summaryrefslogtreecommitdiff
path: root/net/batman-adv
diff options
context:
space:
mode:
authorSven Eckelmann <sven@narfation.org>2018-08-12 21:04:45 +0200
committerBen Hutchings <ben@decadent.org.uk>2018-12-16 22:09:12 +0000
commit62c8a37974b504b33a733d908b067443f3b753f1 (patch)
treed3fe5d9c199286ae3ef6d57e6acf8a1dcabe5d05 /net/batman-adv
parent365a0ea769fb125d2823a6360e8e41a861ce664b (diff)
batman-adv: Prevent duplicated tvlv handler
commit ae3cdc97dc10c7a3b31f297dab429bfb774c9ccb upstream. The function batadv_tvlv_handler_register is responsible for adding new tvlv_handler to the handler_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: ef26157747d4 ("batman-adv: tvlv - basic infrastructure") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net/batman-adv')
-rw-r--r--net/batman-adv/main.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index d1183e882167..1fea2b600b6f 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -1058,15 +1058,20 @@ void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
{
struct batadv_tvlv_handler *tvlv_handler;
+ spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
+
tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
if (tvlv_handler) {
+ spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
batadv_tvlv_handler_free_ref(tvlv_handler);
return;
}
tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
- if (!tvlv_handler)
+ if (!tvlv_handler) {
+ spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
return;
+ }
tvlv_handler->ogm_handler = optr;
tvlv_handler->unicast_handler = uptr;
@@ -1076,7 +1081,6 @@ void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
atomic_set(&tvlv_handler->refcount, 1);
INIT_HLIST_NODE(&tvlv_handler->list);
- spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
}