From: Sven Eckelmann Date: Wed, 6 May 2026 20:20:49 +0000 (+0200) Subject: batman-adv: tp_meter: fix tp_num leak on kmalloc failure X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ce425dd05d0fe7594930a0fb103634f35ac47bb6;p=thirdparty%2Fkernel%2Flinux.git batman-adv: tp_meter: fix tp_num leak on kmalloc failure When batadv_tp_start() or batadv_tp_init_recv() fail to allocate a new tp_vars object, the previously incremented bat_priv->tp_num counter is never decremented. This causes tp_num to drift upward on each allocation failure. Since only BATADV_TP_MAX_NUM sessions can be started and the count is never reduced for these failed allocations, it causes to an exhaustion of throughput meter sessions. In worst case, no new throughput meter session can be started until the mesh interface is removed. The error handling must decrement tp_num releasing the lock and aborting the creation of an throughput meter session Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Signed-off-by: Sven Eckelmann --- diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index 58ca59a2799e..066c76113fc4 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -994,6 +994,7 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, tp_vars = kmalloc_obj(*tp_vars, GFP_ATOMIC); if (!tp_vars) { + atomic_dec(&bat_priv->tp_num); spin_unlock_bh(&bat_priv->tp_list_lock); batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Meter: %s cannot allocate list elements\n", @@ -1366,8 +1367,10 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv, } tp_vars = kmalloc_obj(*tp_vars, GFP_ATOMIC); - if (!tp_vars) + if (!tp_vars) { + atomic_dec(&bat_priv->tp_num); goto out_unlock; + } ether_addr_copy(tp_vars->other_end, icmp->orig); tp_vars->role = BATADV_TP_RECEIVER;