4076aa37dc
any difference now, but in NFSv4 ACLs, there is write_acl permission, which also affects mode changes. Reviewed by: pjd
367 lines
8.9 KiB
C
367 lines
8.9 KiB
C
/*-
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* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/priv.h>
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#include <sys/vnode.h>
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#include <sys/mntent.h>
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#include <sys/mount.h>
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#include <sys/stat.h>
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#include <sys/jail.h>
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#include <sys/policy.h>
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#include <sys/zfs_vfsops.h>
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int
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secpolicy_nfs(struct ucred *cred)
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{
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return (priv_check_cred(cred, PRIV_NFS_DAEMON, 0));
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}
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int
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secpolicy_zfs(struct ucred *cred)
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{
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return (priv_check_cred(cred, PRIV_VFS_MOUNT, 0));
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}
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int
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secpolicy_sys_config(struct ucred *cred, int checkonly __unused)
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{
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return (priv_check_cred(cred, PRIV_ZFS_POOL_CONFIG, 0));
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}
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int
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secpolicy_zinject(struct ucred *cred)
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{
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return (priv_check_cred(cred, PRIV_ZFS_INJECT, 0));
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}
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int
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secpolicy_fs_unmount(struct ucred *cred, struct mount *vfsp __unused)
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{
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return (priv_check_cred(cred, PRIV_VFS_UNMOUNT, 0));
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}
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int
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secpolicy_fs_owner(struct mount *mp, struct ucred *cred)
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{
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if (zfs_super_owner) {
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if (cred->cr_uid == mp->mnt_cred->cr_uid &&
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(!jailed(cred) ||
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cred->cr_prison == mp->mnt_cred->cr_prison)) {
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return (0);
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}
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}
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return (priv_check_cred(cred, PRIV_VFS_MOUNT_OWNER, 0));
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}
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/*
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* This check is done in kern_link(), so we could just return 0 here.
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*/
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extern int hardlink_check_uid;
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int
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secpolicy_basic_link(struct vnode *vp, struct ucred *cred)
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{
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if (!hardlink_check_uid)
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return (0);
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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return (priv_check_cred(cred, PRIV_VFS_LINK, 0));
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}
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int
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secpolicy_vnode_stky_modify(struct ucred *cred)
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{
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return (EPERM);
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}
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int
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secpolicy_vnode_remove(struct vnode *vp, struct ucred *cred)
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{
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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return (priv_check_cred(cred, PRIV_VFS_ADMIN, 0));
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}
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int
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secpolicy_vnode_access(struct ucred *cred, struct vnode *vp, uint64_t owner,
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accmode_t accmode)
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{
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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if ((accmode & VREAD) && priv_check_cred(cred, PRIV_VFS_READ, 0) != 0)
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return (EACCES);
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if ((accmode & VWRITE) &&
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priv_check_cred(cred, PRIV_VFS_WRITE, 0) != 0) {
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return (EACCES);
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}
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if (accmode & VEXEC) {
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if (vp->v_type == VDIR) {
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if (priv_check_cred(cred, PRIV_VFS_LOOKUP, 0) != 0) {
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return (EACCES);
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}
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} else {
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if (priv_check_cred(cred, PRIV_VFS_EXEC, 0) != 0) {
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return (EACCES);
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}
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}
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}
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return (0);
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}
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int
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secpolicy_vnode_setdac(struct vnode *vp, struct ucred *cred, uid_t owner)
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{
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if (owner == cred->cr_uid)
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return (0);
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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return (priv_check_cred(cred, PRIV_VFS_ADMIN, 0));
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}
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int
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secpolicy_vnode_setattr(struct ucred *cred, struct vnode *vp, struct vattr *vap,
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const struct vattr *ovap, int flags,
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int unlocked_access(void *, int, struct ucred *), void *node)
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{
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int mask = vap->va_mask;
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int error;
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if (mask & AT_SIZE) {
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if (vp->v_type == VDIR)
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return (EISDIR);
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error = unlocked_access(node, VWRITE, cred);
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if (error)
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return (error);
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}
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if (mask & AT_MODE) {
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/*
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* If not the owner of the file then check privilege
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* for two things: the privilege to set the mode at all
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* and, if we're setting setuid, we also need permissions
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* to add the set-uid bit, if we're not the owner.
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* In the specific case of creating a set-uid root
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* file, we need even more permissions.
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*/
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error = secpolicy_vnode_setdac(vp, cred, ovap->va_uid);
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if (error)
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return (error);
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error = secpolicy_setid_setsticky_clear(vp, vap, ovap, cred);
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if (error)
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return (error);
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} else {
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vap->va_mode = ovap->va_mode;
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}
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if (mask & (AT_UID | AT_GID)) {
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error = secpolicy_vnode_setdac(vp, cred, ovap->va_uid);
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if (error)
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return (error);
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/*
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* To change the owner of a file, or change the group of a file to a
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* group of which we are not a member, the caller must have
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* privilege.
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*/
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if (((mask & AT_UID) && vap->va_uid != ovap->va_uid) ||
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((mask & AT_GID) && vap->va_gid != ovap->va_gid &&
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!groupmember(vap->va_gid, cred))) {
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if (secpolicy_fs_owner(vp->v_mount, cred) != 0) {
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error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
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if (error)
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return (error);
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}
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}
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if (((mask & AT_UID) && vap->va_uid != ovap->va_uid) ||
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((mask & AT_GID) && vap->va_gid != ovap->va_gid)) {
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secpolicy_setid_clear(vap, vp, cred);
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}
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}
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if (mask & (AT_ATIME | AT_MTIME)) {
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/*
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* From utimes(2):
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* If times is NULL, ... The caller must be the owner of
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* the file, have permission to write the file, or be the
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* super-user.
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* If times is non-NULL, ... The caller must be the owner of
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* the file or be the super-user.
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*/
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error = secpolicy_vnode_setdac(vp, cred, ovap->va_uid);
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if (error && (vap->va_vaflags & VA_UTIMES_NULL))
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error = unlocked_access(node, VWRITE, cred);
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if (error)
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return (error);
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}
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return (0);
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}
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int
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secpolicy_vnode_create_gid(struct ucred *cred)
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{
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return (EPERM);
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}
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int
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secpolicy_vnode_setids_setgids(struct vnode *vp, struct ucred *cred, gid_t gid)
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{
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if (groupmember(gid, cred))
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return (0);
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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return (priv_check_cred(cred, PRIV_VFS_SETGID, 0));
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}
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int
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secpolicy_vnode_setid_retain(struct vnode *vp, struct ucred *cred,
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boolean_t issuidroot __unused)
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{
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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return (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0));
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}
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void
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secpolicy_setid_clear(struct vattr *vap, struct vnode *vp, struct ucred *cred)
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{
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return;
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if ((vap->va_mode & (S_ISUID | S_ISGID)) != 0) {
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if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0)) {
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vap->va_mask |= AT_MODE;
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vap->va_mode &= ~(S_ISUID|S_ISGID);
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}
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}
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}
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int
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secpolicy_setid_setsticky_clear(struct vnode *vp, struct vattr *vap,
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const struct vattr *ovap, struct ucred *cred)
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{
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int error;
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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/*
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* Privileged processes may set the sticky bit on non-directories,
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* as well as set the setgid bit on a file with a group that the process
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* is not a member of. Both of these are allowed in jail(8).
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*/
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if (vp->v_type != VDIR && (vap->va_mode & S_ISTXT)) {
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if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0))
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return (EFTYPE);
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}
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/*
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* Check for privilege if attempting to set the
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* group-id bit.
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*/
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if ((vap->va_mode & S_ISGID) != 0) {
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error = secpolicy_vnode_setids_setgids(vp, cred, ovap->va_gid);
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if (error)
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return (error);
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}
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/*
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* Deny setting setuid if we are not the file owner.
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*/
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if ((vap->va_mode & S_ISUID) && ovap->va_uid != cred->cr_uid) {
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error = priv_check_cred(cred, PRIV_VFS_ADMIN, 0);
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if (error)
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return (error);
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}
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return (0);
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}
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int
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secpolicy_fs_mount(cred_t *cr, vnode_t *mvp, struct mount *vfsp)
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{
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return (priv_check_cred(cr, PRIV_VFS_MOUNT, 0));
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}
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int
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secpolicy_vnode_owner(struct vnode *vp, cred_t *cred, uid_t owner)
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{
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if (owner == cred->cr_uid)
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return (0);
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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/* XXX: vfs_suser()? */
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return (priv_check_cred(cred, PRIV_VFS_MOUNT_OWNER, 0));
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}
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int
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secpolicy_vnode_chown(struct vnode *vp, cred_t *cred, boolean_t check_self)
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{
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if (secpolicy_fs_owner(vp->v_mount, cred) == 0)
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return (0);
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return (priv_check_cred(cred, PRIV_VFS_CHOWN, 0));
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}
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void
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secpolicy_fs_mount_clearopts(cred_t *cr, struct mount *vfsp)
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{
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if (priv_check_cred(cr, PRIV_VFS_MOUNT_NONUSER, 0) != 0) {
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MNT_ILOCK(vfsp);
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vfsp->vfs_flag |= VFS_NOSETUID | MNT_USER;
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vfs_clearmntopt(vfsp, MNTOPT_SETUID);
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vfs_setmntopt(vfsp, MNTOPT_NOSETUID, NULL, 0);
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MNT_IUNLOCK(vfsp);
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}
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}
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/*
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* Check privileges for setting xvattr attributes
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*/
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int
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secpolicy_xvattr(xvattr_t *xvap, uid_t owner, cred_t *cr, vtype_t vtype)
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{
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return (priv_check_cred(cr, PRIV_VFS_SYSFLAGS, 0));
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}
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