[PATCH] fix: net/batman-adv: batadv_interface_kill_vid: extra batadv_meshif_vlan_put after destroy

[WenTao Liang <vulab@iscas.ac.cn>]

In batadv_interface_kill_vid(), batadv_meshif_vlan_get() acquires a
reference on the vlan object. batadv_meshif_destroy_vlan() internally
calls batadv_meshif_vlan_put() which balances that reference. However, an
additional batadv_meshif_vlan_put(vlan) is called after
batadv_meshif_destroy_vlan(), causing a refcount underflow and potential
use-after-free of the vlan object.

Remove the extra batadv_meshif_vlan_put(vlan) call.

Cc: stable@vger.kernel.org
Fixes: 5d2c05b21337 ("batman-adv: add per VLAN interface attribute framework")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
---
 net/batman-adv/mesh-interface.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/net/batman-adv/mesh-interface.c b/net/batman-adv/mesh-interface.c
index e7aa45bc6b7a..cc974f243200 100644
--- a/net/batman-adv/mesh-interface.c
+++ b/net/batman-adv/mesh-interface.c
@@ -691,9 +691,6 @@ static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
 
 	batadv_meshif_destroy_vlan(bat_priv, vlan);
 
-	/* finally free the vlan object */
-	batadv_meshif_vlan_put(vlan);
-
 	return 0;
 }
 
-- 
2.39.5 (Apple Git-154)