freebsd-dev/sys/security/audit/audit_syscalls.c
Christian S.J. Peron 5ac14ef177 Partially roll back a revision which changed the error code being returned
by getaudit(2).  Some applications such has su, id will interpret E2BIG as
requiring the use of getaudit_addr(2) to pull extended audit state (ip6)
from the kernel.

This change un-breaks the ABI when auditing has been activated on a system
and the users are logged in via ip6.

This is a RELENG_7_1 candidate.

MFC after:	1 day
Discussed with:	rwatson
2008-11-30 19:58:03 +00:00

760 lines
17 KiB
C

/*-
* Copyright (c) 1999-2005 Apple 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.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 APPLE OR ITS CONTRIBUTORS 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>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/jail.h>
#include <bsm/audit.h>
#include <bsm/audit_kevents.h>
#include <security/audit/audit.h>
#include <security/audit/audit_private.h>
#include <security/mac/mac_framework.h>
#ifdef AUDIT
/*
* System call to allow a user space application to submit a BSM audit record
* to the kernel for inclusion in the audit log. This function does little
* verification on the audit record that is submitted.
*
* XXXAUDIT: Audit preselection for user records does not currently work,
* since we pre-select only based on the AUE_audit event type, not the event
* type submitted as part of the user audit data.
*/
/* ARGSUSED */
int
audit(struct thread *td, struct audit_args *uap)
{
int error;
void * rec;
struct kaudit_record *ar;
if (jailed(td->td_ucred))
return (ENOSYS);
error = priv_check(td, PRIV_AUDIT_SUBMIT);
if (error)
return (error);
if ((uap->length <= 0) || (uap->length > audit_qctrl.aq_bufsz))
return (EINVAL);
ar = currecord();
/*
* If there's no current audit record (audit() itself not audited)
* commit the user audit record.
*/
if (ar == NULL) {
/*
* This is not very efficient; we're required to allocate a
* complete kernel audit record just so the user record can
* tag along.
*
* XXXAUDIT: Maybe AUE_AUDIT in the system call context and
* special pre-select handling?
*/
td->td_ar = audit_new(AUE_NULL, td);
if (td->td_ar == NULL)
return (ENOTSUP);
ar = td->td_ar;
}
if (uap->length > MAX_AUDIT_RECORD_SIZE)
return (EINVAL);
rec = malloc(uap->length, M_AUDITDATA, M_WAITOK);
error = copyin(uap->record, rec, uap->length);
if (error)
goto free_out;
/* Verify the record. */
if (bsm_rec_verify(rec) == 0) {
error = EINVAL;
goto free_out;
}
#ifdef MAC
error = mac_system_check_audit(td->td_ucred, rec, uap->length);
if (error)
goto free_out;
#endif
/*
* Attach the user audit record to the kernel audit record. Because
* this system call is an auditable event, we will write the user
* record along with the record for this audit event.
*
* XXXAUDIT: KASSERT appropriate starting values of k_udata, k_ulen,
* k_ar_commit & AR_COMMIT_USER?
*/
ar->k_udata = rec;
ar->k_ulen = uap->length;
ar->k_ar_commit |= AR_COMMIT_USER;
/*
* Currently we assume that all preselection has been performed in
* userspace. We unconditionally set these masks so that the records
* get committed both to the trail and pipe. In the future we will
* want to setup kernel based preselection.
*/
ar->k_ar_commit |= (AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE);
return (0);
free_out:
/*
* audit_syscall_exit() will free the audit record on the thread even
* if we allocated it above.
*/
free(rec, M_AUDITDATA);
return (error);
}
/*
* System call to manipulate auditing.
*/
/* ARGSUSED */
int
auditon(struct thread *td, struct auditon_args *uap)
{
struct ucred *cred, *newcred, *oldcred;
int error;
union auditon_udata udata;
struct proc *tp;
if (jailed(td->td_ucred))
return (ENOSYS);
AUDIT_ARG(cmd, uap->cmd);
#ifdef MAC
error = mac_system_check_auditon(td->td_ucred, uap->cmd);
if (error)
return (error);
#endif
error = priv_check(td, PRIV_AUDIT_CONTROL);
if (error)
return (error);
if ((uap->length <= 0) || (uap->length > sizeof(union auditon_udata)))
return (EINVAL);
memset((void *)&udata, 0, sizeof(udata));
/*
* Some of the GET commands use the arguments too.
*/
switch (uap->cmd) {
case A_SETPOLICY:
case A_SETKMASK:
case A_SETQCTRL:
case A_SETSTAT:
case A_SETUMASK:
case A_SETSMASK:
case A_SETCOND:
case A_SETCLASS:
case A_SETPMASK:
case A_SETFSIZE:
case A_SETKAUDIT:
case A_GETCLASS:
case A_GETPINFO:
case A_GETPINFO_ADDR:
case A_SENDTRIGGER:
error = copyin(uap->data, (void *)&udata, uap->length);
if (error)
return (error);
AUDIT_ARG(auditon, &udata);
break;
}
/*
* XXXAUDIT: Locking?
*/
switch (uap->cmd) {
case A_GETPOLICY:
if (!audit_fail_stop)
udata.au_policy |= AUDIT_CNT;
if (audit_panic_on_write_fail)
udata.au_policy |= AUDIT_AHLT;
if (audit_argv)
udata.au_policy |= AUDIT_ARGV;
if (audit_arge)
udata.au_policy |= AUDIT_ARGE;
break;
case A_SETPOLICY:
if (udata.au_policy & ~(AUDIT_CNT|AUDIT_AHLT|AUDIT_ARGV|
AUDIT_ARGE))
return (EINVAL);
/*
* XXX - Need to wake up waiters if the policy relaxes?
*/
audit_fail_stop = ((udata.au_policy & AUDIT_CNT) == 0);
audit_panic_on_write_fail = (udata.au_policy & AUDIT_AHLT);
audit_argv = (udata.au_policy & AUDIT_ARGV);
audit_arge = (udata.au_policy & AUDIT_ARGE);
break;
case A_GETKMASK:
udata.au_mask = audit_nae_mask;
break;
case A_SETKMASK:
audit_nae_mask = udata.au_mask;
break;
case A_GETQCTRL:
udata.au_qctrl = audit_qctrl;
break;
case A_SETQCTRL:
if ((udata.au_qctrl.aq_hiwater > AQ_MAXHIGH) ||
(udata.au_qctrl.aq_lowater >= udata.au_qctrl.aq_hiwater) ||
(udata.au_qctrl.aq_bufsz > AQ_MAXBUFSZ) ||
(udata.au_qctrl.aq_minfree < 0) ||
(udata.au_qctrl.aq_minfree > 100))
return (EINVAL);
audit_qctrl = udata.au_qctrl;
/* XXX The queue delay value isn't used with the kernel. */
audit_qctrl.aq_delay = -1;
break;
case A_GETCWD:
return (ENOSYS);
break;
case A_GETCAR:
return (ENOSYS);
break;
case A_GETSTAT:
return (ENOSYS);
break;
case A_SETSTAT:
return (ENOSYS);
break;
case A_SETUMASK:
return (ENOSYS);
break;
case A_SETSMASK:
return (ENOSYS);
break;
case A_GETCOND:
if (audit_enabled && !audit_suspended)
udata.au_cond = AUC_AUDITING;
else
udata.au_cond = AUC_NOAUDIT;
break;
case A_SETCOND:
if (udata.au_cond == AUC_NOAUDIT)
audit_suspended = 1;
if (udata.au_cond == AUC_AUDITING)
audit_suspended = 0;
if (udata.au_cond == AUC_DISABLED) {
audit_suspended = 1;
audit_shutdown(NULL, 0);
}
break;
case A_GETCLASS:
udata.au_evclass.ec_class = au_event_class(
udata.au_evclass.ec_number);
break;
case A_SETCLASS:
au_evclassmap_insert(udata.au_evclass.ec_number,
udata.au_evclass.ec_class);
break;
case A_GETPINFO:
if (udata.au_aupinfo.ap_pid < 1)
return (ESRCH);
if ((tp = pfind(udata.au_aupinfo.ap_pid)) == NULL)
return (ESRCH);
if ((error = p_cansee(td, tp)) != 0) {
PROC_UNLOCK(tp);
return (error);
}
cred = tp->p_ucred;
if (cred->cr_audit.ai_termid.at_type == AU_IPv6) {
PROC_UNLOCK(tp);
return (EINVAL);
}
udata.au_aupinfo.ap_auid = cred->cr_audit.ai_auid;
udata.au_aupinfo.ap_mask.am_success =
cred->cr_audit.ai_mask.am_success;
udata.au_aupinfo.ap_mask.am_failure =
cred->cr_audit.ai_mask.am_failure;
udata.au_aupinfo.ap_termid.machine =
cred->cr_audit.ai_termid.at_addr[0];
udata.au_aupinfo.ap_termid.port =
(dev_t)cred->cr_audit.ai_termid.at_port;
udata.au_aupinfo.ap_asid = cred->cr_audit.ai_asid;
PROC_UNLOCK(tp);
break;
case A_SETPMASK:
if (udata.au_aupinfo.ap_pid < 1)
return (ESRCH);
newcred = crget();
if ((tp = pfind(udata.au_aupinfo.ap_pid)) == NULL) {
crfree(newcred);
return (ESRCH);
}
if ((error = p_cansee(td, tp)) != 0) {
PROC_UNLOCK(tp);
crfree(newcred);
return (error);
}
oldcred = tp->p_ucred;
crcopy(newcred, oldcred);
newcred->cr_audit.ai_mask.am_success =
udata.au_aupinfo.ap_mask.am_success;
newcred->cr_audit.ai_mask.am_failure =
udata.au_aupinfo.ap_mask.am_failure;
td->td_proc->p_ucred = newcred;
PROC_UNLOCK(tp);
crfree(oldcred);
break;
case A_SETFSIZE:
if ((udata.au_fstat.af_filesz != 0) &&
(udata.au_fstat.af_filesz < MIN_AUDIT_FILE_SIZE))
return (EINVAL);
audit_fstat.af_filesz = udata.au_fstat.af_filesz;
break;
case A_GETFSIZE:
udata.au_fstat.af_filesz = audit_fstat.af_filesz;
udata.au_fstat.af_currsz = audit_fstat.af_currsz;
break;
case A_GETPINFO_ADDR:
if (udata.au_aupinfo_addr.ap_pid < 1)
return (ESRCH);
if ((tp = pfind(udata.au_aupinfo_addr.ap_pid)) == NULL)
return (ESRCH);
cred = tp->p_ucred;
udata.au_aupinfo_addr.ap_auid = cred->cr_audit.ai_auid;
udata.au_aupinfo_addr.ap_mask.am_success =
cred->cr_audit.ai_mask.am_success;
udata.au_aupinfo_addr.ap_mask.am_failure =
cred->cr_audit.ai_mask.am_failure;
udata.au_aupinfo_addr.ap_termid = cred->cr_audit.ai_termid;
udata.au_aupinfo_addr.ap_asid = cred->cr_audit.ai_asid;
PROC_UNLOCK(tp);
break;
case A_GETKAUDIT:
audit_get_kinfo(&udata.au_kau_info);
break;
case A_SETKAUDIT:
if (udata.au_kau_info.ai_termid.at_type != AU_IPv4 &&
udata.au_kau_info.ai_termid.at_type != AU_IPv6)
return (EINVAL);
audit_set_kinfo(&udata.au_kau_info);
break;
case A_SENDTRIGGER:
if ((udata.au_trigger < AUDIT_TRIGGER_MIN) ||
(udata.au_trigger > AUDIT_TRIGGER_MAX))
return (EINVAL);
return (audit_send_trigger(udata.au_trigger));
default:
return (EINVAL);
}
/*
* Copy data back to userspace for the GET comands.
*/
switch (uap->cmd) {
case A_GETPOLICY:
case A_GETKMASK:
case A_GETQCTRL:
case A_GETCWD:
case A_GETCAR:
case A_GETSTAT:
case A_GETCOND:
case A_GETCLASS:
case A_GETPINFO:
case A_GETFSIZE:
case A_GETPINFO_ADDR:
case A_GETKAUDIT:
error = copyout((void *)&udata, uap->data, uap->length);
if (error)
return (error);
break;
}
return (0);
}
/*
* System calls to manage the user audit information.
*/
/* ARGSUSED */
int
getauid(struct thread *td, struct getauid_args *uap)
{
int error;
if (jailed(td->td_ucred))
return (ENOSYS);
error = priv_check(td, PRIV_AUDIT_GETAUDIT);
if (error)
return (error);
return (copyout(&td->td_ucred->cr_audit.ai_auid, uap->auid,
sizeof(td->td_ucred->cr_audit.ai_auid)));
}
/* ARGSUSED */
int
setauid(struct thread *td, struct setauid_args *uap)
{
struct ucred *newcred, *oldcred;
au_id_t id;
int error;
if (jailed(td->td_ucred))
return (ENOSYS);
error = copyin(uap->auid, &id, sizeof(id));
if (error)
return (error);
audit_arg_auid(id);
newcred = crget();
PROC_LOCK(td->td_proc);
oldcred = td->td_proc->p_ucred;
crcopy(newcred, oldcred);
#ifdef MAC
error = mac_proc_check_setauid(oldcred, id);
if (error)
goto fail;
#endif
error = priv_check_cred(oldcred, PRIV_AUDIT_SETAUDIT, 0);
if (error)
goto fail;
newcred->cr_audit.ai_auid = id;
td->td_proc->p_ucred = newcred;
PROC_UNLOCK(td->td_proc);
crfree(oldcred);
return (0);
fail:
PROC_UNLOCK(td->td_proc);
crfree(newcred);
return (error);
}
/*
* System calls to get and set process audit information.
*/
/* ARGSUSED */
int
getaudit(struct thread *td, struct getaudit_args *uap)
{
struct auditinfo ai;
struct ucred *cred;
int error;
cred = td->td_ucred;
if (jailed(cred))
return (ENOSYS);
error = priv_check(td, PRIV_AUDIT_GETAUDIT);
if (error)
return (error);
if (cred->cr_audit.ai_termid.at_type == AU_IPv6)
return (E2BIG);
bzero(&ai, sizeof(ai));
ai.ai_auid = cred->cr_audit.ai_auid;
ai.ai_mask = cred->cr_audit.ai_mask;
ai.ai_asid = cred->cr_audit.ai_asid;
ai.ai_termid.machine = cred->cr_audit.ai_termid.at_addr[0];
ai.ai_termid.port = cred->cr_audit.ai_termid.at_port;
return (copyout(&ai, uap->auditinfo, sizeof(ai)));
}
/* ARGSUSED */
int
setaudit(struct thread *td, struct setaudit_args *uap)
{
struct ucred *newcred, *oldcred;
struct auditinfo ai;
int error;
if (jailed(td->td_ucred))
return (ENOSYS);
error = copyin(uap->auditinfo, &ai, sizeof(ai));
if (error)
return (error);
audit_arg_auditinfo(&ai);
newcred = crget();
PROC_LOCK(td->td_proc);
oldcred = td->td_proc->p_ucred;
crcopy(newcred, oldcred);
#ifdef MAC
error = mac_proc_check_setaudit(oldcred, &ai);
if (error)
goto fail;
#endif
error = priv_check_cred(oldcred, PRIV_AUDIT_SETAUDIT, 0);
if (error)
goto fail;
bzero(&newcred->cr_audit, sizeof(newcred->cr_audit));
newcred->cr_audit.ai_auid = ai.ai_auid;
newcred->cr_audit.ai_mask = ai.ai_mask;
newcred->cr_audit.ai_asid = ai.ai_asid;
newcred->cr_audit.ai_termid.at_addr[0] = ai.ai_termid.machine;
newcred->cr_audit.ai_termid.at_port = ai.ai_termid.port;
newcred->cr_audit.ai_termid.at_type = AU_IPv4;
td->td_proc->p_ucred = newcred;
PROC_UNLOCK(td->td_proc);
crfree(oldcred);
return (0);
fail:
PROC_UNLOCK(td->td_proc);
crfree(newcred);
return (error);
}
/* ARGSUSED */
int
getaudit_addr(struct thread *td, struct getaudit_addr_args *uap)
{
int error;
if (jailed(td->td_ucred))
return (ENOSYS);
if (uap->length < sizeof(*uap->auditinfo_addr))
return (EOVERFLOW);
error = priv_check(td, PRIV_AUDIT_GETAUDIT);
if (error)
return (error);
return (copyout(&td->td_ucred->cr_audit, uap->auditinfo_addr,
sizeof(*uap->auditinfo_addr)));
}
/* ARGSUSED */
int
setaudit_addr(struct thread *td, struct setaudit_addr_args *uap)
{
struct ucred *newcred, *oldcred;
struct auditinfo_addr aia;
int error;
if (jailed(td->td_ucred))
return (ENOSYS);
error = copyin(uap->auditinfo_addr, &aia, sizeof(aia));
if (error)
return (error);
audit_arg_auditinfo_addr(&aia);
if (aia.ai_termid.at_type != AU_IPv6 &&
aia.ai_termid.at_type != AU_IPv4)
return (EINVAL);
newcred = crget();
PROC_LOCK(td->td_proc);
oldcred = td->td_proc->p_ucred;
crcopy(newcred, oldcred);
#ifdef MAC
error = mac_proc_check_setaudit_addr(oldcred, &aia);
if (error)
goto fail;
#endif
error = priv_check_cred(oldcred, PRIV_AUDIT_SETAUDIT, 0);
if (error)
goto fail;
newcred->cr_audit = aia;
td->td_proc->p_ucred = newcred;
PROC_UNLOCK(td->td_proc);
crfree(oldcred);
return (0);
fail:
PROC_UNLOCK(td->td_proc);
crfree(newcred);
return (error);
}
/*
* Syscall to manage audit files.
*/
/* ARGSUSED */
int
auditctl(struct thread *td, struct auditctl_args *uap)
{
struct nameidata nd;
struct ucred *cred;
struct vnode *vp;
int error = 0;
int flags, vfslocked;
if (jailed(td->td_ucred))
return (ENOSYS);
error = priv_check(td, PRIV_AUDIT_CONTROL);
if (error)
return (error);
vp = NULL;
cred = NULL;
/*
* If a path is specified, open the replacement vnode, perform
* validity checks, and grab another reference to the current
* credential.
*
* On Darwin, a NULL path argument is also used to disable audit.
*/
if (uap->path == NULL)
return (EINVAL);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | MPSAFE | AUDITVNODE1,
UIO_USERSPACE, uap->path, td);
flags = AUDIT_OPEN_FLAGS;
error = vn_open(&nd, &flags, 0, NULL);
if (error)
return (error);
vfslocked = NDHASGIANT(&nd);
vp = nd.ni_vp;
#ifdef MAC
error = mac_system_check_auditctl(td->td_ucred, vp);
VOP_UNLOCK(vp, 0);
if (error) {
vn_close(vp, AUDIT_CLOSE_FLAGS, td->td_ucred, td);
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
#else
VOP_UNLOCK(vp, 0);
#endif
NDFREE(&nd, NDF_ONLY_PNBUF);
if (vp->v_type != VREG) {
vn_close(vp, AUDIT_CLOSE_FLAGS, td->td_ucred, td);
VFS_UNLOCK_GIANT(vfslocked);
return (EINVAL);
}
VFS_UNLOCK_GIANT(vfslocked);
cred = td->td_ucred;
crhold(cred);
/*
* XXXAUDIT: Should audit_suspended actually be cleared by
* audit_worker?
*/
audit_suspended = 0;
audit_rotate_vnode(cred, vp);
return (error);
}
#else /* !AUDIT */
int
audit(struct thread *td, struct audit_args *uap)
{
return (ENOSYS);
}
int
auditon(struct thread *td, struct auditon_args *uap)
{
return (ENOSYS);
}
int
getauid(struct thread *td, struct getauid_args *uap)
{
return (ENOSYS);
}
int
setauid(struct thread *td, struct setauid_args *uap)
{
return (ENOSYS);
}
int
getaudit(struct thread *td, struct getaudit_args *uap)
{
return (ENOSYS);
}
int
setaudit(struct thread *td, struct setaudit_args *uap)
{
return (ENOSYS);
}
int
getaudit_addr(struct thread *td, struct getaudit_addr_args *uap)
{
return (ENOSYS);
}
int
setaudit_addr(struct thread *td, struct setaudit_addr_args *uap)
{
return (ENOSYS);
}
int
auditctl(struct thread *td, struct auditctl_args *uap)
{
return (ENOSYS);
}
#endif /* AUDIT */