From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758592Ab2JAXZE (ORCPT ); Mon, 1 Oct 2012 19:25:04 -0400 Received: from 1wt.eu ([62.212.114.60]:35306 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932841Ab2JAXBK (ORCPT ); Mon, 1 Oct 2012 19:01:10 -0400 Message-Id: <20121001225202.523982455@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 02 Oct 2012 00:53:53 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mathias Krause , "David S. Miller" , Greg Kroah-Hartman , Willy Tarreau Subject: [ 116/180] net/tun: fix ioctl() based info leaks In-Reply-To: <6a854f579a99b4fe2efaca1057e8ae22@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Krause [ Upstream commits a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc and 8bbb181308bc348e02bfdbebdedd4e4ec9d452ce ] The tun module leaks up to 36 bytes of memory by not fully 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- drivers/net/tun.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0f77aca..894ad84 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1121,10 +1121,12 @@ static long tun_chr_ioctl(struct file *file, unsigned int cmd, int sndbuf; int ret; - if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) + if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) { if (copy_from_user(&ifr, argp, sizeof ifr)) return -EFAULT; - + } else { + memset(&ifr, 0, sizeof(ifr)); + } if (cmd == TUNGETFEATURES) { /* Currently this just means: "what IFF flags are valid?". * This is needed because we never checked for invalid flags on -- 1.7.2.1.45.g54fbc