[PATCH 4.18 30/35] hv/netvsc: Fix NULL dereference at single queue mode fallback

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai@suse.de>

[ Upstream commit b19b46346f483ae055fa027cb2d5c2ca91484b91 ]

The recent commit 916c5e1413be ("hv/netvsc: fix handling of fallback
to single queue mode") tried to fix the fallback behavior to a single
queue mode, but it changed the function to return zero incorrectly,
while the function should return an object pointer.  Eventually this
leads to a NULL dereference at the callers that expect non-NULL
value.

Fix it by returning the proper net_device object.

Fixes: 916c5e1413be ("hv/netvsc: fix handling of fallback to single queue mode")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/hyperv/rndis_filter.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1338,7 +1338,7 @@ out:
 	/* setting up multiple channels failed */
 	net_device->max_chn = 1;
 	net_device->num_chn = 1;
-	return 0;
+	return net_device;
 
 err_dev_remv:
 	rndis_filter_device_remove(dev, net_device);