| Message ID | 1470913137-29167-4-git-send-email-vkuznets@redhat.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com] > Sent: Thursday, August 11, 2016 6:59 AM > To: netdev@vger.kernel.org > Cc: devel@linuxdriverproject.org; linux-kernel@vger.kernel.org; Haiyang > Zhang <haiyangz@microsoft.com>; KY Srinivasan <kys@microsoft.com> > Subject: [PATCH net 3/4] hv_netvsc: protect module refcount by checking > net_device_ctx->vf_netdev > > We're not guaranteed to see NETDEV_REGISTER/NETDEV_UNREGISTER > notifications > only once per VF but we increase/decrease module refcount unconditionally. > Check vf_netdev to make sure we don't take/release it twice. We presume > that only one VF per netvsc device may exist. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index b3c31e3..874829a 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -1204,7 +1204,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev) net_device_ctx = netdev_priv(ndev); netvsc_dev = net_device_ctx->nvdev; - if (netvsc_dev == NULL) + if (!netvsc_dev || net_device_ctx->vf_netdev) return NOTIFY_DONE; netdev_info(ndev, "VF registering: %s\n", vf_netdev->name); @@ -1334,7 +1334,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev) net_device_ctx = netdev_priv(ndev); netvsc_dev = net_device_ctx->nvdev; - if (netvsc_dev == NULL) + if (!netvsc_dev || !net_device_ctx->vf_netdev) return NOTIFY_DONE; netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name); netvsc_inject_disable(net_device_ctx);
We're not guaranteed to see NETDEV_REGISTER/NETDEV_UNREGISTER notifications only once per VF but we increase/decrease module refcount unconditionally. Check vf_netdev to make sure we don't take/release it twice. We presume that only one VF per netvsc device may exist. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- drivers/net/hyperv/netvsc_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)