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 EF38FC432C0 for ; Wed, 27 Nov 2019 20:42:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C822621781 for ; Wed, 27 Nov 2019 20:42:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574887326; bh=rQC+cGTzMCq1vXMp7OOlM5NKkFtnVplMXAgO3cNKb4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tBPImkBxJFdmzIAl5fiNP8obz/WAFaKaC+Ze3TUh/03IOrUacg4l+wiKWhXfkXIRw HpVcnFL/lKHF5B5oRTbq6rk9Cdokhnb+w0N+uYBdTzucKFBDN64Px/OlHAlU8mB/15 u7Jb0dYPNMhVuMmy7+IEcR/uADfbNGqsx50GAjos= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727509AbfK0UmF (ORCPT ); Wed, 27 Nov 2019 15:42:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:47824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729275AbfK0UmC (ORCPT ); Wed, 27 Nov 2019 15:42:02 -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 C091521741; Wed, 27 Nov 2019 20:42:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574887321; bh=rQC+cGTzMCq1vXMp7OOlM5NKkFtnVplMXAgO3cNKb4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TwSFxHDaT91EapIk1uxL3E7zvy6xen+rwpB6xn8yrX1DopsPk5Ns3rhnps6gapwwA ZdvjCqA/ucyCHASFRWITCp8uOv+3HT9PJZxGj3yo7DE/aFoi4RednEp5QroLwloBP+ svMSxt91PMzOs04+gaHzz/ZijXCXHF56B6WP66DA= 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 4.9 023/151] btrfs: handle error of get_old_root Date: Wed, 27 Nov 2019 21:30:06 +0100 Message-Id: <20191127203014.886551356@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191127203000.773542911@linuxfoundation.org> References: <20191127203000.773542911@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 3df434eb14743..3faccbf35e9f4 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2973,6 +2973,10 @@ 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