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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 0276EC0650F for ; Thu, 8 Aug 2019 19:13:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1B7C2173E for ; Thu, 8 Aug 2019 19:13:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565291617; bh=Nl+kRXkxWwMQ9iim9Tca5FCr6yfWrfnErkAgEcd9sRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DhOnpLYX5fYMoJbpudvE2ZV72p069O0/kNQJmkhyaTszZTVb0DiHa9AieuaQadCwH Y5tNa+jzpLHvERq3VrBby2NEog6yEpJ6KCo7kVMiioSGe2FP/ibudGmtzuIBE0x/kw VTGscT/yvei/WJ75teQqoJZ3D2RDpaa/rJMRTP6k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405139AbfHHTJi (ORCPT ); Thu, 8 Aug 2019 15:09:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:43884 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405119AbfHHTJd (ORCPT ); Thu, 8 Aug 2019 15:09:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3B46C21743; Thu, 8 Aug 2019 19:09:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565291372; bh=Nl+kRXkxWwMQ9iim9Tca5FCr6yfWrfnErkAgEcd9sRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UqgdpfK34WsZJFOBkhAbi25jGhflRZeVX2GC4KtLskaWLe95nD4UdiwlK5F8PvQwD PUrLn2J5t5AwUYcgkxltZetJR1IVL/yqYf7APM5xJvZGnu5yeYx3L5pICno2qTv1IG fWc1zgnW/mPhFQ57hnUrlEfprjmg887XlLVitOQA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexis Bauvin , Jason Wang , "David S. Miller" Subject: [PATCH 4.19 35/45] tun: mark small packets as owned by the tap sock Date: Thu, 8 Aug 2019 21:05:21 +0200 Message-Id: <20190808190455.784595339@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190808190453.827571908@linuxfoundation.org> References: <20190808190453.827571908@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexis Bauvin [ Upstream commit 4b663366246be1d1d4b1b8b01245b2e88ad9e706 ] - v1 -> v2: Move skb_set_owner_w to __tun_build_skb to reduce patch size Small packets going out of a tap device go through an optimized code path that uses build_skb() rather than sock_alloc_send_pskb(). The latter calls skb_set_owner_w(), but the small packet code path does not. The net effect is that small packets are not owned by the userland application's socket (e.g. QEMU), while large packets are. This can be seen with a TCP session, where packets are not owned when the window size is small enough (around PAGE_SIZE), while they are once the window grows (note that this requires the host to support virtio tso for the guest to offload segmentation). All this leads to inconsistent behaviour in the kernel, especially on netfilter modules that uses sk->socket (e.g. xt_owner). Fixes: 66ccbc9c87c2 ("tap: use build_skb() for small packet") Signed-off-by: Alexis Bauvin Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1682,6 +1682,7 @@ static struct sk_buff *tun_build_skb(str skb_reserve(skb, pad - delta); skb_put(skb, len); + skb_set_owner_w(skb, tfile->socket.sk); get_page(alloc_frag->page); alloc_frag->offset += buflen;