From 963abe5c8a0273a1cf5913556da1b1189de0e57a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 15 Nov 2016 22:24:12 -0800 Subject: virtio-net: add a missing synchronize_net() It seems many drivers do not respect napi_hash_del() contract. When napi_hash_del() is used before netif_napi_del(), an RCU grace period is needed before freeing NAPI object. Fixes: 91815639d880 ("virtio-net: rx busy polling support") Signed-off-by: Eric Dumazet Cc: Jason Wang Cc: Michael S. Tsirkin Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/net/virtio_net.c') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fd8b1e62301f..7276d5a95bd0 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1497,6 +1497,11 @@ static void virtnet_free_queues(struct virtnet_info *vi) netif_napi_del(&vi->rq[i].napi); } + /* We called napi_hash_del() before netif_napi_del(), + * we need to respect an RCU grace period before freeing vi->rq + */ + synchronize_net(); + kfree(vi->rq); kfree(vi->sq); } -- cgit v1.2.3-59-g8ed1b