[PATCH net] net/sched: flower: Add lock protection when remove filter handle

[Jianbo Liu <jianbol@nvidia.com>]

As IDR can't protect itself from the concurrent modification, place
idr_remove() under the protection of tp->lock.

Fixes: 08a0063df3ae ("net/sched: flower: Move filter handle initialization earlier")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
---
 net/sched/cls_flower.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index bfedc3d4423d..e1314674b4a9 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -2460,8 +2460,11 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 	}
 
 errout_idr:
-	if (!fold)
+	if (!fold) {
+		spin_lock(&tp->lock);
 		idr_remove(&head->handle_idr, fnew->handle);
+		spin_unlock(&tp->lock);
+	}
 	__fl_put(fnew);
 errout_tb:
 	kfree(tb);
-- 
2.26.2