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=-16.4 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,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 7B073C433ED for ; Wed, 5 May 2021 12:17:35 +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 E634A61182 for ; Wed, 5 May 2021 12:17:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E634A61182 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]:40656 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1leGT7-0007G0-Oo for qemu-devel@archiver.kernel.org; Wed, 05 May 2021 08:17:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36208) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1leGOW-0004lH-Mi for qemu-devel@nongnu.org; Wed, 05 May 2021 08:12:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53679) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1leGOT-0003es-N4 for qemu-devel@nongnu.org; Wed, 05 May 2021 08:12:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620216765; 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=4GXqylJnNq57AGchGlafIrxhk2gns7BoOXwNDgEbIeI=; b=IV5bRqVy9HxwE47eAY8p5+Ej3oiH2IlBEp43M2Ne1zn5ZS4T+a8y5PQg7QIZP7xPg7w2L0 Pl4nXkt58nwUvoYh1b+e1OYxqhF4pGt2ICGLhCi0VPo+MMAmbBJZ5a1szDYM9Exmcwc3Ra CzthHQLj/h+P1NGYZ+oiyF7GnxvUUG4= 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-559-yJGM_paxNKGO007JtB9hWA-1; Wed, 05 May 2021 08:12:40 -0400 X-MC-Unique: yJGM_paxNKGO007JtB9hWA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BAB651009628 for ; Wed, 5 May 2021 12:12:39 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-114-253.ams2.redhat.com [10.36.114.253]) by smtp.corp.redhat.com (Postfix) with ESMTP id D6F926062C; Wed, 5 May 2021 12:12:38 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH 1/2] net/tap: fix FreeBSD portability problem receiving TAP FD Date: Wed, 5 May 2021 13:12:35 +0100 Message-Id: <20210505121236.532755-2-berrange@redhat.com> In-Reply-To: <20210505121236.532755-1-berrange@redhat.com> References: <20210505121236.532755-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.693, 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_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: Jason Wang , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The CMSG_LEN and CMSG_SPACE macros must not be assumed to return the same value. The msg_controllen field must be initialized using CMSG_SPACE when using SCM_RIGHTS. This ought to fix any FD receive issues users might be hitting on 64-bit FeeBSD / NetBSD platforms. The flaw was noticed first in GNULIB https://lists.gnu.org/archive/html/bug-gnulib/2021-02/msg00066.html and QEMU's code has the same logic bug. Signed-off-by: Daniel P. Berrangé --- net/tap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/tap.c b/net/tap.c index bae895e287..276a9077fc 100644 --- a/net/tap.c +++ b/net/tap.c @@ -467,7 +467,7 @@ static int recv_fd(int c) cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); - msg.msg_controllen = cmsg->cmsg_len; + msg.msg_controllen = CMSG_SPACE(sizeof(fd)); iov.iov_base = req; iov.iov_len = sizeof(req); -- 2.31.1