From nobody Fri Dec 19 15:46:35 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1587055955; cv=none; d=zohomail.com; s=zohoarc; b=BLNjit1aVSftjQt5209ZtvIbRZEeRCIRZFjkk1MmhdRQR7ntf8xRgzLRt9TemrztE9jpm2I5j/63L1+pkblgQ5jFVAZF36HB/nVtz11lVreuOuJ7KF2YAvdNoOoZaCIXpVc1GHAiCm+nTs6gMCrfNX4t7qIezbQ2Rn8/5BIkWJk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1587055955; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=OfPb5Xn/B/myf3QvtDqfsuKstRVK4hF/CQiBtI98nAY=; b=Sj2p2Zh2abnpojrTZVyxPss/UOX9B7pWY3WxEwPK2/z0XxCCkp3vxaWLlIvZhl+ZGFtKbhPjeNdASE0bqCrAeQhG3tPPChygJ/LJ4vEtCB2l5eXi5djNbiTRumzpePv+tiLPTZ8c/gSW42aVsFbzBSW4KoN54txLVDI1TaRX97E= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1587055955242362.6213175596728; Thu, 16 Apr 2020 09:52:35 -0700 (PDT) Received: from localhost ([::1]:37142 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jP7kf-0001aI-GF for importer@patchew.org; Thu, 16 Apr 2020 12:52:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:32955) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jP7hm-0006r1-Pn for qemu-devel@nongnu.org; Thu, 16 Apr 2020 12:49:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jP7hl-0000Pr-R4 for qemu-devel@nongnu.org; Thu, 16 Apr 2020 12:49:34 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:30846 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jP7hl-0000Pa-NE for qemu-devel@nongnu.org; Thu, 16 Apr 2020 12:49:33 -0400 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-416-1r7NIdbSNDixjmlBnkk9qw-1; Thu, 16 Apr 2020 12:49:30 -0400 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id B2E58802683 for ; Thu, 16 Apr 2020 16:49:29 +0000 (UTC) Received: from localhost (ovpn-114-223.ams2.redhat.com [10.36.114.223]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE0639A265; Thu, 16 Apr 2020 16:49:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587055773; 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=OfPb5Xn/B/myf3QvtDqfsuKstRVK4hF/CQiBtI98nAY=; b=ZEWZ38OMEwm9w1EFgdOXtsAr4NbTtdjLZ6O9SrxsTQwATjEXfV5RfKYUy4JDLVBvfcrw26 /IRHulMzxz4fV7s4198t8qIOGHSEq0y1Eo0AtlMmNYVseBqDPfoYA8wNia3FO1gfidA06k XgrQJlorRnZLIAKYjAVaTgSIuhINfMI= X-MC-Unique: 1r7NIdbSNDixjmlBnkk9qw-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH 2/2] virtiofsd: drop all capabilities in the wait parent process Date: Thu, 16 Apr 2020 17:49:07 +0100 Message-Id: <20200416164907.244868-3-stefanha@redhat.com> In-Reply-To: <20200416164907.244868-1-stefanha@redhat.com> References: <20200416164907.244868-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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: virtio-fs@redhat.com, Stefan Hajnoczi , "Dr. David Alan Gilbert" , Vivek Goyal Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" All this process does is wait for its child. No capabilities are needed. Signed-off-by: Stefan Hajnoczi Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- tools/virtiofsd/passthrough_ll.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index af97ba1c41..0c3f33b074 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2530,6 +2530,17 @@ static void print_capabilities(void) printf("}\n"); } =20 +/* + * Drop all Linux capabilities because the wait parent process only needs = to + * sit in waitpid(2) and terminate. + */ +static void setup_wait_parent_capabilities(void) +{ + capng_setpid(syscall(SYS_gettid)); + capng_clear(CAPNG_SELECT_BOTH); + capng_apply(CAPNG_SELECT_BOTH); +} + /* * Move to a new mount, net, and pid namespaces to isolate this process. */ @@ -2561,6 +2572,8 @@ static void setup_namespaces(struct lo_data *lo, stru= ct fuse_session *se) pid_t waited; int wstatus; =20 + setup_wait_parent_capabilities(); + /* The parent waits for the child */ do { waited =3D waitpid(child, &wstatus, 0); --=20 2.25.1