47:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574887632; bh=phxjke+MdZknIuPKAZ3hQGzWF9cgS8GpyWlJh7zQ7/8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=swM85izSSqYQckxcIFpcF+CHwGkHTH98zDTNa2J8z7JMgPPoUYN8PrGnzzGqjhUHJ zA3CJ5vXA1qCW6ps7HawTtylXye2I4JkxItEmwscZyihwXpDDFyRxQYilfpx2zfgmP NGqmPT0KtMGaXonzBN2Dj3Apo6o7xr7BcG237F3E= 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 4.14 033/211] btrfs: handle error of get_old_root Date: Wed, 27 Nov 2019 21:29:26 +0100 Message-Id: <20191127203054.972119527@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191127203049.431810767@linuxfoundation.org> References: <20191127203049.431810767@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 27983fd657abd..d2263caff3070 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2988,6 +2988,10 @@ int btrfs_search_old_slot(struct btrfs_root *root, const 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