From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www2881.sakura.ne.jp (www2881.sakura.ne.jp [49.212.198.91]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 895A32C3257 for ; Wed, 25 Mar 2026 20:51:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=49.212.198.91 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774471867; cv=none; b=jpg6jm9AFp0Wx1+hK2zhOwYGADPLhzbdKtVLwGaIR48CWGnHBP9wQZ5NwE7U00IhjbTU0cnimQa3pP03eelHvwywRPsO44avL3K6N3hPbPFAMiz9GnhdLYJD59T5tSbmqHrsG9duNAmCiBIZ5oOXDjZpkwgKsmatQWPeDYfEgmI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774471867; c=relaxed/simple; bh=5G6TUiuRIZ9w4CWAjML67g9Ly4xSYU+OdcnxpggGXdc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=XxTzj7N3UUlFGRRchBW0RDhfC4THg7aX0jQnTQotg8HmKTCvKQpGbGE3ci23/dKt0Mp13Re/p1Bkb14x3b3lAUbDVsuz2oRYaeD/gBXFpYUVC8u59Y+wtO3TM3sh1xnzoCUVIftGEmF0idoYbY7qxHuWgpqKnMEI66D49ebVFyY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enjuk.jp; spf=pass smtp.mailfrom=enjuk.jp; dkim=pass (2048-bit key) header.d=enjuk.jp header.i=@enjuk.jp header.b=lSUT0jRI; arc=none smtp.client-ip=49.212.198.91 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enjuk.jp Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=enjuk.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=enjuk.jp header.i=@enjuk.jp header.b="lSUT0jRI" Received: from ms-a2 (39.25.31.150.dy.iij4u.or.jp [150.31.25.39]) (authenticated bits=0) by www2881.sakura.ne.jp (8.16.1/8.16.1) with ESMTPSA id 62PKou8B020293 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 26 Mar 2026 05:50:56 +0900 (JST) (envelope-from kohei@enjuk.jp) DKIM-Signature: a=rsa-sha256; bh=e+ypmhgEo15svmjeaPLlvAZjVEpBxo8jHbFD3xFAMjM=; c=relaxed/relaxed; d=enjuk.jp; h=From:Message-ID:To:Subject:Date; s=rs20251215; t=1774471856; v=1; b=lSUT0jRI1tAoWK5D8wckc74+l+HU26AoMJa853f/ULNa73hsWYW6Sk3J3x9pcD5y RIeaobmuvBF+s+DVLQYilGkBPgXs0AWQr6B0foQjHbWjgDBCHGDQdFBhleAWmTs3 VuFeLz3y0/XQWGxreyXY55v/9KcfkpCeztMIFzb83ej5bVH4q2uzoQrtbQ2ImzCT H69am2/zMVOqKbaTRqFd7/Tn305KcKzvtSPto3nDh+fCVEtXZIACnKOZQYEvsAlj CWPMUae4CVUrNIZP65nz0xQG8OXoDnc4VxMqoek9v9jiiQEvdiMD63LhV3Fn4/CQ DRVhYrpsEVyqMgod0NUvbQ== From: Kohei Enju To: intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org Cc: Tony Nguyen , Przemek Kitszel , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Shannon Nelson , Jesse Brandeburg , kohei.enju@gmail.com, Kohei Enju Subject: [PATCH iwl-net v1] i40e: don't advertise IFF_SUPP_NOFCS Date: Wed, 25 Mar 2026 20:50:06 +0000 Message-ID: <20260325205054.109822-1-kohei@enjuk.jp> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit i40e advertises IFF_SUPP_NOFCS, allowing users to use the SO_NOFCS socket option. However, this option is silently ignored, as the driver does not check skb->no_fcs, and always enables FCS insertion offload. Fix this by removing the advertisement of IFF_SUPP_NOFCS. This behavior can be reproduced with a simple AF_PACKET socket: import socket s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW) s.setsockopt(socket.SOL_SOCKET, 43, 1) # SO_NOFCS s.bind(("eth0", 0)) s.send(b'\xff' * 64) Previously, send() succeeds but the driver ignores SO_NOFCS. With this change, send() fails with -EPROTONOSUPPORT, as expected. Fixes: 41c445ff0f48 ("i40e: main driver core") Signed-off-by: Kohei Enju --- drivers/net/ethernet/intel/i40e/i40e_main.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 3749f32ef95a..a3c52aa6255b 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -13831,7 +13831,6 @@ static int i40e_config_netdev(struct i40e_vsi *vsi) netdev->neigh_priv_len = sizeof(u32) * 4; netdev->priv_flags |= IFF_UNICAST_FLT; - netdev->priv_flags |= IFF_SUPP_NOFCS; /* Setup netdev TC information */ i40e_vsi_config_netdev_tc(vsi, vsi->tc_config.enabled_tc); -- 2.51.0