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authorSven Eckelmann <sven@narfation.org>2018-08-12 21:04:44 +0200
committerSimon Wunderlich <sw@simonwunderlich.de>2018-09-06 14:37:12 +0200
commite7136e48ffdfb9f37b0820f619380485eb407361 (patch)
tree1e50173ed02b2569a93b9214a24ec9807784dd30 /net/batman-adv
parent94cb82f594ed86be303398d6dfc7640a6f1d45d4 (diff)
batman-adv: Prevent duplicated global TT entry
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>
Diffstat (limited to 'net/batman-adv')
-rw-r--r--net/batman-adv/translation-table.c6
1 files 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 @@ sync_flags:
out:
if (orig_entry)
batadv_tt_orig_list_entry_put(orig_entry);
+
+ spin_unlock_bh(&tt_global->list_lock);
}
/**