/*
- * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
- *
* 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
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * 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_LICENSE_HEADER_END@
- */
-/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
-/*
+ *
+ * @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.
* (c) UNIX System Laboratories, Inc.
* 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
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ *
+ *
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ *
*/
/*
#include <sys/acct.h>
#include <sys/systm.h>
#include <sys/ucred.h>
-#include <sys/proc.h>
+#include <sys/proc_internal.h>
+#include <sys/user.h>
+#include <sys/kauth.h>
#include <sys/timeb.h>
#include <sys/times.h>
#include <sys/malloc.h>
-#include <sys/kern_audit.h>
+#include <sys/persona.h>
+
+#include <security/audit/audit.h>
-#include <sys/mount.h>
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
+
+#include <sys/mount_internal.h>
+#include <sys/sysproto.h>
#include <mach/message.h>
#include <mach/host_security.h>
#include <kern/host.h>
+#include <kern/task.h> /* for current_task() */
+#include <kern/assert.h>
+
+
+/*
+ * Credential debugging; we can track entry into a function that might
+ * change a credential, and we can track actual credential changes that
+ * result.
+ *
+ * Note: Does *NOT* currently include per-thread credential changes
+ *
+ * We don't use kauth_cred_print() in current debugging, but it
+ * can be used if needed when debugging is active.
+ */
+#if DEBUG_CRED
+#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 */
+
+#if DEVELOPMENT || DEBUG
+extern void task_importance_update_owner_info(task_t);
+#endif
+
/*
- * setprivexec: (dis)allow this process to hold
- * task, thread, or execption ports of processes about to exec.
+ * setprivexec
+ *
+ * Description: (dis)allow this process to hold task, thread, or execption
+ * ports of processes about to exec.
+ *
+ * Parameters: uap->flag New value for flag
+ *
+ * Returns: int Previous value of flag
+ *
+ * XXX: Belongs in kern_proc.c
*/
-struct setprivexec_args {
- int flag;
-};
int
-setprivexec(p, uap, retval)
- struct proc *p;
- register struct setprivexec_args *uap;
- register_t *retval;
+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;
}
-/* ARGSUSED */
-getpid(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
-{
+/*
+ * getpid
+ *
+ * Description: get the process ID
+ *
+ * Parameters: (void)
+ *
+ * Returns: pid_t Current process ID
+ *
+ * XXX: Belongs in kern_proc.c
+ */
+int
+getpid(proc_t p, __unused struct getpid_args *uap, int32_t *retval)
+{
*retval = p->p_pid;
-#if COMPAT_43
- retval[1] = p->p_pptr->p_pid;
-#endif
- return (0);
+ return 0;
}
-/* ARGSUSED */
-getppid(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
-{
- *retval = p->p_pptr->p_pid;
- return (0);
+/*
+ * getppid
+ *
+ * Description: get the parent process ID
+ *
+ * Parameters: (void)
+ *
+ * Returns: pid_t Parent process ID
+ *
+ * XXX: Belongs in kern_proc.c
+ */
+int
+getppid(proc_t p, __unused struct getppid_args *uap, int32_t *retval)
+{
+ *retval = p->p_ppid;
+ return 0;
}
-/* Get process group ID; note that POSIX getpgrp takes no parameter */
-getpgrp(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
-{
- *retval = p->p_pgrp->pg_id;
- return (0);
+/*
+ * getpgrp
+ *
+ * Description: get the process group ID of the calling process
+ *
+ * Parameters: (void)
+ *
+ * Returns: pid_t Process group ID
+ *
+ * XXX: Belongs in kern_proc.c
+ */
+int
+getpgrp(proc_t p, __unused struct getpgrp_args *uap, int32_t *retval)
+{
+ *retval = p->p_pgrpid;
+ return 0;
}
-/* Get an arbitary pid's process group id */
-struct getpgid_args {
- pid_t pid;
-};
+/*
+ * getpgid
+ *
+ * Description: Get an arbitary pid's process group id
+ *
+ * Parameters: uap->pid The target pid
+ *
+ * Returns: 0 Success
+ * ESRCH No such process
+ *
+ * Notes: We are permitted to return EPERM in the case that the target
+ * process is not in the same session as the calling process,
+ * which could be a security consideration
+ *
+ * XXX: Belongs in kern_proc.c
+ */
int
-getpgid(p, uap, retval)
- struct proc *p;
- struct getpgid_args *uap;
- register_t *retval;
+getpgid(proc_t p, struct getpgid_args *uap, int32_t *retval)
{
- struct proc *pt;
+ proc_t pt;
+ int refheld = 0;
pt = p;
- if (uap->pid == 0)
+ if (uap->pid == 0) {
goto found;
+ }
- if ((pt = pfind(uap->pid)) == 0)
- return (ESRCH);
+ if ((pt = proc_find(uap->pid)) == 0) {
+ return ESRCH;
+ }
+ refheld = 1;
found:
- *retval = pt->p_pgrp->pg_id;
- return (0);
+ *retval = pt->p_pgrpid;
+ if (refheld != 0) {
+ proc_rele(pt);
+ }
+ return 0;
}
+
/*
- * Get an arbitary pid's session id.
+ * getsid
+ *
+ * Description: Get an arbitary pid's session leaders process group ID
+ *
+ * Parameters: uap->pid The target pid
+ *
+ * Returns: 0 Success
+ * ESRCH No such process
+ *
+ * Notes: We are permitted to return EPERM in the case that the target
+ * process is not in the same session as the calling process,
+ * which could be a security consideration
+ *
+ * XXX: Belongs in kern_proc.c
*/
-struct getsid_args {
- pid_t pid;
-};
-
int
-getsid(p, uap, retval)
- struct proc *p;
- struct getsid_args *uap;
- register_t *retval;
+getsid(proc_t p, struct getsid_args *uap, int32_t *retval)
{
- struct proc *pt;
+ proc_t pt;
+ int refheld = 0;
+ struct session * sessp;
pt = p;
- if (uap->pid == 0)
+ if (uap->pid == 0) {
goto found;
+ }
- if ((pt = pfind(uap->pid)) == 0)
- return (ESRCH);
+ if ((pt = proc_find(uap->pid)) == 0) {
+ return ESRCH;
+ }
+ refheld = 1;
found:
- *retval = pt->p_session->s_sid;
- return (0);
+ sessp = proc_session(pt);
+ *retval = sessp->s_sid;
+ session_rele(sessp);
+
+ if (refheld != 0) {
+ proc_rele(pt);
+ }
+ return 0;
}
-/* ARGSUSED */
-getuid(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
-{
- *retval = p->p_cred->p_ruid;
-#if COMPAT_43
- retval[1] = p->p_ucred->cr_uid;
-#endif
- return (0);
+/*
+ * getuid
+ *
+ * Description: get real user ID for caller
+ *
+ * Parameters: (void)
+ *
+ * Returns: uid_t The real uid of the caller
+ */
+int
+getuid(__unused proc_t p, __unused struct getuid_args *uap, int32_t *retval)
+{
+ *retval = kauth_getruid();
+ return 0;
}
-/* ARGSUSED */
-geteuid(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
-{
- *retval = p->p_ucred->cr_uid;
- return (0);
+/*
+ * geteuid
+ *
+ * Description: get effective user ID for caller
+ *
+ * Parameters: (void)
+ *
+ * Returns: uid_t The effective uid of the caller
+ */
+int
+geteuid(__unused proc_t p, __unused struct geteuid_args *uap, int32_t *retval)
+{
+ *retval = kauth_getuid();
+ return 0;
}
-/* ARGSUSED */
-getgid(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
+
+/*
+ * gettid
+ *
+ * Description: Return the per-thread override identity.
+ *
+ * Parameters: uap->uidp Address of uid_t to get uid
+ * uap->gidp Address of gid_t to get gid
+ *
+ * Returns: 0 Success
+ * ESRCH No per thread identity active
+ */
+int
+gettid(__unused proc_t p, struct gettid_args *uap, int32_t *retval)
{
+ struct uthread *uthread = get_bsdthread_info(current_thread());
+ int error;
- *retval = p->p_cred->p_rgid;
-#if COMPAT_43
- retval[1] = p->p_ucred->cr_groups[0];
-#endif
- return (0);
+ /*
+ * 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 ((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;
}
+
/*
- * Get effective group ID. The "egid" is groups[0], and could be obtained
- * via getgroups. This syscall exists because it is somewhat painful to do
- * correctly in a library function.
+ * getgid
+ *
+ * Description: get the real group ID for the calling process
+ *
+ * Parameters: (void)
+ *
+ * Returns: gid_t The real gid of the caller
*/
-/* ARGSUSED */
-getegid(p, uap, retval)
- struct proc *p;
- void *uap;
- register_t *retval;
+int
+getgid(__unused proc_t p, __unused struct getgid_args *uap, int32_t *retval)
{
+ *retval = kauth_getrgid();
+ return 0;
+}
+
- *retval = p->p_ucred->cr_groups[0];
- return (0);
+/*
+ * getegid
+ *
+ * Description: get the effective group ID for the calling process
+ *
+ * Parameters: (void)
+ *
+ * Returns: gid_t The effective gid of the caller
+ *
+ * Notes: As an implementation detail, the effective gid is stored as
+ * the first element of the supplementary group list.
+ *
+ * This could be implemented in Libc instead because of the above
+ * detail.
+ */
+int
+getegid(__unused proc_t p, __unused struct getegid_args *uap, int32_t *retval)
+{
+ *retval = kauth_getgid();
+ return 0;
}
-struct getgroups_args {
- u_int gidsetsize;
- gid_t *gidset;
-};
-getgroups(p, uap, retval)
- struct proc *p;
- register struct getgroups_args *uap;
- register_t *retval;
+
+/*
+ * getgroups
+ *
+ * Description: get the list of supplementary groups for the calling process
+ *
+ * Parameters: uap->gidsetsize # of gid_t's in user buffer
+ * uap->gidset Pointer to user buffer
+ *
+ * Returns: 0 Success
+ * EINVAL User buffer too small
+ * copyout:EFAULT User buffer invalid
+ *
+ * Retval: -1 Error
+ * !0 # of groups
+ *
+ * Notes: The caller may specify a 0 value for gidsetsize, and we will
+ * then return how large a buffer is required (in gid_t's) to
+ * contain the answer at the time of the call. Otherwise, we
+ * return the number of gid_t's catually copied to user space.
+ *
+ * When called with a 0 gidsetsize from a multithreaded program,
+ * there is no guarantee that another thread may not change the
+ * number of supplementary groups, and therefore a subsequent
+ * call could still fail, unless the maximum possible buffer
+ * size is supplied by the user.
+ *
+ * As an implementation detail, the effective gid is stored as
+ * the first element of the supplementary group list, and will
+ * be returned by this call.
+ */
+int
+getgroups(__unused proc_t p, struct getgroups_args *uap, int32_t *retval)
{
- register struct pcred *pc = p->p_cred;
- register u_int ngrp;
+ int ngrp;
int error;
+ kauth_cred_t cred;
+ posix_cred_t pcred;
+
+ /* grab reference while we muck around with the credential */
+ cred = kauth_cred_get_with_ref();
+ pcred = posix_cred_get(cred);
if ((ngrp = uap->gidsetsize) == 0) {
- *retval = pc->pc_ucred->cr_ngroups;
- return (0);
- }
- if (ngrp < pc->pc_ucred->cr_ngroups)
- return (EINVAL);
- pcred_readlock(p);
- ngrp = pc->pc_ucred->cr_ngroups;
- if (error = copyout((caddr_t)pc->pc_ucred->cr_groups,
- (caddr_t)uap->gidset, ngrp * sizeof(gid_t))) {
- pcred_unlock(p);
- return (error);
- }
- pcred_unlock(p);
+ *retval = pcred->cr_ngroups;
+ kauth_cred_unref(&cred);
+ return 0;
+ }
+ if (ngrp < pcred->cr_ngroups) {
+ kauth_cred_unref(&cred);
+ return EINVAL;
+ }
+ ngrp = pcred->cr_ngroups;
+ if ((error = copyout((caddr_t)pcred->cr_groups,
+ uap->gidset,
+ ngrp * sizeof(gid_t)))) {
+ kauth_cred_unref(&cred);
+ return error;
+ }
+ kauth_cred_unref(&cred);
*retval = ngrp;
- return (0);
+ return 0;
+}
+
+
+/*
+ * Return the per-thread/per-process supplementary groups list.
+ *
+ * XXX implement getsgroups
+ *
+ */
+
+int
+getsgroups(__unused proc_t p, __unused struct getsgroups_args *uap, __unused int32_t *retval)
+{
+ return ENOTSUP;
+}
+
+/*
+ * Return the per-thread/per-process whiteout groups list.
+ *
+ * XXX implement getwgroups
+ *
+ */
+
+int
+getwgroups(__unused proc_t p, __unused struct getwgroups_args *uap, __unused int32_t *retval)
+{
+ return ENOTSUP;
}
-/* ARGSUSED */
-setsid(p, uap, retval)
- register struct proc *p;
- void *uap;
- register_t *retval;
+/*
+ * setsid_internal
+ *
+ * Description: Core implementation of setsid().
+ */
+int
+setsid_internal(proc_t p)
{
+ struct pgrp * pg = PGRP_NULL;
- if (p->p_pgid == p->p_pid || pgfind(p->p_pid) || p->p_flag & P_INVFORK) {
- return (EPERM);
+ 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
+ *
+ * Description: Create a new session and set the process group ID to the
+ * session ID
+ *
+ * Parameters: (void)
+ *
+ * Returns: 0 Success
+ * EPERM Permission denied
+ *
+ * Notes: If the calling process is not the process group leader; there
+ * is no existing process group with its ID, and we are not
+ * currently in vfork, then this function will create a new
+ * session, a new process group, and put the caller in the
+ * process group (as the sole member) and make it the session
+ * leader (as the sole process in the session).
+ *
+ * The existing controlling tty (if any) will be dissociated
+ * from the process, and the next non-O_NOCTTY open of a tty
+ * will establish a new controlling tty.
+ *
+ * XXX: Belongs in kern_proc.c
+ */
+int
+setsid(proc_t p, __unused struct setsid_args *uap, int32_t *retval)
+{
+ int rc = setsid_internal(p);
+ if (rc == 0) {
*retval = p->p_pid;
- return (0);
}
+ return rc;
}
+
/*
- * set process group (setpgid/old setpgrp)
+ * setpgid
+ *
+ * Description: set process group ID for job control
+ *
+ * Parameters: uap->pid Process to change
+ * uap->pgid Process group to join or create
*
- * caller does setpgid(targpid, targpgid)
+ * Returns: 0 Success
+ * ESRCH pid is not the caller or a child of
+ * the caller
+ * enterpgrp:ESRCH No such process
+ * EACCES Permission denied due to exec
+ * EINVAL Invalid argument
+ * EPERM The target process is not in the same
+ * session as the calling process
+ * EPERM The target process is a session leader
+ * EPERM pid and pgid are not the same, and
+ * there is no process in the calling
+ * process whose process group ID matches
+ * pgid
*
- * pid must be caller or child of caller (ESRCH)
- * if a child
- * pid must be in same session (EPERM)
- * pid can't have done an exec (EACCES)
- * if pgid != pid
- * there must exist some pid in same session having pgid (EPERM)
- * pid must not be session leader (EPERM)
+ * Notes: This function will cause the target process to either join
+ * an existing process process group, or create a new process
+ * group in the session of the calling process. It cannot be
+ * used to change the process group ID of a process which is
+ * already a session leader.
+ *
+ * If the target pid is 0, the pid of the calling process is
+ * substituted as the new target; if pgid is 0, the target pid
+ * 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
+ *
+ * XXX: Belongs in kern_proc.c
*/
-struct setpgid_args {
- int pid;
- int pgid;
-};
-/* ARGSUSED */
-setpgid(curp, uap, retval)
- struct proc *curp;
- register struct setpgid_args *uap;
- register_t *retval;
+int
+setpgid(proc_t curp, struct setpgid_args *uap, __unused int32_t *retval)
{
- register struct proc *targp; /* target process */
- register struct pgrp *pgrp; /* 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;
+ struct session * curp_sessp = SESSION_NULL;
+ struct session * targp_sessp = SESSION_NULL;
+
+ curp_sessp = proc_session(curp);
if (uap->pid != 0 && uap->pid != curp->p_pid) {
- if ((targp = pfind(uap->pid)) == 0 || !inferior(targp))
- return (ESRCH);
- if (targp->p_session != curp->p_session)
- return (EPERM);
- if (targp->p_flag & P_EXEC)
- return (EACCES);
- } else
+ if ((targp = proc_find(uap->pid)) == 0 || !inferior(targp)) {
+ if (targp != PROC_NULL) {
+ refheld = 1;
+ }
+ error = ESRCH;
+ goto out;
+ }
+ refheld = 1;
+ targp_sessp = proc_session(targp);
+ if (targp_sessp != curp_sessp) {
+ error = EPERM;
+ goto out;
+ }
+ if (targp->p_flag & P_EXEC) {
+ error = EACCES;
+ goto out;
+ }
+ } else {
targp = curp;
- if (SESS_LEADER(targp))
- return (EPERM);
- if (uap->pgid == 0)
+ targp_sessp = proc_session(targp);
+ }
+
+ if (SESS_LEADER(targp, targp_sessp)) {
+ error = EPERM;
+ goto out;
+ }
+ if (targp_sessp != SESSION_NULL) {
+ session_rele(targp_sessp);
+ targp_sessp = SESSION_NULL;
+ }
+
+ if (uap->pgid < 0) {
+ error = EINVAL;
+ goto out;
+ }
+ if (uap->pgid == 0) {
uap->pgid = targp->p_pid;
- else if (uap->pgid != targp->p_pid)
- if ((pgrp = pgfind(uap->pgid)) == 0 ||
- pgrp->pg_session != curp->p_session)
- return (EPERM);
- return (enterpgrp(targp, 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);
+ pg_rele(pg);
+ if (samesess != 0) {
+ error = EPERM;
+ goto out;
+ }
+ }
+ error = enterpgrp(targp, uap->pgid, 0);
+out:
+ if (targp_sessp != SESSION_NULL) {
+ session_rele(targp_sessp);
+ }
+ if (curp_sessp != SESSION_NULL) {
+ session_rele(curp_sessp);
+ }
+ if (refheld != 0) {
+ proc_rele(targp);
+ }
+ return error;
+}
+
+
+/*
+ * issetugid
+ *
+ * Description: Is current process tainted by uid or gid changes system call
+ *
+ * Parameters: (void)
+ *
+ * Returns: 0 Not tainted
+ * 1 Tainted
+ *
+ * Notes: A process is considered tainted if it was created as a retult
+ * of an execve call from an imnage that had either the SUID or
+ * SGID bit set on the executable, or if it has changed any of its
+ * 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;
}
-struct issetugid_args {
- int dummy;
-};
-issetugid(p, uap, retval)
- struct proc *p;
- struct issetugid_args *uap;
- register_t *retval;
+int
+issetugid(proc_t p, __unused struct issetugid_args *uap, int32_t *retval)
{
/*
* Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
* 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;
}
-struct setuid_args {
- uid_t uid;
-};
-/* ARGSUSED */
-setuid(p, uap, retval)
- struct proc *p;
- struct setuid_args *uap;
- register_t *retval;
+
+/*
+ * setuid
+ *
+ * Description: Set user ID system call
+ *
+ * Parameters: uap->uid uid to set
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permission denied
+ *
+ * Notes: If called by a privileged process, this function will set the
+ * real, effective, and saved uid to the requested value.
+ *
+ * If called from an unprivileged process, but uid is equal to the
+ * real or saved uid, then the effective uid will be set to the
+ * requested value, but the real and saved uid will not change.
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
+ */
+int
+setuid(proc_t p, struct setuid_args *uap, __unused int32_t *retval)
{
- register struct pcred *pc = p->p_cred;
- register uid_t uid;
+ uid_t uid;
+ uid_t svuid = KAUTH_UID_NONE;
+ uid_t ruid = KAUTH_UID_NONE;
+ uid_t gmuid = KAUTH_UID_NONE;
int error;
+ kauth_cred_t my_cred, my_new_cred;
+ posix_cred_t my_pcred;
uid = uap->uid;
- AUDIT_ARG(uid, uid, 0, 0, 0);
- if (uid != pc->p_ruid &&
- (error = suser(pc->pc_ucred, &p->p_acflag)))
- return (error);
- /*
- * Everything's okay, do it.
- * Transfer proc count to new user.
- * Copy credentials so other references do not see our changes.
- */
-
- /* prepare app access profile files */
- prepare_profile_database(uap->uid);
- pcred_writelock(p);
- (void)chgproccnt(pc->p_ruid, -1);
- (void)chgproccnt(uid, 1);
- pc->pc_ucred = crcopy(pc->pc_ucred);
- pc->pc_ucred->cr_uid = uid;
- pc->p_ruid = uid;
- pc->p_svuid = uid;
- pcred_unlock(p);
- set_security_token(p);
- p->p_flag |= P_SUGID;
- return (0);
-}
-struct seteuid_args {
- uid_t euid;
-};
-/* ARGSUSED */
-seteuid(p, uap, retval)
- struct proc *p;
- struct seteuid_args *uap;
- register_t *retval;
-{
- register struct pcred *pc = p->p_cred;
- register uid_t euid;
- int error;
+ /* 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);
- euid = uap->euid;
- AUDIT_ARG(uid, 0, euid, 0, 0);
- if (euid != pc->p_ruid && euid != pc->p_svuid &&
- (error = suser(pc->pc_ucred, &p->p_acflag)))
- return (error);
- /*
- * Everything's okay, do it. Copy credentials so other references do
- * not see our changes.
- */
- pcred_writelock(p);
- pc->pc_ucred = crcopy(pc->pc_ucred);
- pc->pc_ucred->cr_uid = euid;
- pcred_unlock(p);
- set_security_token(p);
- p->p_flag |= P_SUGID;
- return (0);
-}
+ 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);
-struct setgid_args {
- gid_t gid;
-};
-/* ARGSUSED */
-setgid(p, uap, retval)
- struct proc *p;
- struct setgid_args *uap;
- register_t *retval;
-{
- register struct pcred *pc = p->p_cred;
- register gid_t gid;
- int error;
+ 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;
+ }
- gid = uap->gid;
- AUDIT_ARG(gid, gid, 0, 0, 0);
- if (gid != pc->p_rgid && (error = suser(pc->pc_ucred, &p->p_acflag)))
- return (error);
- pcred_writelock(p);
- pc->pc_ucred = crcopy(pc->pc_ucred);
- pc->pc_ucred->cr_groups[0] = gid;
- pc->p_rgid = gid;
- pc->p_svgid = gid; /* ??? */
- pcred_unlock(p);
- set_security_token(p);
- p->p_flag |= P_SUGID;
- return (0);
-}
+ /*
+ * If we are privileged, 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;
+ } 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
+ * of initgroups() to set an explicit group list, or one of the
+ * other group manipulation functions is invoked and results in
+ * a dislocation (i.e. the credential group membership changes
+ * 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)) {
+ gmuid = uid;
+ }
-struct setegid_args {
- gid_t egid;
-};
-/* ARGSUSED */
-setegid(p, uap, retval)
- struct proc *p;
- struct setegid_args *uap;
- register_t *retval;
-{
- register struct pcred *pc = p->p_cred;
- register gid_t egid;
- int 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, 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);
+
+ /*
+ * 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_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;
+ }
+ p->p_ucred = my_new_cred;
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
+
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
+ 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);
- egid = uap->egid;
- AUDIT_ARG(gid, 0, egid, 0, 0);
- if (egid != pc->p_rgid && egid != pc->p_svgid &&
- (error = suser(pc->pc_ucred, &p->p_acflag)))
- return (error);
- pcred_writelock(p);
- pc->pc_ucred = crcopy(pc->pc_ucred);
- pc->pc_ucred->cr_groups[0] = egid;
- pcred_unlock(p);
set_security_token(p);
- p->p_flag |= P_SUGID;
- return (0);
+ return 0;
}
-struct setgroups_args{
- u_int gidsetsize;
- gid_t *gidset;
-};
-
-/* ARGSUSED */
-setgroups(p, uap, retval)
- struct proc *p;
- struct setgroups_args *uap;
- register_t *retval;
-{
- register struct pcred *pc = p->p_cred;
- struct ucred *new, *old;
- register u_int ngrp;
- int error;
- if (error = suser(pc->pc_ucred, &p->p_acflag))
- return (error);
- ngrp = uap->gidsetsize;
- if (ngrp > NGROUPS)
- return (EINVAL);
- new = crget();
-
- if ( ngrp < 1 ) {
- ngrp = 1;
- }
- else {
- error = copyin((caddr_t)uap->gidset,
- (caddr_t)new->cr_groups, ngrp * sizeof(gid_t));
- if (error) {
- crfree(new);
- return (error);
+/*
+ * seteuid
+ *
+ * Description: Set effective user ID system call
+ *
+ * Parameters: uap->euid effective uid to set
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permission denied
+ *
+ * Notes: If called by a privileged process, or called from an
+ * unprivileged process but euid is equal to the real or saved
+ * uid, then the effective uid will be set to the requested
+ * value, but the real and saved uid will not change.
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
+ */
+int
+seteuid(proc_t p, struct seteuid_args *uap, __unused int32_t *retval)
+{
+ uid_t euid;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+ posix_cred_t my_pcred;
+
+ DEBUG_CRED_ENTER("seteuid: %d\n", uap->euid);
+
+ euid = uap->euid;
+ AUDIT_ARG(euid, euid);
+
+ my_cred = kauth_cred_proc_ref(p);
+ my_pcred = posix_cred_get(my_cred);
+
+ 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) {
+ 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_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.
+ */
+ if (p->p_ucred != my_cred) {
+ 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;
+ }
+ p->p_ucred = my_new_cred;
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
+ proc_ucred_unlock(p);
+ }
+ break;
}
- new->cr_ngroups = ngrp;
- AUDIT_ARG(groupset, new->cr_groups, ngrp);
- pcred_writelock(p);
- old = pc->pc_ucred;
- new->cr_uid = old->cr_uid;
- pc->pc_ucred = new;
- pcred_unlock(p);
+ /* drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
set_security_token(p);
- p->p_flag |= P_SUGID;
- if (old != NOCRED)
- crfree(old);
- return (0);
-}
-
-#if COMPAT_43
-struct osetreuid_args{
- int ruid;
- int euid;
-};
-/* ARGSUSED */
-osetreuid(p, uap, retval)
- register struct proc *p;
- struct osetreuid_args *uap;
- register_t *retval;
-{
- struct seteuid_args seuidargs;
- struct setuid_args suidargs;
+ return 0;
+}
- /*
- * There are five cases, and we attempt to emulate them in
- * the following fashion:
- * -1, -1: return 0. This is correct emulation.
- * -1, N: call seteuid(N). This is correct emulation.
- * N, -1: if we called setuid(N), our euid would be changed
- * to N as well. the theory is that we don't want to
- * revoke root access yet, so we call seteuid(N)
- * instead. This is incorrect emulation, but often
- * suffices enough for binary compatibility.
- * N, N: call setuid(N). This is correct emulation.
- * N, M: call setuid(N). This is close to correct emulation.
- */
- if (uap->ruid == (uid_t)-1) {
- if (uap->euid == (uid_t)-1)
- return (0); /* -1, -1 */
- seuidargs.euid = uap->euid; /* -1, N */
- return (seteuid(p, &seuidargs, retval));
+
+/*
+ * setreuid
+ *
+ * Description: Set real and effective user ID system call
+ *
+ * Parameters: uap->ruid real uid to set
+ * uap->euid effective uid to set
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permission denied
+ *
+ * Notes: A value of -1 is a special case indicating that the uid for
+ * which that value is specified not be changed. If both values
+ * are specified as -1, no action is taken.
+ *
+ * If called by a privileged process, the real and effective uid
+ * will be set to the new value(s) specified.
+ *
+ * If called from an unprivileged process, the real uid may be
+ * set to the current value of the real uid, or to the current
+ * value of the saved uid. The effective uid may be set to the
+ * current value of any of the effective, real, or saved uid.
+ *
+ * If the newly requested real uid or effective uid does not
+ * match the saved uid, then set the saved uid to the new
+ * effective uid (potentially unrecoverably dropping saved
+ * privilege).
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
+ */
+int
+setreuid(proc_t p, struct setreuid_args *uap, __unused int32_t *retval)
+{
+ uid_t ruid, euid;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+ posix_cred_t my_pcred;
+
+ DEBUG_CRED_ENTER("setreuid %d %d\n", uap->ruid, uap->euid);
+
+ ruid = uap->ruid;
+ euid = uap->euid;
+ if (ruid == (uid_t)-1) {
+ ruid = KAUTH_UID_NONE;
}
- if (uap->euid == (uid_t)-1) {
- seuidargs.euid = uap->ruid; /* N, -1 */
- return (seteuid(p, &seuidargs, retval));
+ if (euid == (uid_t)-1) {
+ euid = KAUTH_UID_NONE;
}
- suidargs.uid = uap->ruid; /* N, N and N, M */
- return (setuid(p, &suidargs, retval));
+ AUDIT_ARG(euid, euid);
+ AUDIT_ARG(ruid, ruid);
+
+ my_cred = kauth_cred_proc_ref(p);
+ my_pcred = posix_cred_get(my_cred);
+
+ 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 svuid = KAUTH_UID_NONE;
+
+ new_euid = my_pcred->cr_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.
+ */
+ if (euid != KAUTH_UID_NONE && my_pcred->cr_uid != euid) {
+ /* changing the effective UID */
+ new_euid = euid;
+ 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
+ * new effective uid. We are protected from escalation
+ * by the prechecking.
+ */
+ if (my_pcred->cr_svuid != uap->ruid &&
+ my_pcred->cr_svuid != uap->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) {
+ 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);
+
+ /*
+ * 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_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);
+ 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;
+ }
+ /* drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ set_security_token(p);
+ return 0;
}
-struct osetregid_args {
- int rgid;
- int egid;
-};
-/* ARGSUSED */
-osetregid(p, uap, retval)
- register struct proc *p;
- struct osetregid_args *uap;
- register_t *retval;
+
+/*
+ * setgid
+ *
+ * Description: Set group ID system call
+ *
+ * Parameters: uap->gid gid to set
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permission denied
+ *
+ * Notes: If called by a privileged process, this function will set the
+ * real, effective, and saved gid to the requested value.
+ *
+ * If called from an unprivileged process, but gid is equal to the
+ * real or saved gid, then the effective gid will be set to the
+ * requested value, but the real and saved gid will not change.
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
+ *
+ * As an implementation detail, the effective gid is stored as
+ * the first element of the supplementary group list, and
+ * therefore the effective group list may be reordered to keep
+ * the supplementary group list unchanged.
+ */
+int
+setgid(proc_t p, struct setgid_args *uap, __unused int32_t *retval)
{
- struct setegid_args segidargs;
- struct setgid_args sgidargs;
+ gid_t gid;
+ gid_t rgid = KAUTH_GID_NONE;
+ gid_t svgid = KAUTH_GID_NONE;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+ posix_cred_t my_pcred;
- /*
- * There are five cases, described above in osetreuid()
- */
- if (uap->rgid == (gid_t)-1) {
- if (uap->egid == (gid_t)-1)
- return (0); /* -1, -1 */
- segidargs.egid = uap->egid; /* -1, N */
- return (setegid(p, &segidargs, retval));
- }
- if (uap->egid == (gid_t)-1) {
- segidargs.egid = uap->rgid; /* N, -1 */
- return (setegid(p, &segidargs, retval));
+ DEBUG_CRED_ENTER("setgid(%d/%d): %d\n", p->p_pid, (p->p_pptr ? p->p_pptr->p_pid : 0), uap->gid);
+
+ 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);
+
+ 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 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;
+ }
+
+ /*
+ * 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_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.
+ */
+ if (p->p_ucred != my_cred) {
+ 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_ucred_unlock(p);
+ }
+ break;
}
- sgidargs.gid = uap->rgid; /* N, N and N, M */
- return (setgid(p, &sgidargs, retval));
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ set_security_token(p);
+ return 0;
}
-#endif /* COMPAT_43 */
+
/*
- * Check if gid is a member of the group set.
+ * setegid
+ *
+ * Description: Set effective group ID system call
+ *
+ * Parameters: uap->egid effective gid to set
+ *
+ * Returns: 0 Success
+ * suser:EPERM
+ *
+ * Notes: If called by a privileged process, or called from an
+ * unprivileged process but egid is equal to the real or saved
+ * gid, then the effective gid will be set to the requested
+ * value, but the real and saved gid will not change.
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
+ *
+ * As an implementation detail, the effective gid is stored as
+ * the first element of the supplementary group list, and
+ * therefore the effective group list may be reordered to keep
+ * the supplementary group list unchanged.
*/
-groupmember(gid, cred)
- gid_t gid;
- register struct ucred *cred;
+int
+setegid(proc_t p, struct setegid_args *uap, __unused int32_t *retval)
{
- register gid_t *gp;
- gid_t *egp;
+ gid_t egid;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+ posix_cred_t my_pcred;
- egp = &(cred->cr_groups[cred->cr_ngroups]);
- for (gp = cred->cr_groups; gp < egp; gp++)
- if (*gp == gid)
- return (1);
- return (0);
+ DEBUG_CRED_ENTER("setegid %d\n", uap->egid);
+
+ 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);
+
+
+ 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_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.
+ */
+ if (p->p_ucred != my_cred) {
+ 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_ucred_unlock(p);
+ }
+ break;
+ }
+
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ set_security_token(p);
+ return 0;
}
/*
- * Test whether the specified credentials imply "super-user"
- * privilege; if so, and we have accounting info, set the flag
- * indicating use of super-powers.
- * Returns 0 or error.
+ * setregid
+ *
+ * Description: Set real and effective group ID system call
+ *
+ * Parameters: uap->rgid real gid to set
+ * uap->egid effective gid to set
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permission denied
+ *
+ * Notes: A value of -1 is a special case indicating that the gid for
+ * which that value is specified not be changed. If both values
+ * are specified as -1, no action is taken.
+ *
+ * If called by a privileged process, the real and effective gid
+ * will be set to the new value(s) specified.
+ *
+ * If called from an unprivileged process, the real gid may be
+ * set to the current value of the real gid, or to the current
+ * value of the saved gid. The effective gid may be set to the
+ * current value of any of the effective, real, or saved gid.
+ *
+ * If the new real and effective gid will not be equal, or the
+ * new real or effective gid is not the same as the saved gid,
+ * then the saved gid will be updated to reflect the new
+ * effective gid (potentially unrecoverably dropping saved
+ * privilege).
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
+ *
+ * As an implementation detail, the effective gid is stored as
+ * the first element of the supplementary group list, and
+ * therefore the effective group list may be reordered to keep
+ * the supplementary group list unchanged.
*/
-suser(cred, acflag)
- struct ucred *cred;
- u_short *acflag;
+int
+setregid(proc_t p, struct setregid_args *uap, __unused int32_t *retval)
{
-#if DIAGNOSTIC
- if (cred == NOCRED || cred == FSCRED)
- panic("suser");
-#endif
- if (cred->cr_uid == 0) {
- if (acflag)
- *acflag |= ASU;
- return (0);
+ gid_t rgid, egid;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+ posix_cred_t my_pcred;
+
+ DEBUG_CRED_ENTER("setregid %d %d\n", uap->rgid, uap->egid);
+
+ rgid = uap->rgid;
+ egid = uap->egid;
+
+ if (rgid == (uid_t)-1) {
+ rgid = KAUTH_GID_NONE;
+ }
+ if (egid == (uid_t)-1) {
+ egid = KAUTH_GID_NONE;
}
- return (EPERM);
+ 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);
+
+ 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) {
+ /* changing the effective GID */
+ new_egid = egid;
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
+ }
+ if (rgid != KAUTH_UID_NONE && my_pcred->cr_rgid != rgid) {
+ /* changing the real GID */
+ new_rgid = rgid;
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
+ }
+ /*
+ * If the newly requested real gid or effective gid does
+ * not match the saved gid, then set the saved gid to the
+ * new effective gid. We are protected from escalation
+ * by the prechecking.
+ */
+ if (my_pcred->cr_svgid != uap->rgid &&
+ my_pcred->cr_svgid != uap->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_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_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_ucred_unlock(p);
+ }
+ break;
+ }
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ set_security_token(p);
+ 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 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
+ * thread to the requested UID and single GID, and clears all other GIDs.
+ */
int
-is_suser(void)
+settid(proc_t p, struct settid_args *uap, __unused int32_t *retval)
{
- struct proc *p = current_proc();
+ kauth_cred_t uc;
+ struct uthread *uthread = get_bsdthread_info(current_thread());
+ uid_t uid;
+ gid_t gid;
+
+ uid = uap->uid;
+ gid = uap->gid;
+ AUDIT_ARG(uid, uid);
+ AUDIT_ARG(gid, gid);
+
+ 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;
+ }
+
+ /* revert to delayed binding of process credential */
+ uc = kauth_cred_proc_ref(p);
+ kauth_cred_unref(&uthread->uu_ucred);
+ uthread->uu_ucred = uc;
+ uthread->uu_flag &= ~UT_SETUID;
+ } else {
+ kauth_cred_t my_cred, my_new_cred;
- if (!p)
- return (0);
+ /* cannot already be assuming another identity */
+ if ((uthread->uu_flag & UT_SETUID) != 0) {
+ return EPERM;
+ }
+
+ /*
+ * Get a new credential instance from the old if this one
+ * changes; otherwise kauth_cred_setuidgid() returns the
+ * same credential. We take an extra reference on the
+ * current credential while we muck with it, so we can do
+ * the post-compare for changes by pointer.
+ */
+ 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) {
+ uthread->uu_ucred = my_new_cred;
+ }
+ uthread->uu_flag |= UT_SETUID;
- return (suser(p->p_ucred, &p->p_acflag) == 0);
+ /* Drop old uthread reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+ }
+ /*
+ * XXX should potentially set per thread security token (there is
+ * XXX none).
+ * XXX it is unclear whether P_SUGID should be st at this point;
+ * XXX in theory, it is being deprecated.
+ */
+ return 0;
}
+
+/*
+ * Set the per-thread override identity. Use this system call for a thread to
+ * assume the identity of another process or to revert back to normal identity
+ * of the current process.
+ *
+ * When the "assume" argument is non zero the current thread will assume the
+ * identity of the process represented by the pid argument.
+ *
+ * When the assume argument is zero we revert back to our normal identity.
+ */
int
-is_suser1(void)
+settid_with_pid(proc_t p, struct settid_with_pid_args *uap, __unused int32_t *retval)
{
- struct proc *p = current_proc();
+ proc_t target_proc;
+ struct uthread *uthread = get_bsdthread_info(current_thread());
+ kauth_cred_t my_cred, my_target_cred, my_new_cred;
+ posix_cred_t my_target_pcred;
+
+ AUDIT_ARG(pid, uap->pid);
+ AUDIT_ARG(value32, uap->assume);
+
+ if (proc_suser(p) != 0) {
+ return EPERM;
+ }
+
+ /*
+ * XXX should potentially set per thread security token (there is
+ * XXX none).
+ * XXX it is unclear whether P_SUGID should be st at this point;
+ * XXX in theory, it is being deprecated.
+ */
+
+ /*
+ * assume argument tells us to assume the identity of the process with the
+ * id passed in the pid argument.
+ */
+ if (uap->assume != 0) {
+ /* can't do this if we have already assumed an identity */
+ 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) {
+ proc_rele(target_proc);
+ }
+ return ESRCH;
+ }
+
+ /*
+ * Take a reference on the credential used in our target
+ * process then use it as the identity for our current
+ * thread. We take an extra reference on the current
+ * credential while we muck with it, so we can do the
+ * post-compare for changes by pointer.
+ *
+ * The post-compare is needed for the case that our process
+ * credential has been changed to be identical to our thread
+ * credential following our assumption of a per-thread one,
+ * since the credential cache will maintain a unique instance.
+ */
+ 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) {
+ 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;
+ }
+
+ /*
+ * 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 (!p)
- return (0);
+ /* 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 (suser(p->p_ucred, &p->p_acflag) == 0 ||
- p->p_cred->p_ruid == 0 || p->p_cred->p_svuid == 0);
+ return 0;
}
+
/*
- * Allocate a zeroed cred structure.
+ * setgroups1
+ *
+ * Description: Internal implementation for both the setgroups and initgroups
+ * system calls
+ *
+ * Parameters: gidsetsize Number of groups in set
+ * gidset Pointer to group list
+ * gmuid Base gid (initgroups only!)
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permision denied
+ * EINVAL Invalid gidsetsize value
+ * copyin:EFAULT Bad gidset or gidsetsize is
+ * too large
+ *
+ * Notes: When called from a thread running under an assumed per-thread
+ * identity, this function will operate against the per-thread
+ * credential, rather than against the process credential. In
+ * this specific case, the process credential is verified to
+ * still be privileged at the time of the call, rather than the
+ * per-thread credential for this operation to be permitted.
+ *
+ * This effectively means that setgroups/initigroups calls in
+ * a thread running a per-thread credential should occur *after*
+ * the settid call that created it, not before (unlike setuid,
+ * which must be called after, since it will result in privilege
+ * being dropped).
+ *
+ * When called normally (i.e. no per-thread assumed identity),
+ * the per process credential is updated per POSIX.
+ *
+ * If the credential is changed as a result of this call, then we
+ * flag the process as having set privilege since the last exec.
*/
-struct ucred *
-crget()
+static int
+setgroups1(proc_t p, u_int ngrp, user_addr_t gidset, uid_t gmuid, __unused int32_t *retval)
+{
+ 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), ngrp, gidset, gmuid);
+
+ if (ngrp > NGROUPS) {
+ return EINVAL;
+ }
+
+ if (ngrp >= 1) {
+ error = copyin(gidset,
+ (caddr_t)newgroups, ngrp * sizeof(gid_t));
+ if (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)
{
- register struct ucred *cr;
+ 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;
+ }
+
+ 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 */
+ kauth_cred_unref(&my_cred);
+
+ /*
+ * If this thread is under an assumed identity, set the
+ * supplementary grouplist on the thread credential instead
+ * of the process one. If we were the only reference holder,
+ * the credential is updated in place, otherwise, our reference
+ * is dropped and we get back a different cred with a reference
+ * already held on it. Because this is per-thread, we don't
+ * need the referencing/locking/retry required for per-process.
+ */
+ my_cred = uthread->uu_ucred;
+ 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);
+ }
+#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
+ * 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_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_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.
+ */
+ if (p->p_ucred != my_cred) {
+ proc_ucred_unlock(p);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
+ /* try again */
+ continue;
+ }
+ p->p_ucred = my_new_cred;
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
+ proc_ucred_unlock(p);
+ }
+ break;
+ }
+ /* Drop old proc reference or our extra reference */
+ AUDIT_ARG(groupset, posix_cred_get(my_cred)->cr_groups, ngrp);
+ kauth_cred_unref(&my_cred);
+
- MALLOC_ZONE(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK);
- bzero((caddr_t)cr, sizeof(*cr));
- cr->cr_ref = 1;
- return (cr);
+ set_security_token(p);
+ }
+
+ return 0;
}
+
/*
- * Free a cred structure.
- * Throws away space when ref count gets to 0.
+ * initgroups
+ *
+ * Description: Initialize the default supplementary groups list and set the
+ * gmuid for use by the external group resolver (if any)
+ *
+ * Parameters: uap->gidsetsize Number of groups in set
+ * uap->gidset Pointer to group list
+ * uap->gmuid Base gid
+ *
+ * Returns: 0 Success
+ * setgroups1:EPERM Permision denied
+ * setgroups1:EINVAL Invalid gidsetsize value
+ * setgroups1:EFAULT Bad gidset or gidsetsize is
+ *
+ * Notes: This function opts *IN* to memberd participation
+ *
+ * The normal purpose of this function is for a privileged
+ * process to indicate supplementary groups and identity for
+ * participation in extended group membership resolution prior
+ * to dropping privilege by assuming a specific user identity.
+ *
+ * It is the first half of the primary mechanism whereby user
+ * identity is established to the system by programs such as
+ * /usr/bin/login. The second half is the drop of uid privilege
+ * for a specific uid corresponding to the user.
+ *
+ * See also: setgroups1()
*/
-void
-crfree(cr)
- struct ucred *cr;
+int
+initgroups(proc_t p, struct initgroups_args *uap, __unused int32_t *retval)
{
-#if DIAGNOSTIC
- if (cr == NOCRED || cr == FSCRED)
- panic("crfree");
-#endif
- if (--cr->cr_ref == 0)
- FREE_ZONE((caddr_t)cr, sizeof *cr, M_CRED);
+ DEBUG_CRED_ENTER("initgroups\n");
+
+ return setgroups1(p, uap->gidsetsize, uap->gidset, uap->gmuid, retval);
}
+
/*
- * Copy cred structure to a new one and free the old one.
+ * setgroups
+ *
+ * Description: Initialize the default supplementary groups list
+ *
+ * Parameters: gidsetsize Number of groups in set
+ * gidset Pointer to group list
+ *
+ * Returns: 0 Success
+ * setgroups1:EPERM Permision denied
+ * setgroups1:EINVAL Invalid gidsetsize value
+ * setgroups1:EFAULT Bad gidset or gidsetsize is
+ *
+ * Notes: This functions opts *OUT* of memberd participation.
+ *
+ * This function exists for compatibility with POSIX. Most user
+ * programs should use initgroups() instead to ensure correct
+ * participation in group membership resolution when utilizing
+ * a directory service for authentication.
+ *
+ * It is identical to an initgroups() call with a gmuid argument
+ * of KAUTH_UID_NONE.
+ *
+ * See also: setgroups1()
*/
-struct ucred *
-crcopy(cr)
- struct ucred *cr;
+int
+setgroups(proc_t p, struct setgroups_args *uap, __unused int32_t *retval)
{
- struct ucred *newcr;
+ DEBUG_CRED_ENTER("setgroups\n");
-#if DIAGNOSTIC
- if (cr == NOCRED || cr == FSCRED)
- panic("crcopy");
-#endif
- if (cr->cr_ref == 1)
- return (cr);
- newcr = crget();
- *newcr = *cr;
- crfree(cr);
- newcr->cr_ref = 1;
- return (newcr);
+ return setgroups1(p, uap->gidsetsize, uap->gidset, KAUTH_UID_NONE, retval);
}
+
/*
- * Dup cred struct to a new held one.
+ * Set the per-thread/per-process supplementary groups list.
+ *
+ * XXX implement setsgroups
+ *
*/
-struct ucred *
-crdup(cr)
- struct ucred *cr;
+
+int
+setsgroups(__unused proc_t p, __unused struct setsgroups_args *uap, __unused int32_t *retval)
{
- struct ucred *newcr;
+ return ENOTSUP;
+}
-#if DIAGNOSTIC
- if (cr == NOCRED || cr == FSCRED)
- panic("crdup");
-#endif
- newcr = crget();
- *newcr = *cr;
- newcr->cr_ref = 1;
- return (newcr);
+/*
+ * Set the per-thread/per-process whiteout groups list.
+ *
+ * XXX implement setwgroups
+ *
+ */
+
+int
+setwgroups(__unused proc_t p, __unused struct setwgroups_args *uap, __unused int32_t *retval)
+{
+ return ENOTSUP;
}
+
/*
- * compare two cred structs
+ * Check if gid is a member of the group set.
+ *
+ * XXX This interface is going away; use kauth_cred_ismember_gid() directly
+ * XXX instead.
*/
int
-crcmp(cr1, cr2)
- struct ucred *cr1;
- struct ucred *cr2;
+groupmember(gid_t gid, kauth_cred_t cred)
{
- int i;
+ int is_member;
- if (cr1 == cr2)
- return 0;
- if (cr1 == NOCRED || cr1 == FSCRED ||
- cr2 == NOCRED || cr2 == FSCRED)
- return 1;
- if (cr1->cr_uid != cr2->cr_uid)
- return 1;
- if (cr1->cr_ngroups != cr2->cr_ngroups)
+ if (kauth_cred_ismember_gid(cred, gid, &is_member) == 0 && is_member) {
return 1;
- // XXX assumes groups will always be listed in some order
- for (i=0; i < cr1->cr_ngroups; i++)
- if (cr1->cr_groups[i] != cr2->cr_groups[i])
- return 1;
- return (0);
+ }
+ return 0;
+}
+
+
+/*
+ * Test whether the specified credentials imply "super-user"
+ * privilege; if so, and we have accounting info, set the flag
+ * indicating use of super-powers.
+ * Returns 0 or error.
+ *
+ * XXX This interface is going away; use kauth_cred_issuser() directly
+ * XXX instead.
+ *
+ * Note: This interface exists to implement the "has used privilege"
+ * bit (ASU) in the p_acflags field of the process, which is
+ * only externalized via private sysctl and in process accounting
+ * records. The flag is technically not required in either case.
+ */
+int
+suser(kauth_cred_t cred, u_short *acflag)
+{
+#if DIAGNOSTIC
+ if (!IS_VALID_CRED(cred)) {
+ panic("suser");
+ }
+#endif
+ if (kauth_cred_getuid(cred) == 0) {
+ if (acflag) {
+ *acflag |= ASU;
+ }
+ return 0;
+ }
+ return EPERM;
}
+
/*
- * Get login name, if available.
+ * getlogin
+ *
+ * Description: Get login name, if available.
+ *
+ * Parameters: uap->namebuf User buffer for return
+ * uap->namelen User buffer length
+ *
+ * Returns: 0 Success
+ * copyout:EFAULT
+ *
+ * Notes: Intended to obtain a string containing the user name of the
+ * user associated with the controlling terminal for the calling
+ * process.
+ *
+ * Not very useful on modern systems, due to inherent length
+ * limitations for the static array in the session structure
+ * which is used to store the login name.
+ *
+ * Permitted to return NULL
+ *
+ * XXX: Belongs in kern_proc.c
*/
-struct getlogin_args {
- char *namebuf;
- u_int namelen;
-};
-/* ARGSUSED */
-getlogin(p, uap, retval)
- struct proc *p;
- struct getlogin_args *uap;
- register_t *retval;
+int
+getlogin(proc_t p, struct getlogin_args *uap, __unused int32_t *retval)
+{
+ char buffer[MAXLOGNAME + 1];
+ struct session * sessp;
+
+ bzero(buffer, MAXLOGNAME + 1);
+
+ sessp = proc_session(p);
+
+ if (uap->namelen > MAXLOGNAME) {
+ uap->namelen = MAXLOGNAME;
+ }
+
+ 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);
+}
+
+void
+setlogin_internal(proc_t p, const char login[static MAXLOGNAME])
{
+ struct session *sessp = proc_session(p);
- if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login))
- uap->namelen = sizeof (p->p_pgrp->pg_session->s_login);
- return (copyout((caddr_t) p->p_pgrp->pg_session->s_login,
- (caddr_t)uap->namebuf, uap->namelen));
+ if (sessp != SESSION_NULL) {
+ session_lock(sessp);
+ bcopy(login, sessp->s_login, MAXLOGNAME);
+ session_unlock(sessp);
+ session_rele(sessp);
+ }
}
/*
- * Set login name.
+ * setlogin
+ *
+ * Description: Set login name.
+ *
+ * Parameters: uap->namebuf User buffer containing name
+ *
+ * Returns: 0 Success
+ * suser:EPERM Permission denied
+ * copyinstr:EFAULT User buffer invalid
+ * copyinstr:EINVAL Supplied name was too long
+ *
+ * Notes: This is a utility system call to support getlogin().
+ *
+ * XXX: Belongs in kern_proc.c
*/
-struct setlogin_args {
- char *namebuf;
-};
-/* ARGSUSED */
-setlogin(p, uap, retval)
- struct proc *p;
- struct setlogin_args *uap;
- register_t *retval;
+int
+setlogin(proc_t p, struct setlogin_args *uap, __unused int32_t *retval)
{
int error;
- int dummy=0;
-
- if (error = suser(p->p_ucred, &p->p_acflag))
- return (error);
-
- error = copyinstr((caddr_t) uap->namebuf,
- (caddr_t) p->p_pgrp->pg_session->s_login,
- sizeof (p->p_pgrp->pg_session->s_login) - 1, (size_t *)&dummy);
- if (error == ENAMETOOLONG)
+ size_t dummy = 0;
+ char buffer[MAXLOGNAME + 1];
+
+ if ((error = proc_suser(p))) {
+ return error;
+ }
+
+ bzero(&buffer[0], MAXLOGNAME + 1);
+
+
+ error = copyinstr(uap->namebuf,
+ (caddr_t) &buffer[0],
+ MAXLOGNAME - 1, (size_t *)&dummy);
+
+ setlogin_internal(p, buffer);
+
+ if (!error) {
+ AUDIT_ARG(text, buffer);
+ } else if (error == ENAMETOOLONG) {
error = EINVAL;
- return (error);
+ }
+ return error;
}
/* Set the secrity token of the task with current euid and eguid */
-kern_return_t
-set_security_token(struct proc * p)
+/*
+ * XXX This needs to change to give the task a reference and/or an opaque
+ * XXX identifier.
+ */
+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
+ * (since they share a task). Instead, the child will just have to
+ * suffer along using the parent's token until the exec(). It's all
+ * undefined behavior anyway, right?
+ */
+ if (task == current_task()) {
+ uthread_t uthread;
+ uthread = (uthread_t)get_bsdthread_info(current_thread());
+ if (uthread->uu_flag & UT_VFORK) {
+ return 1;
+ }
+ }
+
+ my_cred = kauth_cred_proc_ref(p);
+ my_pcred = posix_cred_get(my_cred);
+
+ /* XXX mach_init doesn't have a p_ucred when it calls this function */
+ if (IS_VALID_CRED(my_cred)) {
+ sec_token.val[0] = kauth_cred_getuid(my_cred);
+ sec_token.val[1] = kauth_cred_getgid(my_cred);
+ } else {
+ sec_token.val[0] = 0;
+ sec_token.val[1] = 0;
+ }
+
+ /*
+ * The current layout of the Mach audit token explicitly
+ * adds these fields. But nobody should rely on such
+ * a literal representation. Instead, the BSM library
+ * provides a function to convert an audit token into
+ * a BSM subject. Use of that mechanism will isolate
+ * the user of the trailer from future representation
+ * changes.
+ */
+ audit_token.val[0] = my_cred->cr_audit.as_aia_p->ai_auid;
+ audit_token.val[1] = my_pcred->cr_uid;
+ audit_token.val[2] = my_pcred->cr_gid;
+ audit_token.val[3] = my_pcred->cr_ruid;
+ audit_token.val[4] = my_pcred->cr_rgid;
+ audit_token.val[5] = p->p_pid;
+ audit_token.val[6] = my_cred->cr_audit.as_aia_p->ai_asid;
+ audit_token.val[7] = p->p_idversion;
+
+ 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)) {
+ host_priv = HOST_PRIV_NULL;
+ }
+#endif
+ kauth_cred_unref(&my_cred);
+
+#if DEVELOPMENT || DEBUG
+ /*
+ * Update the pid an proc name for importance base if any
+ */
+ task_importance_update_owner_info(task);
+#endif
- sec_token.val[0] = p->p_ucred->cr_uid;
- sec_token.val[1] = p->p_ucred->cr_gid;
- audit_token.val[0] = p->p_au->ai_auid;
- audit_token.val[1] = p->p_au->ai_asid;
- /* use au_tid for now, until au_tid_addr is put to use */
- audit_token.val[2] = p->p_au->ai_termid.port;
- audit_token.val[3] = p->p_au->ai_termid.machine;
- audit_token.val[4] = 0;
- audit_token.val[5] = 0;
- audit_token.val[6] = 0;
- audit_token.val[7] = 0;
return host_security_set_task_token(host_security_self(),
- p->task,
- sec_token,
- audit_token,
- (sec_token.val[0]) ?
- HOST_PRIV_NULL :
- host_priv_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;
}
/*
- * Fill in a struct xucred based on a struct ucred.
+ * Fill in a struct xucred based on a kauth_cred_t.
*/
__private_extern__
void
-cru2x(struct ucred *cr, struct xucred *xcr)
+cru2x(kauth_cred_t cr, struct xucred *xcr)
{
+ posix_cred_t pcr = posix_cred_get(cr);
bzero(xcr, sizeof(*xcr));
xcr->cr_version = XUCRED_VERSION;
- xcr->cr_uid = cr->cr_uid;
- xcr->cr_ngroups = cr->cr_ngroups;
- bcopy(cr->cr_groups, xcr->cr_groups, sizeof(xcr->cr_groups));
+ xcr->cr_uid = kauth_cred_getuid(cr);
+ xcr->cr_ngroups = pcr->cr_ngroups;
+ bcopy(pcr->cr_groups, xcr->cr_groups, sizeof(xcr->cr_groups));
}
projects / apple / xnu.git / blobdiff