438 lines
9.9 KiB
C
438 lines
9.9 KiB
C
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/*
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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/types.h>
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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(cred_t *cr)
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{
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return (spl_priv_check_cred(cr, PRIV_NFS_DAEMON));
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}
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int
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secpolicy_zfs(cred_t *cr)
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{
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return (spl_priv_check_cred(cr, PRIV_VFS_MOUNT));
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}
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int
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secpolicy_zfs_proc(cred_t *cr, proc_t *proc)
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{
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return (spl_priv_check_cred(cr, PRIV_VFS_MOUNT));
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}
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int
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secpolicy_sys_config(cred_t *cr, int checkonly __unused)
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{
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return (spl_priv_check_cred(cr, PRIV_ZFS_POOL_CONFIG));
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}
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int
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secpolicy_zinject(cred_t *cr)
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{
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return (spl_priv_check_cred(cr, PRIV_ZFS_INJECT));
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}
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int
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secpolicy_fs_unmount(cred_t *cr, struct mount *vfsp __unused)
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{
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return (spl_priv_check_cred(cr, PRIV_VFS_UNMOUNT));
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}
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int
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secpolicy_fs_owner(struct mount *mp, cred_t *cr)
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{
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if (zfs_super_owner) {
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if (cr->cr_uid == mp->mnt_cred->cr_uid &&
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cr->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 (EPERM);
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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(vnode_t *vp, cred_t *cr)
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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, cr) == 0)
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return (0);
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return (spl_priv_check_cred(cr, PRIV_VFS_LINK));
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}
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int
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secpolicy_vnode_stky_modify(cred_t *cr)
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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(vnode_t *vp, cred_t *cr)
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{
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return (0);
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return (spl_priv_check_cred(cr, PRIV_VFS_ADMIN));
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}
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int
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secpolicy_vnode_access(cred_t *cr, vnode_t *vp, uid_t owner, accmode_t accmode)
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{
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return (0);
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if ((accmode & VREAD) && spl_priv_check_cred(cr, PRIV_VFS_READ) != 0)
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return (EACCES);
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if ((accmode & VWRITE) &&
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spl_priv_check_cred(cr, PRIV_VFS_WRITE) != 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 (spl_priv_check_cred(cr, PRIV_VFS_LOOKUP) != 0)
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return (EACCES);
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} else {
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if (spl_priv_check_cred(cr, PRIV_VFS_EXEC) != 0)
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return (EACCES);
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}
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}
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return (0);
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}
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/*
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* Like secpolicy_vnode_access() but we get the actual wanted mode and the
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* current mode of the file, not the missing bits.
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*/
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int
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secpolicy_vnode_access2(cred_t *cr, vnode_t *vp, uid_t owner,
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accmode_t curmode, accmode_t wantmode)
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{
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accmode_t mode;
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mode = ~curmode & wantmode;
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if (mode == 0)
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return (0);
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return (secpolicy_vnode_access(cr, vp, owner, mode));
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}
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int
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secpolicy_vnode_any_access(cred_t *cr, vnode_t *vp, uid_t owner)
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{
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static int privs[] = {
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PRIV_VFS_ADMIN,
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PRIV_VFS_READ,
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PRIV_VFS_WRITE,
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PRIV_VFS_EXEC,
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PRIV_VFS_LOOKUP
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};
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int i;
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return (0);
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/* Same as secpolicy_vnode_setdac */
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if (owner == cr->cr_uid)
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return (0);
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for (i = 0; i < sizeof (privs)/sizeof (int); i++) {
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int priv;
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switch (priv = privs[i]) {
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case PRIV_VFS_EXEC:
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if (vp->v_type == VDIR)
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continue;
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break;
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case PRIV_VFS_LOOKUP:
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if (vp->v_type != VDIR)
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continue;
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break;
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}
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if (spl_priv_check_cred(cr, priv) == 0)
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return (0);
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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_setdac(vnode_t *vp, cred_t *cr, uid_t owner)
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{
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if (owner == cr->cr_uid)
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return (0);
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return (0);
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return (spl_priv_check_cred(cr, PRIV_VFS_ADMIN));
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}
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int
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secpolicy_vnode_setattr(cred_t *cr, vnode_t *vp, struct vattr *vap,
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const struct vattr *ovap, int flags,
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int unlocked_access(void *, int, cred_t *), 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, cr);
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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, cr, 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, cr);
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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, cr, 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
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* a file to a group of which we are not a member, the
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* caller must have 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, cr))) {
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if (secpolicy_fs_owner(vp->v_mount, cr) != 0) {
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error = spl_priv_check_cred(cr, PRIV_VFS_CHOWN);
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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, cr);
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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, cr, ovap->va_uid);
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if (error && (vap->va_vaflags & VA_UTIMES_NULL))
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error = unlocked_access(node, VWRITE, cr);
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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(cred_t *cr)
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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(vnode_t *vp, cred_t *cr, gid_t gid)
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{
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if (groupmember(gid, cr))
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return (0);
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return (0);
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return (spl_priv_check_cred(cr, PRIV_VFS_SETGID));
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}
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int
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secpolicy_vnode_setid_retain(vnode_t *vp, cred_t *cr,
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boolean_t issuidroot __unused)
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{
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return (0);
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return (spl_priv_check_cred(cr, PRIV_VFS_RETAINSUGID));
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}
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void
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secpolicy_setid_clear(struct vattr *vap, vnode_t *vp, cred_t *cr)
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{
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if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
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return;
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if ((vap->va_mode & (S_ISUID | S_ISGID)) != 0) {
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if (spl_priv_check_cred(cr, PRIV_VFS_RETAINSUGID)) {
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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(vnode_t *vp, struct vattr *vap,
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const struct vattr *ovap, cred_t *cr)
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{
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int error;
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if (secpolicy_fs_owner(vp->v_mount, cr) == 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 (spl_priv_check_cred(cr, PRIV_VFS_STICKYFILE))
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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, cr, 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 != cr->cr_uid) {
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error = spl_priv_check_cred(cr, PRIV_VFS_ADMIN);
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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)
|
||
|
|
{
|
||
|
|
|
||
|
|
return (spl_priv_check_cred(cr, PRIV_VFS_MOUNT));
|
||
|
|
}
|
||
|
|
|
||
|
|
int
|
||
|
|
secpolicy_vnode_owner(vnode_t *vp, cred_t *cr, uid_t owner)
|
||
|
|
{
|
||
|
|
|
||
|
|
if (owner == cr->cr_uid)
|
||
|
|
return (0);
|
||
|
|
if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
|
||
|
|
return (0);
|
||
|
|
|
||
|
|
/* XXX: vfs_suser()? */
|
||
|
|
return (spl_priv_check_cred(cr, PRIV_VFS_MOUNT_OWNER));
|
||
|
|
}
|
||
|
|
|
||
|
|
int
|
||
|
|
secpolicy_vnode_chown(vnode_t *vp, cred_t *cr, uid_t owner)
|
||
|
|
{
|
||
|
|
|
||
|
|
if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
|
||
|
|
return (0);
|
||
|
|
return (spl_priv_check_cred(cr, PRIV_VFS_CHOWN));
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
secpolicy_fs_mount_clearopts(cred_t *cr, struct mount *vfsp)
|
||
|
|
{
|
||
|
|
|
||
|
|
if (spl_priv_check_cred(cr, PRIV_VFS_MOUNT_NONUSER) != 0) {
|
||
|
|
MNT_ILOCK(vfsp);
|
||
|
|
vfsp->vfs_flag |= VFS_NOSETUID | MNT_USER;
|
||
|
|
vfs_clearmntopt(vfsp, MNTOPT_SETUID);
|
||
|
|
vfs_setmntopt(vfsp, MNTOPT_NOSETUID, NULL, 0);
|
||
|
|
MNT_IUNLOCK(vfsp);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Check privileges for setting xvattr attributes
|
||
|
|
*/
|
||
|
|
int
|
||
|
|
secpolicy_xvattr(vnode_t *vp, xvattr_t *xvap, uid_t owner, cred_t *cr,
|
||
|
|
vtype_t vtype)
|
||
|
|
{
|
||
|
|
|
||
|
|
if (secpolicy_fs_owner(vp->v_mount, cr) == 0)
|
||
|
|
return (0);
|
||
|
|
return (spl_priv_check_cred(cr, PRIV_VFS_SYSFLAGS));
|
||
|
|
}
|
||
|
|
|
||
|
|
int
|
||
|
|
secpolicy_smb(cred_t *cr)
|
||
|
|
{
|
||
|
|
|
||
|
|
return (spl_priv_check_cred(cr, PRIV_NETSMB));
|
||
|
|
}
|