netdev - RE: [Intel-wired-lan] [PATCH net 4/4] ice: stop counting UDP csum mismatch as rx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <IA3PR11MB8986B4DB0B102492212901DFE591A@IA3PR11MB8986.namprd11.prod.outlook.com>
Date: Wed, 28 Jan 2026 06:35:03 +0000
From: "Loktionov, Aleksandr" <aleksandr.loktionov@...el.com>
To: "Nguyen, Anthony L" <anthony.l.nguyen@...el.com>, "davem@...emloft.net"
	<davem@...emloft.net>, "kuba@...nel.org" <kuba@...nel.org>,
	"pabeni@...hat.com" <pabeni@...hat.com>, "edumazet@...gle.com"
	<edumazet@...gle.com>, "andrew+netdev@...n.ch" <andrew+netdev@...n.ch>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
CC: "Brandeburg, Jesse" <jbrandeburg@...udflare.com>, "Nguyen, Anthony L"
	<anthony.l.nguyen@...el.com>, "jbrandeb@...nel.org" <jbrandeb@...nel.org>,
	"Kitszel, Przemyslaw" <przemyslaw.kitszel@...el.com>, "Keller, Jacob E"
	<jacob.e.keller@...el.com>, IWL <intel-wired-lan@...ts.osuosl.org>
Subject: RE: [Intel-wired-lan] [PATCH net 4/4] ice: stop counting UDP csum
 mismatch as rx_errors



> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@...osl.org> On Behalf
> Of Tony Nguyen
> Sent: Tuesday, January 27, 2026 11:31 PM
> To: davem@...emloft.net; kuba@...nel.org; pabeni@...hat.com;
> edumazet@...gle.com; andrew+netdev@...n.ch; netdev@...r.kernel.org
> Cc: Brandeburg, Jesse <jbrandeburg@...udflare.com>; Nguyen, Anthony L
> <anthony.l.nguyen@...el.com>; jbrandeb@...nel.org; Kitszel, Przemyslaw
> <przemyslaw.kitszel@...el.com>; Keller, Jacob E
> <jacob.e.keller@...el.com>; IWL <intel-wired-lan@...ts.osuosl.org>
> Subject: [Intel-wired-lan] [PATCH net 4/4] ice: stop counting UDP csum
> mismatch as rx_errors
> 
> From: Jesse Brandeburg <jbrandeburg@...udflare.com>
> 
> 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 <anthony.l.nguyen@...el.com>
> Cc: Jake Keller <jacob.e.keller@...el.com>
> Cc: IWL <intel-wired-lan@...ts.osuosl.org>
> Signed-off-by: Jesse Brandeburg <jbrandeburg@...udflare.com>
> Acked-by: Jacob Keller <jacob.e.keller@...el.com>
> Signed-off-by: Tony Nguyen <anthony.l.nguyen@...el.com>
> ---
>  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 de488185cd4a..71c6d53b461e 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -6982,7 +6982,6 @@ 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 +
>  				    pf->stats.rx_jabber +
>  				    pf->stats.rx_fragments +
>  				    pf->stats.rx_oversize;
> --
> 2.47.1

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@...el.com>