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 5220BC4332F for ; Wed, 2 Nov 2022 18:47:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231435AbiKBSre (ORCPT ); Wed, 2 Nov 2022 14:47:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231706AbiKBSrT (ORCPT ); Wed, 2 Nov 2022 14:47:19 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 71B2C2FFEE; Wed, 2 Nov 2022 11:47:14 -0700 (PDT) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Subject: [PATCH net 6/7] netfilter: nf_nat: Fix possible memory leak in nf_nat_init() Date: Wed, 2 Nov 2022 19:46:58 +0100 Message-Id: <20221102184659.2502-7-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221102184659.2502-1-pablo@netfilter.org> References: <20221102184659.2502-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Chen Zhongjin In nf_nat_init(), register_nf_nat_bpf() can fail and return directly without any error handling. Then nf_nat_bysource will leak and registering of &nat_net_ops, &follow_master_nat and nf_nat_hook won't be reverted. This leaves wild ops in linkedlists and when another module tries to call register_pernet_operations() or nf_ct_helper_expectfn_register() it triggers page fault: BUG: unable to handle page fault for address: fffffbfff81b964c RIP: 0010:register_pernet_operations+0x1b9/0x5f0 Call Trace: register_pernet_subsys+0x29/0x40 ebtables_init+0x58/0x1000 [ebtables] ... Fixes: 820dc0523e05 ("net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.c") Signed-off-by: Chen Zhongjin Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_nat_core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 18319a6e6806..e29e4ccb5c5a 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -1152,7 +1152,16 @@ static int __init nf_nat_init(void) WARN_ON(nf_nat_hook != NULL); RCU_INIT_POINTER(nf_nat_hook, &nat_hook); - return register_nf_nat_bpf(); + ret = register_nf_nat_bpf(); + if (ret < 0) { + RCU_INIT_POINTER(nf_nat_hook, NULL); + nf_ct_helper_expectfn_unregister(&follow_master_nat); + synchronize_net(); + unregister_pernet_subsys(&nat_net_ops); + kvfree(nf_nat_bysource); + } + + return ret; } static void __exit nf_nat_cleanup(void) -- 2.30.2