From: Simon Wunderlich <sw@simonwunderlich.de>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org,
Sven Eckelmann <sven@narfation.org>,
Simon Wunderlich <sw@simonwunderlich.de>
Subject: [B.A.T.M.A.N.] [PATCH 07/11] batman-adv: Prevent duplicated global TT entry
Date: Wed, 19 Sep 2018 14:22:09 +0200 [thread overview]
Message-ID: <20180919122213.23108-8-sw@simonwunderlich.de> (raw)
In-Reply-To: <20180919122213.23108-1-sw@simonwunderlich.de>
From: Sven Eckelmann <sven@narfation.org>
The function batadv_tt_global_orig_entry_add is responsible for adding new
tt_orig_list_entry to the orig_list. It first checks whether the entry
already is in the list or not. If it is, then the creation of a new entry
is aborted.
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: d657e621a0f5 ("batman-adv: add reference counting for type batadv_tt_orig_list_entry")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
net/batman-adv/translation-table.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 12a2b7d21376..d21624c44665 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1613,6 +1613,8 @@ batadv_tt_global_orig_entry_add(struct batadv_tt_global_entry *tt_global,
{
struct batadv_tt_orig_list_entry *orig_entry;
+ spin_lock_bh(&tt_global->list_lock);
+
orig_entry = batadv_tt_global_orig_entry_find(tt_global, orig_node);
if (orig_entry) {
/* refresh the ttvn: the current value could be a bogus one that
@@ -1635,11 +1637,9 @@ batadv_tt_global_orig_entry_add(struct batadv_tt_global_entry *tt_global,
orig_entry->flags = flags;
kref_init(&orig_entry->refcount);
- spin_lock_bh(&tt_global->list_lock);
kref_get(&orig_entry->refcount);
hlist_add_head_rcu(&orig_entry->list,
&tt_global->orig_list);
- spin_unlock_bh(&tt_global->list_lock);
atomic_inc(&tt_global->orig_list_count);
sync_flags:
@@ -1647,6 +1647,8 @@ batadv_tt_global_orig_entry_add(struct batadv_tt_global_entry *tt_global,
out:
if (orig_entry)
batadv_tt_orig_list_entry_put(orig_entry);
+
+ spin_unlock_bh(&tt_global->list_lock);
}
/**
--
2.11.0
next prev parent reply other threads:[~2018-09-19 12:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-19 12:22 [B.A.T.M.A.N.] [PATCH 00/11] pull request for net: batman-adv 2018-09-19 Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 01/11] batman-adv: Avoid probe ELP information leak Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 02/11] batman-adv: Fix segfault when writing to throughput_override Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 03/11] batman-adv: Fix segfault when writing to sysfs elp_interval Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 04/11] batman-adv: Prevent duplicated gateway_node entry Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 05/11] batman-adv: Prevent duplicated nc_node entry Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 06/11] batman-adv: Prevent duplicated softif_vlan entry Simon Wunderlich
2018-09-19 12:22 ` Simon Wunderlich [this message]
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 08/11] batman-adv: Prevent duplicated tvlv handler Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 09/11] batman-adv: fix backbone_gw refcount on queue_work() failure Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 10/11] batman-adv: fix hardif_neigh " Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 11/11] batman-adv: Increase version number to 2018.3 Simon Wunderlich
2018-09-20 3:34 ` [B.A.T.M.A.N.] [PATCH 00/11] pull request for net: batman-adv 2018-09-19 David Miller
2018-09-20 8:09 ` Simon Wunderlich
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