On Tue, Nov 15, 2016 at 10:24:12PM -0800, Eric Dumazet wrote: > From: Eric Dumazet <[email protected]> > > 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 <[email protected]> > Cc: Jason Wang <[email protected]> > Cc: Michael S. Tsirkin <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]> > --- > drivers/net/virtio_net.c | 5 +++++ > 1 file changed, 5 insertions(+) > > 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); > } >
