diff --git a/sys/security/mac_veriexec/mac_veriexec.c b/sys/security/mac_veriexec/mac_veriexec.c
index 99a76abd4afb..6f06a8577212 100644
--- a/sys/security/mac_veriexec/mac_veriexec.c
+++ b/sys/security/mac_veriexec/mac_veriexec.c
@@ -1,882 +1,1029 @@
/*
* $FreeBSD$
*
* Copyright (c) 2011, 2012, 2013, 2015, 2016, 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 "opt_capsicum.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capsicum.h>
#include <sys/eventhandler.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/imgact.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/mac.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <fs/nullfs/null.h>
#include <security/mac/mac_policy.h>
#include "mac_veriexec.h"
#include "mac_veriexec_internal.h"
#define SLOT(l) \
mac_label_get((l), mac_veriexec_slot)
#define SLOT_SET(l, v) \
mac_label_set((l), mac_veriexec_slot, (v))
#ifdef MAC_DEBUG
#define MAC_VERIEXEC_DBG(_lvl, _fmt, ...) \
do { \
VERIEXEC_DEBUG((_lvl), (MAC_VERIEXEC_FULLNAME ": " _fmt \
"\n", ##__VA_ARGS__)); \
} while(0)
#else
#define MAC_VERIEXEC_DBG(_lvl, _fmt, ...)
#endif
static int sysctl_mac_veriexec_state(SYSCTL_HANDLER_ARGS);
static int sysctl_mac_veriexec_db(SYSCTL_HANDLER_ARGS);
+static struct mac_policy_ops mac_veriexec_ops;
SYSCTL_DECL(_security_mac);
SYSCTL_NODE(_security_mac, OID_AUTO, veriexec, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"MAC/veriexec policy controls");
int mac_veriexec_debug;
SYSCTL_INT(_security_mac_veriexec, OID_AUTO, debug, CTLFLAG_RW,
&mac_veriexec_debug, 0, "Debug level");
static int mac_veriexec_state;
SYSCTL_PROC(_security_mac_veriexec, OID_AUTO, state,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
0, 0, sysctl_mac_veriexec_state, "A",
"Verified execution subsystem state");
SYSCTL_PROC(_security_mac_veriexec, OID_AUTO, db,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_NEEDGIANT,
0, 0, sysctl_mac_veriexec_db,
"A", "Verified execution fingerprint database");
+
static int mac_veriexec_slot;
+static int mac_veriexec_block_unlink;
+
MALLOC_DEFINE(M_VERIEXEC, "veriexec", "Verified execution data");
/**
* @internal
* @brief Handler for security.mac.veriexec.db sysctl
*
* Display a human-readable form of the current fingerprint database.
*/
static int
sysctl_mac_veriexec_db(SYSCTL_HANDLER_ARGS)
{
struct sbuf sb;
int error;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sb, NULL, 1024, req);
mac_veriexec_metadata_print_db(&sb);
error = sbuf_finish(&sb);
sbuf_delete(&sb);
return (error);
}
/**
* @internal
* @brief Generate human-readable output about the current verified execution
* state.
*
* @param sbp sbuf to write output to
*/
static void
mac_veriexec_print_state(struct sbuf *sbp)
{
if (mac_veriexec_state & VERIEXEC_STATE_INACTIVE)
sbuf_printf(sbp, "inactive ");
if (mac_veriexec_state & VERIEXEC_STATE_LOADED)
sbuf_printf(sbp, "loaded ");
if (mac_veriexec_state & VERIEXEC_STATE_ACTIVE)
sbuf_printf(sbp, "active ");
if (mac_veriexec_state & VERIEXEC_STATE_ENFORCE)
sbuf_printf(sbp, "enforce ");
if (mac_veriexec_state & VERIEXEC_STATE_LOCKED)
sbuf_printf(sbp, "locked ");
if (mac_veriexec_state != 0)
sbuf_trim(sbp);
}
/**
* @internal
* @brief Handler for security.mac.veriexec.state sysctl
*
* Display a human-readable form of the current verified execution subsystem
* state.
*/
static int
sysctl_mac_veriexec_state(SYSCTL_HANDLER_ARGS)
{
struct sbuf sb;
int error;
sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
mac_veriexec_print_state(&sb);
sbuf_finish(&sb);
error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
sbuf_delete(&sb);
return (error);
}
/**
* @internal
* @brief Event handler called when a virtual file system is mounted.
*
* We need to record the file system identifier in the MAC per-policy slot
* assigned to veriexec, so we have a key to use in order to reference the
* mount point in the meta-data store.
*
* @param arg unused argument
* @param mp mount point that is being mounted
* @param fsrootvp vnode of the file system root
* @param td calling thread
*/
static void
mac_veriexec_vfs_mounted(void *arg __unused, struct mount *mp,
struct vnode *fsrootvp, struct thread *td)
{
struct vattr va;
int error;
error = VOP_GETATTR(fsrootvp, &va, td->td_ucred);
if (error)
return;
SLOT_SET(mp->mnt_label, va.va_fsid);
#ifdef MAC_DEBUG
MAC_VERIEXEC_DBG(3, "set fsid to %ju for mount %p",
(uintmax_t)va.va_fsid, mp);
#endif
}
/**
* @internal
* @brief Event handler called when a virtual file system is unmounted.
*
* If we recorded a file system identifier in the MAC per-policy slot assigned
* to veriexec, then we need to tell the meta-data store to clean up.
*
* @param arg unused argument
* @param mp mount point that is being unmounted
* @param td calling thread
*/
static void
mac_veriexec_vfs_unmounted(void *arg __unused, struct mount *mp,
struct thread *td)
{
dev_t fsid;
fsid = SLOT(mp->mnt_label);
if (fsid) {
MAC_VERIEXEC_DBG(3, "fsid %ju, cleaning up mount",
(uintmax_t)fsid);
mac_veriexec_metadata_unmounted(fsid, td);
}
}
/**
* @internal
* @brief The mount point is being initialized, set the value in the MAC
* per-policy slot for veriexec to zero.
*
* @note A value of zero in this slot indicates no file system identifier
* is assigned.
*
* @param label the label that is being initialized
*/
-static void
-mac_veriexec_mount_init_label(struct label *label)
+static void
+mac_veriexec_mount_init_label(struct label *label)
{
SLOT_SET(label, 0);
}
/**
* @internal
* @brief The mount-point is being destroyed, reset the value in the MAC
* per-policy slot for veriexec back to zero.
*
* @note A value of zero in this slot indicates no file system identifier
* is assigned.
*
* @param label the label that is being destroyed
*/
-static void
-mac_veriexec_mount_destroy_label(struct label *label)
+static void
+mac_veriexec_mount_destroy_label(struct label *label)
{
SLOT_SET(label, 0);
}
/**
* @internal
* @brief The vnode label is being initialized, set the value in the MAC
* per-policy slot for veriexec to @c FINGERPRINT_INVALID
*
* @note @c FINGERPRINT_INVALID indicates the fingerprint is invalid.
*
* @param label the label that is being initialized
*/
static void
mac_veriexec_vnode_init_label(struct label *label)
{
SLOT_SET(label, FINGERPRINT_INVALID);
}
/**
* @internal
* @brief The vnode label is being destroyed, reset the value in the MAC
* per-policy slot for veriexec back to @c FINGERPRINT_INVALID
*
* @note @c FINGERPRINT_INVALID indicates the fingerprint is invalid.
*
* @param label the label that is being destroyed
*/
static void
mac_veriexec_vnode_destroy_label(struct label *label)
{
SLOT_SET(label, FINGERPRINT_INVALID);
}
/**
* @internal
* @brief Copy the value in the MAC per-policy slot assigned to veriexec from
* the @p src label to the @p dest label
*/
-static void
+static void
mac_veriexec_copy_label(struct label *src, struct label *dest)
{
SLOT_SET(dest, SLOT(src));
}
/**
* @internal
* @brief Check if the requested process can be debugged
*
* @param cred credentials to use
* @param p process to debug
*
* @return 0 if debugging is allowed, otherwise an error code.
*/
static int
mac_veriexec_proc_check_debug(struct ucred *cred, struct proc *p)
{
int error, flags;
/* If we are not enforcing veriexec, nothing for us to check */
if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
return (0);
error = mac_veriexec_metadata_get_executable_flags(cred, p, &flags, 0);
if (error != 0)
return (0);
return ((flags & VERIEXEC_NOTRACE) ? EACCES : 0);
}
/**
* @internal
* @brief A KLD load has been requested and needs to be validated.
*
* @param cred credentials to use
* @param vp vnode of the KLD that has been requested
* @param vlabel vnode label assigned to the vnode
*
* @return 0 if the KLD load is allowed, otherwise an error code.
*/
static int
mac_veriexec_kld_check_load(struct ucred *cred, struct vnode *vp,
struct label *vlabel)
{
struct vattr va;
struct thread *td = curthread;
fingerprint_status_t status;
int error;
/*
* If we are not actively enforcing, allow it
*/
if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
return (0);
/* Get vnode attributes */
error = VOP_GETATTR(vp, &va, cred);
if (error)
return (error);
/*
* Fetch the fingerprint status for the vnode
* (starting with files first)
*/
error = mac_veriexec_metadata_fetch_fingerprint_status(vp, &va, td,
VERIEXEC_FILES_FIRST);
if (error && error != EAUTH)
return (error);
/*
* By now we should have status...
*/
status = mac_veriexec_get_fingerprint_status(vp);
switch (status) {
case FINGERPRINT_FILE:
case FINGERPRINT_VALID:
case FINGERPRINT_INDIRECT:
if (error)
return (error);
break;
default:
/*
* kldload should fail unless there is a valid fingerprint
* registered.
*/
MAC_VERIEXEC_DBG(2, "fingerprint status is %d for dev %ju, "
"file %ju.%ju\n", status, (uintmax_t)va.va_fsid,
(uintmax_t)va.va_fileid, (uintmax_t)va.va_gen);
return (EAUTH);
}
/* Everything is good, allow the KLD to be loaded */
return (0);
}
/**
* @internal
* @brief Check privileges that veriexec needs to be concerned about.
*
* The following privileges are checked by this function:
* - PRIV_KMEM_WRITE\n
* Check if writes to /dev/mem and /dev/kmem are allowed\n
* (Only trusted processes are allowed)
*
* @param cred credentials to use
* @param priv privilege to check
*
* @return 0 if the privilege is allowed, error code otherwise.
*/
static int
mac_veriexec_priv_check(struct ucred *cred, int priv)
{
/* If we are not enforcing veriexec, nothing for us to check */
if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
return (0);
switch (priv) {
case PRIV_KMEM_WRITE:
if (!mac_veriexec_proc_is_trusted(cred, curproc))
return (EPERM);
break;
default:
break;
}
return (0);
}
static int
mac_veriexec_sysctl_check(struct ucred *cred, struct sysctl_oid *oidp,
void *arg1, int arg2, struct sysctl_req *req)
{
struct sysctl_oid *oid;
/* If we are not enforcing veriexec, nothing for us to check */
if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
return (0);
oid = oidp;
if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
return (EPERM); /* XXX call mac_veriexec_priv_check? */
}
return 0;
}
/**
* @internal
* @brief A program is being executed and needs to be validated.
*
* @param cred credentials to use
* @param vp vnode of the program that is being executed
* @param label vnode label assigned to the vnode
* @param imgp parameters for the image to be executed
* @param execlabel optional exec label
*
* @return 0 if the program should be allowed to execute, otherwise an error
* code.
*/
static int
mac_veriexec_vnode_check_exec(struct ucred *cred __unused,
struct vnode *vp __unused, struct label *label __unused,
struct image_params *imgp, struct label *execlabel __unused)
{
struct thread *td = curthread;
int error;
error = mac_veriexec_fingerprint_check_image(imgp, 0, td);
return (error);
}
/**
* @brief Check fingerprint for the specified vnode and validate it
*
* @param cred credentials to use
* @param vp vnode of the file
* @param accmode access mode to check (read, write, append, create,
* verify, etc.)
*
* @return 0 if the file validated, otherwise an error code.
*/
static int
mac_veriexec_check_vp(struct ucred *cred, struct vnode *vp, accmode_t accmode)
{
struct vattr va;
struct thread *td = curthread;
fingerprint_status_t status;
int error;
/* Get vnode attributes */
error = VOP_GETATTR(vp, &va, cred);
if (error)
return (error);
/* Get the fingerprint status for the file */
error = mac_veriexec_metadata_fetch_fingerprint_status(vp, &va, td,
VERIEXEC_FILES_FIRST);
if (error && error != EAUTH)
return (error);
/*
* By now we should have status...
*/
status = mac_veriexec_get_fingerprint_status(vp);
if (accmode & VWRITE) {
/*
* If file has a fingerprint then deny the write request,
* otherwise invalidate the status so we don't keep checking
- * for the file having a fingerprint.
+ * for the file having a fingerprint.
*/
switch (status) {
case FINGERPRINT_FILE:
case FINGERPRINT_VALID:
case FINGERPRINT_INDIRECT:
MAC_VERIEXEC_DBG(2,
"attempted write to fingerprinted file for dev "
"%ju, file %ju.%ju\n", (uintmax_t)va.va_fsid,
(uintmax_t)va.va_fileid, (uintmax_t)va.va_gen);
return (EPERM);
default:
break;
}
}
if (accmode & VVERIFY) {
switch (status) {
case FINGERPRINT_FILE:
case FINGERPRINT_VALID:
case FINGERPRINT_INDIRECT:
if (error)
return (error);
break;
default:
/*
* Caller wants open to fail unless there is a valid
- * fingerprint registered.
+ * fingerprint registered.
*/
MAC_VERIEXEC_DBG(2, "fingerprint status is %d for dev "
"%ju, file %ju.%ju\n", status,
(uintmax_t)va.va_fsid, (uintmax_t)va.va_fileid,
(uintmax_t)va.va_gen);
return (EAUTH);
}
}
return (0);
}
/**
* @brief Opening a file has been requested and may need to be validated.
*
* @param cred credentials to use
* @param vp vnode of the file to open
* @param label vnode label assigned to the vnode
* @param accmode access mode to use for opening the file (read, write,
* append, create, verify, etc.)
*
* @return 0 if opening the file should be allowed, otherwise an error code.
*/
static int
mac_veriexec_vnode_check_open(struct ucred *cred, struct vnode *vp,
struct label *label __unused, accmode_t accmode)
{
int error;
/*
* Look for the file on the fingerprint lists iff it has not been seen
* before.
*/
if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
return (0);
error = mac_veriexec_check_vp(cred, vp, accmode);
return (error);
}
+/**
+ * @brief Unlink on a file has been requested and may need to be validated.
+ *
+ * @param cred credentials to use
+ * @param dvp parent directory for file vnode vp
+ * @param dlabel vnode label assigned to the directory vnode
+ * @param vp vnode of the file to unlink
+ * @param label vnode label assigned to the vnode
+ * @param cnp component name for vp
+ *
+ *
+ * @return 0 if opening the file should be allowed, otherwise an error code.
+ */
+static int
+mac_veriexec_vnode_check_unlink(struct ucred *cred, struct vnode *dvp __unused,
+ struct label *dvplabel __unused, struct vnode *vp,
+ struct label *label __unused, struct componentname *cnp __unused)
+{
+ int error;
+
+ /*
+ * Look for the file on the fingerprint lists iff it has not been seen
+ * before.
+ */
+ if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
+ return (0);
+
+ /*
+ * Check if it's a verified file
+ */
+ error = mac_veriexec_check_vp(cred, vp, VVERIFY);
+ if (error == 0) { /* file is verified */
+ MAC_VERIEXEC_DBG(2,
+ "(UNLINK) attempted to unlink a protected file (euid: %u)", cred->cr_uid);
+
+ return (EAUTH);
+ }
+ return (0);
+}
+
+/**
+ * @brief Rename the file has been requested and may need to be validated.
+ *
+ * @param cred credentials to use
+ * @param dvp parent directory for file vnode vp
+ * @param dlabel vnode label assigned to the directory vnode
+ * @param vp vnode of the file to rename
+ * @param label vnode label assigned to the vnode
+ * @param cnp component name for vp
+ *
+ *
+ * @return 0 if opening the file should be allowed, otherwise an error code.
+ */
+static int
+mac_veriexec_vnode_check_rename_from(struct ucred *cred,
+ struct vnode *dvp __unused, struct label *dvplabel __unused,
+ struct vnode *vp, struct label *label __unused,
+ struct componentname *cnp __unused)
+{
+ int error;
+
+ /*
+ * Look for the file on the fingerprint lists iff it has not been seen
+ * before.
+ */
+ if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
+ return (0);
+
+ /*
+ * Check if it's a verified file
+ */
+ error = mac_veriexec_check_vp(cred, vp, VVERIFY);
+ if (error == 0) { /* file is verified */
+ MAC_VERIEXEC_DBG(2,
+ "(RENAME_FROM) attempted to rename a protected file (euid: %u)", cred->cr_uid);
+ return (EAUTH);
+ }
+ return (0);
+}
+
+
+/**
+ * @brief Rename to file into the directory (overwrite the file name) has been
+ * requested and may need to be validated.
+ *
+ * @param cred credentials to use
+ * @param dvp parent directory for file vnode vp
+ * @param dlabel vnode label assigned to the directory vnode
+ * @param vp vnode of the overwritten file
+ * @param label vnode label assigned to the vnode
+ * @param samedir 1 if the source and destination directories are the same
+ * @param cnp component name for vp
+ *
+ *
+ * @return 0 if opening the file should be allowed, otherwise an error code.
+ */
+ static int
+mac_veriexec_vnode_check_rename_to(struct ucred *cred, struct vnode *dvp __unused,
+ struct label *dvplabel __unused, struct vnode *vp,
+ struct label *label __unused, int samedir __unused,
+ struct componentname *cnp __unused)
+{
+ int error;
+ /*
+ * If there is no existing file to overwrite, vp and label will be
+ * NULL.
+ */
+ if (vp == NULL)
+ return (0);
+
+ /*
+ * Look for the file on the fingerprint lists iff it has not been seen
+ * before.
+ */
+ if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
+ return (0);
+
+ /*
+ * Check if it's a verified file
+ */
+ error = mac_veriexec_check_vp(cred, vp, VVERIFY);
+ if (error == 0) { /* file is verified */
+ MAC_VERIEXEC_DBG(2,
+ "(RENAME_TO) attempted to overwrite a protected file (euid: %u)", cred->cr_uid);
+ return (EAUTH);
+ }
+ return (0);
+}
+
+
/**
* @brief Check mode changes on file to ensure they should be allowed.
*
* We cannot allow chmod of SUID or SGID on verified files.
*
* @param cred credentials to use
* @param vp vnode of the file to open
* @param label vnode label assigned to the vnode
* @param mode mode flags to set
*
* @return 0 if the mode change should be allowed, EAUTH otherwise.
*/
static int
mac_veriexec_vnode_check_setmode(struct ucred *cred, struct vnode *vp,
struct label *label __unused, mode_t mode)
{
int error;
if ((mac_veriexec_state & VERIEXEC_STATE_ENFORCE) == 0)
return (0);
/*
* Do not allow chmod (set-[gu]id) of verified file
*/
error = mac_veriexec_check_vp(cred, vp, VVERIFY);
if (error == EAUTH) /* it isn't verified */
return (0);
if (error == 0 && (mode & (S_ISUID|S_ISGID)) != 0)
return (EAUTH);
return (0);
}
/**
* @internal
* @brief Initialize the mac_veriexec MAC policy
*
* @param mpc MAC policy configuration
*/
static void
mac_veriexec_init(struct mac_policy_conf *mpc __unused)
{
/* Initialize state */
mac_veriexec_state = VERIEXEC_STATE_INACTIVE;
/* Initialize meta-data storage */
mac_veriexec_metadata_init();
/* Initialize fingerprint ops */
mac_veriexec_fingerprint_init();
/* Register event handlers */
EVENTHANDLER_REGISTER(vfs_mounted, mac_veriexec_vfs_mounted, NULL,
EVENTHANDLER_PRI_FIRST);
EVENTHANDLER_REGISTER(vfs_unmounted, mac_veriexec_vfs_unmounted, NULL,
EVENTHANDLER_PRI_LAST);
+
+ /* Fetch tunable value in kernel env and define a corresponding read-only sysctl */
+ mac_veriexec_block_unlink = 0;
+ TUNABLE_INT_FETCH("security.mac.veriexec.block_unlink", &mac_veriexec_block_unlink);
+ SYSCTL_INT(_security_mac_veriexec, OID_AUTO, block_unlink,
+ CTLFLAG_RDTUN, &mac_veriexec_block_unlink, 0, "Veriexec unlink protection");
+
+ /* Check if unlink control is activated via tunable value */
+ if (!mac_veriexec_block_unlink)
+ mac_veriexec_ops.mpo_vnode_check_unlink = NULL;
}
/**
* @internal
* @brief MAC policy-specific syscall for mac_veriexec
*
* The following syscalls are implemented:
* - @c MAC_VERIEXEC_CHECK_SYSCALL
* Check if the file referenced by a file descriptor has a fingerprint
* registered in the meta-data store.
*
* @param td calling thread
* @param call system call number
* @param arg arugments to the syscall
*
* @return 0 on success, otherwise an error code.
*/
static int
mac_veriexec_syscall(struct thread *td, int call, void *arg)
{
struct image_params img;
struct nameidata nd;
cap_rights_t rights;
struct vattr va;
struct file *fp;
int error;
switch (call) {
case MAC_VERIEXEC_CHECK_FD_SYSCALL:
/* Get the vnode associated with the file descriptor passed */
error = getvnode(td, (uintptr_t) arg,
cap_rights_init_one(&rights, CAP_READ), &fp);
if (error)
return (error);
if (fp->f_type != DTYPE_VNODE) {
MAC_VERIEXEC_DBG(3, "MAC_VERIEXEC_CHECK_SYSCALL: "
"file is not vnode type (type=0x%x)",
fp->f_type);
error = EINVAL;
goto cleanup_file;
}
/*
* setup the bits of image_params that are used by
* mac_veriexec_check_fingerprint().
*/
bzero(&img, sizeof(img));
img.proc = td->td_proc;
img.vp = fp->f_vnode;
img.attr = &va;
/*
* Get vnode attributes
* (need to obtain a lock on the vnode first)
*/
vn_lock(img.vp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_GETATTR(fp->f_vnode, &va, td->td_ucred);
if (error)
goto check_done;
-
+
MAC_VERIEXEC_DBG(2, "mac_veriexec_fingerprint_check_image: "
"va_mode=%o, check_files=%d\n", va.va_mode,
((va.va_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0));
error = mac_veriexec_fingerprint_check_image(&img,
((va.va_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0), td);
check_done:
/* Release the lock we obtained earlier */
VOP_UNLOCK(img.vp);
cleanup_file:
fdrop(fp, td);
break;
case MAC_VERIEXEC_CHECK_PATH_SYSCALL:
/* Look up the path to get the vnode */
NDINIT(&nd, LOOKUP,
FOLLOW | LOCKLEAF | LOCKSHARED | AUDITVNODE1,
UIO_USERSPACE, arg);
error = namei(&nd);
if (error != 0)
break;
NDFREE_PNBUF(&nd);
/* Check the fingerprint status of the vnode */
error = mac_veriexec_check_vp(td->td_ucred, nd.ni_vp, VVERIFY);
vput(nd.ni_vp);
break;
default:
error = EOPNOTSUPP;
}
return (error);
}
static struct mac_policy_ops mac_veriexec_ops =
{
.mpo_init = mac_veriexec_init,
.mpo_kld_check_load = mac_veriexec_kld_check_load,
.mpo_mount_destroy_label = mac_veriexec_mount_destroy_label,
.mpo_mount_init_label = mac_veriexec_mount_init_label,
.mpo_priv_check = mac_veriexec_priv_check,
.mpo_proc_check_debug = mac_veriexec_proc_check_debug,
.mpo_syscall = mac_veriexec_syscall,
.mpo_system_check_sysctl = mac_veriexec_sysctl_check,
.mpo_vnode_check_exec = mac_veriexec_vnode_check_exec,
.mpo_vnode_check_open = mac_veriexec_vnode_check_open,
+ .mpo_vnode_check_unlink = mac_veriexec_vnode_check_unlink,
+ .mpo_vnode_check_rename_to = mac_veriexec_vnode_check_rename_to,
+ .mpo_vnode_check_rename_from = mac_veriexec_vnode_check_rename_from,
.mpo_vnode_check_setmode = mac_veriexec_vnode_check_setmode,
.mpo_vnode_copy_label = mac_veriexec_copy_label,
.mpo_vnode_destroy_label = mac_veriexec_vnode_destroy_label,
.mpo_vnode_init_label = mac_veriexec_vnode_init_label,
};
MAC_POLICY_SET(&mac_veriexec_ops, mac_veriexec, MAC_VERIEXEC_FULLNAME,
MPC_LOADTIME_FLAG_NOTLATE, &mac_veriexec_slot);
MODULE_VERSION(mac_veriexec, MAC_VERIEXEC_VERSION);
static struct vnode *
mac_veriexec_bottom_vnode(struct vnode *vp)
{
struct vnode *ldvp = NULL;
/*
* XXX This code is bogus. nullfs is not the only stacking
* filesystem. Less bogus code would add a VOP to reach bottom
* vnode and would not make assumptions how to get there.
*/
if (vp->v_mount != NULL &&
strcmp(vp->v_mount->mnt_vfc->vfc_name, "nullfs") == 0)
ldvp = NULLVPTOLOWERVP(vp);
return (ldvp);
}
/**
* @brief Get the fingerprint status set on a vnode.
*
* @param vp vnode to obtain fingerprint status from
*
* @return Fingerprint status assigned to the vnode.
*/
fingerprint_status_t
mac_veriexec_get_fingerprint_status(struct vnode *vp)
{
fingerprint_status_t fps;
struct vnode *ldvp;
fps = SLOT(vp->v_label);
switch (fps) {
case FINGERPRINT_VALID:
case FINGERPRINT_INDIRECT:
case FINGERPRINT_FILE:
break;
default:
/* we may need to recurse */
ldvp = mac_veriexec_bottom_vnode(vp);
if (ldvp != NULL)
return mac_veriexec_get_fingerprint_status(ldvp);
break;
}
return fps;
}
/**
* @brief Get the current verified execution subsystem state.
*
* @return Current set of verified execution subsystem state flags.
*/
int
mac_veriexec_get_state(void)
{
return (mac_veriexec_state);
}
/**
* @brief Determine if the verified execution subsystem state has specific
* flags set.
*
* @param state mask of flags to check
*
* @return State flags set within the masked bits
*/
int
mac_veriexec_in_state(int state)
{
return (mac_veriexec_state & state);
}
/**
* @brief Set the fingerprint status for a vnode
*
* Fingerprint status is stored in the MAC per-policy slot assigned to
* mac_veriexec.
*
* @param vp vnode to store the fingerprint status on
* @param fp_status fingerprint status to store
*/
void
mac_veriexec_set_fingerprint_status(struct vnode *vp,
fingerprint_status_t fp_status)
{
struct vnode *ldvp;
/* recurse until we find the real storage */
ldvp = mac_veriexec_bottom_vnode(vp);
if (ldvp != NULL) {
mac_veriexec_set_fingerprint_status(ldvp, fp_status);
return;
}
SLOT_SET(vp->v_label, fp_status);
}
/**
* @brief Set verified execution subsystem state flags
*
* @note Flags can only be added to the current state, not removed.
*
* @param state state flags to add to the current state
*/
void
mac_veriexec_set_state(int state)
{
mac_veriexec_state |= state;
}
/**
* @brief Determine if the process is trusted
*
* @param cred credentials to use
* @param p the process in question
*
* @return 1 if the process is trusted, otherwise 0.
*/
int
mac_veriexec_proc_is_trusted(struct ucred *cred, struct proc *p)
{
int already_locked, error, flags;
/* Make sure we lock the process if we do not already have the lock */
already_locked = PROC_LOCKED(p);
if (!already_locked)
PROC_LOCK(p);
error = mac_veriexec_metadata_get_executable_flags(cred, p, &flags, 0);
/* Unlock the process if we locked it previously */
if (!already_locked)
PROC_UNLOCK(p);
/* Any errors, deny access */
if (error != 0)
return (0);
/* Check that the trusted flag is set */
return ((flags & VERIEXEC_TRUSTED) == VERIEXEC_TRUSTED);
}