[PATCH 6.6 024/254] net: hv_netvsc: reject RSS hash key programming without RX indirection table

Greg Kroah-Hartman
2026-01-28T15:27:42Z

From: Aditya Garg <gargaditya@linux.microsoft.com>

[ 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 <gargaditya@linux.microsoft.com>
Reviewed-by: Dipayaan Roy <dipayanroy@linux.microsoft.com>
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 aa114240e340d..af001e2e688b2 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1762,6 +1762,9 @@ static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
return -EOPNOTSUPP;

+ if (!ndc->rx_table_sz)
+ return -EOPNOTSUPP;
+
rndis_dev = ndev->extension;
if (indir) {
for (i = 0; i < ndc->rx_table_sz; i++)
--
2.51.0