From patchwork Sun Jul 29 20:58:14 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Krause X-Patchwork-Id: 173933 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 245F32C008D for ; Mon, 30 Jul 2012 06:59:02 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753602Ab2G2U65 (ORCPT ); Sun, 29 Jul 2012 16:58:57 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:45525 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536Ab2G2U64 (ORCPT ); Sun, 29 Jul 2012 16:58:56 -0400 Received: by wibhr14 with SMTP id hr14so1231875wib.1 for ; Sun, 29 Jul 2012 13:58:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer; bh=+eIn69f2D+frZ6NzZR71g8T44/0qoT4WH6wbr/+8RfE=; b=viw5qHTceKROCct7+0U2zl2ggG6WCkAbM62x8KG1E8oR1eNAae8f9pFBjqlz6h1C9S GX7PU+lfFbz5ZWf1OzVCBiAo6PxHTvYkYS8DvRGVlXPusMbBFnF5MsFjuS9qWrTrxeIg ptM2pN1iYlQJkGGVa+U2VtPnVRYs4UwStq62RrbaMNDsbt/mC7S32kBX4ud7PG+LUUYw XNq+gkTA3TGNrKBwNJkxtrMNoTPUCy5XjqP7Nm5e/lrXdV4Ig0OivzkX89LDtOYYJkp9 IYWlBXAiep7mcsEbi+Pps6bTLRTo/IN79wIbDSgKP0hpmvaaLlHYwD4dogPJ5rPZTlro BcpA== Received: by 10.180.81.193 with SMTP id c1mr37298690wiy.12.1343595535239; Sun, 29 Jul 2012 13:58:55 -0700 (PDT) Received: from jig.fritz.box (pD9EB2CAB.dip.t-dialin.net. [217.235.44.171]) by mx.google.com with ESMTPS id z11sm18584652wiv.10.2012.07.29.13.58.53 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 29 Jul 2012 13:58:54 -0700 (PDT) From: Mathias Krause To: "David S. Miller" Cc: netdev@vger.kernel.org, Mathias Krause Subject: [PATCH] net/tun: fix ioctl() based info leaks Date: Sun, 29 Jul 2012 22:58:14 +0200 Message-Id: <1343595494-10414-1-git-send-email-minipli@googlemail.com> X-Mailer: git-send-email 1.7.10.4 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The tun module leaks up to 36 bytes of memory by not initializing a structure located on the stack that gets copied to user memory by the TUNGETIFF and SIOCGIFHWADDR ioctl()s. Signed-off-by: Mathias Krause --- drivers/net/tun.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 987aeef..cadeb94 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1252,9 +1252,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, int vnet_hdr_sz; int ret; - if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) + if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) { if (copy_from_user(&ifr, argp, ifreq_len)) return -EFAULT; + } else { + memset(&ifr, 0, sizeof(ifr)); + } if (cmd == TUNGETFEATURES) { /* Currently this just means: "what IFF flags are valid?".