From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4806D2882DD; Fri, 25 Jul 2025 09:34:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753436047; cv=none; b=sSwdLX7lpwc3m4yDyRmcWsmpl6IliESuIshgu0xyoAaCO7/syv1W5lgBlBSiAjQcAusq7mYfKBGx0tJ0+4QOvWJUGWJgdJx69vxJjn75bADbZxrrb6qfK+cIRaWdUiTEBLhp1agyuVjcRPyNcTiKdEggqp9vrjD1ChiOFam5Phg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753436047; c=relaxed/simple; bh=nQBD86iMxD11aFWKtQSmUj2kVORfTABBMNoeBRIHq0M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jiYMGnUXjJUN4jN6YH/4chqk8cJ9LbiwVpFK8XY/Mfb1muGXM0ur0J29uh7FxvaQ6pbbmesl3R+eIiOInn9x42mUe96xCMz/CIvCXVqcEPcTjZTcYA2tpet9kI075HuIkO+6g8IKXD58ECKReipsIfeBkw83ELSxOH2Ed2c0l7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cu4J+kmu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Cu4J+kmu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B76A7C4CEE7; Fri, 25 Jul 2025 09:34:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753436046; bh=nQBD86iMxD11aFWKtQSmUj2kVORfTABBMNoeBRIHq0M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Cu4J+kmu1ZWRISDF3iNfLeSnbmfRuUUlNlquHv5iEjn99wDW36G7bq/3lHrrpJYXO 8KI0SUI0WYvze0Fm1nf2iqxGWjmGsjVoekgtx2bjPeLoi3tthfMfBMuBy7dTiE/6ST /eai6OlKgN/f2oCrrxADPqAajWSPG2qh2920UiPt6t3c/DC4DslivwrZu19M5ETv7e +m47Mo9gGYtZobeL4k8dpbejDwMAx608Pg8CT6U9Jyg5vOdkzBMZv/KV7Q/4q1+378 +BU7XCYUUphsOiCloacb7eNawyjy0RaJ3XilC74MpOao+bEMjvvuCqpyRhn8NrJFUd cWebY5VYpy4Ew== Date: Fri, 25 Jul 2025 10:34:01 +0100 From: Simon Horman To: Chenyuan Yang Cc: ecree.xilinx@gmail.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, martinh@xilinx.com, netdev@vger.kernel.org, linux-net-drivers@amd.com, bpf@vger.kernel.org, zzjas98@gmail.com Subject: Re: [PATCH] sfc: siena: handle NULL returned by xdp_convert_buff_to_frame() Message-ID: <20250725093401.GA1367887@horms.kernel.org> References: <20250723003230.1243224-1-chenyuan0y@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250723003230.1243224-1-chenyuan0y@gmail.com> On Tue, Jul 22, 2025 at 07:32:30PM -0500, Chenyuan Yang wrote: > The xdp_convert_buff_to_frame() function can return NULL when there is > insufficient headroom in the buffer to store the xdp_frame structure > or when the driver didn't reserve enough tailroom for skb_shared_info. > > Currently, the sfc siena driver does not check for this NULL return value > in the XDP_TX case within efx_do_xdp(). > > Fix by adding a proper NULL check in the XDP_TX case. If conversion > fails, free the RX buffer and increment the bad drops counter, following > the same pattern used for other XDP error conditions in this driver. > > Signed-off-by: Chenyuan Yang > Fixes: d48523cb88e0 ("sfc: Copy shared files needed for Siena (part 2)") > --- > drivers/net/ethernet/sfc/siena/rx.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/net/ethernet/sfc/siena/rx.c b/drivers/net/ethernet/sfc/siena/rx.c > index 98d3c0743c0f..65f6daad3168 100644 > --- a/drivers/net/ethernet/sfc/siena/rx.c > +++ b/drivers/net/ethernet/sfc/siena/rx.c > @@ -310,6 +310,12 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel, > case XDP_TX: > /* Buffer ownership passes to tx on success. */ > xdpf = xdp_convert_buff_to_frame(&xdp); > + if (unlikely(!xdpf)) { > + efx_siena_free_rx_buffers(rx_queue, rx_buf, 1); > + channel->n_rx_xdp_bad_drops++; > + break; > + } I see the incidence of this cleanup code multiplying in this function. I would be nice to follow-up by consolidating that - I'd suggest in the form of a goto label at the end of the function. But as a fix for net this minimal patch seems appropriate to me. Reviewed-by: Simon Horman > + > err = efx_siena_xdp_tx_buffers(efx, 1, &xdpf, true); > if (unlikely(err != 1)) { > efx_siena_free_rx_buffers(rx_queue, rx_buf, 1); > -- > 2.34.1 > >