[PATCH v2] hv_netvsc: Fix net device attach on older Windows hosts

[PATCH v2] hv_netvsc: Fix net device attach on older Windows hosts

[Mohammed Gamal]

On older windows hosts the net_device instance is returned to
the caller of rndis_filter_device_add() without having the presence
bit set first. This would cause any subsequent calls to network device
operations (e.g. MTU change, channel change) to fail after the device
is detached once, returning -ENODEV.

Instead of returning the device instabce, we take the exit path where
we call netif_device_attach()

Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")

Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
---
 drivers/net/hyperv/rndis_filter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 6b127be..e7ca5b5 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1288,7 +1288,7 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
 		   rndis_device->link_state ? "down" : "up");
 
 	if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_5)
-		return net_device;
+		goto out;
 
 	rndis_filter_query_link_speed(rndis_device, net_device);
 
-- 
1.8.3.1

Re: [PATCH v2] hv_netvsc: Fix net device attach on older Windows hosts

[Stephen Hemminger]

On Wed,  9 May 2018 10:17:34 +0200
Mohammed Gamal <mgamal@redhat.com> wrote:

> On older windows hosts the net_device instance is returned to
> the caller of rndis_filter_device_add() without having the presence
> bit set first. This would cause any subsequent calls to network device
> operations (e.g. MTU change, channel change) to fail after the device
> is detached once, returning -ENODEV.
> 
> Instead of returning the device instabce, we take the exit path where
> we call netif_device_attach()
> 
> Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
> 
> Signed-off-by: Mohammed Gamal <mgamal@redhat.com>

The standard for patch submission is no blank lines between Fixes
and Signed-off-by to make it easier for bots.

> ---
>  drivers/net/hyperv/rndis_filter.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
> index 6b127be..e7ca5b5 100644
> --- a/drivers/net/hyperv/rndis_filter.c
> +++ b/drivers/net/hyperv/rndis_filter.c
> @@ -1288,7 +1288,7 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
>  		   rndis_device->link_state ? "down" : "up");
>  
>  	if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_5)
> -		return net_device;
> +		goto out;
>  
>  	rndis_filter_query_link_speed(rndis_device, net_device);
>  


Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>

Re: [PATCH v2] hv_netvsc: Fix net device attach on older Windows hosts

[David Miller]

From: Mohammed Gamal <mgamal@redhat.com>
Date: Wed,  9 May 2018 10:17:34 +0200

> On older windows hosts the net_device instance is returned to
> the caller of rndis_filter_device_add() without having the presence
> bit set first. This would cause any subsequent calls to network device
> operations (e.g. MTU change, channel change) to fail after the device
> is detached once, returning -ENODEV.
> 
> Instead of returning the device instabce, we take the exit path where
> we call netif_device_attach()
> 
> Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
> 
> Signed-off-by: Mohammed Gamal <mgamal@redhat.com>

Applied.