int
crsetugid(cred_t *cr, uid_t uid, gid_t gid)
{
zone_t *zone = crgetzone(cr);
ASSERT(cr->cr_ref <= 2);
if (!VALID_UID(uid, zone) || !VALID_GID(gid, zone))
return (-1);
cr->cr_uid = cr->cr_ruid = cr->cr_suid = uid;
cr->cr_gid = cr->cr_rgid = cr->cr_sgid = gid;
return (0);
}
/*
* Change ownership of file.
*/
int
fchownat(int fd, char *path, uid_t uid, gid_t gid, int flag)
{
struct vattr vattr;
int error;
struct zone *zone = crgetzone(CRED());
if (uid != (uid_t)-1 && !VALID_UID(uid, zone) ||
gid != (gid_t)-1 && !VALID_GID(gid, zone)) {
return (set_errno(EINVAL));
}
vattr.va_uid = uid;
vattr.va_gid = gid;
vattr.va_mask = 0;
if (vattr.va_uid != -1)
vattr.va_mask |= AT_UID;
if (vattr.va_gid != -1)
vattr.va_mask |= AT_GID;
error = fsetattrat(fd, path, flag, &vattr);
if (error)
return (set_errno(error));
return (0);
}
int
setuid(uid_t uid)
{
proc_t *p;
int error;
int do_nocd = 0;
int uidchge = 0;
cred_t *cr, *newcr;
uid_t oldruid = uid;
zoneid_t zoneid = getzoneid();
ksid_t ksid, *ksp;
zone_t *zone = crgetzone(CRED());
if (!VALID_UID(uid, zone))
return (set_errno(EINVAL));
if (uid > MAXUID) {
if (ksid_lookupbyuid(zone, uid, &ksid) != 0)
return (set_errno(EINVAL));
ksp = &ksid;
} else {
ksp = NULL;
}
/*
* Need to pre-allocate the new cred structure before grabbing
* the p_crlock mutex. We can't hold on to the p_crlock for most
* if this though, now that we allow kernel upcalls from the
* policy routines.
*/
newcr = cralloc_ksid();
p = ttoproc(curthread);
retry:
mutex_enter(&p->p_crlock);
retry_locked:
cr = p->p_cred;
crhold(cr);
mutex_exit(&p->p_crlock);
if ((uid == cr->cr_ruid || uid == cr->cr_suid) &&
secpolicy_allow_setid(cr, uid, B_TRUE) != 0) {
mutex_enter(&p->p_crlock);
crfree(cr);
if (cr != p->p_cred)
goto retry_locked;
error = 0;
crcopy_to(cr, newcr);
p->p_cred = newcr;
newcr->cr_uid = uid;
crsetsid(newcr, ksp, KSID_USER);
mutex_exit(&p->p_crlock);
} else if ((error = secpolicy_allow_setid(cr, uid, B_FALSE)) == 0) {
mutex_enter(&p->p_crlock);
crfree(cr);
if (cr != p->p_cred)
goto retry_locked;
if (!uidchge && uid != cr->cr_ruid) {
/*
* The ruid of the process is going to change. In order
* to avoid a race condition involving the
* process-count associated with the newly given ruid,
* we increment the count before assigning the
* credential to the process.
* To do that, we'll have to take pidlock, so we first
* release p_crlock.
*/
mutex_exit(&p->p_crlock);
uidchge = 1;
mutex_enter(&pidlock);
upcount_inc(uid, zoneid);
mutex_exit(&pidlock);
/*
* As we released p_crlock we can't rely on the cr
* we read. So retry the whole thing.
*/
goto retry;
}
/*
* A privileged process that gives up its privilege
* must be marked to produce no core dump.
*/
if (cr->cr_uid != uid ||
cr->cr_ruid != uid ||
cr->cr_suid != uid)
do_nocd = 1;
oldruid = cr->cr_ruid;
crcopy_to(cr, newcr);
p->p_cred = newcr;
newcr->cr_ruid = uid;
newcr->cr_suid = uid;
newcr->cr_uid = uid;
crsetsid(newcr, ksp, KSID_USER);
priv_reset_PA(newcr, B_TRUE);
ASSERT(uid != oldruid ? uidchge : 1);
mutex_exit(&p->p_crlock);
} else {
crfree(newcr);
crfree(cr);
if (ksp != NULL)
ksid_rele(ksp);
}
/*
* We decrement the number of processes associated with the oldruid
* to match the increment above, even if the ruid of the process
* did not change or an error occurred (oldruid == uid).
*/
if (uidchge) {
mutex_enter(&pidlock);
upcount_dec(oldruid, zoneid);
mutex_exit(&pidlock);
}
if (error == 0) {
if (do_nocd) {
mutex_enter(&p->p_lock);
p->p_flag |= SNOCD;
mutex_exit(&p->p_lock);
}
crset(p, newcr); /* broadcast to process threads */
return (0);
}
return (set_errno(error));
}
/*
* Buy-back from SunOS 4.x
*
* Like setuid() and seteuid() combined -except- that non-root users
* can change cr_ruid to cr_uid, and the semantics of cr_suid are
* subtly different.
*/
int
setreuid(uid_t ruid, uid_t euid)
{
proc_t *p;
int error = 0;
int do_nocd = 0;
int uidchge = 0;
uid_t oldruid = ruid;
cred_t *cr, *newcr;
zoneid_t zoneid = getzoneid();
ksid_t ksid, *ksp;
zone_t *zone = crgetzone(CRED());
if ((ruid != -1 && !VALID_UID(ruid, zone)) ||
(euid != -1 && !VALID_UID(euid, zone)))
return (set_errno(EINVAL));
if (euid != -1 && euid > MAXUID) {
if (ksid_lookupbyuid(zone, euid, &ksid) != 0)
return (set_errno(EINVAL));
ksp = &ksid;
} else {
ksp = NULL;
}
/*
* Need to pre-allocate the new cred structure before grabbing
* the p_crlock mutex.
*/
newcr = cralloc_ksid();
p = ttoproc(curthread);
retry:
mutex_enter(&p->p_crlock);
retry_locked:
crhold(cr = p->p_cred);
mutex_exit(&p->p_crlock);
if (ruid != -1 && ruid != cr->cr_ruid && ruid != cr->cr_uid &&
secpolicy_allow_setid(cr, ruid, B_FALSE) != 0) {
mutex_enter(&p->p_crlock);
crfree(cr);
if (cr != p->p_cred)
goto retry_locked;
error = EPERM;
} else if (euid != -1 &&
euid != cr->cr_ruid && euid != cr->cr_uid &&
euid != cr->cr_suid && secpolicy_allow_setid(cr, euid, B_FALSE)) {
mutex_enter(&p->p_crlock);
crfree(cr);
if (cr != p->p_cred)
goto retry_locked;
error = EPERM;
} else {
mutex_enter(&p->p_crlock);
crfree(cr);
if (cr != p->p_cred)
goto retry_locked;
if (!uidchge && ruid != -1 && cr->cr_ruid != ruid) {
/*
* The ruid of the process is going to change. In order
* to avoid a race condition involving the
* process-count associated with the newly given ruid,
* we increment the count before assigning the
* credential to the process.
* To do that, we'll have to take pidlock, so we first
* release p_crlock.
*/
mutex_exit(&p->p_crlock);
uidchge = 1;
mutex_enter(&pidlock);
upcount_inc(ruid, zoneid);
mutex_exit(&pidlock);
/*
* As we released p_crlock we can't rely on the cr
* we read. So retry the whole thing.
*/
goto retry;
}
crhold(cr);
crcopy_to(cr, newcr);
p->p_cred = newcr;
if (euid != -1) {
newcr->cr_uid = euid;
crsetsid(newcr, ksp, KSID_USER);
}
if (ruid != -1) {
oldruid = newcr->cr_ruid;
newcr->cr_ruid = ruid;
ASSERT(ruid != oldruid ? uidchge : 1);
}
/*
* "If the real uid is being changed, or the effective uid is
* being changed to a value not equal to the real uid, the
* saved uid is set to the new effective uid."
*/
if (ruid != -1 ||
(euid != -1 && newcr->cr_uid != newcr->cr_ruid))
newcr->cr_suid = newcr->cr_uid;
/*
* A process that gives up its privilege
* must be marked to produce no core dump.
*/
if ((cr->cr_uid != newcr->cr_uid ||
cr->cr_ruid != newcr->cr_ruid ||
cr->cr_suid != newcr->cr_suid))
do_nocd = 1;
priv_reset_PA(newcr, ruid != -1 && euid != -1 && ruid == euid);
crfree(cr);
}
mutex_exit(&p->p_crlock);
/*
* We decrement the number of processes associated with the oldruid
* to match the increment above, even if the ruid of the process
* did not change or an error occurred (oldruid == uid).
*/
if (uidchge) {
ASSERT(oldruid != -1 && ruid != -1);
mutex_enter(&pidlock);
upcount_dec(oldruid, zoneid);
mutex_exit(&pidlock);
}
if (error == 0) {
if (do_nocd) {
mutex_enter(&p->p_lock);
p->p_flag |= SNOCD;
mutex_exit(&p->p_lock);
}
crset(p, newcr); /* broadcast to process threads */
return (0);
}
crfree(newcr);
if (ksp != NULL)
ksid_rele(ksp);
return (set_errno(error));
}
int
seteuid(uid_t uid)
{
proc_t *p;
int error = EPERM;
int do_nocd = 0;
cred_t *cr, *newcr;
ksid_t ksid, *ksp;
zone_t *zone = crgetzone(CRED());
if (!VALID_UID(uid, zone))
return (set_errno(EINVAL));
if (uid > MAXUID) {
if (ksid_lookupbyuid(zone, uid, &ksid) != 0)
return (set_errno(EINVAL));
ksp = &ksid;
} else {
ksp = NULL;
}
/*
* Need to pre-allocate the new cred structure before grabbing
* the p_crlock mutex.
*/
newcr = cralloc_ksid();
p = ttoproc(curthread);
mutex_enter(&p->p_crlock);
retry:
crhold(cr = p->p_cred);
mutex_exit(&p->p_crlock);
if (uid == cr->cr_ruid || uid == cr->cr_uid || uid == cr->cr_suid ||
(error = secpolicy_allow_setid(cr, uid, B_FALSE)) == 0) {
/*
* A privileged process that makes itself look like a
* set-uid process must be marked to produce no core dump,
* if the effective uid did changed.
*/
mutex_enter(&p->p_crlock);
crfree(cr);
if (cr != p->p_cred)
goto retry;
if (cr->cr_uid != uid && error == 0)
do_nocd = 1;
error = 0;
crcopy_to(cr, newcr);
p->p_cred = newcr;
newcr->cr_uid = uid;
crsetsid(newcr, ksp, KSID_USER);
priv_reset_PA(newcr, B_FALSE);
mutex_exit(&p->p_crlock);
if (do_nocd) {
mutex_enter(&p->p_lock);
p->p_flag |= SNOCD;
mutex_exit(&p->p_lock);
}
crset(p, newcr); /* broadcast to process threads */
return (0);
}
crfree(newcr);
crfree(cr);
if (ksp != NULL)
ksid_rele(ksp);
return (set_errno(error));
}
