From patchwork Sat Jun 3 13:18:16 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 9764211 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 07D53602B6 for ; Sat, 3 Jun 2017 13:18:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED93628470 for ; Sat, 3 Jun 2017 13:18:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E275F28579; Sat, 3 Jun 2017 13:18:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8AFF928470 for ; Sat, 3 Jun 2017 13:18:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751245AbdFCNSy (ORCPT ); Sat, 3 Jun 2017 09:18:54 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:36169 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149AbdFCNSy (ORCPT ); Sat, 3 Jun 2017 09:18:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=lyzB9wxZVeYlrmYGZBvtHh+nTLPgBC9XiE46FsQ0haU=; b=qAs9Q6oLdB+buurUAgyE/k4wL r6xYvkCOMC+3OYjju+vhrLMoiwLSwWXhTY5ced7Zez9CuUc5W9+bIkiaGh8k3Lu+TSVKt61hPV+6O 6VpmCSVqyFqYgQUcS1nm6PNs5Vu7t2oi3GTj56lza0OqWfZZAIijikXwFEf1qFNS1yvoAw+N0lBaQ IbfSeKSHQSbhRTUvHVHbombInvzmtUqM7fC3u+BYAK6vc5+sMPdpRLgaAF2oXEuauEUXM1VwDkbSO 5zty3TKN7XdQknucKEaNsEAwdlCu8PlNHaWVGAJFZII63ZaY91np//IKF9ZXJzHqVQPvqBtqShnhz zbTI6YunA==; Received: from p4ff2fcbf.dip0.t-ipconnect.de ([79.242.252.191] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.87 #1 (Red Hat Linux)) id 1dH8xB-00006C-F8; Sat, 03 Jun 2017 13:18:53 +0000 From: Christoph Hellwig To: stable@vger.kernel.org Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" Subject: [PATCH 05/25] xfs: fix over-copying of getbmap parameters from userspace Date: Sat, 3 Jun 2017 15:18:16 +0200 Message-Id: <20170603131836.26661-6-hch@lst.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170603131836.26661-1-hch@lst.de> References: <20170603131836.26661-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: "Darrick J. Wong" commit be6324c00c4d1e0e665f03ed1fc18863a88da119 upstream. In xfs_ioc_getbmap, we should only copy the fields of struct getbmap from userspace, or else we end up copying random stack contents into the kernel. struct getbmap is a strict subset of getbmapx, so a partial structure copy should work fine. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_ioctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index a39197501a7c..73cfc7179124 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1542,10 +1542,11 @@ xfs_ioc_getbmap( unsigned int cmd, void __user *arg) { - struct getbmapx bmx; + struct getbmapx bmx = { 0 }; int error; - if (copy_from_user(&bmx, arg, sizeof(struct getbmapx))) + /* struct getbmap is a strict subset of struct getbmapx. */ + if (copy_from_user(&bmx, arg, offsetof(struct getbmapx, bmv_iflags))) return -EFAULT; if (bmx.bmv_count < 2)