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=-9.0 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 4943EC04AAC for ; Mon, 20 May 2019 19:08:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 318C420675 for ; Mon, 20 May 2019 19:08:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725976AbfETTId (ORCPT ); Mon, 20 May 2019 15:08:33 -0400 Received: from mail.us.es ([193.147.175.20]:38362 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbfETTId (ORCPT ); Mon, 20 May 2019 15:08:33 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 10BBCBAEE8 for ; Mon, 20 May 2019 21:08:31 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id EF901DA70E for ; Mon, 20 May 2019 21:08:30 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id E56ACDA70C; Mon, 20 May 2019 21:08:30 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id E17A7DA702; Mon, 20 May 2019 21:08:28 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Mon, 20 May 2019 21:08:28 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from salvia.here (sys.soleta.eu [212.170.55.40]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id B76B34265A31; Mon, 20 May 2019 21:08:28 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: phil@nwl.cc, fw@strlen.de Subject: [PATCH iptables 1/6] nft: keep original cache in case of ERESTART Date: Mon, 20 May 2019 21:08:17 +0200 Message-Id: <20190520190822.18873-2-pablo@netfilter.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190520190822.18873-1-pablo@netfilter.org> References: <20190520190822.18873-1-pablo@netfilter.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Phil Sutter says: "The problem is that data in h->obj_list potentially sits in cache, too. At least rules have to be there so insert with index works correctly. If the cache is flushed before regenerating the batch, use-after-free occurs which crashes the program." This patch keeps around the original cache until we have refreshed the batch. Fixes: 862818ac3a0de ("xtables: add and use nft_build_cache") Signed-off-by: Pablo Neira Ayuso --- iptables/nft.c | 23 ++++++++++++++++++++--- iptables/nft.h | 3 ++- 2 files changed, 22 insertions(+), 4 deletions(-) diff --git a/iptables/nft.c b/iptables/nft.c index 172beec9ae27..288ada4af3ca 100644 --- a/iptables/nft.c +++ b/iptables/nft.c @@ -811,7 +811,7 @@ int nft_init(struct nft_handle *h, const struct builtin_table *t) h->portid = mnl_socket_get_portid(h->nl); h->tables = t; - h->cache = &h->__cache; + h->cache = &h->__cache[0]; INIT_LIST_HEAD(&h->obj_list); INIT_LIST_HEAD(&h->err_list); @@ -1618,14 +1618,30 @@ void nft_build_cache(struct nft_handle *h) __nft_build_cache(h); } -static void nft_rebuild_cache(struct nft_handle *h) +static void __nft_flush_cache(struct nft_handle *h) { - if (!h->have_cache) + if (!h->cache_index) { + h->cache_index++; + h->cache = &h->__cache[h->cache_index]; + } else { flush_chain_cache(h, NULL); + } +} + +static void nft_rebuild_cache(struct nft_handle *h) +{ + if (h->have_cache) + __nft_flush_cache(h); __nft_build_cache(h); } +static void nft_release_cache(struct nft_handle *h) +{ + if (h->cache_index) + flush_cache(&h->__cache[0], h->tables, NULL); +} + struct nftnl_chain_list *nft_chain_list_get(struct nft_handle *h, const char *table) { @@ -2957,6 +2973,7 @@ retry: batch_obj_del(h, n); } + nft_release_cache(h); mnl_batch_reset(h->batch); if (i) diff --git a/iptables/nft.h b/iptables/nft.h index dc0797d302b8..43eb8a39dd9c 100644 --- a/iptables/nft.h +++ b/iptables/nft.h @@ -48,7 +48,8 @@ struct nft_handle { struct list_head err_list; struct nft_family_ops *ops; const struct builtin_table *tables; - struct nft_cache __cache; + unsigned int cache_index; + struct nft_cache __cache[2]; struct nft_cache *cache; bool have_cache; bool restore; -- 2.11.0