From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1EC473B19BC; Fri, 4 Sep 2026 05:33:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500011; cv=none; b=CV7OEw3I/qhh1aLnjcV7p8fqf7S223ccGGvXLOvrSXU9qRcoVZGUq+pxsqAr1JFkK8VFRAYVJ5aVPcIMB6YYwyh7Z8v8uKP2OoAbJuOrsrvXFvoDMV8jjxRxB3wqXuk3MG03TBpBFYqam/Q0+RgkAK43BP2nTPmfDZIZ+SNQG6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500011; c=relaxed/simple; bh=Q7BWC0Xv57lnoG5aH+zxCCO7U1N0dW4zjfykQzMqy+I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C+HJAEzfRG0g4xbhcZwlNL+GN79RDOszxa7H0Vqqcla4aGg3ywdD8SXfPBPGuc99cBVIn9kaeOEHvOm+FdowyrP2lGT7RQUt2XejeBwVmIiujaFyVMj7MCcnpfu8/pzQdjj+419LHHW4os/aTDS/hkpxBFqOyLfzjUoEa3vqMUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oBn2TfsI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="oBn2TfsI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7900F1F00A3D; Fri, 4 Sep 2026 05:33:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788500010; bh=4YSVSvzvmtajvNfJyh/dOYk9JBMDhD/PRavphK7Hj44=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oBn2TfsITpCsrmgDnNUJR/G19zFODOtwykD2EIxLwcMhBzQW6Qz19UFObCI4OFJ+G BOdz77rb54VdeFCNi4vpbr88mW5kSM4lTdk/JSEh+wAoZ2/ZJ69ZeptN6HoSnSjT1o RU7WeIhZ6gtxpQU3dn7BiDe+n4VravbmrDDQVP3Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Glenn Judd , Tariq Toukan , Jakub Kicinski Subject: [PATCH 7.2 618/713] net/mlx5e: do not HW-GRO coalesce small frames Date: Fri, 4 Sep 2026 06:59:46 +0200 Message-ID: <20260904045817.679930092@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045803.810145556@linuxfoundation.org> References: <20260904045803.810145556@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Glenn Judd commit e2466392a0b8496000e12181cb1ee1535eb0da25 upstream. When hardware GRO (SHAMPO) coalesces a small IPv4/TCP segment that was padded up to the 60-byte minimum Ethernet frame, the trailing padding is folded into the merged payload causing padding to be delivered to the user as payload. Detecting and reproducing the issue: the selftest tools/testing/selftests/drivers/net/gro.py subtest hw_ipv4_data_lrg_1byte sends {100, 1} expecting to receive {101}. In current code, it receives {106} (100 + 1 payload + 5 pad) instead. This patch avoids giving the user padding as payload by simply not coalescing small packets (which fails the subtest; the same approach and behavior as sw gro). This gains code simplicity at the cost of more computation (passing an extra skb up the stack) for small packets that could be coalesced. The threshold is chosen as ETH_ZLEN + 2 * VLAN_HLEN. This is the largest frame that may still contain minimum-frame padding (+ 2 VLAN tags), so anything larger is safe to consider for coalesce. (We do not include ETH_FCS_LEN in that threshold computation as netdev_fix_features() drops NETIF_F_GRO_HW whenever NETIF_F_RXFCS is set, so retained FCS can't reach this path.) Fixes: 92552d3abd32 ("net/mlx5e: HW_GRO cqe handler implementation") Cc: stable@vger.kernel.org Signed-off-by: Glenn Judd Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/20260816064259.3279548-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -2263,6 +2263,11 @@ static void mlx5e_handle_rx_cqe_mpwrq_sh data_offset = wqe_offset & (page_size - 1); page_idx = wqe_offset >> rq->mpwqe.page_shift; + if (unlikely(cqe_bcnt <= ETH_ZLEN + 2 * VLAN_HLEN)) { + match = false; + flush = true; + } + if (*skb && !(match && mlx5e_hw_gro_skb_has_enough_space(*skb, data_bcnt, page_size))) {