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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 C2E42C52D50 for ; Thu, 27 Feb 2020 14:06:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BDBF2468D for ; Thu, 27 Feb 2020 14:06:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582812392; bh=W4/xiG4eiTXSVrIJ6XH12CjYjNUG6YQO84OF6694ykI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eCrpv6pmagRWRG0sV30z9ZlIGhl0Y+17AVjwRuY+wwUNq3+OUgueop12sWKqfjGEb 921HmviAMKhbIiQxwnt0+WpfLR1O/2/TDKg3UiVLcFbVSRW38nVNy4qMlDnWf1Tax7 1SuGCJk+Jz+EiXnvkqI3DPXNrwdza5TV4hUHNwsY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387943AbgB0OGa (ORCPT ); Thu, 27 Feb 2020 09:06:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:43548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387925AbgB0OGY (ORCPT ); Thu, 27 Feb 2020 09:06:24 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CB1B420578; Thu, 27 Feb 2020 14:06:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582812384; bh=W4/xiG4eiTXSVrIJ6XH12CjYjNUG6YQO84OF6694ykI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ya9EyIV5W6ihSA5Il3cQa9LrD3gaX1qXzq3CTjz9PZqudt07YMHiF7EQQHpL/ZtgD YHFSG4WKQDg4sf5JFDVMngZ+mE+5xygKVua2RMAdc+k4/iTcg38jADtmJd210iOuym XxEDm3nRay1ND3DMWYHKZ/m/VBRKCQ5CZKwe3Pes= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Cong Wang , Florian Westphal , Pablo Neira Ayuso , syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com Subject: [PATCH 4.19 93/97] netfilter: xt_hashlimit: limit the max size of hashtable Date: Thu, 27 Feb 2020 14:37:41 +0100 Message-Id: <20200227132229.871748531@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132214.553656188@linuxfoundation.org> References: <20200227132214.553656188@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Cong Wang commit 8d0015a7ab76b8b1e89a3e5f5710a6e5103f2dd5 upstream. The user-specified hashtable size is unbound, this could easily lead to an OOM or a hung task as we hold the global mutex while allocating and initializing the new hashtable. Add a max value to cap both cfg->size and cfg->max, as suggested by Florian. Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com Signed-off-by: Cong Wang Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/xt_hashlimit.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -845,6 +845,8 @@ hashlimit_mt(const struct sk_buff *skb, return hashlimit_mt_common(skb, par, hinfo, &info->cfg, 3); } +#define HASHLIMIT_MAX_SIZE 1048576 + static int hashlimit_mt_check_common(const struct xt_mtchk_param *par, struct xt_hashlimit_htable **hinfo, struct hashlimit_cfg3 *cfg, @@ -855,6 +857,14 @@ static int hashlimit_mt_check_common(con if (cfg->gc_interval == 0 || cfg->expire == 0) return -EINVAL; + if (cfg->size > HASHLIMIT_MAX_SIZE) { + cfg->size = HASHLIMIT_MAX_SIZE; + pr_info_ratelimited("size too large, truncated to %u\n", cfg->size); + } + if (cfg->max > HASHLIMIT_MAX_SIZE) { + cfg->max = HASHLIMIT_MAX_SIZE; + pr_info_ratelimited("max too large, truncated to %u\n", cfg->max); + } if (par->family == NFPROTO_IPV4) { if (cfg->srcmask > 32 || cfg->dstmask > 32) return -EINVAL;