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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 70FC5C432C3 for ; Sat, 16 Nov 2019 16:05:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3DA522184B for ; Sat, 16 Nov 2019 16:05:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573920330; bh=rQC+cGTzMCq1vXMp7OOlM5NKkFtnVplMXAgO3cNKb4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZP5Xfi/ctrxXcy7Ae86p0RzrmzU0IQyXJmSAAgZTi46aDoo/8rVz9lM0mmY5Ayx2y hopIiVRNRxGml/DbLbW4GYSKzXJH1rdoEwHsbd2/8av0Ozdnuzq+C/bSW2hJ+lYOOe pk3bDTxlOYW0I9jQQIq9PLD4YZcbDQjoolxR4c9w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730028AbfKPQF3 (ORCPT ); Sat, 16 Nov 2019 11:05:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:59878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730713AbfKPPvS (ORCPT ); Sat, 16 Nov 2019 10:51:18 -0500 Received: from sasha-vm.mshome.net (unknown [50.234.116.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ED3F1208E3; Sat, 16 Nov 2019 15:51:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573919477; bh=rQC+cGTzMCq1vXMp7OOlM5NKkFtnVplMXAgO3cNKb4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UXjQH3RlbzrKQQUmudiA398nFEcONwXB1IFbJ7Mt6yUuoudg1bij+lrpnYfzbXt6K AqWjBXZ+9PAZAYk6pFH5ZGb9pFAREMO/Cx6cpcEQrK4SHl0ibL/hL9jDWwT2a8HjYO v8TAY1zypNVA4HqTltdPxZJAl56sc+X+bAmYFSVE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nikolay Borisov , Lu Fengqi , David Sterba , Sasha Levin , linux-btrfs@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 11/99] btrfs: handle error of get_old_root Date: Sat, 16 Nov 2019 10:49:34 -0500 Message-Id: <20191116155103.10971-11-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191116155103.10971-1-sashal@kernel.org> References: <20191116155103.10971-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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