# \[PATCH net v3 1/2\] net: ethtool: Don't check if RSS context exists in case of context 0 - From: Gal Pressman \ - Date: 2025-06-12 07:19:55 - List: netdev - Page: https://ratatoskr.run/netdev/2025/06/11329266 - Thread: https://ratatoskr.run/netdev/2025/06/11329265/t.md ```text Context 0 (default context) always exists, there is no need to check whether it exists or not when adding a flow steering rule. The existing check fails when creating a flow steering rule for context 0 as it is not stored in the rss_ctx xarray. For example: $ ethtool --config-ntuple eth2 flow-type tcp4 dst-ip 194.237.147.23 dst-port 19983 context 0 loc 618 rmgr: Cannot insert RX class rule: Invalid argument Cannot insert classification rule An example usecase for this could be: - A high-priority rule (loc 0) directing specific port traffic to context 0. - A low-priority rule (loc 1) directing all other TCP traffic to context 1. This is a user-visible regression that was caught in our testing environment, it was not reported by a user yet. Fixes: de7f7582dff2 ("net: ethtool: prevent flow steering to RSS contexts which don't exist") Cc: Jakub Kicinski Reviewed-by: Tariq Toukan Reviewed-by: Nimrod Oren Signed-off-by: Gal Pressman Reviewed-by: Joe Damato --- net/ethtool/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 39ec920f5de7..71c828d0bf31 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1083,7 +1083,8 @@ static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev, ethtool_get_flow_spec_ring(info.fs.ring_cookie)) return -EINVAL; - if (!xa_load(&dev->ethtool->rss_ctx, info.rss_context)) + if (info.rss_context && + !xa_load(&dev->ethtool->rss_ctx, info.rss_context)) return -EINVAL; } -- 2.40.1 ```