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=unavailable 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 570F3C432C0 for ; Wed, 27 Nov 2019 20:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FAB82084D for ; Wed, 27 Nov 2019 20:57:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574888233; bh=rsnNf15HrUbaGOrIbi6wyozb9yMbdByNuffKHCgCcss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kDrjY3wyTTRYrwmrFtqBUUbOl5c0cmuwcSOxICyfSnYKqlQ/PWmVgFjR1ik2DkkIv rGTTNsBeGyXr1sVNmb5rrolrAeFx7Bpgd2hpMJUFn0iqsQMfbG+8PRQdP0N4eg5/Iy xIJTePeEweun0xIolPpyltrz18DxgCrVnhdkPN9E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731145AbfK0U5I (ORCPT ); Wed, 27 Nov 2019 15:57:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:47952 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730754AbfK0U5C (ORCPT ); Wed, 27 Nov 2019 15:57:02 -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 632A821556; Wed, 27 Nov 2019 20:57:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574888221; bh=rsnNf15HrUbaGOrIbi6wyozb9yMbdByNuffKHCgCcss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IZD49FNIyTb9tcjGVAeOV21b2IyeqxlKS+Qxhg0IrVDPuUOK7yAsGo/56tnaGIb3Q WOnNU2bw4heg2OJnkgEJcDH161jjfDY4GaK7aJrXUR9RKcWfE6XcbWU6opd7p1dbRA m94fZZoEUZ9knkCDFYvsA1fZjsgrMBG5eQPVwGPc= 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 4.19 049/306] btrfs: handle error of get_old_root Date: Wed, 27 Nov 2019 21:28:19 +0100 Message-Id: <20191127203118.381291584@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191127203114.766709977@linuxfoundation.org> References: <20191127203114.766709977@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 9fd383285f0ea..fc764f350f05a 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -3031,6 +3031,10 @@ 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