From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9BDFDC4321D for ; Thu, 23 Aug 2018 08:08:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5367C2064E for ; Thu, 23 Aug 2018 08:08:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5367C2064E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729129AbeHWLhQ (ORCPT ); Thu, 23 Aug 2018 07:37:16 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45040 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726277AbeHWLhP (ORCPT ); Thu, 23 Aug 2018 07:37:15 -0400 Received: from localhost (5355525A.cm-6-6b.dynamic.ziggo.nl [83.85.82.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id B01E1BB6; Thu, 23 Aug 2018 08:08:48 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.9 050/130] netfilter: nf_log: fix uninit read in nf_log_proc_dostring Date: Thu, 23 Aug 2018 09:52:46 +0200 Message-Id: <20180823074930.466685460@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180823074927.161454870@linuxfoundation.org> References: <20180823074927.161454870@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jann Horn [ Upstream commit dffd22aed2aa1e804bccf19b30a421e89ee2ae61 ] When proc_dostring() is called with a non-zero offset in strict mode, it doesn't just write to the ->data buffer, it also reads. Make sure it doesn't read uninitialized data. Fixes: c6ac37d8d884 ("netfilter: nf_log: fix error on write NONE to [...]") Signed-off-by: Jann Horn Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_log.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -426,6 +426,10 @@ static int nf_log_proc_dostring(struct c if (write) { struct ctl_table tmp = *table; + /* proc_dostring() can append to existing strings, so we need to + * initialize it as an empty string. + */ + buf[0] = '\0'; tmp.data = buf; r = proc_dostring(&tmp, write, buffer, lenp, ppos); if (r)