From: Vitaly Kuznetsov Date: Mon, 15 Aug 2016 15:48:42 +0000 (+0200) Subject: hv_netvsc: protect module refcount by checking net_device_ctx->vf_netdev X-Git-Tag: v4.14-rc1~2626^2~5^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0f20d795f78d182c4b743d880a5e8dc4d39892fe;p=platform%2Fkernel%2Flinux-rpi.git 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 Acked-by: Haiyang Zhang Signed-off-by: David S. Miller --- diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 2c90883..62a4e6e 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -1193,7 +1193,7 @@ 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); @@ -1312,7 +1312,7 @@ 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);