From patchwork Fri Feb 5 00:17:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 376713 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 9455DC433E6 for ; Fri, 5 Feb 2021 00:18:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65BC164F3C for ; Fri, 5 Feb 2021 00:18:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231831AbhBEASe (ORCPT ); Thu, 4 Feb 2021 19:18:34 -0500 Received: from correo.us.es ([193.147.175.20]:40578 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231768AbhBEASQ (ORCPT ); Thu, 4 Feb 2021 19:18:16 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id DD25A2A325B for ; Fri, 5 Feb 2021 01:17:33 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id C7315DA78D for ; Fri, 5 Feb 2021 01:17:33 +0100 (CET) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id BC37BDA78A; Fri, 5 Feb 2021 01:17:33 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 16FA5DA73F; Fri, 5 Feb 2021 01:17:31 +0100 (CET) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Fri, 05 Feb 2021 01:17:31 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from localhost.localdomain (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPSA id DDA8942EF9E1; Fri, 5 Feb 2021 01:17:30 +0100 (CET) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH net 1/4] netfilter: xt_recent: Fix attempt to update deleted entry Date: Fri, 5 Feb 2021 01:17:24 +0100 Message-Id: <20210205001727.2125-2-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210205001727.2125-1-pablo@netfilter.org> References: <20210205001727.2125-1-pablo@netfilter.org> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jozsef Kadlecsik When both --reap and --update flag are specified, there's a code path at which the entry to be updated is reaped beforehand, which then leads to kernel crash. Reap only entries which won't be updated. Fixes kernel bugzilla #207773. Link: https://bugzilla.kernel.org/show_bug.cgi?id=207773 Reported-by: Reindl Harald Fixes: 0079c5aee348 ("netfilter: xt_recent: add an entry reaper") Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_recent.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index 606411869698..0446307516cd 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -152,7 +152,8 @@ static void recent_entry_remove(struct recent_table *t, struct recent_entry *e) /* * Drop entries with timestamps older then 'time'. */ -static void recent_entry_reap(struct recent_table *t, unsigned long time) +static void recent_entry_reap(struct recent_table *t, unsigned long time, + struct recent_entry *working, bool update) { struct recent_entry *e; @@ -161,6 +162,12 @@ static void recent_entry_reap(struct recent_table *t, unsigned long time) */ e = list_entry(t->lru_list.next, struct recent_entry, lru_list); + /* + * Do not reap the entry which are going to be updated. + */ + if (e == working && update) + return; + /* * The last time stamp is the most recent. */ @@ -303,7 +310,8 @@ recent_mt(const struct sk_buff *skb, struct xt_action_param *par) /* info->seconds must be non-zero */ if (info->check_set & XT_RECENT_REAP) - recent_entry_reap(t, time); + recent_entry_reap(t, time, e, + info->check_set & XT_RECENT_UPDATE && ret); } if (info->check_set & XT_RECENT_SET ||