From patchwork Tue Jan 19 16:56:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 12030511 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96767C10F05 for ; Tue, 19 Jan 2021 18:28:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6836622CAD for ; Tue, 19 Jan 2021 18:28:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389574AbhASQ7i (ORCPT ); Tue, 19 Jan 2021 11:59:38 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:56234 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389995AbhASQ6i (ORCPT ); Tue, 19 Jan 2021 11:58:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611075430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=48FwshhjZ+G2oqgIV5odTogbJUPrwxPmjTGXHjXAe4w=; b=RU1RhMKqylsGBlcffPlUQsCOeXlwFFpCaVDTTpVQLUNibAnQGXf2HU+KRaM2jU7udqEBoC yUTMWp9Ve1UwNFUM8UESNSRACnKwBMyINHCw7yFpYgqVnN7a4n5AmSZypZnV9QMbiHi3pq MTgLFDC64aU+NyK+k+jBw2zHBuYMYCY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-434-7bRAmpjIMh6GYMqYG6OAqQ-1; Tue, 19 Jan 2021 11:57:07 -0500 X-MC-Unique: 7bRAmpjIMh6GYMqYG6OAqQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AD4371005504; Tue, 19 Jan 2021 16:57:04 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-115-139.ams2.redhat.com [10.36.115.139]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3EBEF60C0F; Tue, 19 Jan 2021 16:57:03 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , Alexander Duyck , Xin Long Subject: [PATCH v2 net-next] net: fix GSO for SG-enabled devices. Date: Tue, 19 Jan 2021 17:56:56 +0100 Message-Id: <861947c2d2d087db82af93c21920ce8147d15490.1611074818.git.pabeni@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The commit dbd50f238dec ("net: move the hsize check to the else block in skb_segment") introduced a data corruption for devices supporting scatter-gather. The problem boils down to signed/unsigned comparison given unexpected results: if signed 'hsize' is negative, it will be considered greater than a positive 'len', which is unsigned. This commit addresses resorting to the old checks order, so that 'hsize' never has a negative value when compared with 'len'. v1 -> v2: - reorder hsize checks instead of explicit cast (Alex) Bisected-by: Matthieu Baerts Fixes: dbd50f238dec ("net: move the hsize check to the else block in skb_segment") Signed-off-by: Paolo Abeni Reviewed-by: Xin Long Reviewed-by: Xin Long --- net/core/skbuff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index e835193cabcc3..cf2c4dcf42579 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3938,10 +3938,10 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, skb_release_head_state(nskb); __skb_push(nskb, doffset); } else { + if (hsize < 0) + hsize = 0; if (hsize > len || !sg) hsize = len; - else if (hsize < 0) - hsize = 0; nskb = __alloc_skb(hsize + doffset + headroom, GFP_ATOMIC, skb_alloc_rx_flag(head_skb),