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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,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 B43ADC432BE for ; Tue, 31 Aug 2021 13:02:13 +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 356976103D for ; Tue, 31 Aug 2021 13:02:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 356976103D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:48504 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mL3P2-00062h-83 for qemu-devel@archiver.kernel.org; Tue, 31 Aug 2021 09:02:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35688) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mL2wd-0005gr-JD; Tue, 31 Aug 2021 08:32:52 -0400 Received: from mail-ej1-x635.google.com ([2a00:1450:4864:20::635]:35807) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mL2wc-0003Uy-1r; Tue, 31 Aug 2021 08:32:51 -0400 Received: by mail-ej1-x635.google.com with SMTP id i21so38357569ejd.2; Tue, 31 Aug 2021 05:32:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oBbkUGUbQNQfW8zDCJh2GTovLeF/kSQLYf/CTezdX9o=; b=UjHd3puR1J51v1cHhi0pLY9HYHFJ5Iz2g3UTIMO3LTOl9wWXFjp4eEyTxEclv9oDWa r4+TbdRx8AGU0uVa1KVkTnImFfUsHhX19e4yz6XMBUG/ISG+/VG0BChzy2qmu+buUuLf jkgQl2flVZQDqQAOr8nDbut7mXjvXPTNMEYx23XUdFi+T9sz2ts7j6TzIzTFu6pmqm/R FJxBPBWEpoWCTsdzmGqqj7MRnO1I0vhq9/kcX3X/BBxt1CL62aR1+7WUSJ74gu0dlFHu dArbxVyHR4R45DdXRujrak+kFFPL+SWWgHUuX8ZhE4APUwaJlmWrDkGha/hxSZn7/Ckp aObg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oBbkUGUbQNQfW8zDCJh2GTovLeF/kSQLYf/CTezdX9o=; b=hAAetzpXgu46AQZqJn/2XYYk2DIc41lEsDDAUuS5H+K1GnUCN2uvgdDh9GiVHURC/Y SWWK1P2hxVZR+qIYYZidbSlpmeLVeNy7WqcdAnGvnY4MBUJIxBqkFwfz6GRT5zDZZJMz Onmlfxv2o5Ik57m5hn6xBajHToPGQlzRcoRLouDbR9yHKrw60PUjeHfok7Wnztoi1ATc q9G5QT9KY7n8dVgfdoAwOXRlwdOFxLFOD3Nduc3zDJXpoAWf0225JnGlr4ZB0/CDjLnX vwg4E6PmlDZhMu/tRIt9xsYtGZ3VOP6GrVekaQ74EVheB3/cY1e50hHQbQT4Y0iU27Fi x7KA== X-Gm-Message-State: AOAM530QbU1n8stiEFj+ida8faWiTtCy+o2vR4hiyxdp5hysmowImijB xfvLbyPZNH6e0V08a94QdAZnagByHq5gYnXtRzfBhoAefaZdlg== X-Google-Smtp-Source: ABdhPJylX2lm0CLTAFwimmv4vPYxR76hwpaXklwR9n+7FR8tji+GzyzIktrI0wX9Gca6J4ZlW3VkzuDSunInyUptw1s= X-Received: by 2002:a17:906:9742:: with SMTP id o2mr31084900ejy.532.1630413168124; Tue, 31 Aug 2021 05:32:48 -0700 (PDT) MIME-Version: 1.0 References: <20210830225449.1509719-1-mjt@msgid.tls.msk.ru> In-Reply-To: <20210830225449.1509719-1-mjt@msgid.tls.msk.ru> From: =?UTF-8?B?TWFyYy1BbmRyw6kgTHVyZWF1?= Date: Tue, 31 Aug 2021 16:32:36 +0400 Message-ID: Subject: Re: qemu-sockets: account for trailing \0 byte in unix socket pathname To: Michael Tokarev Content-Type: multipart/alternative; boundary="000000000000b928f505cada2580" Received-SPF: pass client-ip=2a00:1450:4864:20::635; envelope-from=marcandre.lureau@gmail.com; helo=mail-ej1-x635.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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: QEMU , qemu-stable Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --000000000000b928f505cada2580 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi On Tue, Aug 31, 2021 at 3:00 AM Michael Tokarev wrote: > Linux kernel can return size of af_unix socket to be > one byte larger than sockaddr_un structure - adding > the trailing zero byte. > > Signed-off-by: Michael Tokarev > Fixes: 4cfd970ec188558daa6214f26203fe553fb1e01f (first in 6.1.0) > Cc: qemu-stable@nongnu.org > > diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c > index f2f3676d1f..83926dc2bc 100644 > --- a/util/qemu-sockets.c > +++ b/util/qemu-sockets.c > @@ -1345,8 +1345,9 @@ socket_sockaddr_to_address_unix(struct > sockaddr_storage *sa, > SocketAddress *addr; > struct sockaddr_un *su =3D (struct sockaddr_un *)sa; > > + /* kernel might have added \0 terminator to non-abstract socket */ > assert(salen >=3D sizeof(su->sun_family) + 1 && > - salen <=3D sizeof(struct sockaddr_un)); > + salen <=3D sizeof(struct sockaddr_un) + su->sun_path[0] ? 1 := 0); > > Looks right, but we may want to drop the upper bound check altogether. I thought the path must always fit the sockaddr_un, but since that's not the case it's only harmful here. Reviewed-by: Marc-Andr=C3=A9 Lureau addr =3D g_new0(SocketAddress, 1); > addr->type =3D SOCKET_ADDRESS_TYPE_UNIX; > > --=20 Marc-Andr=C3=A9 Lureau --000000000000b928f505cada2580 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi

On Tue, Aug 31, 2021 at 3:00 AM Michael Tokar= ev <mjt@tls.msk.ru> wrote:
<= /div>
Linux kernel can ret= urn size of af_unix socket to be
one byte larger than sockaddr_un structure - adding
the trailing zero byte.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Fixes: 4cfd970ec188558daa6214f26203fe553fb1e01f (first in 6.1.0)
Cc: qemu-stable= @nongnu.org

diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index f2f3676d1f..83926dc2bc 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -1345,8 +1345,9 @@ socket_sockaddr_to_address_unix(struct sockaddr_stora= ge *sa,
=C2=A0 =C2=A0 =C2=A0SocketAddress *addr;
=C2=A0 =C2=A0 =C2=A0struct sockaddr_un *su =3D (struct sockaddr_un *)sa;
+=C2=A0 =C2=A0 /* kernel might have added \0 terminator to non-abstract soc= ket */
=C2=A0 =C2=A0 =C2=A0assert(salen >=3D sizeof(su->sun_family) + 1 &= ;&
-=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0salen <=3D sizeof(struct socka= ddr_un));
+=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0salen <=3D sizeof(struct socka= ddr_un) + su->sun_path[0] ? 1 : 0);


Looks right, but we may want to drop t= he upper bound check altogether. I thought the path must always fit the soc= kaddr_un, but since that's not the case it's only harmful here.
=

Reviewed-by: Marc-Andr=C3=A9 Lureau <marcandre.lureau@redhat.com>=

=C2=A0 =C2=A0 =C2=A0addr =3D g_new0(SocketAddress, 1);
=C2=A0 =C2=A0 =C2=A0addr->type =3D SOCKET_ADDRESS_TYPE_UNIX;



--
Marc-Andr=C3=A9 Lureau
--000000000000b928f505cada2580--