From patchwork Thu May 1 23:35:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antonio Quartulli X-Patchwork-Id: 3984 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=178.209.62.157; helo=s3.neomailbox.net; envelope-from=antonio@meshcoding.com; receiver=b.a.t.m.a.n@lists.open-mesh.org Received: from s3.neomailbox.net (s3.neomailbox.net [178.209.62.157]) by open-mesh.org (Postfix) with ESMTPS id 1AA3760066A for ; Fri, 2 May 2014 01:36:07 +0200 (CEST) From: Antonio Quartulli To: b.a.t.m.a.n@lists.open-mesh.org Date: Fri, 2 May 2014 01:35:13 +0200 Message-Id: <1398987313-11934-1-git-send-email-antonio@meshcoding.com> Cc: Antonio Quartulli Subject: [B.A.T.M.A.N.] [PATCHv2 maint] batman-adv: increase orig refcount when storing ref in gw_node X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 May 2014 23:36:08 -0000 From: Antonio Quartulli A pointer to the orig_node representing a bat-gateway is stored in the gw_node->orig_node member, but the refcount for such orig_node is never increased. This leads to memory faults when gw_node->orig_node is accessed and the originator has already been freed. Fix this by increasing the refcount on gw_node creation and decreasing it on gw_node free. Signed-off-by: Antonio Quartulli --- Change since v1: - properly release orig_node in case of gw_node allocation failure gateway_client.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/gateway_client.c b/gateway_client.c index d7fafc1..d5a40ab 100644 --- a/gateway_client.c +++ b/gateway_client.c @@ -42,8 +42,10 @@ static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node) { - if (atomic_dec_and_test(&gw_node->refcount)) + if (atomic_dec_and_test(&gw_node->refcount)) { + batadv_orig_node_free_ref(gw_node->orig_node); kfree_rcu(gw_node, rcu); + } } static struct batadv_gw_node * @@ -406,9 +408,14 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv, if (gateway->bandwidth_down == 0) return; + if (!atomic_inc_not_zero(&orig_node->refcount)) + return; + gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC); - if (!gw_node) + if (!gw_node) { + batadv_orig_node_free_ref(orig_node); return; + } INIT_HLIST_NODE(&gw_node->list); gw_node->orig_node = orig_node;