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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 090F5C4332B for ; Thu, 19 Mar 2020 13:12:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4744208D6 for ; Thu, 19 Mar 2020 13:12:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623554; bh=BSxw+pLw6st8V9vF81u25Ulzfsz8BRozPqj0a4IdzRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LCcwoxc7F8+a+GiOwW782B9eDgV+ffMhPob9HQ5SeCkFdbR7axrEbtVX+1H9OCvvg 4+T23ghIw9sRc94OBi7dSh4fmMygR1vYuL+tLQmdNQtdqfFDugcSYjriy9H87kZXDE v8U/zZfeprcj5Gf+n/gOYsPsLjMqlwgRqrpCd0QQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727112AbgCSNMa (ORCPT ); Thu, 19 Mar 2020 09:12:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:58482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728934AbgCSNMa (ORCPT ); Thu, 19 Mar 2020 09:12:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BB738214D8; Thu, 19 Mar 2020 13:12:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623549; bh=BSxw+pLw6st8V9vF81u25Ulzfsz8BRozPqj0a4IdzRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LYay8miPLzepD9wlwuaU1UngBBo9BX4juVvJnkUEWMRgJ1yNlcGtpqzcq0k89MaqG 9ZlR7FHzHPSPEcIGhQPHv5n6LdxrRTR9SkVEwSVyvmunzITcoYMI8xBugTgcIqaLjL nbAR//32TAzghWBPJ9BTJIk/8B99EnW/p9LUoS6U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Marek Lindner , Sven Eckelmann , Simon Wunderlich Subject: [PATCH 4.9 65/90] batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs Date: Thu, 19 Mar 2020 14:00:27 +0100 Message-Id: <20200319123948.689283801@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123928.635114118@linuxfoundation.org> References: <20200319123928.635114118@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marek Lindner commit 16116dac23396e73c01eeee97b102e4833a4b205 upstream. A translation table TVLV changset sent with an OGM consists of a number of headers (one per VLAN) plus the changeset itself (addition and/or deletion of entries). The per-VLAN headers are used by OGM recipients for consistency checks. Said consistency check might determine that a full translation table request is needed to restore consistency. If the TT sender adds per-VLAN headers of empty VLANs into the OGM, recipients are led to believe to have reached an inconsistent state and thus request a full table update. The full table does not contain empty VLANs (due to missing entries) the cycle restarts when the next OGM is issued. Consequently, when the translation table TVLV headers are composed, empty VLANs are to be excluded. Fixes: 21a57f6e7a3b ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Marek Lindner Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/translation-table.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -936,15 +936,20 @@ batadv_tt_prepare_tvlv_local_data(struct struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_softif_vlan *vlan; u16 num_vlan = 0; - u16 num_entries = 0; + u16 vlan_entries = 0; + u16 total_entries = 0; u16 tvlv_len; u8 *tt_change_ptr; int change_offset; spin_lock_bh(&bat_priv->softif_vlan_list_lock); hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + if (vlan_entries < 1) + continue; + num_vlan++; - num_entries += atomic_read(&vlan->tt.num_entries); + total_entries += vlan_entries; } change_offset = sizeof(**tt_data); @@ -952,7 +957,7 @@ batadv_tt_prepare_tvlv_local_data(struct /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) - *tt_len = batadv_tt_len(num_entries); + *tt_len = batadv_tt_len(total_entries); tvlv_len = *tt_len; tvlv_len += change_offset; @@ -969,6 +974,10 @@ batadv_tt_prepare_tvlv_local_data(struct tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + if (vlan_entries < 1) + continue; + tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc);