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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 739D5C0015E for ; Fri, 7 Jul 2023 09:39:28 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qHhup-0007Vg-Tm; Fri, 07 Jul 2023 05:38:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qHhuo-0007UL-AV for qemu-devel@nongnu.org; Fri, 07 Jul 2023 05:38:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qHhum-0000tN-5C for qemu-devel@nongnu.org; Fri, 07 Jul 2023 05:38:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688722689; h=from:from:reply-to: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=4yz1C/j3fpDV+3qKoIACdnHqaJPv1ql4+qSLsiQ3694=; b=LxyVd9o6vj0SgEPWfTQgHC3PSxdCZcp+hDog9pqHeUvgufWRs0D7JVE3e8/m3SYTkgRHTW mBzcZhpgYBKzjEyfPvroGwiSySGzAZuT4UAo8NPsFPaDlBq5ulKq+o7zo/zYzVu8l1vtjI C2oKUHLjWh81ZibbD+JD1Uc1uOGNBPE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-191-ThswCoQqOCCdWzfPpmFhJw-1; Fri, 07 Jul 2023 05:38:07 -0400 X-MC-Unique: ThswCoQqOCCdWzfPpmFhJw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C8C1F1C04B63; Fri, 7 Jul 2023 09:38:05 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.184]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4D50BF640B; Fri, 7 Jul 2023 09:38:04 +0000 (UTC) Date: Fri, 7 Jul 2023 10:38:02 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, qemu-stable@nongnu.org, Mauro Matteo Cascella , jiangyegen Subject: Re: [PATCH] io: remove io watch if TLS channel is closed during handshake Message-ID: References: <20230705181718.387522-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Jul 07, 2023 at 01:30:16PM +0400, Marc-André Lureau wrote: > On Wed, Jul 5, 2023 at 10:20 PM Daniel P. Berrangé > wrote: > > > The TLS handshake make take some time to complete, during which time an > > I/O watch might be registered with the main loop. If the owner of the > > I/O channel invokes qio_channel_close() while the handshake is waiting > > to continue the I/O watch must be removed. Failing to remove it will > > later trigger the completion callback which the owner is not expecting > > to receive. In the case of the VNC server, this results in a SEGV as > > vnc_disconnect_start() tries to shutdown a client connection that is > > already gone / NULL. > > > > CVE-2023-3354 > > Reported-by: jiangyegen > > Signed-off-by: Daniel P. Berrangé > > > > > > > --- > > include/io/channel-tls.h | 1 + > > io/channel-tls.c | 18 ++++++++++++------ > > 2 files changed, 13 insertions(+), 6 deletions(-) > > > > diff --git a/include/io/channel-tls.h b/include/io/channel-tls.h > > index 5672479e9e..26c67f17e2 100644 > > --- a/include/io/channel-tls.h > > +++ b/include/io/channel-tls.h > > @@ -48,6 +48,7 @@ struct QIOChannelTLS { > > QIOChannel *master; > > QCryptoTLSSession *session; > > QIOChannelShutdown shutdown; > > + guint hs_ioc_tag; > > }; > > > > /** > > diff --git a/io/channel-tls.c b/io/channel-tls.c > > index 9805dd0a3f..e327e6a5c2 100644 > > --- a/io/channel-tls.c > > +++ b/io/channel-tls.c > > @@ -198,12 +198,13 @@ static void > > qio_channel_tls_handshake_task(QIOChannelTLS *ioc, > > } > > > > trace_qio_channel_tls_handshake_pending(ioc, status); > > - qio_channel_add_watch_full(ioc->master, > > - condition, > > - qio_channel_tls_handshake_io, > > - data, > > - NULL, > > - context); > > + ioc->hs_ioc_tag = > > + qio_channel_add_watch_full(ioc->master, > > + condition, > > + qio_channel_tls_handshake_io, > > + data, > > + NULL, > > + context); > > } > > } > > > > @@ -218,6 +219,7 @@ static gboolean > > qio_channel_tls_handshake_io(QIOChannel *ioc, > > QIOChannelTLS *tioc = QIO_CHANNEL_TLS( > > qio_task_get_source(task)); > > > > + tioc->hs_ioc_tag = 0; > > g_free(data); > > qio_channel_tls_handshake_task(tioc, task, context); > > > > @@ -378,6 +380,10 @@ static int qio_channel_tls_close(QIOChannel *ioc, > > { > > QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc); > > > > + if (tioc->hs_ioc_tag) { > > + g_source_remove(tioc->hs_ioc_tag); > > > > set it to 0 ? > or > g_clear_handle_id(&tios->hs_ioc_tag, g_source_remove); Yes, close can be called mutliple times, so we must set to zero. > > + } > > + > > return qio_channel_close(tioc->master, errp); > > } > > > > -- > > 2.41.0 > > > > > > > > -- > Marc-André Lureau With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|