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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 90097C07E85 for ; Tue, 11 Dec 2018 15:45:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 569B320989 for ; Tue, 11 Dec 2018 15:45:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544543128; bh=aPecmDf+aDRZf1h00CyDF1yv5ZDW4FZxLrzTzm87QdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qqpzBO7WUgvaeZLA0puQN744oolTRJ2wWSi8MfC1Xb+XRijPKaDnhuNlRl0SOZHz6 /r9zX7bSLOXqe4rfHGpNQYvPeB1f2VwczKgs0USKCrSr71sq00Wqr+/YmM10X+6nuK aIolk8v54xXxH7exm5uQowi/OeH3sDb57YxAuZtw= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 569B320989 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728107AbeLKPp1 (ORCPT ); Tue, 11 Dec 2018 10:45:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:33840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728092AbeLKPpY (ORCPT ); Tue, 11 Dec 2018 10:45:24 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 097F720870; Tue, 11 Dec 2018 15:45:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544543124; bh=aPecmDf+aDRZf1h00CyDF1yv5ZDW4FZxLrzTzm87QdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ili5hFN/mQxz44N6OHhQR8mT2gvfuwkbV2vCH+EeQcBBeZleYMAQbpbwZEVyJxgig gWTuSVUHA9/ENPaw9EVlIgA+00YYP8brrPpChoz/nPfGL6ahAPlJ+iHz9l9FLbzhGV D7S8bGp4kYASHwhjaPRy1x7Kf0zZaJzjpUdmMtqg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pan Bian , Jan Kara Subject: [PATCH 4.4 14/91] ext2: fix potential use after free Date: Tue, 11 Dec 2018 16:40:33 +0100 Message-Id: <20181211151607.080046791@linuxfoundation.org> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20181211151606.026852373@linuxfoundation.org> References: <20181211151606.026852373@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pan Bian commit ecebf55d27a11538ea84aee0be643dd953f830d5 upstream. The function ext2_xattr_set calls brelse(bh) to drop the reference count of bh. After that, bh may be freed. However, following brelse(bh), it reads bh->b_data via macro HDR(bh). This may result in a use-after-free bug. This patch moves brelse(bh) after reading field. CC: stable@vger.kernel.org Signed-off-by: Pan Bian Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/ext2/xattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -605,9 +605,9 @@ skip_replace: } cleanup: - brelse(bh); if (!(bh && header == HDR(bh))) kfree(header); + brelse(bh); up_write(&EXT2_I(inode)->xattr_sem); return error;