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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,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 478A9C433E0 for ; Tue, 9 Mar 2021 15:51:46 +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 B925265237 for ; Tue, 9 Mar 2021 15:51:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B925265237 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]:48486 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJee8-0002Sm-GS for qemu-devel@archiver.kernel.org; Tue, 09 Mar 2021 10:51:44 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:55688) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJe78-0003Bo-5a for qemu-devel@nongnu.org; Tue, 09 Mar 2021 10:17:38 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23452) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lJe75-0002rS-HB for qemu-devel@nongnu.org; Tue, 09 Mar 2021 10:17:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615303053; 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: in-reply-to:in-reply-to:references:references; bh=qFtcJeGYXMATfkj41zpL0LajkY9gNExE6E06kdWBkxc=; b=PLExN6wZcNGu1L2sMdqaH/VhCFj93CamRb4DtYSrHcBsDSo+ilTR1SbutfcRaMlIE4kjx6 IxgagPASO3Kj4m5v5QcnuqOWqXYP4EN+fQwaY8aa36nIpwkzVpot3OSMb9mZcGNy35b3v9 rmvvbZl40Ck5fT6+1Qg7DHESwV33YE0= 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-95-EMylsZTMNTu0cRVd5fD44w-1; Tue, 09 Mar 2021 10:17:28 -0500 X-MC-Unique: EMylsZTMNTu0cRVd5fD44w-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 432231842144; Tue, 9 Mar 2021 15:17:27 +0000 (UTC) Received: from localhost (ovpn-115-70.ams2.redhat.com [10.36.115.70]) by smtp.corp.redhat.com (Postfix) with ESMTP id 39F4819C46; Tue, 9 Mar 2021 15:17:23 +0000 (UTC) Date: Tue, 9 Mar 2021 15:17:21 +0000 From: Stefan Hajnoczi To: Greg Kurz Subject: Re: [PATCH 2/4] vhost-user: Convert slave channel to QIOChannelSocket Message-ID: References: <20210308123141.26444-1-groug@kaod.org> <20210308123141.26444-3-groug@kaod.org> MIME-Version: 1.0 In-Reply-To: <20210308123141.26444-3-groug@kaod.org> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="MIuVGyLk4znvSjFm" Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.251, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=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: "Michael S. Tsirkin" , qemu-devel@nongnu.org, Vivek Goyal , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --MIuVGyLk4znvSjFm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 08, 2021 at 01:31:39PM +0100, Greg Kurz wrote: > + g_autofree int *fd =3D NULL; > + size_t fdsize =3D 0; > + int i; > =20 > /* Read header */ > iov.iov_base =3D &hdr; > iov.iov_len =3D VHOST_USER_HDR_SIZE; > =20 > do { > - size =3D recvmsg(u->slave_fd, &msgh, 0); > - } while (size < 0 && (errno =3D=3D EINTR || errno =3D=3D EAGAIN)); > + size =3D qio_channel_readv_full(ioc, &iov, 1, &fd, &fdsize, NULL= ); > + } while (size =3D=3D QIO_CHANNEL_ERR_BLOCK); Is it possible to leak file descriptors and fd[] memory if we receive a short message and then loop around? qio_channel_readv_full() will overwrite &fd and that's how the leak occurs. On the other hand, it looks like ioc is in blocking mode. I'm not sure QIO_CHANNEL_ERR_BLOCK can occur? > @@ -1500,8 +1479,8 @@ static void slave_read(void *opaque) > =20 > /* Read payload */ > do { > - size =3D read(u->slave_fd, &payload, hdr.size); > - } while (size < 0 && (errno =3D=3D EINTR || errno =3D=3D EAGAIN)); > + size =3D qio_channel_read(ioc, (char *) &payload, hdr.size, NULL= ); > + } while (size =3D=3D QIO_CHANNEL_ERR_BLOCK); Same question here. --MIuVGyLk4znvSjFm Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmBHkYEACgkQnKSrs4Gr c8gGGgf/YuF+2GYgiE/5kG61UHxg6A5wbV/xmNm9UFvK72CrQgRRSZIDQGl2K74V bBEYnpA2lsClkqdgdlcIM77a1HqBxcMstcYHUPSbY0+hlnH1q9rVD7YdytrwRiMj o2hXbL3pvilYqgGrVbf6BHbXbbglzV8Kk8Scxh+DopFysF+WyNchvbv4jvjYufsT HT6yXuC9sjrOXMng98zSACyjn4pEyxAwihC3mwZaQC4QdwmEEHGuDt2lWabWibn7 XvvFTmRxVLlX7TClBnnGG5oOHqpGiup7T8knl6p5VVRYxd65md4xcD/7tbSawYDz u+IhVp5YfkC81FEYAIiD+Hidlw4Fhw== =JGRN -----END PGP SIGNATURE----- --MIuVGyLk4znvSjFm--