Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756272AbaBEVCz (ORCPT ); Wed, 5 Feb 2014 16:02:55 -0500 Received: from mail.windriver.com ([147.11.1.11]:54603 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754376AbaBEUFJ (ORCPT ); Wed, 5 Feb 2014 15:05:09 -0500 From: Paul Gortmaker To: , CC: Mathias Krause , "David S. Miller" , Paul Gortmaker Subject: [v2.6.34-stable 059/213] net/tun: fix ioctl() based info leaks Date: Wed, 5 Feb 2014 15:00:14 -0500 Message-ID: <1391630568-49251-60-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mathias Krause ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc upstream. 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: Paul Gortmaker --- drivers/net/tun.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 7b4a88b2f696..c777d8ebdaa8 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1177,9 +1177,11 @@ 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, ifreq_len)) return -EFAULT; + } else + memset(&ifr, 0, sizeof(ifr)); if (cmd == TUNGETFEATURES) { /* Currently this just means: "what IFF flags are valid?". -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/