/*
- * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
*
* @(#)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.
+ */
/*
* System calls related to processes and protection
#include <bsm/audit_kernel.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 <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>
+
int groupmember(gid_t gid, kauth_cred_t cred);
-int is_suser(void);
-int is_suser1(void);
-extern int prepare_profile_database(int user);
+/*
+ * 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 */
+
+
/*
- * 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
*/
int
-setprivexec(struct proc *p, struct setprivexec_args *uap, register_t *retval)
+setprivexec(proc_t p, struct setprivexec_args *uap, register_t *retval)
{
AUDIT_ARG(value, uap->flag);
*retval = p->p_debugger;
return(0);
}
-/* ARGSUSED */
+
+/*
+ * getpid
+ *
+ * Description: get the process ID
+ *
+ * Parameters: (void)
+ *
+ * Returns: pid_t Current process ID
+ *
+ * XXX: Belongs in kern_proc.c
+ */
int
-getpid(struct proc *p, __unused struct getpid_args *uap, register_t *retval)
+getpid(proc_t p, __unused struct getpid_args *uap, register_t *retval)
{
*retval = p->p_pid;
return (0);
}
-/* ARGSUSED */
+
+/*
+ * getppid
+ *
+ * Description: get the parent process ID
+ *
+ * Parameters: (void)
+ *
+ * Returns: pid_t Parent process ID
+ *
+ * XXX: Belongs in kern_proc.c
+ */
int
-getppid(struct proc *p, __unused struct getppid_args *uap, register_t *retval)
+getppid(proc_t p, __unused struct getppid_args *uap, register_t *retval)
{
- *retval = p->p_pptr->p_pid;
+ *retval = p->p_ppid;
return (0);
}
-/* Get process group ID; note that POSIX getpgrp takes no parameter */
+
+/*
+ * 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(struct proc *p, __unused struct getpgrp_args *uap, register_t *retval)
+getpgrp(proc_t p, __unused struct getpgrp_args *uap, register_t *retval)
{
- *retval = p->p_pgrp->pg_id;
+ *retval = p->p_pgrpid;
return (0);
}
-/* Get an arbitary pid's process group id */
+
+/*
+ * 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(struct proc *p, struct getpgid_args *uap, register_t *retval)
+getpgid(proc_t p, struct getpgid_args *uap, register_t *retval)
{
- struct proc *pt;
+ proc_t pt;
+ int refheld = 0;
pt = p;
if (uap->pid == 0)
goto found;
- if ((pt = pfind(uap->pid)) == 0)
+ if ((pt = proc_find(uap->pid)) == 0)
return (ESRCH);
+ refheld = 1;
found:
- *retval = pt->p_pgrp->pg_id;
+ *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
*/
-
int
-getsid(struct proc *p, struct getsid_args *uap, register_t *retval)
+getsid(proc_t p, struct getsid_args *uap, register_t *retval)
{
- struct proc *pt;
+ proc_t pt;
+ int refheld = 0;
+ struct session * sessp;
pt = p;
if (uap->pid == 0)
goto found;
- if ((pt = pfind(uap->pid)) == 0)
+ if ((pt = proc_find(uap->pid)) == 0)
return (ESRCH);
+ refheld = 1;
found:
- *retval = pt->p_session->s_sid;
+ sessp = proc_session(pt);
+ *retval = sessp->s_sid;
+ session_rele(sessp);
+
+ if (refheld != 0)
+ proc_rele(pt);
return (0);
}
-/* ARGSUSED */
+
+/*
+ * getuid
+ *
+ * Description: get real user ID for caller
+ *
+ * Parameters: (void)
+ *
+ * Returns: uid_t The real uid of the caller
+ */
int
-getuid(__unused struct proc *p, __unused struct getuid_args *uap, register_t *retval)
+getuid(__unused proc_t p, __unused struct getuid_args *uap, register_t *retval)
{
*retval = kauth_getruid();
return (0);
}
-/* ARGSUSED */
+
+/*
+ * geteuid
+ *
+ * Description: get effective user ID for caller
+ *
+ * Parameters: (void)
+ *
+ * Returns: uid_t The effective uid of the caller
+ */
int
-geteuid(__unused struct proc *p, __unused struct geteuid_args *uap, register_t *retval)
+geteuid(__unused proc_t p, __unused struct geteuid_args *uap, register_t *retval)
{
*retval = kauth_getuid();
return (0);
}
+
/*
- * Return the per-thread override identity.
+ * 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 struct proc *p, struct gettid_args *uap, register_t *retval)
+gettid(__unused proc_t p, struct gettid_args *uap, register_t *retval)
{
struct uthread *uthread = get_bsdthread_info(current_thread());
int error;
return (0);
}
-/* ARGSUSED */
+
+/*
+ * getgid
+ *
+ * Description: get the real group ID for the calling process
+ *
+ * Parameters: (void)
+ *
+ * Returns: gid_t The real gid of the caller
+ */
int
-getgid(__unused struct proc *p, __unused struct getgid_args *uap, register_t *retval)
+getgid(__unused proc_t p, __unused struct getgid_args *uap, register_t *retval)
{
*retval = kauth_getrgid();
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.
+ * 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.
*/
-/* ARGSUSED */
int
-getegid(struct proc *p, __unused struct getegid_args *uap, register_t *retval)
+getegid(__unused proc_t p, __unused struct getegid_args *uap, register_t *retval)
{
*retval = kauth_getgid();
return (0);
}
+
+/*
+ * 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 struct proc *p, struct getgroups_args *uap, register_t *retval)
+getgroups(__unused proc_t p, struct getgroups_args *uap, register_t *retval)
{
- register int ngrp;
+ int ngrp;
int error;
kauth_cred_t cred;
if ((ngrp = uap->gidsetsize) == 0) {
*retval = cred->cr_ngroups;
- kauth_cred_rele(cred);
+ kauth_cred_unref(&cred);
return (0);
}
if (ngrp < cred->cr_ngroups) {
- kauth_cred_rele(cred);
+ kauth_cred_unref(&cred);
return (EINVAL);
}
ngrp = cred->cr_ngroups;
if ((error = copyout((caddr_t)cred->cr_groups,
uap->gidset,
ngrp * sizeof(gid_t)))) {
- kauth_cred_rele(cred);
+ kauth_cred_unref(&cred);
return (error);
}
- kauth_cred_rele(cred);
+ kauth_cred_unref(&cred);
*retval = ngrp;
return (0);
}
+
/*
* Return the per-thread/per-process supplementary groups list.
*/
-#warning XXX implement
+#warning XXX implement getsgroups
int
-getsgroups(__unused struct proc *p, __unused struct getsgroups_args *uap, __unused register_t *retval)
+getsgroups(__unused proc_t p, __unused struct getsgroups_args *uap, __unused register_t *retval)
{
/* XXX implement */
return(ENOTSUP);
/*
* Return the per-thread/per-process whiteout groups list.
*/
-#warning XXX implement
+#warning XXX implement getwgroups
int
-getwgroups(__unused struct proc *p, __unused struct getwgroups_args *uap, __unused register_t *retval)
+getwgroups(__unused proc_t p, __unused struct getwgroups_args *uap, __unused register_t *retval)
{
/* XXX implement */
return(ENOTSUP);
}
-/* ARGSUSED */
+
+/*
+ * 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(struct proc *p, __unused struct setsid_args *uap, register_t *retval)
+setsid(proc_t p, __unused struct setsid_args *uap, register_t *retval)
{
+ struct pgrp * pg = PGRP_NULL;
- if (p->p_pgid == p->p_pid || pgfind(p->p_pid) || p->p_flag & P_INVFORK) {
+ 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);
*retval = p->p_pid;
return (0);
}
}
+
/*
- * set process group (setpgid/old setpgrp)
+ * setpgid
*
- * caller does setpgid(targpid, targpgid)
+ * Description: set process group ID for job control
*
- * 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)
- * ig pgid is -ve return EINVAL (as per SUV spec)
- * if pgid != pid
- * there must exist some pid in same session having pgid (EPERM)
- * pid must not be session leader (EPERM)
+ * Parameters: uap->pid Process to change
+ * uap->pgid Process group to join or create
+ *
+ * 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
+ *
+ * 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
*/
-/* ARGSUSED */
int
-setpgid(struct proc *curp, register struct setpgid_args *uap, __unused register_t *retval)
+setpgid(proc_t curp, register struct setpgid_args *uap, __unused register_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)
- return(EINVAL);
+ 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
-issetugid(struct proc *p, __unused struct issetugid_args *uap, register_t *retval)
+issetugid(proc_t p, __unused struct issetugid_args *uap, register_t *retval)
{
/*
* Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
return (0);
}
-/* ARGSUSED */
+
+/*
+ * 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(struct proc *p, struct setuid_args *uap, __unused register_t *retval)
+setuid(proc_t p, struct setuid_args *uap, __unused register_t *retval)
{
- 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;
+
uid = uap->uid;
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ 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, 0, 0, 0);
- if (uid != p->p_ucred->cr_ruid &&
- (error = suser(p->p_ucred, &p->p_acflag)))
+
+ if (uid != my_cred->cr_ruid && /* allow setuid(getuid()) */
+ uid != my_cred->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.
- * 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);
- (void)chgproccnt(kauth_getruid(), -1);
- (void)chgproccnt(uid, 1);
+ /*
+ * 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
+ */
+ (void)chgproccnt(uid, 1);
+ (void)chgproccnt(kauth_getruid(), -1);
+ }
/* get current credential and take a reference while we muck with it */
for (;;) {
- my_cred = kauth_cred_proc_ref(p);
-
- /*
- * set the credential with new info. If there is no change we get back
- * the same credential we passed in.
+ /*
+ * 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).
*/
- my_new_cred = kauth_cred_setuid(my_cred, uid);
+ if (!(my_cred->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_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
proc_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.
+ /*
+ * 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_unlock(p);
- kauth_cred_rele(my_cred);
- kauth_cred_rele(my_new_cred);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
/* try again */
continue;
}
p->p_ucred = my_new_cred;
- p->p_flag |= P_SUGID;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
proc_unlock(p);
}
- /* drop our extra reference */
- kauth_cred_rele(my_cred);
break;
}
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
set_security_token(p);
return (0);
}
-/* ARGSUSED */
+
+/*
+ * 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(struct proc *p, struct seteuid_args *uap, __unused register_t *retval)
+seteuid(proc_t p, struct seteuid_args *uap, __unused register_t *retval)
{
- register uid_t euid;
+ uid_t euid;
int error;
kauth_cred_t my_cred, my_new_cred;
+ DEBUG_CRED_ENTER("seteuid: %d\n", uap->euid);
+
euid = uap->euid;
AUDIT_ARG(uid, 0, euid, 0, 0);
- if (euid != p->p_ucred->cr_ruid && euid != p->p_ucred->cr_svuid &&
- (error = suser(p->p_ucred, &p->p_acflag)))
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ if (euid != my_cred->cr_ruid && euid != my_cred->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 (;;) {
+ /*
+ * 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_cred->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_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
+ proc_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_unlock(p);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
+ /* try again */
+ continue;
+ }
+ p->p_ucred = my_new_cred;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
+ proc_unlock(p);
+ }
+ break;
+ }
+ /* drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ set_security_token(p);
+ return (0);
+}
+
+
+/*
+ * 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 register_t *retval)
+{
+ uid_t ruid, euid;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+
+ 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 (euid == (uid_t)-1)
+ euid = KAUTH_UID_NONE;
+ AUDIT_ARG(uid, euid, ruid, 0, 0);
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ if (((ruid != KAUTH_UID_NONE && /* allow no change of ruid */
+ ruid != my_cred->cr_ruid && /* allow ruid = ruid */
+ ruid != my_cred->cr_uid && /* allow ruid = euid */
+ ruid != my_cred->cr_svuid) || /* allow ruid = svuid */
+ (euid != KAUTH_UID_NONE && /* allow no change of euid */
+ euid != my_cred->cr_uid && /* allow euid = euid */
+ euid != my_cred->cr_ruid && /* allow euid = ruid */
+ euid != my_cred->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 (;;) {
- my_cred = kauth_cred_proc_ref(p);
+ uid_t new_euid;
+ uid_t new_ruid;
+ uid_t svuid = KAUTH_UID_NONE;
+
+ new_euid = my_cred->cr_uid;
+ new_ruid = my_cred->cr_ruid;
- /*
- * set the credential with new info. If there is no change we get back
- * the same credential we passed in.
+ /*
+ * 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_cred->cr_uid != euid) {
+ /* changing the effective UID */
+ new_euid = euid;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
+ }
+ if (ruid != KAUTH_UID_NONE && my_cred->cr_ruid != ruid) {
+ /* changing the real UID; must do user accounting */
+ /* chgproccnt uses list lock for protection */
+ (void)chgproccnt(ruid, 1);
+ (void)chgproccnt(my_cred->cr_ruid, -1);
+ new_ruid = ruid;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&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.
*/
- my_new_cred = kauth_cred_seteuid(p->p_ucred, euid);
+ if (my_cred->cr_svuid != uap->ruid &&
+ my_cred->cr_svuid != uap->euid) {
+ svuid = new_euid;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
+ }
+
+ my_new_cred = kauth_cred_setresuid(my_cred, ruid, euid, svuid, my_cred->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_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
proc_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.
+ /*
+ * 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_unlock(p);
- kauth_cred_rele(my_cred);
- kauth_cred_rele(my_new_cred);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
/* try again */
continue;
}
p->p_ucred = my_new_cred;
- p->p_flag |= P_SUGID;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag); /* XXX redundant? */
proc_unlock(p);
}
- /* drop our extra reference */
- kauth_cred_rele(my_cred);
break;
}
+ /* drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
set_security_token(p);
return (0);
}
-/* ARGSUSED */
+
+/*
+ * 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(struct proc *p, struct setgid_args *uap, __unused register_t *retval)
+setgid(proc_t p, struct setgid_args *uap, __unused register_t *retval)
{
- register gid_t gid;
+ 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;
+ 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, 0, 0, 0);
- if (gid != p->p_ucred->cr_rgid && (error = suser(p->p_ucred, &p->p_acflag)))
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ if (gid != my_cred->cr_rgid && /* allow setgid(getgid()) */
+ gid != my_cred->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;
+ }
/* get current credential and take a reference while we muck with it */
for (;;) {
- my_cred = kauth_cred_proc_ref(p);
- /*
- * set the credential with new info. If there is no change we get back
- * the same credential we passed in.
- */
- my_new_cred = kauth_cred_setgid(p->p_ucred, gid);
+ /*
+ * 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);
- /* 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.
+ /*
+ * 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_unlock(p);
- kauth_cred_rele(my_cred);
- kauth_cred_rele(my_new_cred);
+ kauth_cred_unref(&my_new_cred);
/* try again */
+ my_cred = kauth_cred_proc_ref(p);
continue;
}
p->p_ucred = my_new_cred;
- p->p_flag |= P_SUGID;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
proc_unlock(p);
}
- /* drop our extra reference */
- kauth_cred_rele(my_cred);
break;
}
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
set_security_token(p);
return (0);
}
-/* ARGSUSED */
+
+/*
+ * 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.
+ */
int
-setegid(struct proc *p, struct setegid_args *uap, __unused register_t *retval)
+setegid(proc_t p, struct setegid_args *uap, __unused register_t *retval)
{
- register gid_t egid;
+ gid_t egid;
int error;
kauth_cred_t my_cred, my_new_cred;
+ DEBUG_CRED_ENTER("setegid %d\n", uap->egid);
+
egid = uap->egid;
AUDIT_ARG(gid, 0, egid, 0, 0);
- if (egid != p->p_ucred->cr_rgid && egid != p->p_ucred->cr_svgid &&
- (error = suser(p->p_ucred, &p->p_acflag)))
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ if (egid != my_cred->cr_rgid &&
+ egid != my_cred->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 (;;) {
- my_cred = kauth_cred_proc_ref(p);
+ /*
+ * 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_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
+ proc_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_unlock(p);
+ kauth_cred_unref(&my_new_cred);
+ /* try again */
+ my_cred = kauth_cred_proc_ref(p);
+ continue;
+ }
+ p->p_ucred = my_new_cred;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
+ proc_unlock(p);
+ }
+ break;
+ }
+
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ set_security_token(p);
+ return (0);
+}
+
+/*
+ * 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.
+ */
+int
+setregid(proc_t p, struct setregid_args *uap, __unused register_t *retval)
+{
+ gid_t rgid, egid;
+ int error;
+ kauth_cred_t my_cred, my_new_cred;
+
+ 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;
+ AUDIT_ARG(gid, egid, rgid, 0, 0);
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ if (((rgid != KAUTH_UID_NONE && /* allow no change of rgid */
+ rgid != my_cred->cr_rgid && /* allow rgid = rgid */
+ rgid != my_cred->cr_gid && /* allow rgid = egid */
+ rgid != my_cred->cr_svgid) || /* allow rgid = svgid */
+ (egid != KAUTH_UID_NONE && /* allow no change of egid */
+ egid != my_cred->cr_groups[0] && /* allow no change of egid */
+ egid != my_cred->cr_gid && /* allow egid = egid */
+ egid != my_cred->cr_rgid && /* allow egid = rgid */
+ egid != my_cred->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 (;;) {
+ uid_t new_egid = my_cred->cr_gid;
+ uid_t new_rgid = my_cred->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.
+ /*
+ * 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_cred->cr_groups[0] != egid) {
+ /* changing the effective GID */
+ new_egid = egid;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
+ }
+ if (rgid != KAUTH_UID_NONE && my_cred->cr_rgid != rgid) {
+ /* changing the real GID */
+ new_rgid = rgid;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&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.
*/
- my_new_cred = kauth_cred_setegid(p->p_ucred, egid);
+ if (my_cred->cr_svgid != uap->rgid &&
+ my_cred->cr_svgid != uap->egid) {
+ svgid = new_egid;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&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_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
proc_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.
+ /* 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);
- kauth_cred_rele(my_cred);
- kauth_cred_rele(my_new_cred);
+ kauth_cred_unref(&my_new_cred);
/* try again */
+ my_cred = kauth_cred_proc_ref(p);
continue;
}
p->p_ucred = my_new_cred;
- p->p_flag |= P_SUGID;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag); /* XXX redundant? */
proc_unlock(p);
}
- /* drop our extra reference */
- kauth_cred_rele(my_cred);
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 priviledged, it
* thread to the requested UID and single GID, and clears all other GIDs.
*/
int
-settid(struct proc *p, struct settid_args *uap, __unused register_t *retval)
+settid(proc_t p, struct settid_args *uap, __unused register_t *retval)
{
kauth_cred_t uc;
struct uthread *uthread = get_bsdthread_info(current_thread());
- register uid_t uid;
- register gid_t gid;
+ uid_t uid;
+ gid_t gid;
uid = uap->uid;
gid = uap->gid;
AUDIT_ARG(uid, uid, gid, gid, 0);
- if (suser(p->p_ucred, &p->p_acflag) != 0) {
+ if (proc_suser(p) != 0)
return (EPERM);
- }
if (uid == KAUTH_UID_NONE) {
/* revert to delayed binding of process credential */
uc = kauth_cred_proc_ref(p);
- kauth_cred_rele(uthread->uu_ucred);
+ kauth_cred_unref(&uthread->uu_ucred);
uthread->uu_ucred = uc;
uthread->uu_flag &= ~UT_SETUID;
} else {
}
/*
- * get a new credential instance from the old if this one changes else
- * kauth_cred_setuidgid returns the same credential. we take an extra
- * reference on the current credential while we muck wit it here.
+ * 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;
uthread->uu_ucred = my_new_cred;
uthread->uu_flag |= UT_SETUID;
- /* drop our extra reference */
- kauth_cred_rele(my_cred);
+ /* Drop old uthread reference or our extra reference */
+ kauth_cred_unref(&my_cred);
}
/*
* XXX should potentially set per thread security token (there is
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
+ * 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
+ *
+ * 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
-settid_with_pid(struct proc *p, struct settid_with_pid_args *uap, __unused register_t *retval)
+settid_with_pid(proc_t p, struct settid_with_pid_args *uap, __unused register_t *retval)
{
proc_t target_proc;
struct uthread *uthread = get_bsdthread_info(current_thread());
AUDIT_ARG(pid, uap->pid);
AUDIT_ARG(value, uap->assume);
- if (suser(p->p_ucred, &p->p_acflag) != 0) {
+ if (proc_suser(p) != 0) {
return (EPERM);
}
if ((uthread->uu_flag & UT_SETUID) != 0)
return (EPERM);
- target_proc = pfind(uap->pid);
+ 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.
+ * 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;
uthread->uu_flag |= UT_SETUID;
- /* drop our extra references */
- kauth_cred_rele(my_cred);
- kauth_cred_rele(my_target_cred);
+ /* 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);
}
- /* we are reverting back to normal mode of operation where delayed binding
- * of the process credential sets the credential in the thread (uu_ucred)
+ /*
+ * 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);
/* revert to delayed binding of process credential */
my_new_cred = kauth_cred_proc_ref(p);
- kauth_cred_rele(uthread->uu_ucred);
+ kauth_cred_unref(&uthread->uu_ucred);
uthread->uu_ucred = my_new_cred;
uthread->uu_flag &= ~UT_SETUID;
return (0);
}
-/* ARGSUSED */
+
+/*
+ * 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.
+ */
static int
-setgroups1(struct proc *p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused register_t *retval)
+setgroups1(proc_t p, u_int gidsetsize, user_addr_t gidset, uid_t gmuid, __unused register_t *retval)
{
- register u_int ngrp;
+ 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());
- if ((error = suser(p->p_ucred, &p->p_acflag)))
- return (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);
+
ngrp = gidsetsize;
if (ngrp > NGROUPS)
return (EINVAL);
if ( ngrp < 1 ) {
ngrp = 1;
- }
- else {
+ } else {
error = copyin(gidset,
(caddr_t)newgroups, ngrp * sizeof(gid_t));
if (error) {
}
}
+ my_cred = kauth_cred_proc_ref(p);
+ if ((error = suser(my_cred, &p->p_acflag))) {
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
+
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
* 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.
- *
- * Hack: this opts into memberd to avoid needing to use a per
- * thread credential initgroups() instead of setgroups() in
- * AFP server to address <rdar://4561060>
*/
my_cred = uthread->uu_ucred;
- uthread->uu_ucred = kauth_cred_setgroups(my_cred, &newgroups[0], ngrp, my_cred->cr_gmuid);
+ 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 {
/*
* with it
*/
for (;;) {
- my_cred = kauth_cred_proc_ref(p);
-
/*
- * set the credential with new info. If there is no
- * change we get back the same credential we passed in.
+ * 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_lock(p);
/*
- * need to protect for a race where another
+ * 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
*/
if (p->p_ucred != my_cred) {
proc_unlock(p);
- kauth_cred_rele(my_cred);
- kauth_cred_rele(my_new_cred);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
/* try again */
continue;
}
p->p_ucred = my_new_cred;
- p->p_flag |= P_SUGID;
+ OSBitOrAtomic(P_SUGID, (UInt32 *)&p->p_flag);
proc_unlock(p);
}
- /* drop our extra reference */
- kauth_cred_rele(my_cred);
break;
}
+ /* Drop old proc reference or our extra reference */
+ AUDIT_ARG(groupset, my_cred->cr_groups, ngrp);
+ kauth_cred_unref(&my_cred);
+
- AUDIT_ARG(groupset, p->p_ucred->cr_groups, ngrp);
set_security_token(p);
}
return (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()
+ */
int
-initgroups(struct proc *p, struct initgroups_args *uap, __unused register_t *retval)
+initgroups(proc_t p, struct initgroups_args *uap, __unused register_t *retval)
{
+ DEBUG_CRED_ENTER("initgroups\n");
+
return(setgroups1(p, uap->gidsetsize, uap->gidset, uap->gmuid, retval));
}
+
+/*
+ * 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()
+ */
int
-setgroups(struct proc *p, struct setgroups_args *uap, __unused register_t *retval)
+setgroups(proc_t p, struct setgroups_args *uap, __unused register_t *retval)
{
+ DEBUG_CRED_ENTER("setgroups\n");
+
return(setgroups1(p, uap->gidsetsize, uap->gidset, KAUTH_UID_NONE, retval));
}
+
/*
* Set the per-thread/per-process supplementary groups list.
*/
-#warning XXX implement
+#warning XXX implement setsgroups
int
-setsgroups(__unused struct proc *p, __unused struct setsgroups_args *uap, __unused register_t *retval)
+setsgroups(__unused proc_t p, __unused struct setsgroups_args *uap, __unused register_t *retval)
{
return(ENOTSUP);
}
/*
* Set the per-thread/per-process whiteout groups list.
*/
-#warning XXX implement
+#warning XXX implement setwgroups
int
-setwgroups(__unused struct proc *p, __unused struct setwgroups_args *uap, __unused register_t *retval)
+setwgroups(__unused proc_t p, __unused struct setwgroups_args *uap, __unused register_t *retval)
{
return(ENOTSUP);
}
+
/*
* Check if gid is a member of the group set.
*
- * XXX This interface is going away
+ * XXX This interface is going away; use kauth_cred_ismember_gid() directly
+ * XXX instead.
*/
int
groupmember(gid_t gid, kauth_cred_t cred)
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
+ * 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 (cred == NOCRED || cred == FSCRED)
+ if (!IS_VALID_CRED(cred))
panic("suser");
#endif
if (kauth_cred_getuid(cred) == 0) {
return (EPERM);
}
+
+/*
+ * XXX This interface is going away; use kauth_cred_issuser() directly
+ * XXX instead.
+ */
int
is_suser(void)
{
- struct proc *p = current_proc();
+ proc_t p = current_proc();
if (!p)
return (0);
- return (suser(p->p_ucred, &p->p_acflag) == 0);
+ return (proc_suser(p) == 0);
}
+
+/*
+ * XXX This interface is going away; use kauth_cred_issuser() directly
+ * XXX instead.
+ */
int
is_suser1(void)
{
- struct proc *p = current_proc();
+ proc_t p = current_proc();
+ kauth_cred_t my_cred;
+ int err;
if (!p)
return (0);
- return (suser(p->p_ucred, &p->p_acflag) == 0 ||
- p->p_ucred->cr_ruid == 0 || p->p_ucred->cr_svuid == 0);
+ my_cred = kauth_cred_proc_ref(p);
+
+ err = (suser(my_cred, &p->p_acflag) == 0 ||
+ my_cred->cr_ruid == 0 || my_cred->cr_svuid == 0);
+ kauth_cred_unref(&my_cred);
+ return(err);
}
+
/*
- * 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
*/
-/* ARGSUSED */
int
-getlogin(struct proc *p, struct getlogin_args *uap, __unused register_t *retval)
+getlogin(proc_t p, struct getlogin_args *uap, __unused register_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);
- 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,
- uap->namebuf, uap->namelen));
+ return (copyout((caddr_t)buffer, uap->namebuf, uap->namelen));
}
+
/*
- * 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
*/
-/* ARGSUSED */
int
-setlogin(struct proc *p, struct setlogin_args *uap, __unused register_t *retval)
+setlogin(proc_t p, struct setlogin_args *uap, __unused register_t *retval)
{
int error;
int dummy=0;
+ char buffer[MAXLOGNAME+1];
+ struct session * sessp;
- if ((error = suser(p->p_ucred, &p->p_acflag)))
+ if ((error = proc_suser(p)))
return (error);
-
+
+ bzero(&buffer[0], MAXLOGNAME+1);
+
+
error = copyinstr(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)
- AUDIT_ARG(text, p->p_pgrp->pg_session->s_login);
- else if (error == ENAMETOOLONG)
+ (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);
+ }
+
+
+ if (!error) {
+ AUDIT_ARG(text, buffer);
+ } else if (error == ENAMETOOLONG)
error = EINVAL;
return (error);
}
* XXX identifier.
*/
int
-set_security_token(struct proc * p)
+set_security_token(proc_t p)
{
security_token_t sec_token;
audit_token_t audit_token;
+ kauth_cred_t my_cred;
+ host_priv_t host_priv;
/*
* Don't allow a vfork child to override the parent's token settings
return (1);
}
+ my_cred = kauth_cred_proc_ref(p);
/* XXX mach_init doesn't have a p_ucred when it calls this function */
- if (p->p_ucred != NOCRED && p->p_ucred != FSCRED) {
- sec_token.val[0] = kauth_cred_getuid(p->p_ucred);
- sec_token.val[1] = p->p_ucred->cr_gid;
+ if (IS_VALID_CRED(my_cred)) {
+ sec_token.val[0] = kauth_cred_getuid(my_cred);
+ sec_token.val[1] = my_cred->cr_gid;
} else {
sec_token.val[0] = 0;
sec_token.val[1] = 0;
* the user of the trailer from future representation
* changes.
*/
- audit_token.val[0] = p->p_ucred->cr_au.ai_auid;
- audit_token.val[1] = p->p_ucred->cr_uid;
- audit_token.val[2] = p->p_ucred->cr_gid;
- audit_token.val[3] = p->p_ucred->cr_ruid;
- audit_token.val[4] = p->p_ucred->cr_rgid;
+ audit_token.val[0] = my_cred->cr_au.ai_auid;
+ audit_token.val[1] = my_cred->cr_uid;
+ audit_token.val[2] = my_cred->cr_gid;
+ audit_token.val[3] = my_cred->cr_ruid;
+ audit_token.val[4] = my_cred->cr_rgid;
audit_token.val[5] = p->p_pid;
- audit_token.val[6] = p->p_ucred->cr_au.ai_asid;
- audit_token.val[7] = p->p_ucred->cr_au.ai_termid.port;
+ audit_token.val[6] = my_cred->cr_au.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))
+ 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,
- (sec_token.val[0]) ?
- HOST_PRIV_NULL :
- host_priv_self()) != KERN_SUCCESS);
+ host_priv) != KERN_SUCCESS);
}
xcr->cr_ngroups = cr->cr_ngroups;
bcopy(cr->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 register_t *retval)
+{
+ proc_t p;
+ struct lctx *l;
+ int error = 0;
+ int refheld = 0;
+
+ AUDIT_ARG(pid, uap->pid);
+ AUDIT_ARG(value, 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, register_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, register_t *retval)
+{
+
+ return (ENOSYS);
+}
+
+int
+getlcid(proc_t p0, struct getlcid_args *uap, register_t *retval)
+{
+
+ return (ENOSYS);
+}
+#endif /* !LCTX */
projects / apple / xnu.git / blobdiff