Index: sys/netinet/tcp_timer.c
===================================================================
--- sys/netinet/tcp_timer.c
+++ sys/netinet/tcp_timer.c
@@ -941,21 +941,9 @@
 		}
 
 	if (tp->t_timers->tt_flags & timer_type) {
-		if (callout_stop(t_callout) &&
-		    (tp->t_timers->tt_flags & f_reset)) {
+		if (callout_drain_async(t_callout, f_callout, tp)) {
+			/* callout is no longer executing */
 			tp->t_timers->tt_flags &= ~(timer_type | f_reset);
-		} else {
-			/*
-			 * Can't stop the callout, defer tcpcb actual deletion
-			 * to the last tcp timer discard callout.
-			 * The TT_STOPPED flag will ensure that no tcp timer
-			 * callouts can be restarted on our behalf, and
-			 * past this point currently running callouts waiting
-			 * on inp lock will return right away after the
-			 * classical check for callout reset/stop events:
-			 * callout_pending() || !callout_active()
-			 */
-			callout_reset(t_callout, 1, f_callout, tp);
 		}
 	}
 }