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 8EC98C432C3 for ; Sat, 16 Nov 2019 16:27:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AD49214DE for ; Sat, 16 Nov 2019 16:27:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573921626; bh=rsnNf15HrUbaGOrIbi6wyozb9yMbdByNuffKHCgCcss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=P/QhQgxOp47Mb1AdbzDymSn3zLl2tKT5E16rMKhWx01arVG0aJ/PIVnhn3CzGuKPX ircmoWXO7zf1vgx2edYEVVZI8z36pQLTQJnb0NZUujZBXYBs1cs7Dn64IgXNPCuz9k m0r4BhWmYJpgTQWpTmnR7XdBopLV5X3JZPSXK+58= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732073AbfKPQ1F (ORCPT ); Sat, 16 Nov 2019 11:27:05 -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-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