From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030812Ab2HGWlC (ORCPT ); Tue, 7 Aug 2012 18:41:02 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:56573 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030795Ab2HGWk4 (ORCPT ); Tue, 7 Aug 2012 18:40:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Mathias Krause , "David S. Miller" Subject: [ 094/109] net/tun: fix ioctl() based info leaks Date: Tue, 7 Aug 2012 15:35:53 -0700 Message-Id: <20120807222051.335989141@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120807222043.089735600@linuxfoundation.org> References: <20120807222043.089735600@linuxfoundation.org> User-Agent: quilt/0.60-20.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.4-stable 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 --- drivers/net/tun.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1255,10 +1255,12 @@ static long __tun_chr_ioctl(struct file 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?". * This is needed because we never checked for invalid flags on