From patchwork Sun Aug 12 19:04:41 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 17456 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 F2A4C82D26; Sun, 12 Aug 2018 21:04:54 +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="R6y381X0"; dkim-atps=neutral Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=79.140.41.39; helo=v3-1039.vlinux.de; envelope-from=sven@narfation.org; receiver= Received: from v3-1039.vlinux.de (narfation.org [79.140.41.39]) by open-mesh.org (Postfix) with ESMTPS id 0E131805A7 for ; Sun, 12 Aug 2018 21:04:52 +0200 (CEST) Received: from sven-desktop.home.narfation.org (p200300C593C7FBFD0000000000008096.dip0.t-ipconnect.de [IPv6:2003:c5:93c7:fbfd::8096]) by v3-1039.vlinux.de (Postfix) with ESMTPSA id 88C86110135; Sun, 12 Aug 2018 21:04:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=narfation.org; s=20121; t=1534100691; bh=cPYggqOD3bWJxNYWjTwGqZTDmpSUfrBVJGKJM3YA/t0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R6y381X0dkeMOO34DP0LF2zy7/hLLRATO3O6jTnAa7Yk6XXCa5VXo8B7L33RTWANS jxk6MEZFX2cgUdy4xLkQ0UKA8Zt5CycOHS/faJGBemj2wpWrb+iuLqkrGQ5Ju7FFk8 uH73Z6F2cxRoMBfgLKtlUA2qQyNqn+gsSD4g+AMA= From: Sven Eckelmann To: b.a.t.m.a.n@lists.open-mesh.org Date: Sun, 12 Aug 2018 21:04:41 +0200 Message-Id: <20180812190445.28013-2-sven@narfation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180812190445.28013-1-sven@narfation.org> References: <20180812190445.28013-1-sven@narfation.org> Subject: [B.A.T.M.A.N.] [PATCH 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 --- net/batman-adv/gateway_client.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index 8b198ee7..0df4e87d 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 @@ -355,6 +356,8 @@ 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 +372,8 @@ 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 +429,14 @@ 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))