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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 985EEC33CB3 for ; Thu, 16 Jan 2020 08:06:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A168207FF for ; Thu, 16 Jan 2020 08:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729862AbgAPIG7 (ORCPT ); Thu, 16 Jan 2020 03:06:59 -0500 Received: from Chamillionaire.breakpoint.cc ([193.142.43.52]:33146 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729619AbgAPIG6 (ORCPT ); Thu, 16 Jan 2020 03:06:58 -0500 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1is0B5-0003Mm-CC; Thu, 16 Jan 2020 09:06:55 +0100 From: Florian Westphal To: netfilter-devel@vger.kernel.org Cc: syzkaller-bugs@googlegroups.com, netdev@vger.kernel.org, Florian Westphal , syzbot+0e63ae76d117ae1c3a01@syzkaller.appspotmail.com Subject: [PATCH nf] netfilter: nf_tables: remove WARN and add NLA_STRING upper limits Date: Thu, 16 Jan 2020 09:06:50 +0100 Message-Id: <20200116080650.4798-1-fw@strlen.de> X-Mailer: git-send-email 2.24.1 In-Reply-To: <000000000000b9fc96059c36db9e@google.com> References: <000000000000b9fc96059c36db9e@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This WARN can trigger because some of the names fed to the module autoload function can be of arbitrary length. Remove the WARN and add limits for all NLA_STRING attributes. Reported-by: syzbot+0e63ae76d117ae1c3a01@syzkaller.appspotmail.com Fixes: 452238e8d5ffd8 ("netfilter: nf_tables: add and use helper for module autoload") Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 43f05b3acd60..5a1a6632e3a6 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -22,6 +22,8 @@ #include #include +#define NFT_MODULE_AUTOLOAD_LIMIT (MODULE_NAME_LEN - sizeof("nft-expr-255-")) + static LIST_HEAD(nf_tables_expressions); static LIST_HEAD(nf_tables_objects); static LIST_HEAD(nf_tables_flowtables); @@ -585,7 +587,7 @@ static void nft_request_module(struct net *net, const char *fmt, ...) va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); va_end(args); - if (WARN(ret >= MODULE_NAME_LEN, "truncated: '%s' (len %d)", module_name, ret)) + if (ret >= MODULE_NAME_LEN) return; mutex_unlock(&net->nft.commit_mutex); @@ -1241,7 +1243,8 @@ static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = { .len = NFT_CHAIN_MAXNAMELEN - 1 }, [NFTA_CHAIN_HOOK] = { .type = NLA_NESTED }, [NFTA_CHAIN_POLICY] = { .type = NLA_U32 }, - [NFTA_CHAIN_TYPE] = { .type = NLA_STRING }, + [NFTA_CHAIN_TYPE] = { .type = NLA_STRING, + .len = NFT_MODULE_AUTOLOAD_LIMIT }, [NFTA_CHAIN_COUNTERS] = { .type = NLA_NESTED }, [NFTA_CHAIN_FLAGS] = { .type = NLA_U32 }, }; @@ -2355,7 +2358,8 @@ static const struct nft_expr_type *nft_expr_type_get(struct net *net, } static const struct nla_policy nft_expr_policy[NFTA_EXPR_MAX + 1] = { - [NFTA_EXPR_NAME] = { .type = NLA_STRING }, + [NFTA_EXPR_NAME] = { .type = NLA_STRING, + .len = NFT_MODULE_AUTOLOAD_LIMIT }, [NFTA_EXPR_DATA] = { .type = NLA_NESTED }, }; @@ -4198,7 +4202,8 @@ static const struct nla_policy nft_set_elem_policy[NFTA_SET_ELEM_MAX + 1] = { [NFTA_SET_ELEM_USERDATA] = { .type = NLA_BINARY, .len = NFT_USERDATA_MAXLEN }, [NFTA_SET_ELEM_EXPR] = { .type = NLA_NESTED }, - [NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING }, + [NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING, + .len = NFT_OBJ_MAXNAMELEN - 1 }, }; static const struct nla_policy nft_set_elem_list_policy[NFTA_SET_ELEM_LIST_MAX + 1] = { -- 2.24.1