From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933251AbbIDNKk (ORCPT ); Fri, 4 Sep 2015 09:10:40 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50467 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933180AbbIDNKa (ORCPT ); Fri, 4 Sep 2015 09:10:30 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Marek Lindner , Antonio Quartulli , Luis Henriques Subject: [PATCH 3.16.y-ckt 121/130] batman-adv: protect tt_local_entry from concurrent delete events Date: Fri, 4 Sep 2015 14:08:29 +0100 Message-Id: <1441372118-5933-122-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1441372118-5933-1-git-send-email-luis.henriques@canonical.com> References: <1441372118-5933-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt17 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Marek Lindner commit ef72706a0543d0c3a5ab29bd6378fdfb368118d9 upstream. 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. Fixes: 068ee6e204e1 ("batman-adv: roaming handling mechanism redesign") Reported-by: alfonsname@web.de Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli Signed-off-by: Luis Henriques --- net/batman-adv/translation-table.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index dc0a67fff85b..4503069e29b5 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -1018,6 +1018,7 @@ 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) @@ -1045,7 +1046,15 @@ 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 */