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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCF1FC0015E for ; Tue, 25 Jul 2023 11:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230398AbjGYLo4 (ORCPT ); Tue, 25 Jul 2023 07:44:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232977AbjGYLoi (ORCPT ); Tue, 25 Jul 2023 07:44:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B1171BFE for ; Tue, 25 Jul 2023 04:44:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D6F3A615BA for ; Tue, 25 Jul 2023 11:44:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9F54C433C8; Tue, 25 Jul 2023 11:44:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690285476; bh=AhuwpEBkZU2pCjZEu13c3eyP6vz4F/lG3b/hLyL7zCc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iJMfEZ9gyri5BC9PTS2l9WPpxJVQOC0z9eBT4cj/iFEJ36TmSoeh0Ysnw5n6POLZt itfIlBj1cBOooszu04qmHESPAnxqK8Rt7woFHzBRteskthIHJCmK60XmIhftis4wvZ B7zcQusuKHdEL4AI0S6kL4yM+B1URjZeLxDcTbmU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florent Revest , Florian Westphal , Pablo Neira Ayuso Subject: [PATCH 5.4 189/313] netfilter: conntrack: Avoid nf_ct_helper_hash uses after free Date: Tue, 25 Jul 2023 12:45:42 +0200 Message-ID: <20230725104529.150106898@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104521.167250627@linuxfoundation.org> References: <20230725104521.167250627@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Florent Revest commit 6eef7a2b933885a17679eb8ed0796ddf0ee5309b upstream. If nf_conntrack_init_start() fails (for example due to a register_nf_conntrack_bpf() failure), the nf_conntrack_helper_fini() clean-up path frees the nf_ct_helper_hash map. When built with NF_CONNTRACK=y, further netfilter modules (e.g: netfilter_conntrack_ftp) can still be loaded and call nf_conntrack_helpers_register(), independently of whether nf_conntrack initialized correctly. This accesses the nf_ct_helper_hash dangling pointer and causes a uaf, possibly leading to random memory corruption. This patch guards nf_conntrack_helper_register() from accessing a freed or uninitialized nf_ct_helper_hash pointer and fixes possible uses-after-free when loading a conntrack module. Cc: stable@vger.kernel.org Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure") Signed-off-by: Florent Revest Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_conntrack_helper.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -404,6 +404,9 @@ int nf_conntrack_helper_register(struct BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1); + if (!nf_ct_helper_hash) + return -ENOENT; + if (me->expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) return -EINVAL; @@ -587,4 +590,5 @@ void nf_conntrack_helper_fini(void) { nf_ct_extend_unregister(&helper_extend); kvfree(nf_ct_helper_hash); + nf_ct_helper_hash = NULL; }