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=-17.3 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,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1C003C43460 for ; Fri, 23 Apr 2021 06:03:49 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A668561445 for ; Fri, 23 Apr 2021 06:03:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A668561445 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39998 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lZoup-0007B7-Pu for qemu-devel@archiver.kernel.org; Fri, 23 Apr 2021 02:03:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59420) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZou8-0006lA-0t for qemu-devel@nongnu.org; Fri, 23 Apr 2021 02:03:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46431) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZou6-000266-C9 for qemu-devel@nongnu.org; Fri, 23 Apr 2021 02:03:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619157781; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qrJFyHq7DheV8OjQc5dfdDE2w8JF+TvxwNVXbe0uVtU=; b=Dw9g+BtiOcsmOkPOVzs596xAaSUgu9IRjIGGLVq1Ya+9YjlaRGff2qcswqYztT7Lw4IUeQ Gi7+wx2GPRUx1qFjN+0Yjsql/xHD5RiDZPNQKNJ5OURFZhWOYnaAPynFnK3/tRzKFxt2uj y8H+eaQDTD7/mBrES4ApgwSHDhAJFHw= 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-211-t4-stKNqOeO4HIuXq872WA-1; Fri, 23 Apr 2021 02:02:59 -0400 X-MC-Unique: t4-stKNqOeO4HIuXq872WA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1FFD0107ACF5; Fri, 23 Apr 2021 06:02:58 +0000 (UTC) Received: from wangxiaodeMacBook-Air.local (ovpn-13-225.pek2.redhat.com [10.72.13.225]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5C4DA1B5AB; Fri, 23 Apr 2021 06:02:54 +0000 (UTC) Subject: Re: [PATCH for 6.0] net: check the existence of peer before trying to pad To: Stefan Weil , samuel.thibault@ens-lyon.org, qemu-devel@nongnu.org References: <20210423031803.1479-1-jasowang@redhat.com> <45b74435-2bcd-d6f4-4ada-8d357bd33d4d@weilnetz.de> From: Jason Wang Message-ID: Date: Fri, 23 Apr 2021 14:02:53 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <45b74435-2bcd-d6f4-4ada-8d357bd33d4d@weilnetz.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jasowang@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, bmeng.cn@gmail.com, philmd@redhat.com, crobinso@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 在 2021/4/23 下午1:42, Stefan Weil 写道: > Am 23.04.21 um 05:18 schrieb Jason Wang: > >> There could be case that peer is NULL. This can happen when during >> network device hot-add where net device needs to be added first. So >> the patch check the existence of peer before trying to do the pad. >> >> Fixes: 969e50b61a285 ("net: Pad short frames to minimum size before >> sending from SLiRP/TAP") >> Signed-off-by: Jason Wang >> --- >>   include/net/net.h | 5 +++++ >>   net/slirp.c       | 2 +- >>   net/tap-win32.c   | 2 +- >>   net/tap.c         | 2 +- >>   4 files changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/include/net/net.h b/include/net/net.h >> index eff24519d2..1ef536d771 100644 >> --- a/include/net/net.h >> +++ b/include/net/net.h >> @@ -241,4 +241,9 @@ uint32_t net_crc32_le(const uint8_t *p, int len); >>       .offset     = vmstate_offset_macaddr(_state, _field), > \ >>   } >>   +static inline bool net_peer_needs_padding(NetClientState *nc) >> +{ >> +  return nc->peer && !nc->peer->do_not_pad; >> +} >> + >>   #endif >> diff --git a/net/slirp.c b/net/slirp.c >> index a01a0fccd3..7a4e96db5c 100644 >> --- a/net/slirp.c >> +++ b/net/slirp.c >> @@ -119,7 +119,7 @@ static ssize_t net_slirp_send_packet(const void >> *pkt,size_t pkt_len, >>       uint8_t min_pkt[ETH_ZLEN]; >>       size_t min_pktsz = sizeof(min_pkt); >>   -    if (!s->nc.peer->do_not_pad) { >> +    if (net_peer_needs_padding(&s->nc)) { >>           if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pkt_len)) { >>               pkt = min_pkt; >>               pkt_len = min_pktsz; >> diff --git a/net/tap-win32.c b/net/tap-win32.c >> index 897bd18e32..6096972f5d 100644 >> --- a/net/tap-win32.c >> +++ b/net/tap-win32.c >> @@ -696,7 +696,7 @@ static void tap_win32_send(void *opaque) >>       if (size > 0) { >>           orig_buf = buf; >>   -        if (!s->nc.peer->do_not_pad) { >> +        if (net_peer_needs_padding(&s->nc)) { >>               if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) { >>                   buf = min_pkt; >>                   size = min_pktsz; >> diff --git a/net/tap.c b/net/tap.c >> index 7d53cedaec..820872fde8 100644 >> --- a/net/tap.c >> +++ b/net/tap.c >> @@ -203,7 +203,7 @@ static void tap_send(void *opaque) >>               size -= s->host_vnet_hdr_len; >>           } >>   -        if (!s->nc.peer->do_not_pad) { >> +        if (net_peer_needs_padding(&s->nc)) { >>               if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) { >>                   buf = min_pkt; >>                   size = min_pktsz; > > > I assume that you had a test case which triggered that null pointer > access? Yes, it's simple to trigger by just adding a tap device and assign an IP to that. Thanks > If yes, than this should indeed be applied before releasing 6.0. > > The modification is simple enough for a last minute change. > > Reviewed-by: Stefan Weil > > > >