From patchwork Mon Nov 6 15:33:41 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 834785 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yVxSX4mWPz9s7p for ; Tue, 7 Nov 2017 02:34:36 +1100 (AEDT) Received: from localhost ([::1]:48703 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eBjQ2-0000f7-LS for incoming@patchwork.ozlabs.org; Mon, 06 Nov 2017 10:34:34 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56795) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eBjPP-0000ce-Bv for qemu-devel@nongnu.org; Mon, 06 Nov 2017 10:33:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eBjPM-0002cg-Ie for qemu-devel@nongnu.org; Mon, 06 Nov 2017 10:33:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35172) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eBjPM-0002cS-7u for qemu-devel@nongnu.org; Mon, 06 Nov 2017 10:33:52 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5118A85A05; Mon, 6 Nov 2017 15:33:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 5118A85A05 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=berrange@redhat.com Received: from localhost.localdomain.com (unknown [10.42.22.189]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3D36D7820A; Mon, 6 Nov 2017 15:33:50 +0000 (UTC) From: "Daniel P. Berrange" To: qemu-devel@nongnu.org Date: Mon, 6 Nov 2017 15:33:41 +0000 Message-Id: <20171106153342.24147-2-berrange@redhat.com> In-Reply-To: <20171106153342.24147-1-berrange@redhat.com> References: <20171106153342.24147-1-berrange@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 06 Nov 2017 15:33:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v1 1/2] sockets: avoid leak of listen file descriptor X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" If we iterate over the full port range without successfully binding+listening on the socket, we'll try the next address, whereupon we overwrite the slisten file descriptor variable without closing it. Rather than having two places where we open + close socket FDs on different iterations of nested for loops, re-arrange the code to always open+close within the same loop iteration. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrange --- util/qemu-sockets.c | 52 +++++++++++++++++++++++++++++----------------------- 1 file changed, 29 insertions(+), 23 deletions(-) diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c index b47fb45885..8b75541ce4 100644 --- a/util/qemu-sockets.c +++ b/util/qemu-sockets.c @@ -207,7 +207,7 @@ static int inet_listen_saddr(InetSocketAddress *saddr, char uaddr[INET6_ADDRSTRLEN+1]; char uport[33]; int rc, port_min, port_max, p; - int slisten = 0; + int slisten = -1; int saved_errno = 0; bool socket_created = false; Error *err = NULL; @@ -267,31 +267,42 @@ static int inet_listen_saddr(InetSocketAddress *saddr, uaddr,INET6_ADDRSTRLEN,uport,32, NI_NUMERICHOST | NI_NUMERICSERV); - slisten = create_fast_reuse_socket(e); - if (slisten < 0) { - continue; - } - - socket_created = true; port_min = inet_getport(e); port_max = saddr->has_to ? saddr->to + port_offset : port_min; for (p = port_min; p <= port_max; p++) { inet_setport(e, p); - rc = try_bind(slisten, saddr, e); - if (rc) { - if (errno == EADDRINUSE) { + + slisten = create_fast_reuse_socket(e); + if (slisten < 0) { + /* First time we expect we might fail to create the socket + * eg if 'e' has AF_INET6 but ipv6 kmod is not loaded. + * Later iterations should always succeed if first iteration + * worked though, so treat that as fatal. + */ + if (p == port_min) { continue; } else { - error_setg_errno(errp, errno, "Failed to bind socket"); + error_setg_errno(errp, errno, + "Failed to recreate failed listening socket"); goto listen_failed; } } - if (!listen(slisten, 1)) { - goto listen_ok; - } - if (errno != EADDRINUSE) { - error_setg_errno(errp, errno, "Failed to listen on socket"); - goto listen_failed; + socket_created = true; + + rc = try_bind(slisten, saddr, e); + if (rc < 0) { + if (errno != EADDRINUSE) { + error_setg_errno(errp, errno, "Failed to bind socket"); + goto listen_failed; + } + } else { + if (!listen(slisten, 1)) { + goto listen_ok; + } + if (errno != EADDRINUSE) { + error_setg_errno(errp, errno, "Failed to listen on socket"); + goto listen_failed; + } } /* Someone else managed to bind to the same port and beat us * to listen on it! Socket semantics does not allow us to @@ -299,12 +310,7 @@ static int inet_listen_saddr(InetSocketAddress *saddr, * socket to allow bind attempts for subsequent ports: */ closesocket(slisten); - slisten = create_fast_reuse_socket(e); - if (slisten < 0) { - error_setg_errno(errp, errno, - "Failed to recreate failed listening socket"); - goto listen_failed; - } + slisten = -1; } } error_setg_errno(errp, errno,