net: hv_netvsc: reject RSS hash key programming without RX indirection table

[PATCH net-next] net: hv_netvsc: reject RSS hash key programming without RX indirection table

Posted by Aditya Garg 3 weeks, 5 days ago

RSS configuration requires a valid RX indirection table. When the device
reports a single receive queue, rndis_filter_device_add() does not
allocate an indirection table, accepting RSS hash key updates in this
state leads to a hang.

Fix this by gating netvsc_set_rxfh() on ndc->rx_table_sz and return
-EOPNOTSUPP when the table is absent. This aligns set_rxfh with the device
capabilities and prevents incorrect behavior.

Fixes: 962f3fee83a4 ("netvsc: add ethtool ops to get/set RSS key")
Signed-off-by: Aditya Garg <gargaditya@linux.microsoft.com>
Reviewed-by: Dipayaan Roy <dipayanroy@linux.microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 3d47d749ef9f..cbd52cb79268 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1750,6 +1750,9 @@ static int netvsc_set_rxfh(struct net_device *dev,
 	    rxfh->hfunc != ETH_RSS_HASH_TOP)
 		return -EOPNOTSUPP;
 
+	if (!ndc->rx_table_sz)
+		return -EOPNOTSUPP;
+
 	rndis_dev = ndev->extension;
 	if (rxfh->indir) {
 		for (i = 0; i < ndc->rx_table_sz; i++)
-- 
2.43.0

Re: [PATCH net-next] net: hv_netvsc: reject RSS hash key programming without RX indirection table

Posted by Dipayaan Roy 3 weeks, 5 days ago

On Mon, Jan 12, 2026 at 02:01:33AM -0800, Aditya Garg wrote:
> RSS configuration requires a valid RX indirection table. When the device
> reports a single receive queue, rndis_filter_device_add() does not
> allocate an indirection table, accepting RSS hash key updates in this
> state leads to a hang.
> 
> Fix this by gating netvsc_set_rxfh() on ndc->rx_table_sz and return
> -EOPNOTSUPP when the table is absent. This aligns set_rxfh with the device
> capabilities and prevents incorrect behavior.
> 
> Fixes: 962f3fee83a4 ("netvsc: add ethtool ops to get/set RSS key")
> Signed-off-by: Aditya Garg <gargaditya@linux.microsoft.com>
> Reviewed-by: Dipayaan Roy <dipayanroy@linux.microsoft.com>
> ---
>  drivers/net/hyperv/netvsc_drv.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 3d47d749ef9f..cbd52cb79268 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -1750,6 +1750,9 @@ static int netvsc_set_rxfh(struct net_device *dev,
>  	    rxfh->hfunc != ETH_RSS_HASH_TOP)
>  		return -EOPNOTSUPP;
>  
> +	if (!ndc->rx_table_sz)
> +		return -EOPNOTSUPP;
> +
>  	rndis_dev = ndev->extension;
>  	if (rxfh->indir) {
>  		for (i = 0; i < ndc->rx_table_sz; i++)
> -- 
> 2.43.0
>

LGTM.

Reviewed-by: Dipayaan Roy <dipayanroy@linux.microsoft.com>