From patchwork Wed Jun 17 16:00:11 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Lindner X-Patchwork-Id: 4467 Return-Path: Received-SPF: Softfail (domain owner discourages use of this host) identity=mailfrom; client-ip=5.148.176.57; helo=s1.neomailbox.net; envelope-from=mareklindner@neomailbox.ch; receiver=b.a.t.m.a.n@lists.open-mesh.org Received: from s1.neomailbox.net (s1.neomailbox.net [5.148.176.57]) by open-mesh.org (Postfix) with ESMTPS id 784C3602087 for ; Wed, 17 Jun 2015 18:00:22 +0200 (CEST) From: Marek Lindner To: b.a.t.m.a.n@lists.open-mesh.org Date: Thu, 18 Jun 2015 00:00:11 +0800 Message-Id: <1434556811-4120-1-git-send-email-mareklindner@neomailbox.ch> Cc: Marek Lindner Subject: [B.A.T.M.A.N.] [PATCHv2 maint] batman-adv: protect tt_local_entry from concurrent delete events 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: Wed, 17 Jun 2015 16:00:23 -0000 The tt_local_entry deletion performed in batadv_tt_local_remove() was neither protecting against simultaneous deletes nor checking whether the element was still part of the list before calling hlist_del_rcu(). Replacing the hlist_del_rcu() call with batadv_hash_remove() provides adequate protection via hash spinlocks as well as an is-element-still-in-hash check to avoid 'blind' hash removal. Reported-by: alfonsname@web.de Signed-off-by: Marek Lindner Acked-by: Antonio Quartulli --- translation-table.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/translation-table.c b/translation-table.c index e95a424..fa90a6a 100644 --- a/translation-table.c +++ b/translation-table.c @@ -1015,6 +1015,7 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv, struct batadv_tt_local_entry *tt_local_entry; uint16_t flags, curr_flags = BATADV_NO_FLAGS; struct batadv_softif_vlan *vlan; + void *tt_entry_exists; tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid); if (!tt_local_entry) @@ -1042,7 +1043,15 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv, * immediately purge it */ batadv_tt_local_event(bat_priv, tt_local_entry, BATADV_TT_CLIENT_DEL); - hlist_del_rcu(&tt_local_entry->common.hash_entry); + + tt_entry_exists = batadv_hash_remove(bat_priv->tt.local_hash, + batadv_compare_tt, + batadv_choose_tt, + &tt_local_entry->common); + if (!tt_entry_exists) + goto out; + + /* extra call to free the local tt entry */ batadv_tt_local_entry_free_ref(tt_local_entry); /* decrease the reference held for this vlan */