From patchwork Tue Mar 30 14:09:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 1460057 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=gKa2f7mu; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4F8rwP2Jbhz9sWV for ; Wed, 31 Mar 2021 01:11:33 +1100 (AEDT) Received: from localhost ([::1]:51080 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lRF5e-00044i-87 for incoming@patchwork.ozlabs.org; Tue, 30 Mar 2021 10:11:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53902) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRF44-0002vM-SP for qemu-devel@nongnu.org; Tue, 30 Mar 2021 10:09:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26116) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRF3v-00055i-AW for qemu-devel@nongnu.org; Tue, 30 Mar 2021 10:09:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617113380; 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=VD9imHUYCrYXbqORd8UehuR2aJYG8zcPhvQ2cCVRuE4=; b=gKa2f7muNjS3r/3/jBIe+eCw47wly4H480gDSgwIf3lQUTSJJKPuy/pbM7MyNVK6EsBl2D aUW7cUQdIT4OVnLTXK8K08uk9ylPlpyf9PGJfUerWt5iwEmx+ASsrr0NTLrtLqWp0722Gf HXRVjNQvgQgRieyCJWxAeJfVM7UfO6c= 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-187-AuhV_j25PCe-9ep4qZyIKg-1; Tue, 30 Mar 2021 10:09:37 -0400 X-MC-Unique: AuhV_j25PCe-9ep4qZyIKg-1 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 E226410055D0; Tue, 30 Mar 2021 14:09:35 +0000 (UTC) Received: from horse.redhat.com (ovpn-116-118.rdu2.redhat.com [10.10.116.118]) by smtp.corp.redhat.com (Postfix) with ESMTP id 802B360613; Tue, 30 Mar 2021 14:09:35 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 28DE6223D99; Tue, 30 Mar 2021 10:09:34 -0400 (EDT) From: Vivek Goyal To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH v6 2/5] virtiofsd: Add capability to change/restore umask Date: Tue, 30 Mar 2021 10:09:22 -0400 Message-Id: <20210330140925.730449-3-vgoyal@redhat.com> In-Reply-To: <20210330140925.730449-1-vgoyal@redhat.com> References: <20210330140925.730449-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vgoyal@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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: lhenriques@suse.de, Stefan Hajnoczi , dgilbert@redhat.com, vgoyal@redhat.com, miklos@szeredi.hu Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" When parent directory has default acl and a file is created in that directory, then umask is ignored and final file permissions are determined using default acl instead. (man 2 umask). Currently, fuse applies the umask and sends modified mode in create request accordingly. fuse server can set FUSE_DONT_MASK and tell fuse client to not apply umask and fuse server will take care of it as needed. With posix acls enabled, requirement will be that we want umask to determine final file mode if parent directory does not have default acl. So if posix acls are enabled, opt in for FUSE_DONT_MASK. virtiofsd will set umask of the thread doing file creation. And host kernel should use that umask if parent directory does not have default acls, otherwise umask does not take affect. Miklos mentioned that we already call unshare(CLONE_FS) for every thread. That means umask has now become property of per thread and it should be ok to manipulate it in file creation path. This patch only adds capability to change umask and restore it. It does not enable it yet. Next patch will add capability to enable it based on if user enabled posix_acl or not. This should fix fstest generic/099. Reported-by: Luis Henriques Signed-off-by: Vivek Goyal Reviewed-by: Stefan Hajnoczi --- tools/virtiofsd/passthrough_ll.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index b144320e48..e6ae3d38d7 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -122,6 +122,7 @@ struct lo_inode { struct lo_cred { uid_t euid; gid_t egid; + mode_t umask; }; enum { @@ -172,6 +173,8 @@ struct lo_data { /* An O_PATH file descriptor to /proc/self/fd/ */ int proc_self_fd; int user_killpriv_v2, killpriv_v2; + /* If set, virtiofsd is responsible for setting umask during creation */ + bool change_umask; }; static const struct fuse_opt lo_opts[] = { @@ -1134,7 +1137,8 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name) * ownership of caller. * TODO: What about selinux context? */ -static int lo_change_cred(fuse_req_t req, struct lo_cred *old) +static int lo_change_cred(fuse_req_t req, struct lo_cred *old, + bool change_umask) { int res; @@ -1154,11 +1158,14 @@ static int lo_change_cred(fuse_req_t req, struct lo_cred *old) return errno_save; } + if (change_umask) { + old->umask = umask(req->ctx.umask); + } return 0; } /* Regain Privileges */ -static void lo_restore_cred(struct lo_cred *old) +static void lo_restore_cred(struct lo_cred *old, bool restore_umask) { int res; @@ -1173,6 +1180,9 @@ static void lo_restore_cred(struct lo_cred *old) fuse_log(FUSE_LOG_ERR, "setegid(%u): %m\n", old->egid); exit(1); } + + if (restore_umask) + umask(old->umask); } static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, @@ -1202,7 +1212,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, return; } - saverr = lo_change_cred(req, &old); + saverr = lo_change_cred(req, &old, lo->change_umask && !S_ISLNK(mode)); if (saverr) { goto out; } @@ -1211,7 +1221,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, saverr = errno; - lo_restore_cred(&old); + lo_restore_cred(&old, lo->change_umask && !S_ISLNK(mode)); if (res == -1) { goto out; @@ -1918,7 +1928,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name, return; } - err = lo_change_cred(req, &old); + err = lo_change_cred(req, &old, lo->change_umask); if (err) { goto out; } @@ -1929,7 +1939,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name, fd = openat(parent_inode->fd, name, fi->flags | O_CREAT | O_EXCL, mode); err = fd == -1 ? errno : 0; - lo_restore_cred(&old); + lo_restore_cred(&old, lo->change_umask); /* Ignore the error if file exists and O_EXCL was not given */ if (err && (err != EEXIST || (fi->flags & O_EXCL))) {