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

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

From: Aditya Garg <redacted>

[ Upstream commit d23564955811da493f34412d7de60fa268c8cb50 ]

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 <redacted>
Reviewed-by: Dipayaan Roy <redacted>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://patch.msgid.link/1768212093-1594-1-git-send-email-gargaditya@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 d6fe8b5184a99..5f612528aa53a 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c

@@ -1765,6 +1765,9 @@ 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++)

-- 
2.51.0