From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5D518EB64DA for ; Thu, 15 Jun 2023 15:02:34 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id E54CF41958; Thu, 15 Jun 2023 15:02:33 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org E54CF41958 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osuosl.org; s=default; t=1686841353; bh=BaEE4qC7l5fKb6WiQUsV5P4gawDZ56+p9pPneeHgfTQ=; h=Date:From:To:References:In-Reply-To:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: Cc:From; b=LdW86OJ+NsR+GNWTlEUU5fdhQeR6bkB7f00/wh0yCA3UCzcaPF2rA4kwqSz+tdvxv LJ0TCv1A5eAakVUfc4dhLnO28s290WoNxGt/6tSyUPdLtg1KalVVPUW/n8CTvoojEv q0DyySpwg1Qclvh8yGYXWpUkqeA5NYAvl9xGDf74RO8PcEk7NeRlISzhNsXKgKOP2Q 1PyWtO2KeDwTdzaOXfg1RoQfLhHzOF0mqZnusNeI985SfacaCgdUmyKkPrOYLaNo2b 2vqKb4Twhs4AcgoveBkmSfPYbDmV8Zot74t+KmUvx78Bjk2qRU+qg5JqqaGLLhZxfc q8OuFDlvCDIjA== X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id g3hic51PPRPV; Thu, 15 Jun 2023 15:02:33 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by smtp2.osuosl.org (Postfix) with ESMTP id D605041948; Thu, 15 Jun 2023 15:02:32 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org D605041948 Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by ash.osuosl.org (Postfix) with ESMTP id C28581BF276 for ; Thu, 15 Jun 2023 11:27:56 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 9B18740549 for ; Thu, 15 Jun 2023 11:27:56 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 9B18740549 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yZQ0Gn08YvkF for ; Thu, 15 Jun 2023 11:27:56 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org DFE01403AA Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by smtp2.osuosl.org (Postfix) with ESMTPS id DFE01403AA for ; Thu, 15 Jun 2023 11:27:55 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C6209626B2; Thu, 15 Jun 2023 11:27:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1756C433C0; Thu, 15 Jun 2023 11:27:50 +0000 (UTC) Date: Thu, 15 Jun 2023 13:27:47 +0200 From: Simon Horman To: Maciej Fijalkowski Message-ID: References: <20230615-igc-err-ptr-v1-1-a17145eb8d62@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Thu, 15 Jun 2023 15:02:27 +0000 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686828474; bh=U9pbntIrNXfG7wu+B1aeTFIpvtosIyr2h3tcLbTgri8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i+umpez4rTb0T0Gfhbn1Qo6jRT/lDlcLnZC7hndaemOrDSx8FT43ipPhAi8TbNSlz ko/kbrXg7ZgjMbc3Ww0yJSQS4654qIk6cQm5XGz7rrslKJxFEmXmUqRzE+G7GuH7po UpVW4AgzAIxJPPiEbyrzMb5QSBY14r0vC2PNNuUsiaXpOr8pt6aDnPBmLE7GSmiyp8 rLDmXJajhvT70ygSb91xjfZeA2s1JwPjvJrxZMdcaGNUKUwcXHyKrRfPXq7XhrUUNk wucQFjr76cOeHQd03uhwET/usUzGdIi2SIthQpUbPuhz+wSYEbplMPm9euq3gUc9SJ UKcwpzQ/mOLVw== X-Mailman-Original-Authentication-Results: smtp2.osuosl.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=i+umpez4 Subject: Re: [Intel-wired-lan] [PATCH RFC net] igc: Avoid dereference of ptr_err in igc_clean_rx_irq() X-BeenThere: intel-wired-lan@osuosl.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Wired Ethernet Linux Kernel Driver Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andre Guedes , Jesper Dangaard Brouer , Daniel Borkmann , Jithu Joseph , intel-wired-lan@lists.osuosl.org, John Fastabend , Jesse Brandeburg , Alexei Starovoitov , Eric Dumazet , Tony Nguyen , Vedang Patel , netdev@vger.kernel.org, Jakub Kicinski , bpf@vger.kernel.org, Paolo Abeni , "David S. Miller" , Dan Carpenter Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-wired-lan-bounces@osuosl.org Sender: "Intel-wired-lan" On Thu, Jun 15, 2023 at 11:55:29AM +0200, Maciej Fijalkowski wrote: > On Thu, Jun 15, 2023 at 11:45:36AM +0200, Simon Horman wrote: Hi Marciej, > Hi Simon, > > > In igc_clean_rx_irq() the result of a call to igc_xdp_run_prog() is assigned > > to the skb local variable. This may be an ERR_PTR. > > > > A little later the following is executed, which seems to be a > > possible dereference of an ERR_PTR. > > > > total_bytes += skb->len; > > > > Avoid this problem by continuing the loop in which all of the > > above occurs once the handling of the NULL case completes. > > > > This proposed fix is speculative - I do not have deep knowledge of this > > driver. And I am concerned about the effect of skipping the following > > logic: > > > > igc_put_rx_buffer(rx_ring, rx_buffer, rx_buffer_pgcnt); > > cleaned_count++; > > this will break - you have to recycle the buffer to have it going. Thanks. As I said I wasn't sure about the fix: it was a strawman. > > Flagged by Smatch as: > > > > .../igc_main.c:2467 igc_xdp_run_prog() warn: passing zero to 'ERR_PTR' > > how about PTR_ERR_OR_ZERO() ? this would silence smatch and is not an > intrusive change. another way is to get rid of ERR_PTR() around skb/xdp > run result but i think the former would be just fine. Sorry, there were two warnings. And I accidently trimmed the one that is more relevant instead of the one that is less relevant. I do agree the one above does not appear to be a bug. But I am concerned abut this one: .../igc_main.c:2618 igc_clean_rx_irq() error: 'skb' dereferencing possible ERR_PTR() If skb is an error pointer, e.g. ERR_PTR(-IGC_XDP_PASS), and it is dereferenced, that would be a problem, right? Perhaps I'm missing something obvious and this can't occur. But it does seem possible to me. > > > > > Compile tested only. > > > > Fixes: 26575105d6ed ("igc: Add initial XDP support") > > Signed-off-by: Simon Horman > > --- > > drivers/net/ethernet/intel/igc/igc_main.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c > > index 88145c30c919..b58c8a674bd1 100644 > > --- a/drivers/net/ethernet/intel/igc/igc_main.c > > +++ b/drivers/net/ethernet/intel/igc/igc_main.c > > @@ -2586,6 +2586,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) > > > > total_packets++; > > total_bytes += size; > > + continue; > > } else if (skb) > > igc_add_rx_frag(rx_ring, rx_buffer, skb, size); > > else if (ring_uses_build_skb(rx_ring)) > > > > > _______________________________________________ Intel-wired-lan mailing list Intel-wired-lan@osuosl.org https://lists.osuosl.org/mailman/listinfo/intel-wired-lan