From d5487249a81ea658717614009c8f46acc5b7101a Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Wed, 13 May 2026 10:43:54 +0200 Subject: [PATCH] batman-adv: tp_meter: directly shut down timer on cleanup batadv_tp_sender_cleanup() was calling timer_delete_sync() followed by timer_delete() to guard against the timer handler re-arming itself between the two calls. This double-deletion hack relied on the sending status being set to 0 to suppress re-arming. Replace both calls with a single timer_shutdown_sync(). This function both waits for any running timer callback to complete (like timer_delete_sync()) and permanently disarms the timer so it cannot be re-armed afterwards, making re-arming prevention unconditional and self-documenting. The re-arming property is also required because otherwise: 1. context 0 (batadv_tp_recv_ack()) checks in batadv_tp_reset_sender_timer() if sending is still 1 -> it is 2. context 1 changes in batadv_tp_sender_shutdown() sending to 0 and in this process forces the kthread to stop timer in batadv_tp_sender_cleanup() 3. context 0 continues in batadv_tp_reset_sender_timer() and rearms the timer -> but the reference for it is already gone Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index a3593d104caa..1fd1526059d8 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -401,13 +401,7 @@ static void batadv_tp_sender_cleanup(struct batadv_tp_vars *tp_vars) batadv_tp_list_detach(tp_vars); /* kill the timer and remove its reference */ - timer_delete_sync(&tp_vars->timer); - /* the worker might have rearmed itself therefore we kill it again. Note - * that if the worker should run again before invoking the following - * timer_delete(), it would not re-arm itself once again because the status - * is OFF now - */ - timer_delete(&tp_vars->timer); + timer_shutdown_sync(&tp_vars->timer); batadv_tp_vars_put(tp_vars); }