]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/kern_prot.c
xnu-6153.81.5.tar.gz
[apple/xnu.git] / bsd / kern / kern_prot.c
index d2408a2f3e3005e8df9c0dfcbc3d5c474e551da9..4a4a662edb986f6f89313bb6ebefcdeadc5620ca 100644 (file)
@@ -2,7 +2,7 @@
  * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  *
  *
  * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
- * 
+ *
  *
  * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
  *     The Regents of the University of California.  All rights reserved.
@@ -66,7 +66,7 @@
  * SUCH DAMAGE.
  *
  *     @(#)kern_prot.c 8.9 (Berkeley) 2/14/95
- * 
+ *
  *
  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  * support for mandatory and extensible security protections.  This notice
 #include <sys/timeb.h>
 #include <sys/times.h>
 #include <sys/malloc.h>
+#include <sys/persona.h>
 
 #include <security/audit/audit.h>
 
-#if CONFIG_LCTX
-#include <sys/lctx.h>
-#endif
-
 #if CONFIG_MACF
 #include <security/mac_framework.h>
-#if CONFIG_MACF_MACH
-#include <secuity/mac_mach_internal.h>
-#endif
 #endif
 
 #include <sys/mount_internal.h>
 #include <mach/host_security.h>
 
 #include <kern/host.h>
-#include <kern/task.h>         /* for current_task() */
+#include <kern/task.h>          /* for current_task() */
 #include <kern/assert.h>
 
 
  *             can be used if needed when debugging is active.
  */
 #if DEBUG_CRED
-#define        DEBUG_CRED_ENTER                printf
-#define        DEBUG_CRED_CHANGE               printf
+#define DEBUG_CRED_ENTER                printf
+#define DEBUG_CRED_CHANGE               printf
 extern void kauth_cred_print(kauth_cred_t cred);
-#else  /* !DEBUG_CRED */
-#define        DEBUG_CRED_ENTER(fmt, ...)      do {} while (0)
-#define        DEBUG_CRED_CHANGE(fmt, ...)     do {} while (0)
-#endif /* !DEBUG_CRED */
+#else   /* !DEBUG_CRED */
+#define DEBUG_CRED_ENTER(fmt, ...)      do {} while (0)
+#define DEBUG_CRED_CHANGE(fmt, ...)     do {} while (0)
+#endif  /* !DEBUG_CRED */
 
+#if DEVELOPMENT || DEBUG
+extern void task_importance_update_owner_info(task_t);
+#endif
 
 
 /*
@@ -158,7 +155,7 @@ setprivexec(proc_t p, struct setprivexec_args *uap, int32_t *retval)
        AUDIT_ARG(value32, uap->flag);
        *retval = p->p_debugger;
        p->p_debugger = (uap->flag != 0);
-       return(0);
+       return 0;
 }
 
 
@@ -176,9 +173,8 @@ setprivexec(proc_t p, struct setprivexec_args *uap, int32_t *retval)
 int
 getpid(proc_t p, __unused struct getpid_args *uap, int32_t *retval)
 {
-
        *retval = p->p_pid;
-       return (0);
+       return 0;
 }
 
 
@@ -196,9 +192,8 @@ getpid(proc_t p, __unused struct getpid_args *uap, int32_t *retval)
 int
 getppid(proc_t p, __unused struct getppid_args *uap, int32_t *retval)
 {
-
        *retval = p->p_ppid;
-       return (0);
+       return 0;
 }
 
 
@@ -216,9 +211,8 @@ getppid(proc_t p, __unused struct getppid_args *uap, int32_t *retval)
 int
 getpgrp(proc_t p, __unused struct getpgrp_args *uap, int32_t *retval)
 {
-
        *retval = p->p_pgrpid;
-       return (0);
+       return 0;
 }
 
 
@@ -245,17 +239,20 @@ getpgid(proc_t p, struct getpgid_args *uap, int32_t *retval)
        int refheld = 0;
 
        pt = p;
-       if (uap->pid == 0)
+       if (uap->pid == 0) {
                goto found;
+       }
 
-       if ((pt = proc_find(uap->pid)) == 0)
-               return (ESRCH);
+       if ((pt = proc_find(uap->pid)) == 0) {
+               return ESRCH;
+       }
        refheld = 1;
 found:
        *retval = pt->p_pgrpid;
-       if (refheld != 0)
+       if (refheld != 0) {
                proc_rele(pt);
-       return (0);
+       }
+       return 0;
 }
 
 
@@ -283,20 +280,23 @@ getsid(proc_t p, struct getsid_args *uap, int32_t *retval)
        struct session * sessp;
 
        pt = p;
-       if (uap->pid == 0)
+       if (uap->pid == 0) {
                goto found;
+       }
 
-       if ((pt = proc_find(uap->pid)) == 0)
-               return (ESRCH);
+       if ((pt = proc_find(uap->pid)) == 0) {
+               return ESRCH;
+       }
        refheld = 1;
 found:
        sessp = proc_session(pt);
        *retval = sessp->s_sid;
        session_rele(sessp);
 
-       if (refheld != 0)
+       if (refheld != 0) {
                proc_rele(pt);
-       return (0);
+       }
+       return 0;
 }
 
 
@@ -312,9 +312,8 @@ found:
 int
 getuid(__unused proc_t p, __unused struct getuid_args *uap, int32_t *retval)
 {
-
-       *retval = kauth_getruid();
-       return (0);
+       *retval = kauth_getruid();
+       return 0;
 }
 
 
@@ -330,9 +329,8 @@ getuid(__unused proc_t p, __unused struct getuid_args *uap, int32_t *retval)
 int
 geteuid(__unused proc_t p, __unused struct geteuid_args *uap, int32_t *retval)
 {
-
-       *retval = kauth_getuid();
-       return (0);
+       *retval = kauth_getuid();
+       return 0;
 }
 
 
@@ -351,22 +349,25 @@ int
 gettid(__unused proc_t p, struct gettid_args *uap, int32_t *retval)
 {
        struct uthread *uthread = get_bsdthread_info(current_thread());
-       int     error;
+       int     error;
 
        /*
         * If this thread is not running with an override identity, we can't
         * return one to the caller, so return an error instead.
         */
-       if (!(uthread->uu_flag & UT_SETUID))
-               return (ESRCH);
+       if (!(uthread->uu_flag & UT_SETUID)) {
+               return ESRCH;
+       }
 
-       if ((error = suword(uap->uidp, kauth_cred_getruid(uthread->uu_ucred))))
-               return (error);
-       if ((error = suword(uap->gidp, kauth_cred_getrgid(uthread->uu_ucred))))
-               return (error);
+       if ((error = suword(uap->uidp, kauth_cred_getruid(uthread->uu_ucred)))) {
+               return error;
+       }
+       if ((error = suword(uap->gidp, kauth_cred_getrgid(uthread->uu_ucred)))) {
+               return error;
+       }
 
        *retval = 0;
-       return (0);
+       return 0;
 }
 
 
@@ -382,9 +383,8 @@ gettid(__unused proc_t p, struct gettid_args *uap, int32_t *retval)
 int
 getgid(__unused proc_t p, __unused struct getgid_args *uap, int32_t *retval)
 {
-
        *retval = kauth_getrgid();
-       return (0);
+       return 0;
 }
 
 
@@ -406,9 +406,8 @@ getgid(__unused proc_t p, __unused struct getgid_args *uap, int32_t *retval)
 int
 getegid(__unused proc_t p, __unused struct getegid_args *uap, int32_t *retval)
 {
-
        *retval = kauth_getgid();
-       return (0);
+       return 0;
 }
 
 
@@ -457,22 +456,22 @@ getgroups(__unused proc_t p, struct getgroups_args *uap, int32_t *retval)
        if ((ngrp = uap->gidsetsize) == 0) {
                *retval = pcred->cr_ngroups;
                kauth_cred_unref(&cred);
-               return (0);
+               return 0;
        }
        if (ngrp < pcred->cr_ngroups) {
                kauth_cred_unref(&cred);
-               return (EINVAL);
+               return EINVAL;
        }
        ngrp = pcred->cr_ngroups;
        if ((error = copyout((caddr_t)pcred->cr_groups,
-                                       uap->gidset, 
-                                       ngrp * sizeof(gid_t)))) {
+           uap->gidset,
+           ngrp * sizeof(gid_t)))) {
                kauth_cred_unref(&cred);
-               return (error);
+               return error;
        }
        kauth_cred_unref(&cred);
        *retval = ngrp;
-       return (0);
+       return 0;
 }
 
 
@@ -486,12 +485,12 @@ getgroups(__unused proc_t p, struct getgroups_args *uap, int32_t *retval)
 int
 getsgroups(__unused proc_t p, __unused struct getsgroups_args *uap, __unused int32_t *retval)
 {
-       return(ENOTSUP);
+       return ENOTSUP;
 }
 
 /*
  * Return the per-thread/per-process whiteout groups list.
- * 
+ *
  * XXX implement getwgroups
  *
  */
@@ -499,9 +498,30 @@ getsgroups(__unused proc_t p, __unused struct getsgroups_args *uap, __unused int
 int
 getwgroups(__unused proc_t p, __unused struct getwgroups_args *uap, __unused int32_t *retval)
 {
-       return(ENOTSUP);
+       return ENOTSUP;
 }
 
+/*
+ * setsid_internal
+ *
+ * Description:        Core implementation of setsid().
+ */
+int
+setsid_internal(proc_t p)
+{
+       struct pgrp * pg = PGRP_NULL;
+
+       if (p->p_pgrpid == p->p_pid || (pg = pgfind(p->p_pid)) || p->p_lflag & P_LINVFORK) {
+               if (pg != PGRP_NULL) {
+                       pg_rele(pg);
+               }
+               return EPERM;
+       } else {
+               /* enter pgrp works with its own pgrp refcount */
+               (void)enterpgrp(p, p->p_pid, 1);
+               return 0;
+       }
+}
 
 /*
  * setsid
@@ -530,18 +550,11 @@ getwgroups(__unused proc_t p, __unused struct getwgroups_args *uap, __unused int
 int
 setsid(proc_t p, __unused struct setsid_args *uap, int32_t *retval)
 {
-       struct pgrp * pg = PGRP_NULL;
-
-       if (p->p_pgrpid == p->p_pid || (pg = pgfind(p->p_pid)) || p->p_lflag & P_LINVFORK) {
-               if (pg != PGRP_NULL)
-                       pg_rele(pg);
-               return (EPERM);
-       } else {
-               /* enter pgrp works with its own pgrp refcount */
-               (void)enterpgrp(p, p->p_pid, 1);
+       int rc = setsid_internal(p);
+       if (rc == 0) {
                *retval = p->p_pid;
-               return (0);
        }
+       return rc;
 }
 
 
@@ -578,15 +591,15 @@ setsid(proc_t p, __unused struct setsid_args *uap, int32_t *retval)
  *             is used as the target process group ID.
  *
  * Legacy:     This system call entry point is also used to implement the
- *             legacy library routine setpgrp(), which under POSIX 
+ *             legacy library routine setpgrp(), which under POSIX
  *
  * XXX:                Belongs in kern_proc.c
  */
 int
-setpgid(proc_t curp, register struct setpgid_args *uap, __unused int32_t *retval)
+setpgid(proc_t curp, struct setpgid_args *uap, __unused int32_t *retval)
 {
-       proc_t targp = PROC_NULL;       /* target process */
-       struct pgrp *pg = PGRP_NULL;    /* target pgrp */
+       proc_t targp = PROC_NULL;       /* target process */
+       struct pgrp *pg = PGRP_NULL;    /* target pgrp */
        int error = 0;
        int refheld = 0;
        int samesess = 0;
@@ -597,8 +610,9 @@ setpgid(proc_t curp, register struct setpgid_args *uap, __unused int32_t *retval
 
        if (uap->pid != 0 && uap->pid != curp->p_pid) {
                if ((targp = proc_find(uap->pid)) == 0 || !inferior(targp)) {
-                       if (targp != PROC_NULL)
+                       if (targp != PROC_NULL) {
                                refheld = 1;
+                       }
                        error = ESRCH;
                        goto out;
                }
@@ -630,14 +644,14 @@ setpgid(proc_t curp, register struct setpgid_args *uap, __unused int32_t *retval
                error = EINVAL;
                goto out;
        }
-       if (uap->pgid == 0)
+       if (uap->pgid == 0) {
                uap->pgid = targp->p_pid;
-       else if (uap->pgid != targp->p_pid) {
-               if ((pg = pgfind(uap->pgid)) == 0){
+       else if (uap->pgid != targp->p_pid) {
+               if ((pg = pgfind(uap->pgid)) == 0) {
                        error = EPERM;
                        goto out;
                }
-               samesess = (pg->pg_session != curp_sessp); 
+               samesess = (pg->pg_session != curp_sessp);
                pg_rele(pg);
                if (samesess != 0) {
                        error = EPERM;
@@ -646,13 +660,16 @@ setpgid(proc_t curp, register struct setpgid_args *uap, __unused int32_t *retval
        }
        error = enterpgrp(targp, uap->pgid, 0);
 out:
-       if (targp_sessp != SESSION_NULL)
+       if (targp_sessp != SESSION_NULL) {
                session_rele(targp_sessp);
-       if (curp_sessp != SESSION_NULL)
+       }
+       if (curp_sessp != SESSION_NULL) {
                session_rele(curp_sessp);
-       if (refheld != 0)
+       }
+       if (refheld != 0) {
                proc_rele(targp);
-       return(error);
+       }
+       return error;
 }
 
 
@@ -672,6 +689,12 @@ out:
  *             real, effective, or saved user or group IDs since beginning
  *             execution.
  */
+int
+proc_issetugid(proc_t p)
+{
+       return (p->p_flag & P_SUGID) ? 1 : 0;
+}
+
 int
 issetugid(proc_t p, __unused struct issetugid_args *uap, int32_t *retval)
 {
@@ -684,8 +707,8 @@ issetugid(proc_t p, __unused struct issetugid_args *uap, int32_t *retval)
         * that libc *might* have put in their data segment.
         */
 
-       *retval = (p->p_flag & P_SUGID) ? 1 : 0;
-       return (0);
+       *retval = proc_issetugid(p);
+       return 0;
 }
 
 
@@ -720,42 +743,34 @@ setuid(proc_t p, struct setuid_args *uap, __unused int32_t *retval)
        kauth_cred_t my_cred, my_new_cred;
        posix_cred_t my_pcred;
 
-
        uid = uap->uid;
 
+       /* get current credential and take a reference while we muck with it */
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
        DEBUG_CRED_ENTER("setuid (%d/%d): %p %d\n", p->p_pid, (p->p_pptr ? p->p_pptr->p_pid : 0), my_cred, uap->uid);
        AUDIT_ARG(uid, uid);
 
-       if (uid != my_pcred->cr_ruid &&         /* allow setuid(getuid()) */
-           uid != my_pcred->cr_svuid &&        /* allow setuid(saved uid) */
-           (error = suser(my_cred, &p->p_acflag))) {
-               kauth_cred_unref(&my_cred);
-               return (error);
-       }
-       /*
-        * Everything's okay, do it.
-        */
+       for (;;) {
+               if (uid != my_pcred->cr_ruid &&         /* allow setuid(getuid()) */
+                   uid != my_pcred->cr_svuid &&        /* allow setuid(saved uid) */
+                   (error = suser(my_cred, &p->p_acflag))) {
+                       kauth_cred_unref(&my_cred);
+                       return error;
+               }
 
-       /*
-        * If we are priviledged, then set the saved and real UID too;
-        * otherwise, just set the effective UID
-        */
-       if (suser(my_cred, &p->p_acflag) == 0) {
-               svuid = uid;
-               ruid = uid;
                /*
-                * Transfer proc count to new user.
-                * chgproccnt uses list lock for protection
+                * If we are privileged, then set the saved and real UID too;
+                * otherwise, just set the effective UID
                 */
-               (void)chgproccnt(uid, 1);
-               (void)chgproccnt(my_pcred->cr_ruid, -1);
-       }
-
-       /* get current credential and take a reference while we muck with it */
-       for (;;) {
+               if (suser(my_cred, &p->p_acflag) == 0) {
+                       svuid = uid;
+                       ruid = uid;
+               } else {
+                       svuid = KAUTH_UID_NONE;
+                       ruid = KAUTH_UID_NONE;
+               }
                /*
                 * Only set the gmuid if the current cred has not opt'ed out;
                 * this normally only happens when calling setgroups() instead
@@ -765,32 +780,54 @@ setuid(proc_t p, struct setuid_args *uap, __unused int32_t *retval)
                 * to something other than the default list for the user, as
                 * in entering a group or leaving an exclusion group).
                 */
-               if (!(my_pcred->cr_flags & CRF_NOMEMBERD))
+               if (!(my_pcred->cr_flags & CRF_NOMEMBERD)) {
                        gmuid = uid;
+               }
 
-               /* 
+               /*
                 * Set the credential with new info.  If there is no change,
                 * we get back the same credential we passed in; if there is
                 * a change, we drop the reference on the credential we
                 * passed in.  The subsequent compare is safe, because it is
                 * a pointer compare rather than a contents compare.
-                */
+                */
                my_new_cred = kauth_cred_setresuid(my_cred, ruid, uid, svuid, gmuid);
                if (my_cred != my_new_cred) {
-
                        DEBUG_CRED_CHANGE("setuid CH(%d): %p/0x%08x -> %p/0x%08x\n", p->p_pid, my_cred, my_pcred->cr_flags, my_new_cred, posix_cred_get(my_new_cred)->cr_flags);
 
-                       proc_lock(p);
+                       /*
+                        * If we're changing the ruid from A to B, we might race with another thread that's setting ruid from B to A.
+                        * The current locking mechanisms don't allow us to make the entire credential switch operation atomic,
+                        * thus we may be able to change the process credentials from ruid A to B, but get preempted before incrementing the proc
+                        * count of B. If a second thread sees the new process credentials and switches back to ruid A, that other thread
+                        * may be able to decrement the proc count of B before we can increment it. This results in a panic.
+                        * Incrementing the proc count of the target ruid, B, before setting the process credentials prevents this race.
+                        */
+                       if (ruid != KAUTH_UID_NONE && !proc_has_persona(p)) {
+                               (void)chgproccnt(ruid, 1);
+                       }
+
+                       proc_ucred_lock(p);
                        /*
                         * We need to protect for a race where another thread
                         * also changed the credential after we took our
                         * reference.  If p_ucred has changed then we should
                         * restart this again with the new cred.
+                        *
+                        * Note: the kauth_cred_setresuid has consumed a reference to my_cred, it p_ucred != my_cred, then my_cred must not be dereferenced!
                         */
                        if (p->p_ucred != my_cred) {
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
+                               /*
+                                * We didn't successfully switch to the new ruid, so decrement
+                                * the procs/uid count that we incremented above.
+                                */
+                               if (ruid != KAUTH_UID_NONE && !proc_has_persona(p)) {
+                                       (void)chgproccnt(ruid, -1);
+                               }
                                kauth_cred_unref(&my_new_cred);
                                my_cred = kauth_cred_proc_ref(p);
+                               my_pcred = posix_cred_get(my_cred);
                                /* try again */
                                continue;
                        }
@@ -799,15 +836,22 @@ setuid(proc_t p, struct setuid_args *uap, __unused int32_t *retval)
                        PROC_UPDATE_CREDS_ONPROC(p);
 
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
-                       proc_unlock(p);
+                       proc_ucred_unlock(p);
+                       /*
+                        * If we've updated the ruid, decrement the count of procs running
+                        * under the previous ruid
+                        */
+                       if (ruid != KAUTH_UID_NONE && !proc_has_persona(p)) {
+                               (void)chgproccnt(my_pcred->cr_ruid, -1);
+                       }
                }
                break;
        }
        /* Drop old proc reference or our extra reference */
        kauth_cred_unref(&my_cred);
-       
+
        set_security_token(p);
-       return (0);
+       return 0;
 }
 
 
@@ -845,32 +889,26 @@ seteuid(proc_t p, struct seteuid_args *uap, __unused int32_t *retval)
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
-       if (euid != my_pcred->cr_ruid && euid != my_pcred->cr_svuid &&
-           (error = suser(my_cred, &p->p_acflag))) {
-               kauth_cred_unref(&my_cred);
-               return (error);
-       }
-
-       /*
-        * Everything's okay, do it.  Copy credentials so other references do
-        * not see our changes.  get current credential and take a reference 
-        * while we muck with it
-        */
        for (;;) {
-               /* 
+               if (euid != my_pcred->cr_ruid && euid != my_pcred->cr_svuid &&
+                   (error = suser(my_cred, &p->p_acflag))) {
+                       kauth_cred_unref(&my_cred);
+                       return error;
+               }
+
+               /*
                 * Set the credential with new info.  If there is no change,
                 * we get back the same credential we passed in; if there is
                 * a change, we drop the reference on the credential we
                 * passed in.  The subsequent compare is safe, because it is
                 * a pointer compare rather than a contents compare.
-                */
+                */
                my_new_cred = kauth_cred_setresuid(my_cred, KAUTH_UID_NONE, euid, KAUTH_UID_NONE, my_pcred->cr_gmuid);
-       
-               if (my_cred != my_new_cred) {
 
+               if (my_cred != my_new_cred) {
                        DEBUG_CRED_CHANGE("seteuid CH(%d): %p/0x%08x -> %p/0x%08x\n", p->p_pid, my_cred, my_pcred->cr_flags, my_new_cred, posix_cred_get(my_new_cred)->cr_flags);
 
-                       proc_lock(p);
+                       proc_ucred_lock(p);
                        /*
                         * We need to protect for a race where another thread
                         * also changed the credential after we took our
@@ -878,9 +916,10 @@ seteuid(proc_t p, struct seteuid_args *uap, __unused int32_t *retval)
                         * should restart this again with the new cred.
                         */
                        if (p->p_ucred != my_cred) {
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
                                kauth_cred_unref(&my_new_cred);
                                my_cred = kauth_cred_proc_ref(p);
+                               my_pcred = posix_cred_get(my_cred);
                                /* try again */
                                continue;
                        }
@@ -888,7 +927,7 @@ seteuid(proc_t p, struct seteuid_args *uap, __unused int32_t *retval)
                        /* update cred on proc */
                        PROC_UPDATE_CREDS_ONPROC(p);
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
-                       proc_unlock(p);
+                       proc_ucred_unlock(p);
                }
                break;
        }
@@ -896,7 +935,7 @@ seteuid(proc_t p, struct seteuid_args *uap, __unused int32_t *retval)
        kauth_cred_unref(&my_cred);
 
        set_security_token(p);
-       return (0);
+       return 0;
 }
 
 
@@ -943,62 +982,48 @@ setreuid(proc_t p, struct setreuid_args *uap, __unused int32_t *retval)
 
        ruid = uap->ruid;
        euid = uap->euid;
-       if (ruid == (uid_t)-1)
+       if (ruid == (uid_t)-1) {
                ruid = KAUTH_UID_NONE;
-       if (euid == (uid_t)-1)
+       }
+       if (euid == (uid_t)-1) {
                euid = KAUTH_UID_NONE;
+       }
        AUDIT_ARG(euid, euid);
        AUDIT_ARG(ruid, ruid);
 
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
-       if (((ruid != KAUTH_UID_NONE &&         /* allow no change of ruid */
-             ruid != my_pcred->cr_ruid &&      /* allow ruid = ruid */
-             ruid != my_pcred->cr_uid &&       /* allow ruid = euid */
-             ruid != my_pcred->cr_svuid) ||    /* allow ruid = svuid */
-            (euid != KAUTH_UID_NONE &&         /* allow no change of euid */
-             euid != my_pcred->cr_uid &&       /* allow euid = euid */
-             euid != my_pcred->cr_ruid &&      /* allow euid = ruid */
-             euid != my_pcred->cr_svuid)) &&   /* allow euid = svui */
-           (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
-               kauth_cred_unref(&my_cred);
-               return (error);
-       }
-
-       /*
-        * Everything's okay, do it.  Copy credentials so other references do
-        * not see our changes.  get current credential and take a reference 
-        * while we muck with it
-        */
        for (;;) {
+               if (((ruid != KAUTH_UID_NONE &&         /* allow no change of ruid */
+                   ruid != my_pcred->cr_ruid &&        /* allow ruid = ruid */
+                   ruid != my_pcred->cr_uid &&         /* allow ruid = euid */
+                   ruid != my_pcred->cr_svuid) ||      /* allow ruid = svuid */
+                   (euid != KAUTH_UID_NONE &&          /* allow no change of euid */
+                   euid != my_pcred->cr_uid &&         /* allow euid = euid */
+                   euid != my_pcred->cr_ruid &&        /* allow euid = ruid */
+                   euid != my_pcred->cr_svuid)) &&     /* allow euid = svuid */
+                   (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
+                       kauth_cred_unref(&my_cred);
+                       return error;
+               }
+
                uid_t new_euid;
-               uid_t new_ruid;
                uid_t svuid = KAUTH_UID_NONE;
 
                new_euid = my_pcred->cr_uid;
-               new_ruid = my_pcred->cr_ruid;
-       
-               /* 
+               /*
                 * Set the credential with new info.  If there is no change,
                 * we get back the same credential we passed in; if there is
                 * a change, we drop the reference on the credential we
                 * passed in.  The subsequent compare is safe, because it is
                 * a pointer compare rather than a contents compare.
-                */
-               if (euid == KAUTH_UID_NONE && my_pcred->cr_uid != euid) {
+                */
+               if (euid != KAUTH_UID_NONE && my_pcred->cr_uid != euid) {
                        /* changing the effective UID */
                        new_euid = euid;
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
                }
-               if (ruid != KAUTH_UID_NONE && my_pcred->cr_ruid != ruid) {
-                       /* changing the real UID; must do user accounting */
-                       /* chgproccnt uses list lock for protection */
-                       (void)chgproccnt(ruid, 1);
-                       (void)chgproccnt(my_pcred->cr_ruid, -1);
-                       new_ruid = ruid;
-                       OSBitOrAtomic(P_SUGID, &p->p_flag);
-               }
                /*
                 * If the newly requested real uid or effective uid does
                 * not match the saved uid, then set the saved uid to the
@@ -1007,35 +1032,65 @@ setreuid(proc_t p, struct setreuid_args *uap, __unused int32_t *retval)
                 */
                if (my_pcred->cr_svuid != uap->ruid &&
                    my_pcred->cr_svuid != uap->euid) {
-                       svuid = new_euid;
+                       svuid = new_euid;
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
                }
 
                my_new_cred = kauth_cred_setresuid(my_cred, ruid, euid, svuid, my_pcred->cr_gmuid);
-       
-               if (my_cred != my_new_cred) {
 
+               if (my_cred != my_new_cred) {
                        DEBUG_CRED_CHANGE("setreuid CH(%d): %p/0x%08x -> %p/0x%08x\n", p->p_pid, my_cred, my_pcred->cr_flags, my_new_cred, posix_cred_get(my_new_cred)->cr_flags);
 
-                       proc_lock(p);
+                       /*
+                        * If we're changing the ruid from A to B, we might race with another thread that's setting ruid from B to A.
+                        * The current locking mechanisms don't allow us to make the entire credential switch operation atomic,
+                        * thus we may be able to change the process credentials from ruid A to B, but get preempted before incrementing the proc
+                        * count of B. If a second thread sees the new process credentials and switches back to ruid A, that other thread
+                        * may be able to decrement the proc count of B before we can increment it. This results in a panic.
+                        * Incrementing the proc count of the target ruid, B, before setting the process credentials prevents this race.
+                        */
+                       if (ruid != KAUTH_UID_NONE && !proc_has_persona(p)) {
+                               (void)chgproccnt(ruid, 1);
+                       }
+
+                       proc_ucred_lock(p);
                        /*
                         * We need to protect for a race where another thread
                         * also changed the credential after we took our
                         * reference.  If p_ucred has changed then we should
                         * restart this again with the new cred.
+                        *
+                        * Note: the kauth_cred_setresuid has consumed a reference to my_cred, it p_ucred != my_cred, then my_cred must not be dereferenced!
                         */
                        if (p->p_ucred != my_cred) {
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
+                               if (ruid != KAUTH_UID_NONE && !proc_has_persona(p)) {
+                                       /*
+                                        * We didn't successfully switch to the new ruid, so decrement
+                                        * the procs/uid count that we incremented above.
+                                        */
+                                       (void)chgproccnt(ruid, -1);
+                               }
                                kauth_cred_unref(&my_new_cred);
                                my_cred = kauth_cred_proc_ref(p);
+                               my_pcred = posix_cred_get(my_cred);
                                /* try again */
                                continue;
                        }
+
                        p->p_ucred = my_new_cred;
                        /* update cred on proc */
                        PROC_UPDATE_CREDS_ONPROC(p);
-                       OSBitOrAtomic(P_SUGID, &p->p_flag); /* XXX redundant? */
-                       proc_unlock(p);
+                       OSBitOrAtomic(P_SUGID, &p->p_flag);
+                       proc_ucred_unlock(p);
+
+                       if (ruid != KAUTH_UID_NONE && !proc_has_persona(p)) {
+                               /*
+                                * We switched to a new ruid, so decrement the count of procs running
+                                * under the previous ruid
+                                */
+                               (void)chgproccnt(my_pcred->cr_ruid, -1);
+                       }
                }
                break;
        }
@@ -1043,7 +1098,7 @@ setreuid(proc_t p, struct setreuid_args *uap, __unused int32_t *retval)
        kauth_cred_unref(&my_cred);
 
        set_security_token(p);
-       return (0);
+       return 0;
 }
 
 
@@ -1087,41 +1142,42 @@ setgid(proc_t p, struct setgid_args *uap, __unused int32_t *retval)
        gid = uap->gid;
        AUDIT_ARG(gid, gid);
 
+       /* get current credential and take a reference while we muck with it */
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
-       if (gid != my_pcred->cr_rgid &&         /* allow setgid(getgid()) */
-           gid != my_pcred->cr_svgid &&        /* allow setgid(saved gid) */
-           (error = suser(my_cred, &p->p_acflag))) {
-               kauth_cred_unref(&my_cred);
-               return (error);
-       }
+       for (;;) {
+               if (gid != my_pcred->cr_rgid &&         /* allow setgid(getgid()) */
+                   gid != my_pcred->cr_svgid &&        /* allow setgid(saved gid) */
+                   (error = suser(my_cred, &p->p_acflag))) {
+                       kauth_cred_unref(&my_cred);
+                       return error;
+               }
 
-       /*
-        * If we are priviledged, then set the saved and real GID too;
-        * otherwise, just set the effective GID
-        */
-       if (suser(my_cred,  &p->p_acflag) == 0) {
-               svgid = gid;
-               rgid = gid;
-       }
+               /*
+                * If we are privileged, then set the saved and real GID too;
+                * otherwise, just set the effective GID
+                */
+               if (suser(my_cred, &p->p_acflag) == 0) {
+                       svgid = gid;
+                       rgid = gid;
+               } else {
+                       svgid = KAUTH_GID_NONE;
+                       rgid = KAUTH_GID_NONE;
+               }
 
-       /* get current credential and take a reference while we muck with it */
-       for (;;) {
-               
-               /* 
+               /*
                 * Set the credential with new info.  If there is no change,
                 * we get back the same credential we passed in; if there is
                 * a change, we drop the reference on the credential we
                 * passed in.  The subsequent compare is safe, because it is
                 * a pointer compare rather than a contents compare.
-                */
+                */
                my_new_cred = kauth_cred_setresgid(my_cred, rgid, gid, svgid);
                if (my_cred != my_new_cred) {
-
                        DEBUG_CRED_CHANGE("setgid(CH)%d: %p/0x%08x->%p/0x%08x\n", p->p_pid, my_cred, my_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
 
-                       proc_lock(p);
+                       proc_ucred_lock(p);
                        /*
                         * We need to protect for a race where another thread
                         * also changed the credential after we took our
@@ -1129,25 +1185,26 @@ setgid(proc_t p, struct setgid_args *uap, __unused int32_t *retval)
                         * should restart this again with the new cred.
                         */
                        if (p->p_ucred != my_cred) {
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
                                kauth_cred_unref(&my_new_cred);
                                /* try again */
                                my_cred = kauth_cred_proc_ref(p);
+                               my_pcred = posix_cred_get(my_cred);
                                continue;
                        }
                        p->p_ucred = my_new_cred;
                        /* update cred on proc */
                        PROC_UPDATE_CREDS_ONPROC(p);
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
-                       proc_unlock(p);
+                       proc_ucred_unlock(p);
                }
                break;
        }
        /* Drop old proc reference or our extra reference */
        kauth_cred_unref(&my_cred);
-       
+
        set_security_token(p);
-       return (0);
+       return 0;
 }
 
 
@@ -1187,31 +1244,30 @@ setegid(proc_t p, struct setegid_args *uap, __unused int32_t *retval)
        egid = uap->egid;
        AUDIT_ARG(egid, egid);
 
+       /* get current credential and take a reference while we muck with it */
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
-       if (egid != my_pcred->cr_rgid &&
-           egid != my_pcred->cr_svgid &&
-           (error = suser(my_cred, &p->p_acflag))) {
-               kauth_cred_unref(&my_cred);
-               return (error);
-       }
 
-       /* get current credential and take a reference while we muck with it */
        for (;;) {
-               /* 
+               if (egid != my_pcred->cr_rgid &&
+                   egid != my_pcred->cr_svgid &&
+                   (error = suser(my_cred, &p->p_acflag))) {
+                       kauth_cred_unref(&my_cred);
+                       return error;
+               }
+               /*
                 * Set the credential with new info.  If there is no change,
                 * we get back the same credential we passed in; if there is
                 * a change, we drop the reference on the credential we
                 * passed in.  The subsequent compare is safe, because it is
                 * a pointer compare rather than a contents compare.
-                */
+                */
                my_new_cred = kauth_cred_setresgid(my_cred, KAUTH_GID_NONE, egid, KAUTH_GID_NONE);
                if (my_cred != my_new_cred) {
-
                        DEBUG_CRED_CHANGE("setegid(CH)%d: %p/0x%08x->%p/0x%08x\n", p->p_pid, my_cred, my_pcred->cr_flags, my_new_cred, posix_cred_get(my_new_cred)->cr_flags);
 
-                       proc_lock(p);
+                       proc_ucred_lock(p);
                        /*
                         * We need to protect for a race where another thread
                         * also changed the credential after we took our
@@ -1219,17 +1275,18 @@ setegid(proc_t p, struct setegid_args *uap, __unused int32_t *retval)
                         * should restart this again with the new cred.
                         */
                        if (p->p_ucred != my_cred) {
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
                                kauth_cred_unref(&my_new_cred);
                                /* try again */
                                my_cred = kauth_cred_proc_ref(p);
+                               my_pcred = posix_cred_get(my_cred);
                                continue;
                        }
                        p->p_ucred = my_new_cred;
                        /* update cred on proc */
                        PROC_UPDATE_CREDS_ONPROC(p);
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
-                       proc_unlock(p);
+                       proc_ucred_unlock(p);
                }
                break;
        }
@@ -1238,7 +1295,7 @@ setegid(proc_t p, struct setegid_args *uap, __unused int32_t *retval)
        kauth_cred_unref(&my_cred);
 
        set_security_token(p);
-       return (0);
+       return 0;
 }
 
 /*
@@ -1291,45 +1348,47 @@ setregid(proc_t p, struct setregid_args *uap, __unused int32_t *retval)
        rgid = uap->rgid;
        egid = uap->egid;
 
-       if (rgid == (uid_t)-1)
+       if (rgid == (uid_t)-1) {
                rgid = KAUTH_GID_NONE;
-       if (egid == (uid_t)-1)
+       }
+       if (egid == (uid_t)-1) {
                egid = KAUTH_GID_NONE;
+       }
        AUDIT_ARG(egid, egid);
        AUDIT_ARG(rgid, rgid);
 
+       /* get current credential and take a reference while we muck with it */
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
-       if (((rgid != KAUTH_UID_NONE &&         /* allow no change of rgid */
-             rgid != my_pcred->cr_rgid &&      /* allow rgid = rgid */
-             rgid != my_pcred->cr_gid &&       /* allow rgid = egid */
-             rgid != my_pcred->cr_svgid) ||    /* allow rgid = svgid */
-            (egid != KAUTH_UID_NONE &&         /* allow no change of egid */
-             egid != my_pcred->cr_groups[0] && /* allow no change of egid */
-             egid != my_pcred->cr_gid &&       /* allow egid = egid */
-             egid != my_pcred->cr_rgid &&      /* allow egid = rgid */
-             egid != my_pcred->cr_svgid)) &&   /* allow egid = svgid */
-           (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
-               kauth_cred_unref(&my_cred);
-               return (error);
-       }
-
-       /* get current credential and take a reference while we muck with it */
        for (;;) {
+               if (((rgid != KAUTH_UID_NONE &&         /* allow no change of rgid */
+                   rgid != my_pcred->cr_rgid &&        /* allow rgid = rgid */
+                   rgid != my_pcred->cr_gid &&         /* allow rgid = egid */
+                   rgid != my_pcred->cr_svgid) ||      /* allow rgid = svgid */
+                   (egid != KAUTH_UID_NONE &&          /* allow no change of egid */
+                   egid != my_pcred->cr_groups[0] &&   /* allow no change of egid */
+                   egid != my_pcred->cr_gid &&         /* allow egid = egid */
+                   egid != my_pcred->cr_rgid &&        /* allow egid = rgid */
+                   egid != my_pcred->cr_svgid)) &&     /* allow egid = svgid */
+                   (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
+                       kauth_cred_unref(&my_cred);
+                       return error;
+               }
+
                uid_t new_egid = my_pcred->cr_gid;
                uid_t new_rgid = my_pcred->cr_rgid;
                uid_t svgid = KAUTH_UID_NONE;
 
-               
-               /* 
+
+               /*
                 * Set the credential with new info.  If there is no change,
                 * we get back the same credential we passed in; if there is
                 * a change, we drop the reference on the credential we
                 * passed in.  The subsequent compare is safe, because it is
                 * a pointer compare rather than a contents compare.
-                */
-               if (egid == KAUTH_UID_NONE && my_pcred->cr_gid != egid) {
+                */
+               if (egid != KAUTH_UID_NONE && my_pcred->cr_gid != egid) {
                        /* changing the effective GID */
                        new_egid = egid;
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
@@ -1347,33 +1406,33 @@ setregid(proc_t p, struct setregid_args *uap, __unused int32_t *retval)
                 */
                if (my_pcred->cr_svgid != uap->rgid &&
                    my_pcred->cr_svgid != uap->egid) {
-                       svgid = new_egid;
+                       svgid = new_egid;
                        OSBitOrAtomic(P_SUGID, &p->p_flag);
                }
 
                my_new_cred = kauth_cred_setresgid(my_cred, rgid, egid, svgid);
                if (my_cred != my_new_cred) {
-
                        DEBUG_CRED_CHANGE("setregid(CH)%d: %p/0x%08x->%p/0x%08x\n", p->p_pid, my_cred, my_pcred->cr_flags, my_new_cred, posix_cred_get(my_new_cred)->cr_flags);
 
-                       proc_lock(p);
+                       proc_ucred_lock(p);
                        /* need to protect for a race where another thread
                         * also changed the credential after we took our
                         * reference.  If p_ucred has changed then we
                         * should restart this again with the new cred.
                         */
                        if (p->p_ucred != my_cred) {
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
                                kauth_cred_unref(&my_new_cred);
                                /* try again */
                                my_cred = kauth_cred_proc_ref(p);
+                               my_pcred = posix_cred_get(my_cred);
                                continue;
                        }
                        p->p_ucred = my_new_cred;
                        /* update cred on proc */
                        PROC_UPDATE_CREDS_ONPROC(p);
                        OSBitOrAtomic(P_SUGID, &p->p_flag); /* XXX redundant? */
-                       proc_unlock(p);
+                       proc_ucred_unlock(p);
                }
                break;
        }
@@ -1381,13 +1440,13 @@ setregid(proc_t p, struct setregid_args *uap, __unused int32_t *retval)
        kauth_cred_unref(&my_cred);
 
        set_security_token(p);
-       return (0);
+       return 0;
 }
 
 
 /*
  * Set the per-thread override identity.  The first parameter can be the
- * current real UID, KAUTH_UID_NONE, or, if the caller is priviledged, it
+ * current real UID, KAUTH_UID_NONE, or, if the caller is privileged, it
  * can be any UID.  If it is KAUTH_UID_NONE, then as a special case, this
  * means "revert to the per process credential"; otherwise, if permitted,
  * it changes the effective, real, and saved UIDs and GIDs for the current
@@ -1406,14 +1465,15 @@ settid(proc_t p, struct settid_args *uap, __unused int32_t *retval)
        AUDIT_ARG(uid, uid);
        AUDIT_ARG(gid, gid);
 
-       if (proc_suser(p) != 0) 
-               return (EPERM);
-       
-       if (uid == KAUTH_UID_NONE) {
+       if (proc_suser(p) != 0) {
+               return EPERM;
+       }
 
+       if (uid == KAUTH_UID_NONE) {
                /* must already be assuming another identity in order to revert back */
-               if ((uthread->uu_flag & UT_SETUID) == 0)
-                       return (EPERM);
+               if ((uthread->uu_flag & UT_SETUID) == 0) {
+                       return EPERM;
+               }
 
                /* revert to delayed binding of process credential */
                uc = kauth_cred_proc_ref(p);
@@ -1425,7 +1485,7 @@ settid(proc_t p, struct settid_args *uap, __unused int32_t *retval)
 
                /* cannot already be assuming another identity */
                if ((uthread->uu_flag & UT_SETUID) != 0) {
-                       return (EPERM);
+                       return EPERM;
                }
 
                /*
@@ -1435,11 +1495,12 @@ settid(proc_t p, struct settid_args *uap, __unused int32_t *retval)
                 * current credential while we muck with it, so we can do
                 * the post-compare for changes by pointer.
                 */
-               kauth_cred_ref(uthread->uu_ucred); 
+               kauth_cred_ref(uthread->uu_ucred);
                my_cred = uthread->uu_ucred;
                my_new_cred = kauth_cred_setuidgid(my_cred, uid, gid);
-               if (my_cred != my_new_cred)
+               if (my_cred != my_new_cred) {
                        uthread->uu_ucred = my_new_cred;
+               }
                uthread->uu_flag |= UT_SETUID;
 
                /* Drop old uthread reference or our extra reference */
@@ -1451,7 +1512,7 @@ settid(proc_t p, struct settid_args *uap, __unused int32_t *retval)
         * XXX it is unclear whether P_SUGID should be st at this point;
         * XXX in theory, it is being deprecated.
         */
-       return (0);
+       return 0;
 }
 
 
@@ -1477,7 +1538,7 @@ settid_with_pid(proc_t p, struct settid_with_pid_args *uap, __unused int32_t *re
        AUDIT_ARG(value32, uap->assume);
 
        if (proc_suser(p) != 0) {
-               return (EPERM);
+               return EPERM;
        }
 
        /*
@@ -1493,17 +1554,19 @@ settid_with_pid(proc_t p, struct settid_with_pid_args *uap, __unused int32_t *re
         */
        if (uap->assume != 0) {
                /* can't do this if we have already assumed an identity */
-               if ((uthread->uu_flag & UT_SETUID) != 0)
-                       return (EPERM);
-       
+               if ((uthread->uu_flag & UT_SETUID) != 0) {
+                       return EPERM;
+               }
+
                target_proc = proc_find(uap->pid);
                /* can't assume the identity of the kernel process */
                if (target_proc == NULL || target_proc == kernproc) {
-                       if (target_proc!= NULL)
+                       if (target_proc != NULL) {
                                proc_rele(target_proc);
-                       return (ESRCH);
+                       }
+                       return ESRCH;
                }
-       
+
                /*
                 * Take a reference on the credential used in our target
                 * process then use it as the identity for our current
@@ -1516,39 +1579,41 @@ settid_with_pid(proc_t p, struct settid_with_pid_args *uap, __unused int32_t *re
                 * credential following our assumption of a per-thread one,
                 * since the credential cache will maintain a unique instance.
                 */
-               kauth_cred_ref(uthread->uu_ucred); 
+               kauth_cred_ref(uthread->uu_ucred);
                my_cred = uthread->uu_ucred;
                my_target_cred = kauth_cred_proc_ref(target_proc);
                my_target_pcred = posix_cred_get(my_target_cred);
                my_new_cred = kauth_cred_setuidgid(my_cred, my_target_pcred->cr_uid, my_target_pcred->cr_gid);
-               if (my_cred != my_new_cred)
+               if (my_cred != my_new_cred) {
                        uthread->uu_ucred = my_new_cred;
-       
+               }
+
                uthread->uu_flag |= UT_SETUID;
-               
+
                /* Drop old uthread reference or our extra reference */
                proc_rele(target_proc);
                kauth_cred_unref(&my_cred);
                kauth_cred_unref(&my_target_cred);
 
-               return (0);
+               return 0;
        }
-       
+
        /*
         * Otherwise, we are reverting back to normal mode of operation where
         * delayed binding of the process credential sets the credential in
         * the thread (uu_ucred)
         */
-       if ((uthread->uu_flag & UT_SETUID) == 0)
-               return (EPERM);
+       if ((uthread->uu_flag & UT_SETUID) == 0) {
+               return EPERM;
+       }
 
        /* revert to delayed binding of process credential */
        my_new_cred = kauth_cred_proc_ref(p);
        kauth_cred_unref(&uthread->uu_ucred);
        uthread->uu_ucred = my_new_cred;
        uthread->uu_flag &= ~UT_SETUID;
-       
-       return (0);
+
+       return 0;
 }
 
 
@@ -1588,40 +1653,50 @@ settid_with_pid(proc_t p, struct settid_with_pid_args *uap, __unused int32_t *re
  *             flag the process as having set privilege since the last exec.
  */
 static int
-setgroups1(proc_t p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused int32_t *retval)
+setgroups1(proc_t p, u_int ngrp, user_addr_t gidset, uid_t gmuid, __unused int32_t *retval)
 {
-       u_int ngrp;
-       gid_t   newgroups[NGROUPS] = { 0 };
-       int     error;
-       kauth_cred_t my_cred, my_new_cred;
-       struct uthread *uthread = get_bsdthread_info(current_thread());
+       gid_t   newgroups[NGROUPS] = { 0 };
+       int     error;
 
-       DEBUG_CRED_ENTER("setgroups1 (%d/%d): %d 0x%016x %d\n", p->p_pid, (p->p_pptr ? p->p_pptr->p_pid : 0), gidsetsize, gidset, gmuid);
+       DEBUG_CRED_ENTER("setgroups1 (%d/%d): %d 0x%016x %d\n", p->p_pid,
+           (p->p_pptr ? p->p_pptr->p_pid : 0), ngrp, gidset, gmuid);
 
-       ngrp = gidsetsize;
-       if (ngrp > NGROUPS)
-               return (EINVAL);
+       if (ngrp > NGROUPS) {
+               return EINVAL;
+       }
 
-       if ( ngrp < 1 ) {
-               ngrp = 1;
-       } else {
+       if (ngrp >= 1) {
                error = copyin(gidset,
-                       (caddr_t)newgroups, ngrp * sizeof(gid_t));
+                   (caddr_t)newgroups, ngrp * sizeof(gid_t));
                if (error) {
-                       return (error);
+                       return error;
                }
        }
+       return setgroups_internal(p, ngrp, newgroups, gmuid);
+}
+
+int
+setgroups_internal(proc_t p, u_int ngrp, gid_t *newgroups, uid_t gmuid)
+{
+       struct uthread *uthread = get_bsdthread_info(current_thread());
+       kauth_cred_t my_cred, my_new_cred;
+       int     error;
 
        my_cred = kauth_cred_proc_ref(p);
        if ((error = suser(my_cred, &p->p_acflag))) {
                kauth_cred_unref(&my_cred);
-               return (error);
+               return error;
+       }
+
+       if (ngrp < 1) {
+               ngrp = 1;
+               newgroups[0] = 0;
        }
 
        if ((uthread->uu_flag & UT_SETUID) != 0) {
 #if DEBUG_CRED
                int my_cred_flags = uthread->uu_ucred->cr_flags;
-#endif /* DEBUG_CRED */
+#endif  /* DEBUG_CRED */
                kauth_cred_unref(&my_cred);
 
                /*
@@ -1637,17 +1712,16 @@ setgroups1(proc_t p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused
                uthread->uu_ucred = kauth_cred_setgroups(my_cred, &newgroups[0], ngrp, gmuid);
 #if DEBUG_CRED
                if (my_cred != uthread->uu_ucred) {
-                       DEBUG_CRED_CHANGE("setgroups1(CH)%d: %p/0x%08x->%p/0x%08x\n", p->p_pid, my_cred, my_cred_flags, uthread->uu_ucred , uthread->uu_ucred ->cr_flags);
+                       DEBUG_CRED_CHANGE("setgroups1(CH)%d: %p/0x%08x->%p/0x%08x\n", p->p_pid, my_cred, my_cred_flags, uthread->uu_ucred, uthread->uu_ucred->cr_flags);
                }
-#endif /* DEBUG_CRED */
+#endif  /* DEBUG_CRED */
        } else {
-
                /*
                 * get current credential and take a reference while we muck
                 * with it
                 */
                for (;;) {
-                       /* 
+                       /*
                         * Set the credential with new info.  If there is no
                         * change, we get back the same credential we passed
                         * in; if there is a change, we drop the reference on
@@ -1657,19 +1731,18 @@ setgroups1(proc_t p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused
                         */
                        my_new_cred = kauth_cred_setgroups(my_cred, &newgroups[0], ngrp, gmuid);
                        if (my_cred != my_new_cred) {
-
                                DEBUG_CRED_CHANGE("setgroups1(CH)%d: %p/0x%08x->%p/0x%08x\n", p->p_pid, my_cred, my_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
 
-                               proc_lock(p);
+                               proc_ucred_lock(p);
                                /*
                                 * We need to protect for a race where another
                                 * thread also changed the credential after we
-                                * took our reference.  If p_ucred has 
+                                * took our reference.  If p_ucred has
                                 * changed then we should restart this again
                                 * with the new cred.
                                 */
                                if (p->p_ucred != my_cred) {
-                                       proc_unlock(p);
+                                       proc_ucred_unlock(p);
                                        kauth_cred_unref(&my_new_cred);
                                        my_cred = kauth_cred_proc_ref(p);
                                        /* try again */
@@ -1679,7 +1752,7 @@ setgroups1(proc_t p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused
                                /* update cred on proc */
                                PROC_UPDATE_CREDS_ONPROC(p);
                                OSBitOrAtomic(P_SUGID, &p->p_flag);
-                               proc_unlock(p);
+                               proc_ucred_unlock(p);
                        }
                        break;
                }
@@ -1691,7 +1764,7 @@ setgroups1(proc_t p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused
                set_security_token(p);
        }
 
-       return (0);
+       return 0;
 }
 
 
@@ -1729,7 +1802,7 @@ initgroups(proc_t p, struct initgroups_args *uap, __unused int32_t *retval)
 {
        DEBUG_CRED_ENTER("initgroups\n");
 
-       return(setgroups1(p, uap->gidsetsize, uap->gidset, uap->gmuid, retval));
+       return setgroups1(p, uap->gidsetsize, uap->gidset, uap->gmuid, retval);
 }
 
 
@@ -1763,13 +1836,13 @@ setgroups(proc_t p, struct setgroups_args *uap, __unused int32_t *retval)
 {
        DEBUG_CRED_ENTER("setgroups\n");
 
-       return(setgroups1(p, uap->gidsetsize, uap->gidset, KAUTH_UID_NONE, retval));
+       return setgroups1(p, uap->gidsetsize, uap->gidset, KAUTH_UID_NONE, retval);
 }
 
 
 /*
  * Set the per-thread/per-process supplementary groups list.
- * 
+ *
  * XXX implement setsgroups
  *
  */
@@ -1777,12 +1850,12 @@ setgroups(proc_t p, struct setgroups_args *uap, __unused int32_t *retval)
 int
 setsgroups(__unused proc_t p, __unused struct setsgroups_args *uap, __unused int32_t *retval)
 {
-       return(ENOTSUP);
+       return ENOTSUP;
 }
 
 /*
  * Set the per-thread/per-process whiteout groups list.
- * 
+ *
  * XXX implement setwgroups
  *
  */
@@ -1790,7 +1863,7 @@ setsgroups(__unused proc_t p, __unused struct setsgroups_args *uap, __unused int
 int
 setwgroups(__unused proc_t p, __unused struct setwgroups_args *uap, __unused int32_t *retval)
 {
-       return(ENOTSUP);
+       return ENOTSUP;
 }
 
 
@@ -1805,9 +1878,10 @@ groupmember(gid_t gid, kauth_cred_t cred)
 {
        int is_member;
 
-       if (kauth_cred_ismember_gid(cred, gid, &is_member) == 0 && is_member)
-               return (1);
-       return (0);
+       if (kauth_cred_ismember_gid(cred, gid, &is_member) == 0 && is_member) {
+               return 1;
+       }
+       return 0;
 }
 
 
@@ -1829,56 +1903,17 @@ int
 suser(kauth_cred_t cred, u_short *acflag)
 {
 #if DIAGNOSTIC
-       if (!IS_VALID_CRED(cred))
+       if (!IS_VALID_CRED(cred)) {
                panic("suser");
+       }
 #endif
        if (kauth_cred_getuid(cred) == 0) {
-               if (acflag)
+               if (acflag) {
                        *acflag |= ASU;
-               return (0);
+               }
+               return 0;
        }
-       return (EPERM);
-}
-
-
-/*
- * XXX This interface is going away; use kauth_cred_issuser() directly
- * XXX instead.
- */
-int
-is_suser(void)
-{
-       proc_t p = current_proc();
-
-       if (!p)
-               return (0);
-
-       return (proc_suser(p) == 0);
-}
-
-
-/*
- * XXX This interface is going away; use kauth_cred_issuser() directly
- * XXX instead.
- */
-int
-is_suser1(void)
-{
-       proc_t p = current_proc();
-       kauth_cred_t my_cred;
-       posix_cred_t my_pcred;
-       int err;
-
-       if (!p)
-               return (0);
-
-       my_cred = kauth_cred_proc_ref(p);
-       my_pcred = posix_cred_get(my_cred);
-
-       err =  (suser(my_cred, &p->p_acflag) == 0 ||
-                       my_pcred->cr_ruid == 0 || my_pcred->cr_svuid == 0);
-       kauth_cred_unref(&my_cred);
-       return(err);
+       return EPERM;
 }
 
 
@@ -1908,26 +1943,39 @@ is_suser1(void)
 int
 getlogin(proc_t p, struct getlogin_args *uap, __unused int32_t *retval)
 {
-       char buffer[MAXLOGNAME+1];
+       char buffer[MAXLOGNAME + 1];
        struct session * sessp;
 
-       bzero(buffer, MAXLOGNAME+1);
+       bzero(buffer, MAXLOGNAME + 1);
 
        sessp = proc_session(p);
 
-       if (uap->namelen > MAXLOGNAME)
+       if (uap->namelen > MAXLOGNAME) {
                uap->namelen = MAXLOGNAME;
+       }
 
-       if(sessp != SESSION_NULL) {
+       if (sessp != SESSION_NULL) {
                session_lock(sessp);
                bcopy( sessp->s_login, buffer, uap->namelen);
                session_unlock(sessp);
        }
        session_rele(sessp);
 
-       return (copyout((caddr_t)buffer, uap->namebuf, uap->namelen));
+       return copyout((caddr_t)buffer, uap->namebuf, uap->namelen);
 }
 
+void
+setlogin_internal(proc_t p, const char login[static MAXLOGNAME])
+{
+       struct session *sessp = proc_session(p);
+
+       if (sessp != SESSION_NULL) {
+               session_lock(sessp);
+               bcopy(login, sessp->s_login, MAXLOGNAME);
+               session_unlock(sessp);
+               session_rele(sessp);
+       }
+}
 
 /*
  * setlogin
@@ -1949,35 +1997,28 @@ int
 setlogin(proc_t p, struct setlogin_args *uap, __unused int32_t *retval)
 {
        int error;
-       size_t dummy=0;
-       char buffer[MAXLOGNAME+1];
-       struct session * sessp;
+       size_t dummy = 0;
+       char buffer[MAXLOGNAME + 1];
 
-       if ((error = proc_suser(p)))
-               return (error);
+       if ((error = proc_suser(p))) {
+               return error;
+       }
 
-       bzero(&buffer[0], MAXLOGNAME+1);
+       bzero(&buffer[0], MAXLOGNAME + 1);
 
 
        error = copyinstr(uap->namebuf,
            (caddr_t) &buffer[0],
            MAXLOGNAME - 1, (size_t *)&dummy);
 
-       sessp = proc_session(p);
-
-       if (sessp != SESSION_NULL) {
-               session_lock(sessp);
-               bcopy(buffer, sessp->s_login, MAXLOGNAME);
-               session_unlock(sessp);
-               session_rele(sessp);
-       }
-
+       setlogin_internal(p, buffer);
 
        if (!error) {
                AUDIT_ARG(text, buffer);
-        } else if (error == ENAMETOOLONG)
+       } else if (error == ENAMETOOLONG) {
                error = EINVAL;
-       return (error);
+       }
+       return error;
 }
 
 
@@ -1988,12 +2029,25 @@ setlogin(proc_t p, struct setlogin_args *uap, __unused int32_t *retval)
  */
 int
 set_security_token(proc_t p)
+{
+       return set_security_token_task_internal(p, p->task);
+}
+
+/*
+ * Set the secrity token of the task with current euid and eguid
+ * The function takes a proc and a task, where proc->task might point to a
+ * different task if called from exec.
+ */
+
+int
+set_security_token_task_internal(proc_t p, void *t)
 {
        security_token_t sec_token;
        audit_token_t    audit_token;
        kauth_cred_t my_cred;
        posix_cred_t my_pcred;
        host_priv_t host_priv;
+       task_t task = t;
 
        /*
         * Don't allow a vfork child to override the parent's token settings
@@ -2001,13 +2055,14 @@ set_security_token(proc_t p)
         * suffer along using the parent's token until the exec().  It's all
         * undefined behavior anyway, right?
         */
-       if (p->task == current_task()) {
-               uthread_t        uthread;
+       if (task == current_task()) {
+               uthread_t        uthread;
                uthread = (uthread_t)get_bsdthread_info(current_thread());
-               if (uthread->uu_flag & UT_VFORK)
-                       return (1);
+               if (uthread->uu_flag & UT_VFORK) {
+                       return 1;
+               }
        }
-               
+
        my_cred = kauth_cred_proc_ref(p);
        my_pcred = posix_cred_get(my_cred);
 
@@ -2038,22 +2093,39 @@ set_security_token(proc_t p)
        audit_token.val[6] = my_cred->cr_audit.as_aia_p->ai_asid;
        audit_token.val[7] = p->p_idversion;
 
-#if CONFIG_MACF_MACH
-       mac_task_label_update_cred(my_cred, p->task);
-#endif
-       
        host_priv = (sec_token.val[0]) ? HOST_PRIV_NULL : host_priv_self();
 #if CONFIG_MACF
-       if (host_priv != HOST_PRIV_NULL && mac_system_check_host_priv(my_cred))
+       if (host_priv != HOST_PRIV_NULL && mac_system_check_host_priv(my_cred)) {
                host_priv = HOST_PRIV_NULL;
+       }
 #endif
        kauth_cred_unref(&my_cred);
 
-       return (host_security_set_task_token(host_security_self(),
-                                          p->task,
-                                          sec_token,
-                                          audit_token,
-                                          host_priv) != KERN_SUCCESS);
+#if DEVELOPMENT || DEBUG
+       /*
+        * Update the pid an proc name for importance base if any
+        */
+       task_importance_update_owner_info(task);
+#endif
+
+       return host_security_set_task_token(host_security_self(),
+                  task,
+                  sec_token,
+                  audit_token,
+                  host_priv) != KERN_SUCCESS;
+}
+
+
+int get_audit_token_pid(audit_token_t *audit_token);
+
+int
+get_audit_token_pid(audit_token_t *audit_token)
+{
+       /* keep in-sync with set_security_token (above) */
+       if (audit_token) {
+               return (int)audit_token->val[5];
+       }
+       return -1;
 }
 
 
@@ -2072,170 +2144,3 @@ cru2x(kauth_cred_t cr, struct xucred *xcr)
        xcr->cr_ngroups = pcr->cr_ngroups;
        bcopy(pcr->cr_groups, xcr->cr_groups, sizeof(xcr->cr_groups));
 }
-
-#if CONFIG_LCTX
-
-/*
- * Set Login Context ID
- */
-/*
- * MPSAFE - assignment of (visible) process to context protected by ALLLCTX_LOCK,
- *         LCTX by its own locks.
- */
-int
-setlcid(proc_t p0, struct setlcid_args *uap, __unused int32_t *retval)
-{
-       proc_t p;
-       struct lctx *l;
-       int error = 0;
-       int refheld = 0;
-
-       AUDIT_ARG(pid, uap->pid);
-       AUDIT_ARG(value32, uap->lcid);
-       if (uap->pid == LCID_PROC_SELF) {       /* Create/Join/Leave */
-               p = p0;
-       } else {                                /* Adopt/Orphan */
-               p = proc_find(uap->pid);
-               if (p == NULL)
-                       return (ESRCH);
-               refheld = 1;
-       }
-
-#if CONFIG_MACF
-       error = mac_proc_check_setlcid(p0, p, uap->pid, uap->lcid);
-       if (error)
-               goto out;
-#endif
-
-       switch (uap->lcid) {
-       /* Leave/Orphan */
-       case LCID_REMOVE:
-
-               /* Only root may Leave/Orphan. */
-               if (!is_suser1()) {
-                       error = EPERM;
-                       goto out;
-               }
-
-               /* Process not in login context. */
-               if (p->p_lctx == NULL) {
-                       error = ENOATTR;
-                       goto out;
-               }
-
-               l = NULL;
-
-               break;
-
-       /* Create */
-       case LCID_CREATE:
-
-               /* Create only valid for self! */
-               if (uap->pid != LCID_PROC_SELF) {
-                       error = EPERM;
-                       goto out;
-               }
-
-               /* Already in a login context. */
-               if (p->p_lctx != NULL) {
-                       error = EPERM;
-                       goto out;
-               }
-
-               l = lccreate();
-               if (l == NULL) {
-                       error = ENOMEM;
-                       goto out;
-               }
-
-               LCTX_LOCK(l);
-
-               break;
-
-       /* Join/Adopt */
-       default:
-
-               /* Only root may Join/Adopt. */
-               if (!is_suser1()) {
-                       error = EPERM;
-                       goto out;
-               }
-
-               l = lcfind(uap->lcid);
-               if (l == NULL) {
-                       error = ENOATTR;
-                       goto out;
-               }
-
-               break;
-       }
-
-       ALLLCTX_LOCK;
-       leavelctx(p);
-       enterlctx(p, l, (uap->lcid == LCID_CREATE) ? 1 : 0);
-       ALLLCTX_UNLOCK;
-
-out:
-       if (refheld != 0)
-               proc_rele(p);
-       return (error);
-}
-
-/*
- * Get Login Context ID
- */
-/*
- * MPSAFE - membership of (visible) process in a login context
- *         protected by the all-context lock.
- */
-int
-getlcid(proc_t p0, struct getlcid_args *uap, int32_t *retval)
-{
-       proc_t p;
-       int error = 0;
-       int refheld = 0;
-
-       AUDIT_ARG(pid, uap->pid);
-       if (uap->pid == LCID_PROC_SELF) {
-               p = p0;
-       } else {
-               p = proc_find(uap->pid);
-               if (p == NULL)
-                       return (ESRCH);
-               refheld = 1;
-       }
-
-#if CONFIG_MACF
-       error = mac_proc_check_getlcid(p0, p, uap->pid);
-       if (error)
-               goto out;
-#endif
-       ALLLCTX_LOCK;
-       if (p->p_lctx == NULL) {
-               error = ENOATTR;
-               ALLLCTX_UNLOCK;
-               goto out;
-       }
-       *retval = p->p_lctx->lc_id;
-       ALLLCTX_UNLOCK;
- out:
-       if (refheld != 0)
-               proc_rele(p);
-
-       return (error);
-}
-#else  /* LCTX */
-int
-setlcid(proc_t p0, struct setlcid_args *uap, int32_t *retval)
-{
-
-       return (ENOSYS);
-}
-
-int
-getlcid(proc_t p0, struct getlcid_args *uap, int32_t *retval)
-{
-
-       return (ENOSYS);
-}
-#endif /* !LCTX */