[PATCH] virtio_net: roll back RSS state on control failure
From: Xiong Weimin
Date: Mon Aug 10 2026 - 22:19:24 EST
The ethtool RSS and RXHASH paths update the driver's cached RSS state
before committing the change to the device. If the control virtqueue
command fails, the cached hash types, key or indirection table can then
report a configuration that the device did not accept.
Preserve the previous local state around RSS/hash control commands and
restore it when the device update fails, while propagating the error to
the caller.
v1 -> v2:
- Use kvmemdup() instead of kmemdup() in virtnet_set_rxfh() for the
saved RSS header, since the indirection table can push the header
size up to ~128K.
Signed-off-by: Xiong Weimin <xiongweimin@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ccd96315a..995ca4640 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -5573,8 +5573,8 @@ static int virtnet_set_rxfh(struct net_device *dev,
}
if (rxfh->indir) {
- old_rss_hdr = kmemdup(vi->rss_hdr, virtnet_rss_hdr_size(vi),
- GFP_KERNEL);
+ old_rss_hdr = kvmemdup(vi->rss_hdr, virtnet_rss_hdr_size(vi),
+ GFP_KERNEL);
if (!old_rss_hdr)
return -ENOMEM;
--
2.43.0