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=-7.7 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 600B6C04EB8 for ; Tue, 4 Dec 2018 11:01:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26028214DB for ; Tue, 4 Dec 2018 11:01:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="myXM9n1I" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26028214DB 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 S1727445AbeLDLBH (ORCPT ); Tue, 4 Dec 2018 06:01:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:46494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725910AbeLDLBF (ORCPT ); Tue, 4 Dec 2018 06:01:05 -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 658F22087F; Tue, 4 Dec 2018 11:01:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543921264; bh=ywzChOnqT3RfbB9tXiNGAC671Jm6Dn91pnw1DSomS6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=myXM9n1IDxd6jI7ed2T8u/j8LzbUR/3bJoFUkdK0pLmSQaqYqJHx0ftOJJRJ5/9Ia uKPYxSKm7uTeHXCfBpXccs8kkwXKOO+DnzeeLIhqgEo6cwFltn8RXJF2QE89Yvgrx8 qeMdedTwe1r0f9/PltNiHesu8aSxiyeV2HBVv2Qk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pan Bian , Jan Kara Subject: [PATCH 4.19 118/139] ext2: fix potential use after free Date: Tue, 4 Dec 2018 11:49:59 +0100 Message-Id: <20181204103655.510462440@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181204103649.950154335@linuxfoundation.org> References: <20181204103649.950154335@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 Archived-At: List-Archive: List-Post: 4.19-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 @@ -612,9 +612,9 @@ skip_replace: } cleanup: - brelse(bh); if (!(bh && header == HDR(bh))) kfree(header); + brelse(bh); up_write(&EXT2_I(inode)->xattr_sem); return error;