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 40AEFC0015E for ; Tue, 25 Jul 2023 11:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234598AbjGYLZq (ORCPT ); Tue, 25 Jul 2023 07:25:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234600AbjGYLZp (ORCPT ); Tue, 25 Jul 2023 07:25:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 096F69D for ; Tue, 25 Jul 2023 04:25:45 -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) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9C10361683 for ; Tue, 25 Jul 2023 11:25:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A26CDC433C8; Tue, 25 Jul 2023 11:25:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690284344; bh=AhuwpEBkZU2pCjZEu13c3eyP6vz4F/lG3b/hLyL7zCc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F9MmFmSx5DBbHST8r7y0npzdtkHZVZPvbucRtBcRd/Fk7dLklQX09mRzsCYirTVvB WHfuF/9SVJhc5FUm4G/ml33rCXAE+W0j3S80PsIzfG8n787o/+r1A37MERtE4LpGBu TgcdGRC/FG5vpDzdWbwUY4qj08hj6VL5cdJ6FzVo= 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 5.10 323/509] netfilter: conntrack: Avoid nf_ct_helper_hash uses after free Date: Tue, 25 Jul 2023 12:44:22 +0200 Message-ID: <20230725104608.485040318@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104553.588743331@linuxfoundation.org> References: <20230725104553.588743331@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; }