diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 853b1770df36..e58c03c504c1 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1383,6 +1383,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 		   tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE),
 		   tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE));
 
+	rcu_read_lock();
 	/*
 	 * Update has_rules[] flags for the updated tg's subtree.  A tg is
 	 * considered to have rules if either the tg itself or any of its
@@ -1410,6 +1411,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 		this_tg->latency_target = max(this_tg->latency_target,
 				parent_tg->latency_target);
 	}
+	rcu_read_unlock();
 
 	/*
 	 * We're already holding queue_lock and know @tg is valid.  Let's