/* * $FreeBSD$ * * Copyright (c) 2011-2013, 2015, 2019 Juniper Networks, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/cdefs.h> #include <sys/param.h> #include <sys/systm.h> #include <sys/buf.h> #include <sys/conf.h> #include <sys/errno.h> #include <sys/fcntl.h> #include <sys/file.h> #include <sys/filedesc.h> #include <sys/ioccom.h> #include <sys/jail.h> #include <sys/kernel.h> #include <sys/lock.h> #include <sys/malloc.h> #include <sys/mdioctl.h> #include <sys/mount.h> #include <sys/mutex.h> #include <sys/namei.h> #include <sys/priv.h> #include <sys/proc.h> #include <sys/queue.h> #include <sys/vnode.h> #include <security/mac_veriexec/mac_veriexec.h> #include <security/mac_veriexec/mac_veriexec_internal.h> #include "veriexec_ioctl.h" /* * We need a mutex while updating lists etc. */ extern struct mtx ve_mutex; /* * Handle the ioctl for the device */ static int verifiedexecioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, struct thread *td) { struct nameidata nid; struct vattr vattr; struct verified_exec_label_params *lparams; struct verified_exec_params *params; int error = 0; /* * These commands are considered safe requests for anyone who has * permission to access to device node. */ switch (cmd) { case VERIEXEC_GETSTATE: { int *ip = (int *)data; if (ip) *ip = mac_veriexec_get_state(); else error = EINVAL; return (error); } break; default: break; } /* * Anything beyond this point is considered dangerous, so we need to * only allow processes that have kmem write privs to do them. * * MAC/veriexec will grant kmem write privs to "trusted" processes. */ error = priv_check(td, PRIV_KMEM_WRITE); if (error) return (error); lparams = (struct verified_exec_label_params *)data; if (cmd == VERIEXEC_LABEL_LOAD) params = &lparams->params; else params = (struct verified_exec_params *)data; switch (cmd) { case VERIEXEC_ACTIVE: mtx_lock(&ve_mutex); if (mac_veriexec_in_state(VERIEXEC_STATE_LOADED)) mac_veriexec_set_state(VERIEXEC_STATE_ACTIVE); else error = EINVAL; mtx_unlock(&ve_mutex); break; case VERIEXEC_DEBUG_ON: mtx_lock(&ve_mutex); { int *ip = (int *)data; mac_veriexec_debug++; if (ip) { if (*ip > 0) mac_veriexec_debug = *ip; *ip = mac_veriexec_debug; } } mtx_unlock(&ve_mutex); break; case VERIEXEC_DEBUG_OFF: mac_veriexec_debug = 0; break; case VERIEXEC_ENFORCE: mtx_lock(&ve_mutex); if (mac_veriexec_in_state(VERIEXEC_STATE_LOADED)) mac_veriexec_set_state(VERIEXEC_STATE_ACTIVE | VERIEXEC_STATE_ENFORCE); else error = EINVAL; mtx_unlock(&ve_mutex); break; case VERIEXEC_GETVERSION: { int *ip = (int *)data; if (ip) *ip = MAC_VERIEXEC_VERSION; else error = EINVAL; } break; case VERIEXEC_LOCK: mtx_lock(&ve_mutex); mac_veriexec_set_state(VERIEXEC_STATE_LOCKED); mtx_unlock(&ve_mutex); break; case VERIEXEC_LOAD: if (prison0.pr_securelevel > 0) return (EPERM); /* no updates when secure */ /* FALLTHROUGH */ case VERIEXEC_LABEL_LOAD: case VERIEXEC_SIGNED_LOAD: /* * If we use a loader that will only use a * digitally signed hash list - which it verifies. * We can load fingerprints provided veriexec is not locked. */ if (prison0.pr_securelevel > 0 && !mac_veriexec_in_state(VERIEXEC_STATE_LOADED)) { /* * If securelevel has been raised and we * do not have any fingerprints loaded, * it would dangerous to do so now. */ return (EPERM); } if (mac_veriexec_in_state(VERIEXEC_STATE_LOCKED)) error = EPERM; else { size_t labellen = 0; int flags = FREAD; int override = (cmd != VERIEXEC_LOAD); /* * Get the attributes for the file name passed * stash the file's device id and inode number * along with it's fingerprint in a list for * exec to use later. */ /* * FreeBSD seems to copy the args to kernel space */ NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE, params->file, td); if ((error = vn_open(&nid, &flags, 0, NULL)) != 0) return (error); error = VOP_GETATTR(nid.ni_vp, &vattr, td->td_ucred); if (error != 0) { mac_veriexec_set_fingerprint_status(nid.ni_vp, FINGERPRINT_INVALID); VOP_UNLOCK(nid.ni_vp); (void) vn_close(nid.ni_vp, FREAD, td->td_ucred, td); return (error); } if (override) { /* * If the file is on a "verified" filesystem * someone may be playing games. */ if ((nid.ni_vp->v_mount->mnt_flag & MNT_VERIFIED) != 0) override = 0; } /* * invalidate the node fingerprint status * which will have been set in the vn_open * and would always be FINGERPRINT_NOTFOUND */ mac_veriexec_set_fingerprint_status(nid.ni_vp, FINGERPRINT_INVALID); VOP_UNLOCK(nid.ni_vp); (void) vn_close(nid.ni_vp, FREAD, td->td_ucred, td); if (params->flags & VERIEXEC_LABEL) labellen = strnlen(lparams->label, sizeof(lparams->label) - 1) + 1; mtx_lock(&ve_mutex); error = mac_veriexec_metadata_add_file( ((params->flags & VERIEXEC_FILE) != 0), vattr.va_fsid, vattr.va_fileid, vattr.va_gen, params->fingerprint, (params->flags & VERIEXEC_LABEL) ? lparams->label : NULL, labellen, params->flags, params->fp_type, override); mac_veriexec_set_state(VERIEXEC_STATE_LOADED); mtx_unlock(&ve_mutex); } break; default: error = ENODEV; } return (error); } struct cdevsw veriexec_cdevsw = { .d_version = D_VERSION, .d_ioctl = verifiedexecioctl, .d_name = "veriexec", }; static void veriexec_drvinit(void *unused __unused) { make_dev(&veriexec_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "veriexec"); } SYSINIT(veriexec, SI_SUB_PSEUDO, SI_ORDER_ANY, veriexec_drvinit, NULL); MODULE_DEPEND(veriexec, mac_veriexec, 1, 1, 1);