> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Jesse Brandeburg
> Sent: Tuesday, December 2, 2025 12:39 AM
> To: [email protected]
> Cc: Brandeburg, Jesse <[email protected]>; Nguyen, Anthony L
> <[email protected]>; Keller, Jacob E
> <[email protected]>; IWL <[email protected]>;
> Kitszel, Przemyslaw <[email protected]>; Andrew Lunn
> <[email protected]>; David S. Miller <[email protected]>; Eric
> Dumazet <[email protected]>; Jakub Kicinski <[email protected]>; Paolo
> Abeni <[email protected]>; Brett Creeley <[email protected]>
> Subject: [Intel-wired-lan] [PATCH net v1] ice: stop counting UDP csum
> mismatch as rx_errors
>
> From: Jesse Brandeburg <[email protected]>
>
> Since the beginning, the Intel ice driver has counted receive checksum
> offload mismatches into the rx_errors member of the rtnl_link_stats64
> struct. In ethtool -S these show up as rx_csum_bad.nic.
>
> I believe counting these in rx_errors is fundamentally wrong, as it's
> pretty clear from the comments in if_link.h and from every other
> statistic
> the driver is summing into rx_errors, that all of them would cause a
> "hardware drop" except for the UDP checksum mismatch, as well as the
> fact
> that all the other causes for rx_errors are L2 reasons, and this L4
> UDP
> "mismatch" is an outlier.
>
> A last nail in the coffin is that rx_errors is monitored in production
> and
> can indicate a bad NIC/cable/Switch port, but instead some random
> series of
> UDP packets with bad checksums will now trigger this alert. This false
> positive makes the alert useless and affects us as well as other
> companies.
>
> This packet with presumably a bad UDP checksum is *already* passed to
> the
> stack, just not marked as offloaded by the hardware/driver. If it is
> dropped by the stack it will show up as UDP_MIB_CSUMERRORS.
>
> And one more thing, none of the other Intel drivers, and at least
> bnxt_en
> and mlx5 both don't appear to count UDP offload mismatches as
> rx_errors.
>
> Here is a related customer complaint:
> https://community.intel.com/t5/Ethernet-Products/ice-rx-errros-is-too-
> sensitive-to-IP-TCP-attack-packets-Intel/td-p/1662125
>
> Fixes: 4f1fe43c920b ("ice: Add more Rx errors to netdev's rx_error
> counter")
> Cc: Tony Nguyen <[email protected]>
> Cc: Jake Keller <[email protected]>
> Cc: IWL <[email protected]>
> Signed-off-by: Jesse Brandeburg <[email protected]>
> --
> I am sending this to net as I consider it a bug, and it will backport
> cleanly.
> ---
> drivers/net/ethernet/intel/ice/ice_main.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c
> b/drivers/net/ethernet/intel/ice/ice_main.c
> index 86f5859e88ef..d004acfa0f36 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -6995,7 +6995,6 @@ void ice_update_vsi_stats(struct ice_vsi *vsi)
> cur_ns->rx_errors = pf->stats.crc_errors +
> pf->stats.illegal_bytes +
> pf->stats.rx_undersize +
> - pf->hw_csum_rx_error +
Good day , Jesse
It looks like you remove the single place where the ' hw_csum_rx_error' var is
being really used.
What about removing it's declaration and calculation then?
> pf->stats.rx_jabber +
> pf->stats.rx_fragments +
> pf->stats.rx_oversize;
> --
> 2.47.3
