From patchwork Thu Sep 6 12:35:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 17467 X-Patchwork-Delegate: sw@simonwunderlich.de Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from open-mesh.org (localhost [IPv6:::1]) by open-mesh.org (Postfix) with ESMTP id 6FF4D82F21; Thu, 6 Sep 2018 14:35:37 +0200 (CEST) Authentication-Results: open-mesh.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=narfation.org header.i=@narfation.org header.b="VOwm/+4O"; dkim-atps=neutral Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2001:4d88:2000:7::2; helo=v3-1039.vlinux.de; envelope-from=sven@narfation.org; receiver= Received: from v3-1039.vlinux.de (narfation.org [IPv6:2001:4d88:2000:7::2]) by open-mesh.org (Postfix) with ESMTPS id 557A782F16 for ; Thu, 6 Sep 2018 14:35:35 +0200 (CEST) Received: from sven-desktop.home.narfation.org (p200300C593D79FFA9732AEE00057D068.dip0.t-ipconnect.de [IPv6:2003:c5:93d7:9ffa:9732:aee0:57:d068]) by v3-1039.vlinux.de (Postfix) with ESMTPSA id A69051100E1; Thu, 6 Sep 2018 14:35:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=narfation.org; s=20121; t=1536237334; bh=QDF4JNLAuDP7K2U9clvCmM6NtGenHF6tG0LnPWVOD24=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VOwm/+4OoqD1ShWlK3MDaOa8/FiNe8qYnGrv9xOHVJJEF1GMyOTadh1QCmChOMuHT p7t3vOVJtHztnf5/48hf54CaUGxeHbJiZ2zdaxDPLCtj75Woobrsew0GKyEIrA0fKG jo2WAPh26u+UQTd+ad9dEj7ZDAt0nBePAn3I9Rdg= From: Sven Eckelmann To: b.a.t.m.a.n@lists.open-mesh.org Date: Thu, 6 Sep 2018 14:35:24 +0200 Message-Id: <20180906123528.30490-2-sven@narfation.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180906123528.30490-1-sven@narfation.org> References: <20180906123528.30490-1-sven@narfation.org> Subject: [B.A.T.M.A.N.] [PATCH v2 1/5] batman-adv: Prevent duplicated gateway_node entry X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Errors-To: b.a.t.m.a.n-bounces@lists.open-mesh.org Sender: "B.A.T.M.A.N" The function batadv_gw_node_add is responsible for adding new gw_node to the gateway_list. It is expecting that the caller already checked that there is not already an entry with the same key or not. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: bc3538cabac5 ("batman-adv: adding gateway functionality") Signed-off-by: Sven Eckelmann Acked-by: Marek Lindner --- v2: * added kerneldoc about the locking requirements net/batman-adv/gateway_client.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index 8b198ee7..140c61a3 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -348,6 +349,9 @@ void batadv_gw_check_election(struct batadv_priv *bat_priv, * @bat_priv: the bat priv with all the soft interface information * @orig_node: originator announcing gateway capabilities * @gateway: announced bandwidth information + * + * Has to be called with the appropriate locks being acquired + * (gw.list_lock). */ static void batadv_gw_node_add(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, @@ -355,6 +359,8 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv, { struct batadv_gw_node *gw_node; + lockdep_assert_held(&bat_priv->gw.list_lock); + if (gateway->bandwidth_down == 0) return; @@ -369,10 +375,8 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv, gw_node->bandwidth_down = ntohl(gateway->bandwidth_down); gw_node->bandwidth_up = ntohl(gateway->bandwidth_up); - spin_lock_bh(&bat_priv->gw.list_lock); kref_get(&gw_node->refcount); hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.gateway_list); - spin_unlock_bh(&bat_priv->gw.list_lock); batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n", @@ -428,11 +432,14 @@ void batadv_gw_node_update(struct batadv_priv *bat_priv, { struct batadv_gw_node *gw_node, *curr_gw = NULL; + spin_lock_bh(&bat_priv->gw.list_lock); gw_node = batadv_gw_node_get(bat_priv, orig_node); if (!gw_node) { batadv_gw_node_add(bat_priv, orig_node, gateway); + spin_unlock_bh(&bat_priv->gw.list_lock); goto out; } + spin_unlock_bh(&bat_priv->gw.list_lock); if (gw_node->bandwidth_down == ntohl(gateway->bandwidth_down) && gw_node->bandwidth_up == ntohl(gateway->bandwidth_up))