diff options
| author | Sven Eckelmann <sven@narfation.org> | 2016-01-31 13:28:00 +0100 |
|---|---|---|
| committer | Antonio Quartulli <a@unstable.cc> | 2016-02-16 17:52:26 +0800 |
| commit | 3db152093efb750bc47fd4d69355b90b18113105 (patch) | |
| tree | 2c4040232edddcee0aa51d02e6d88de289d2adb8 | |
| parent | c18bdd018e8912ca73ad6c12120b7283b5038875 (diff) | |
| download | linux-3db152093efb750bc47fd4d69355b90b18113105.tar.bz2 | |
batman-adv: Only put orig_node_vlan list reference when removed
The batadv_orig_node_vlan reference counter in batadv_tt_global_size_mod
can only be reduced when the list entry was actually removed. Otherwise the
reference counter may reach zero when batadv_tt_global_size_mod is called
from two different contexts for the same orig_node_vlan but only one
context is actually removing the entry from the list.
The release function for this orig_node_vlan is not called inside the
vlan_list_lock spinlock protected region because the function
batadv_tt_global_size_mod still holds a orig_node_vlan reference for the
object pointer on the stack. Thus the actual release function (when
required) will be called only at the end of the function.
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
| -rw-r--r-- | net/batman-adv/translation-table.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index cdfc85fa2743..0e80fd1461ab 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -303,9 +303,11 @@ static void batadv_tt_global_size_mod(struct batadv_orig_node *orig_node, if (atomic_add_return(v, &vlan->tt.num_entries) == 0) { spin_lock_bh(&orig_node->vlan_list_lock); - hlist_del_init_rcu(&vlan->list); + if (!hlist_unhashed(&vlan->list)) { + hlist_del_init_rcu(&vlan->list); + batadv_orig_node_vlan_free_ref(vlan); + } spin_unlock_bh(&orig_node->vlan_list_lock); - batadv_orig_node_vlan_free_ref(vlan); } batadv_orig_node_vlan_free_ref(vlan); |