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 D013DC432C3 for ; Sat, 16 Nov 2019 16:27:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9D84214DE for ; Sat, 16 Nov 2019 16:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573921628; bh=rsnNf15HrUbaGOrIbi6wyozb9yMbdByNuffKHCgCcss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wLofygmtYFz7s0iStIVbdcxDDz3q3WVTvI3Qeid0xgk/nkiZec9FwZ6pISvTTU0un yrT8ZS0gfE6xfiUaeP6lil9tXBGOkgxjwhNI/h3q9aaZ7ZjqdOwNtO9zmFHggIu4Qk AXHdrmdMwQKSg7ua5plSnE8F8kUE0QUoU2/Pp3Xo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729676AbfKPQ1E (ORCPT ); Sat, 16 Nov 2019 11:27:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:44944 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727969AbfKPPll (ORCPT ); Sat, 16 Nov 2019 10:41:41 -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 609AE2081E; Sat, 16 Nov 2019 15:41:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573918900; bh=rsnNf15HrUbaGOrIbi6wyozb9yMbdByNuffKHCgCcss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m9ItCvsSC2uJjajHlASRqYoi5HM99qCHZ6y+K2+rYf4dq+DxdMO+2QRNyjeQkHiuZ dOUT+5mQWyo0hbVLovnj63vTf9GV18Vq2FYNK4qSYPEsIVOHtFGwN+p86u4+nPxTBy 9GmQj1uoTxjaQssmABcI2JvGUFbuZBXQ1hGSB3A4= 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 4.19 029/237] btrfs: handle error of get_old_root Date: Sat, 16 Nov 2019 10:37:44 -0500 Message-Id: <20191116154113.7417-29-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191116154113.7417-1-sashal@kernel.org> References: <20191116154113.7417-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@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