#include <sys/times.h>
#include <sys/malloc.h>
-#include <security/audit/audit.h>
+#define chgproccnt_ok(p) 1
-#if CONFIG_LCTX
-#include <sys/lctx.h>
-#endif
+#include <security/audit/audit.h>
#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>
#define DEBUG_CRED_CHANGE(fmt, ...) do {} while (0)
#endif /* !DEBUG_CRED */
+#if DEVELOPMENT || DEBUG
+extern void task_importance_update_owner_info(task_t);
+#endif
/*
kauth_cred_t my_cred, my_new_cred;
posix_cred_t my_pcred;
-
uid = uap->uid;
+ /* get current credential and take a reference while we muck with it */
my_cred = kauth_cred_proc_ref(p);
my_pcred = posix_cred_get(my_cred);
DEBUG_CRED_ENTER("setuid (%d/%d): %p %d\n", p->p_pid, (p->p_pptr ? p->p_pptr->p_pid : 0), my_cred, uap->uid);
AUDIT_ARG(uid, uid);
- if (uid != my_pcred->cr_ruid && /* allow setuid(getuid()) */
- uid != my_pcred->cr_svuid && /* allow setuid(saved uid) */
- (error = suser(my_cred, &p->p_acflag))) {
- kauth_cred_unref(&my_cred);
- return (error);
- }
- /*
- * Everything's okay, do it.
- */
+ for (;;) {
+ if (uid != my_pcred->cr_ruid && /* allow setuid(getuid()) */
+ uid != my_pcred->cr_svuid && /* allow setuid(saved uid) */
+ (error = suser(my_cred, &p->p_acflag))) {
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
- /*
- * If we are priviledged, then set the saved and real UID too;
- * otherwise, just set the effective UID
- */
- if (suser(my_cred, &p->p_acflag) == 0) {
- svuid = uid;
- ruid = uid;
/*
- * Transfer proc count to new user.
- * chgproccnt uses list lock for protection
+ * If we are privileged, then set the saved and real UID too;
+ * otherwise, just set the effective UID
*/
- (void)chgproccnt(uid, 1);
- (void)chgproccnt(my_pcred->cr_ruid, -1);
- }
-
- /* get current credential and take a reference while we muck with it */
- for (;;) {
+ if (suser(my_cred, &p->p_acflag) == 0) {
+ svuid = uid;
+ ruid = uid;
+ } else {
+ svuid = KAUTH_UID_NONE;
+ ruid = KAUTH_UID_NONE;
+ }
/*
* Only set the gmuid if the current cred has not opt'ed out;
* this normally only happens when calling setgroups() instead
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 && chgproccnt_ok(p)) {
+ (void)chgproccnt(ruid, 1);
+ }
+
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.
+ *
+ * Note: the kauth_cred_setresuid has consumed a reference to my_cred, it p_ucred != my_cred, then my_cred must not be dereferenced!
*/
if (p->p_ucred != my_cred) {
proc_unlock(p);
+ /*
+ * We didn't successfully switch to the new ruid, so decrement
+ * the procs/uid count that we incremented above.
+ */
+ if (ruid != KAUTH_UID_NONE && chgproccnt_ok(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;
}
OSBitOrAtomic(P_SUGID, &p->p_flag);
proc_unlock(p);
+ /*
+ * If we've updated the ruid, decrement the count of procs running
+ * under the previous ruid
+ */
+ if (ruid != KAUTH_UID_NONE && chgproccnt_ok(p)) {
+ (void)chgproccnt(my_pcred->cr_ruid, -1);
+ }
}
break;
}
my_cred = kauth_cred_proc_ref(p);
my_pcred = posix_cred_get(my_cred);
- if (euid != my_pcred->cr_ruid && euid != my_pcred->cr_svuid &&
- (error = suser(my_cred, &p->p_acflag))) {
- kauth_cred_unref(&my_cred);
- return (error);
- }
-
- /*
- * Everything's okay, do it. Copy credentials so other references do
- * not see our changes. get current credential and take a reference
- * while we muck with it
- */
for (;;) {
+
+ if (euid != my_pcred->cr_ruid && euid != my_pcred->cr_svuid &&
+ (error = suser(my_cred, &p->p_acflag))) {
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
+
/*
* Set the credential with new info. If there is no change,
* we get back the same credential we passed in; if there is
proc_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;
}
my_cred = kauth_cred_proc_ref(p);
my_pcred = posix_cred_get(my_cred);
- if (((ruid != KAUTH_UID_NONE && /* allow no change of ruid */
- ruid != my_pcred->cr_ruid && /* allow ruid = ruid */
- ruid != my_pcred->cr_uid && /* allow ruid = euid */
- ruid != my_pcred->cr_svuid) || /* allow ruid = svuid */
- (euid != KAUTH_UID_NONE && /* allow no change of euid */
- euid != my_pcred->cr_uid && /* allow euid = euid */
- euid != my_pcred->cr_ruid && /* allow euid = ruid */
- euid != my_pcred->cr_svuid)) && /* allow euid = svui */
- (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
- kauth_cred_unref(&my_cred);
- return (error);
- }
-
- /*
- * Everything's okay, do it. Copy credentials so other references do
- * not see our changes. get current credential and take a reference
- * while we muck with it
- */
for (;;) {
+
+ if (((ruid != KAUTH_UID_NONE && /* allow no change of ruid */
+ ruid != my_pcred->cr_ruid && /* allow ruid = ruid */
+ ruid != my_pcred->cr_uid && /* allow ruid = euid */
+ ruid != my_pcred->cr_svuid) || /* allow ruid = svuid */
+ (euid != KAUTH_UID_NONE && /* allow no change of euid */
+ euid != my_pcred->cr_uid && /* allow euid = euid */
+ euid != my_pcred->cr_ruid && /* allow euid = ruid */
+ euid != my_pcred->cr_svuid)) && /* allow euid = svuid */
+ (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
+
uid_t new_euid;
- uid_t new_ruid;
uid_t svuid = KAUTH_UID_NONE;
new_euid = my_pcred->cr_uid;
- new_ruid = my_pcred->cr_ruid;
-
/*
* Set the credential with new info. If there is no change,
* we get back the same credential we passed in; if there is
* passed in. The subsequent compare is safe, because it is
* a pointer compare rather than a contents compare.
*/
- if (euid == KAUTH_UID_NONE && my_pcred->cr_uid != euid) {
+ if (euid != KAUTH_UID_NONE && my_pcred->cr_uid != euid) {
/* changing the effective UID */
new_euid = euid;
OSBitOrAtomic(P_SUGID, &p->p_flag);
}
- if (ruid != KAUTH_UID_NONE && my_pcred->cr_ruid != ruid) {
- /* changing the real UID; must do user accounting */
- /* chgproccnt uses list lock for protection */
- (void)chgproccnt(ruid, 1);
- (void)chgproccnt(my_pcred->cr_ruid, -1);
- new_ruid = ruid;
- OSBitOrAtomic(P_SUGID, &p->p_flag);
- }
/*
* If the newly requested real uid or effective uid does
* not match the saved uid, then set the saved uid to the
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 && chgproccnt_ok(p)) {
+ (void)chgproccnt(ruid, 1);
+ }
+
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.
+ *
+ * Note: the kauth_cred_setresuid has consumed a reference to my_cred, it p_ucred != my_cred, then my_cred must not be dereferenced!
*/
if (p->p_ucred != my_cred) {
proc_unlock(p);
+ if (ruid != KAUTH_UID_NONE && chgproccnt_ok(p)) {
+ /*
+ * We didn't successfully switch to the new ruid, so decrement
+ * the procs/uid count that we incremented above.
+ */
+ (void)chgproccnt(ruid, -1);
+ }
kauth_cred_unref(&my_new_cred);
my_cred = kauth_cred_proc_ref(p);
+ my_pcred = posix_cred_get(my_cred);
/* try again */
continue;
}
+
p->p_ucred = my_new_cred;
/* update cred on proc */
PROC_UPDATE_CREDS_ONPROC(p);
- OSBitOrAtomic(P_SUGID, &p->p_flag); /* XXX redundant? */
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
proc_unlock(p);
+
+ if (ruid != KAUTH_UID_NONE && chgproccnt_ok(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;
}
gid = uap->gid;
AUDIT_ARG(gid, gid);
+ /* get current credential and take a reference while we muck with it */
my_cred = kauth_cred_proc_ref(p);
my_pcred = posix_cred_get(my_cred);
- if (gid != my_pcred->cr_rgid && /* allow setgid(getgid()) */
- gid != my_pcred->cr_svgid && /* allow setgid(saved gid) */
- (error = suser(my_cred, &p->p_acflag))) {
- kauth_cred_unref(&my_cred);
- return (error);
- }
+ for (;;) {
+ if (gid != my_pcred->cr_rgid && /* allow setgid(getgid()) */
+ gid != my_pcred->cr_svgid && /* allow setgid(saved gid) */
+ (error = suser(my_cred, &p->p_acflag))) {
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
- /*
- * If we are priviledged, then set the saved and real GID too;
- * otherwise, just set the effective GID
- */
- if (suser(my_cred, &p->p_acflag) == 0) {
- svgid = gid;
- rgid = gid;
- }
+ /*
+ * If we are privileged, then set the saved and real GID too;
+ * otherwise, just set the effective GID
+ */
+ if (suser(my_cred, &p->p_acflag) == 0) {
+ svgid = gid;
+ rgid = gid;
+ } else {
+ svgid = KAUTH_GID_NONE;
+ rgid = KAUTH_GID_NONE;
+ }
- /* get current credential and take a reference while we muck with it */
- for (;;) {
-
/*
* Set the credential with new info. If there is no change,
* we get back the same credential we passed in; if there is
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;
egid = uap->egid;
AUDIT_ARG(egid, egid);
+ /* get current credential and take a reference while we muck with it */
my_cred = kauth_cred_proc_ref(p);
my_pcred = posix_cred_get(my_cred);
- if (egid != my_pcred->cr_rgid &&
- egid != my_pcred->cr_svgid &&
- (error = suser(my_cred, &p->p_acflag))) {
- kauth_cred_unref(&my_cred);
- return (error);
- }
- /* get current credential and take a reference while we muck with it */
for (;;) {
+ if (egid != my_pcred->cr_rgid &&
+ egid != my_pcred->cr_svgid &&
+ (error = suser(my_cred, &p->p_acflag))) {
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
/*
* Set the credential with new info. If there is no change,
* we get back the same credential we passed in; if there is
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;
AUDIT_ARG(egid, egid);
AUDIT_ARG(rgid, rgid);
+ /* get current credential and take a reference while we muck with it */
my_cred = kauth_cred_proc_ref(p);
my_pcred = posix_cred_get(my_cred);
- if (((rgid != KAUTH_UID_NONE && /* allow no change of rgid */
- rgid != my_pcred->cr_rgid && /* allow rgid = rgid */
- rgid != my_pcred->cr_gid && /* allow rgid = egid */
- rgid != my_pcred->cr_svgid) || /* allow rgid = svgid */
- (egid != KAUTH_UID_NONE && /* allow no change of egid */
- egid != my_pcred->cr_groups[0] && /* allow no change of egid */
- egid != my_pcred->cr_gid && /* allow egid = egid */
- egid != my_pcred->cr_rgid && /* allow egid = rgid */
- egid != my_pcred->cr_svgid)) && /* allow egid = svgid */
- (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
- kauth_cred_unref(&my_cred);
- return (error);
- }
-
- /* get current credential and take a reference while we muck with it */
for (;;) {
+
+ if (((rgid != KAUTH_UID_NONE && /* allow no change of rgid */
+ rgid != my_pcred->cr_rgid && /* allow rgid = rgid */
+ rgid != my_pcred->cr_gid && /* allow rgid = egid */
+ rgid != my_pcred->cr_svgid) || /* allow rgid = svgid */
+ (egid != KAUTH_UID_NONE && /* allow no change of egid */
+ egid != my_pcred->cr_groups[0] && /* allow no change of egid */
+ egid != my_pcred->cr_gid && /* allow egid = egid */
+ egid != my_pcred->cr_rgid && /* allow egid = rgid */
+ egid != my_pcred->cr_svgid)) && /* allow egid = svgid */
+ (error = suser(my_cred, &p->p_acflag))) { /* allow root user any */
+ kauth_cred_unref(&my_cred);
+ return (error);
+ }
+
uid_t new_egid = my_pcred->cr_gid;
uid_t new_rgid = my_pcred->cr_rgid;
uid_t svgid = KAUTH_UID_NONE;
* passed in. The subsequent compare is safe, because it is
* a pointer compare rather than a contents compare.
*/
- if (egid == KAUTH_UID_NONE && my_pcred->cr_gid != egid) {
+ if (egid != KAUTH_UID_NONE && my_pcred->cr_gid != egid) {
/* changing the effective GID */
new_egid = egid;
OSBitOrAtomic(P_SUGID, &p->p_flag);
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;
/*
* Set the per-thread override identity. The first parameter can be the
- * current real UID, KAUTH_UID_NONE, or, if the caller is priviledged, it
+ * current real UID, KAUTH_UID_NONE, or, if the caller is privileged, it
* can be any UID. If it is KAUTH_UID_NONE, then as a special case, this
* means "revert to the per process credential"; otherwise, if permitted,
* it changes the effective, real, and saved UIDs and GIDs for the current
}
-/*
- * XXX This interface is going away; use kauth_cred_issuser() directly
- * XXX instead.
- */
-int
-is_suser(void)
-{
- proc_t p = current_proc();
-
- if (!p)
- return (0);
-
- return (proc_suser(p) == 0);
-}
-
-
-/*
- * XXX This interface is going away; use kauth_cred_issuser() directly
- * XXX instead.
- */
-int
-is_suser1(void)
-{
- proc_t p = current_proc();
- kauth_cred_t my_cred;
- posix_cred_t my_pcred;
- int err;
-
- if (!p)
- return (0);
-
- my_cred = kauth_cred_proc_ref(p);
- my_pcred = posix_cred_get(my_cred);
-
- err = (suser(my_cred, &p->p_acflag) == 0 ||
- my_pcred->cr_ruid == 0 || my_pcred->cr_svuid == 0);
- kauth_cred_unref(&my_cred);
- return(err);
-}
-
-
/*
* getlogin
*
audit_token.val[6] = my_cred->cr_audit.as_aia_p->ai_asid;
audit_token.val[7] = p->p_idversion;
-#if CONFIG_MACF_MACH
- mac_task_label_update_cred(my_cred, p->task);
-#endif
-
host_priv = (sec_token.val[0]) ? HOST_PRIV_NULL : host_priv_self();
#if CONFIG_MACF
if (host_priv != HOST_PRIV_NULL && mac_system_check_host_priv(my_cred))
#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(p->task);
+#endif
+
return (host_security_set_task_token(host_security_self(),
p->task,
sec_token,
}
+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 kauth_cred_t.
*/
xcr->cr_ngroups = pcr->cr_ngroups;
bcopy(pcr->cr_groups, xcr->cr_groups, sizeof(xcr->cr_groups));
}
-
-#if CONFIG_LCTX
-
-/*
- * Set Login Context ID
- */
-/*
- * MPSAFE - assignment of (visible) process to context protected by ALLLCTX_LOCK,
- * LCTX by its own locks.
- */
-int
-setlcid(proc_t p0, struct setlcid_args *uap, __unused int32_t *retval)
-{
- proc_t p;
- struct lctx *l;
- int error = 0;
- int refheld = 0;
-
- AUDIT_ARG(pid, uap->pid);
- AUDIT_ARG(value32, uap->lcid);
- if (uap->pid == LCID_PROC_SELF) { /* Create/Join/Leave */
- p = p0;
- } else { /* Adopt/Orphan */
- p = proc_find(uap->pid);
- if (p == NULL)
- return (ESRCH);
- refheld = 1;
- }
-
-#if CONFIG_MACF
- error = mac_proc_check_setlcid(p0, p, uap->pid, uap->lcid);
- if (error)
- goto out;
-#endif
-
- switch (uap->lcid) {
- /* Leave/Orphan */
- case LCID_REMOVE:
-
- /* Only root may Leave/Orphan. */
- if (!is_suser1()) {
- error = EPERM;
- goto out;
- }
-
- /* Process not in login context. */
- if (p->p_lctx == NULL) {
- error = ENOATTR;
- goto out;
- }
-
- l = NULL;
-
- break;
-
- /* Create */
- case LCID_CREATE:
-
- /* Create only valid for self! */
- if (uap->pid != LCID_PROC_SELF) {
- error = EPERM;
- goto out;
- }
-
- /* Already in a login context. */
- if (p->p_lctx != NULL) {
- error = EPERM;
- goto out;
- }
-
- l = lccreate();
- if (l == NULL) {
- error = ENOMEM;
- goto out;
- }
-
- LCTX_LOCK(l);
-
- break;
-
- /* Join/Adopt */
- default:
-
- /* Only root may Join/Adopt. */
- if (!is_suser1()) {
- error = EPERM;
- goto out;
- }
-
- l = lcfind(uap->lcid);
- if (l == NULL) {
- error = ENOATTR;
- goto out;
- }
-
- break;
- }
-
- ALLLCTX_LOCK;
- leavelctx(p);
- enterlctx(p, l, (uap->lcid == LCID_CREATE) ? 1 : 0);
- ALLLCTX_UNLOCK;
-
-out:
- if (refheld != 0)
- proc_rele(p);
- return (error);
-}
-
-/*
- * Get Login Context ID
- */
-/*
- * MPSAFE - membership of (visible) process in a login context
- * protected by the all-context lock.
- */
-int
-getlcid(proc_t p0, struct getlcid_args *uap, int32_t *retval)
-{
- proc_t p;
- int error = 0;
- int refheld = 0;
-
- AUDIT_ARG(pid, uap->pid);
- if (uap->pid == LCID_PROC_SELF) {
- p = p0;
- } else {
- p = proc_find(uap->pid);
- if (p == NULL)
- return (ESRCH);
- refheld = 1;
- }
-
-#if CONFIG_MACF
- error = mac_proc_check_getlcid(p0, p, uap->pid);
- if (error)
- goto out;
-#endif
- ALLLCTX_LOCK;
- if (p->p_lctx == NULL) {
- error = ENOATTR;
- ALLLCTX_UNLOCK;
- goto out;
- }
- *retval = p->p_lctx->lc_id;
- ALLLCTX_UNLOCK;
- out:
- if (refheld != 0)
- proc_rele(p);
-
- return (error);
-}
-#else /* LCTX */
-int
-setlcid(proc_t p0, struct setlcid_args *uap, int32_t *retval)
-{
-
- return (ENOSYS);
-}
-
-int
-getlcid(proc_t p0, struct getlcid_args *uap, int32_t *retval)
-{
-
- return (ENOSYS);
-}
-#endif /* !LCTX */
projects / apple / xnu.git / blobdiff