From patchwork Wed Jul 29 22:14:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11691813 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EA07B14E3 for ; Wed, 29 Jul 2020 22:15:38 +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 C000C20656 for ; Wed, 29 Jul 2020 22:15:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="T4z/j33M" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C000C20656 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:50064 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k0uML-0005Nt-UR for patchwork-qemu-devel@patchwork.kernel.org; Wed, 29 Jul 2020 18:15:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55546) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k0uLV-0003eB-7x for qemu-devel@nongnu.org; Wed, 29 Jul 2020 18:14:45 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:25758 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k0uLS-0001B0-9l for qemu-devel@nongnu.org; Wed, 29 Jul 2020 18:14:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596060880; 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=yWt3zKX5kSTo4Po7yflNFrC7QnaOp+4ZYcdeS58v6Ig=; b=T4z/j33MlJOfxnjvYxOLRhkSEOy+DEO1DrcbK1iWKP+rdTikxS8F/iTa+3D0VK8cBqAJAZ tt/XTk3k8LIRgEVwdBMkXqBLZGQtrH882INfSsi5SkNOTHcjw4oWYUZ+5Q4kdlxMT3G45u K4l680OjrLCAXpXPgHS+mWeS3IyHBR0= 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-328-qRVLW7a7OxGu3VEwcyv9Aw-1; Wed, 29 Jul 2020 18:14:38 -0400 X-MC-Unique: qRVLW7a7OxGu3VEwcyv9Aw-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 D84FD102C7EC for ; Wed, 29 Jul 2020 22:14:37 +0000 (UTC) Received: from horse.redhat.com (ovpn-116-149.rdu2.redhat.com [10.10.116.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 41EF775559; Wed, 29 Jul 2020 22:14:32 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id C8210223D05; Wed, 29 Jul 2020 18:14:31 -0400 (EDT) From: Vivek Goyal To: qemu-devel@nongnu.org Subject: [PATCH 2/5] virtiofsd: create lock/pid file in per user cache dir Date: Wed, 29 Jul 2020 18:14:07 -0400 Message-Id: <20200729221410.147556-3-vgoyal@redhat.com> In-Reply-To: <20200729221410.147556-1-vgoyal@redhat.com> References: <20200729221410.147556-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/29 09:18:45 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H2=-1, 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: berrange@redhat.com, vromanso@redhat.com, dgilbert@redhat.com, virtio-fs@redhat.com, stefanha@redhat.com, vgoyal@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Right now we create lock/pid file in /usr/local/var/... and unprivliged user does not have access to create files there. So create this file in per user cache dir as queried as specified by environment variable XDG_RUNTIME_DIR. Note: "su $USER" does not update XDG_RUNTIME_DIR and it still points to root user's director. So for now I create a directory /tmp/$UID to save lock/pid file. Dan pointed out that it can be a problem if a malicious app already has /tmp/$UID created. So we probably need to get rid of this. Signed-off-by: Vivek Goyal --- tools/virtiofsd/fuse_virtio.c | 40 ++++++++++++++++++++++++++++++----- 1 file changed, 35 insertions(+), 5 deletions(-) diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index 6b21a93841..f763a70ba5 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -972,13 +972,43 @@ static bool fv_socket_lock(struct fuse_session *se) g_autofree gchar *pidfile = NULL; g_autofree gchar *dir = NULL; Error *local_err = NULL; + gboolean unprivileged = false; - dir = qemu_get_local_state_pathname("run/virtiofsd"); + if (geteuid() != 0) + unprivileged = true; - if (g_mkdir_with_parents(dir, S_IRWXU) < 0) { - fuse_log(FUSE_LOG_ERR, "%s: Failed to create directory %s: %s", - __func__, dir, strerror(errno)); - return false; + /* + * Unpriviliged users don't have access to /usr/local/var. Hence + * store lock/pid file in per user directory. Use environment + * variable XDG_RUNTIME_DIR. + * If one logs into the system as root and then does "su" then + * XDG_RUNTIME_DIR still points to root user directory. In that + * case create a directory for user in /tmp/$UID + */ + if (unprivileged) { + gchar *user_dir = NULL; + gboolean create_dir = false; + user_dir = g_strdup(g_get_user_runtime_dir()); + if (!user_dir || g_str_has_suffix(user_dir, "/0")) { + user_dir = g_strdup_printf("/tmp/%d", geteuid()); + create_dir = true; + } + + if (create_dir && g_mkdir_with_parents(user_dir, S_IRWXU) < 0) { + fuse_log(FUSE_LOG_ERR, "%s: Failed to create directory %s: %s", + __func__, user_dir, strerror(errno)); + g_free(user_dir); + return false; + } + dir = g_strdup(user_dir); + g_free(user_dir); + } else { + dir = qemu_get_local_state_pathname("run/virtiofsd"); + if (g_mkdir_with_parents(dir, S_IRWXU) < 0) { + fuse_log(FUSE_LOG_ERR, "%s: Failed to create directory %s: %s", + __func__, dir, strerror(errno)); + return false; + } } sk_name = g_strdup(se->vu_socket_path);