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=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 2ECF9C432C3 for ; Sat, 16 Nov 2019 15:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F18AC21479 for ; Sat, 16 Nov 2019 15:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573919994; bh=28UcTghOrsaTsVNgqi4hwzYOQG18W8MsP+t0Js06z9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MxmqtEu7hOMn7m+ZN0DJ50O9eyUOeNCChbpRpXXZ5IHVQ5Pe7LtxO5snFb4yz29Rz zIBmoQi3jv8qU1sK2bJZATaFBzbY2TvDtwhD9m7HmIncbB37i1gAPkRZ3lTlUy5+GG akU1LVDhtrtRTRdd60EtRMvGTnqEi7sXniPcv+Oo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731538AbfKPP7w (ORCPT ); Sat, 16 Nov 2019 10:59:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:35110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731316AbfKPPxt (ORCPT ); Sat, 16 Nov 2019 10:53:49 -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 D86FB2168B; Sat, 16 Nov 2019 15:53:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573919629; bh=28UcTghOrsaTsVNgqi4hwzYOQG18W8MsP+t0Js06z9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MdHoewWZan58GFI8xDKokD8D2D6Kbil5F1AUOGNHoZ4VRPx2mGBkb3Jwq1vKZYwet nPxYhCRDfW8GCOMpNHdpPZOZYQH4B+f7j+ubsVfwU9cvomqeUGdqteK1Kbghcb3D9w CXnCBgARZID61VRwfKltpf04qzQyGuHAoC1tNOEI= 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 4.4 10/77] btrfs: handle error of get_old_root Date: Sat, 16 Nov 2019 10:52:32 -0500 Message-Id: <20191116155339.11909-10-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191116155339.11909-1-sashal@kernel.org> References: <20191116155339.11909-1-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 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