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sudo/plugins/sudoers/set_perms.c

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/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 1994-1996, 1998-2020 Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F39502-99-1-0512.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef _AIX
# include <sys/id.h>
#endif
#include <pwd.h>
#include <errno.h>
#include <grp.h>
#include <sudoers.h>
#include <timestamp.h>
/* No change when passed to setresuid(), etc. */
#define NO_UID (uid_t)-1
#define NO_GID (gid_t)-1
/*
* Prototypes
*/
#if defined(HAVE_SETRESUID) || defined(HAVE_SETREUID) || defined(HAVE_SETEUID)
static struct gid_list *runas_setgroups(const struct sudoers_context *ctx);
#endif
/*
* We keep track of the current permissions and use a stack to restore
* the old permissions. A depth of 16 is overkill.
*/
struct perm_state {
uid_t ruid;
uid_t euid;
#if defined(HAVE_SETRESUID) || defined(ID_SAVED)
uid_t suid;
#endif
gid_t rgid;
gid_t egid;
#if defined(HAVE_SETRESUID) || defined(ID_SAVED)
gid_t sgid;
#endif
struct gid_list *gidlist;
};
#define PERM_STACK_MAX 16
static struct perm_state perm_stack[PERM_STACK_MAX];
static int perm_stack_depth = 0;
#undef ID
#define ID(x) (state->x == ostate->x ? NO_UID : state->x)
#undef OID
#define OID(x) (ostate->x == state->x ? NO_UID : ostate->x)
bool
rewind_perms(void)
{
debug_decl(rewind_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth > 0) {
while (perm_stack_depth > 1) {
if (!restore_perms())
debug_return_bool(false);
}
sudo_gidlist_delref(perm_stack[0].gidlist);
}
debug_return_bool(true);
}
#if defined(HAVE_SETRESUID)
#define UID_CHANGED (state->ruid != ostate->ruid || state->euid != ostate->euid || state->suid != ostate->suid)
#define GID_CHANGED (state->rgid != ostate->rgid || state->egid != ostate->egid || state->sgid != ostate->sgid)
/*
* Set real and effective and saved uids and gids based on perm.
* We always retain a saved uid of 0 unless we are headed for an exec().
* We only flip the effective gid since it only changes for PERM_SUDOERS.
* The ctx argument may be NULL for PERM_ROOT, PERM_SUDOERS and PERM_TIMESTAMP.
* This version of set_perms() works fine with the "stay_setuid" option.
*/
bool
set_perms(const struct sudoers_context *ctx, int perm)
{
struct perm_state *state, *ostate = NULL;
char errbuf[1024];
const char *errstr = errbuf;
debug_decl(set_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth == PERM_STACK_MAX) {
errstr = N_("perm stack overflow");
errno = EINVAL;
goto bad;
}
if (perm == PERM_INITIAL) {
if (perm_stack_depth > 1)
rewind_perms();
perm_stack_depth = 0;
} else {
if (perm_stack_depth == 0) {
errstr = N_("perm stack underflow");
errno = EINVAL;
goto bad;
}
ostate = &perm_stack[perm_stack_depth - 1];
}
state = &perm_stack[perm_stack_depth];
switch (perm) {
case PERM_INITIAL:
/* Stash initial state */
#ifdef HAVE_GETRESUID
if (getresuid(&state->ruid, &state->euid, &state->suid)) {
errstr = "PERM_INITIAL: getresuid";
goto bad;
}
if (getresgid(&state->rgid, &state->egid, &state->sgid)) {
errstr = "PERM_INITIAL: getresgid";
goto bad;
}
#else
state->ruid = getuid();
state->euid = geteuid();
state->suid = state->euid; /* in case we are setuid */
state->rgid = getgid();
state->egid = getegid();
state->sgid = state->egid; /* in case we are setgid */
#endif
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_INITIAL: "
"ruid: %d, euid: %d, suid: %d, rgid: %d, egid: %d, sgid: %d",
__func__, (int)state->ruid, (int)state->euid, (int)state->suid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
break;
case PERM_ROOT:
state->ruid = ROOT_UID;
state->euid = ROOT_UID;
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setresuid(ID(ruid), ID(euid), ID(suid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_ROOT: setresuid(%d, %d, %d)",
(int)ID(ruid), (int)ID(euid), (int)ID(suid));
goto bad;
}
state->rgid = ostate->rgid;
state->egid = ROOT_GID;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setresgid(ID(rgid), ID(egid), ID(sgid))) {
errstr = N_("unable to change to root gid");
goto bad;
}
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
break;
case PERM_USER:
state->rgid = ostate->rgid;
state->egid = ctx->user.gid;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setresgid(ID(rgid), ID(egid), ID(sgid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setresgid(%d, %d, %d)",
(int)ID(rgid), (int)ID(egid), (int)ID(sgid));
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
state->euid = ctx->user.uid;
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setresuid(ID(ruid), ID(euid), ID(suid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setresuid(%d, %d, %d)",
(int)ID(ruid), (int)ID(euid), (int)ID(suid));
goto bad;
}
break;
case PERM_FULL_USER:
/* headed for exec() */
state->rgid = ctx->user.gid;
state->egid = ctx->user.gid;
state->sgid = ctx->user.gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setresgid(ID(rgid), ID(egid), ID(sgid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setresgid(%d, %d, %d)",
(int)ID(rgid), (int)ID(egid), (int)ID(sgid));
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_FULL_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
state->euid = ctx->user.uid;
state->suid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setresuid(ID(ruid), ID(euid), ID(suid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setresuid(%d, %d, %d)",
(int)ID(ruid), (int)ID(euid), (int)ID(suid));
goto bad;
}
break;
case PERM_RUNAS:
state->rgid = ostate->rgid;
state->egid = ctx->runas.gr ? ctx->runas.gr->gr_gid : ctx->runas.pw->pw_gid; // -V595
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setresgid(ID(rgid), ID(egid), ID(sgid))) {
errstr = N_("unable to change to runas gid");
goto bad;
}
state->gidlist = runas_setgroups(ctx);
if (state->gidlist == NULL) {
errstr = N_("unable to set runas group vector");
goto bad;
}
state->ruid = ostate->ruid;
state->euid = ctx->runas.pw ? ctx->runas.pw->pw_uid : ctx->user.uid;
state->suid = ostate->suid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setresuid(ID(ruid), ID(euid), ID(suid))) {
errstr = N_("unable to change to runas uid");
goto bad;
}
break;
case PERM_SUDOERS: {
const uid_t sudoers_uid = sudoers_file_uid();
const gid_t sudoers_gid = sudoers_file_gid();
const mode_t sudoers_mode = sudoers_file_mode();
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
/* assumes euid == ROOT_UID, ruid == user */
state->rgid = ostate->rgid;
state->egid = sudoers_gid;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setresgid(ID(rgid), ID(egid), ID(sgid))) {
errstr = N_("unable to change to sudoers gid");
goto bad;
}
state->ruid = ROOT_UID;
/*
* If sudoers_uid == ROOT_UID and sudoers_mode is group readable
* we use a non-zero uid in order to avoid NFS lossage.
* Using uid 1 is a bit bogus but should work on all OS's.
*/
if (sudoers_uid == ROOT_UID && (sudoers_mode & S_IRGRP))
state->euid = 1;
else
state->euid = sudoers_uid;
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setresuid(ID(ruid), ID(euid), ID(suid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_SUDOERS: setresuid(%d, %d, %d)",
(int)ID(ruid), (int)ID(euid), (int)ID(suid));
goto bad;
}
break;
}
case PERM_TIMESTAMP:
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
state->rgid = ostate->rgid;
state->egid = ostate->egid;
state->sgid = ostate->sgid;
state->ruid = ROOT_UID;
state->euid = timestamp_get_uid();
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_TIMESTAMP: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setresuid(ID(ruid), ID(euid), ID(suid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_TIMESTAMP: setresuid(%d, %d, %d)",
(int)ID(ruid), (int)ID(euid), (int)ID(suid));
goto bad;
}
break;
}
perm_stack_depth++;
debug_return_bool(true);
bad:
if (errno == EAGAIN)
sudo_warnx(U_("%s: %s"), U_(errstr), U_("too many processes"));
else
sudo_warn("%s", U_(errstr));
debug_return_bool(false);
}
bool
restore_perms(void)
{
struct perm_state *state, *ostate;
debug_decl(restore_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth < 2) {
sudo_warnx("%s", U_("perm stack underflow"));
debug_return_bool(true);
}
state = &perm_stack[perm_stack_depth - 1];
ostate = &perm_stack[perm_stack_depth - 2];
perm_stack_depth--;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: uid: [%d, %d, %d] -> [%d, %d, %d]",
__func__, (int)state->ruid, (int)state->euid, (int)state->suid,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: gid: [%d, %d, %d] -> [%d, %d, %d]",
__func__, (int)state->rgid, (int)state->egid, (int)state->sgid,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid);
/* XXX - more cases here where euid != ruid */
if (OID(euid) == ROOT_UID) {
if (setresuid(NO_UID, ROOT_UID, NO_UID)) {
sudo_warn("setresuid() [%d, %d, %d] -> [%d, %d, %d]",
(int)state->ruid, (int)state->euid, (int)state->suid,
-1, ROOT_UID, -1);
goto bad;
}
}
if (setresgid(OID(rgid), OID(egid), OID(sgid))) {
sudo_warn("setresgid() [%d, %d, %d] -> [%d, %d, %d]",
(int)state->rgid, (int)state->egid, (int)state->sgid,
(int)OID(rgid), (int)OID(egid), (int)OID(sgid));
goto bad;
}
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(ostate->gidlist->ngids, ostate->gidlist->gids)) {
sudo_warn("setgroups()");
goto bad;
}
}
if (setresuid(OID(ruid), OID(euid), OID(suid))) {
sudo_warn("setresuid() [%d, %d, %d] -> [%d, %d, %d]",
(int)state->ruid, (int)state->euid, (int)state->suid,
(int)OID(ruid), (int)OID(euid), (int)OID(suid));
goto bad;
}
sudo_gidlist_delref(state->gidlist);
debug_return_bool(true);
bad:
debug_return_bool(false);
}
#elif defined(_AIX) && defined(ID_SAVED)
#define UID_CHANGED (state->ruid != ostate->ruid || state->euid != ostate->euid || state->suid != ostate->suid)
#define GID_CHANGED (state->rgid != ostate->rgid || state->egid != ostate->egid || state->sgid != ostate->sgid)
/*
* Set real and effective and saved uids and gids based on perm.
* We always retain a saved uid of 0 unless we are headed for an exec().
* We only flip the effective gid since it only changes for PERM_SUDOERS.
* The ctx argument may be NULL for PERM_ROOT, PERM_SUDOERS and PERM_TIMESTAMP.
* This version of set_perms() works fine with the "stay_setuid" option.
*/
bool
set_perms(const struct sudoers_context *ctx, int perm)
{
struct perm_state *state, *ostate = NULL;
char errbuf[1024];
const char *errstr = errbuf;
debug_decl(set_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth == PERM_STACK_MAX) {
errstr = N_("perm stack overflow");
errno = EINVAL;
goto bad;
}
if (perm == PERM_INITIAL) {
if (perm_stack_depth > 1)
rewind_perms();
perm_stack_depth = 0;
} else {
if (perm_stack_depth == 0) {
errstr = N_("perm stack underflow");
errno = EINVAL;
goto bad;
}
ostate = &perm_stack[perm_stack_depth - 1];
}
state = &perm_stack[perm_stack_depth];
switch (perm) {
case PERM_INITIAL:
/* Stash initial state */
state->ruid = getuidx(ID_REAL);
state->euid = getuidx(ID_EFFECTIVE);
state->suid = getuidx(ID_SAVED);
state->rgid = getgidx(ID_REAL);
state->egid = getgidx(ID_EFFECTIVE);
state->sgid = getgidx(ID_SAVED);
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_INITIAL: "
"ruid: %d, euid: %d, suid: %d, rgid: %d, egid: %d, sgid: %d",
__func__, (int)state->ruid, (int)state->euid, (int)state->suid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
break;
case PERM_ROOT:
state->ruid = ROOT_UID;
state->euid = ROOT_UID;
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_ROOT: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
ROOT_UID);
goto bad;
}
state->rgid = ostate->rgid;
state->egid = ROOT_GID;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setgidx(ID_EFFECTIVE, ROOT_GID)) {
errstr = N_("unable to change to root gid");
goto bad;
}
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
break;
case PERM_USER:
state->rgid = ostate->rgid;
state->egid = ctx->user.gid;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setgidx(ID_EFFECTIVE, ctx->user.gid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setgidx(ID_EFFECTIVE, %d)", (int)ctx->user.gid);
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
state->euid = ctx->user.uid;
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (ostate->euid != ROOT_UID || ostate->suid != ROOT_UID) {
if (setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
ROOT_UID);
goto bad;
}
}
if (setuidx(ID_EFFECTIVE|ID_REAL, ctx->user.uid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setuidx(ID_EFFECTIVE|ID_REAL, %d)", (int)ctx->user.uid);
goto bad;
}
break;
case PERM_FULL_USER:
/* headed for exec() */
state->rgid = ctx->user.gid;
state->egid = ctx->user.gid;
state->sgid = ctx->user.gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setgidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, ctx->user.gid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setgidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
(int)ctx->user.gid);
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_FULL_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
state->euid = ctx->user.uid;
state->suid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, ctx->user.uid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
(int)ctx->user.uid);
goto bad;
}
break;
case PERM_RUNAS:
state->rgid = ostate->rgid;
state->egid = ctx->runas.gr ? ctx->runas.gr->gr_gid : ctx->runas.pw->pw_gid;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setgidx(ID_EFFECTIVE, state->egid)) {
errstr = N_("unable to change to runas gid");
goto bad;
}
state->gidlist = runas_setgroups(ctx);
if (state->gidlist == NULL) {
errstr = N_("unable to set runas group vector");
goto bad;
}
state->ruid = ostate->ruid;
state->euid = ctx->runas.pw ? ctx->runas.pw->pw_uid : ctx->user.uid;
state->suid = ostate->suid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED && setuidx(ID_EFFECTIVE, state->euid)) {
errstr = N_("unable to change to runas uid");
goto bad;
}
break;
case PERM_SUDOERS: {
const uid_t sudoers_uid = sudoers_file_uid();
const gid_t sudoers_gid = sudoers_file_gid();
const mode_t sudoers_mode = sudoers_file_mode();
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
/* assume euid == ROOT_UID, ruid == user */
state->rgid = ostate->rgid;
state->egid = sudoers_gid;
state->sgid = ostate->sgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: gid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid,
(int)state->rgid, (int)state->egid, (int)state->sgid);
if (GID_CHANGED && setgidx(ID_EFFECTIVE, sudoers_gid)) {
errstr = N_("unable to change to sudoers gid");
goto bad;
}
state->ruid = ROOT_UID;
/*
* If sudoers_uid == ROOT_UID and sudoers_mode is group readable
* we use a non-zero uid in order to avoid NFS lossage.
* Using uid 1 is a bit bogus but should work on all OS's.
*/
if (sudoers_uid == ROOT_UID && (sudoers_mode & S_IRGRP))
state->euid = 1;
else
state->euid = sudoers_uid;
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED) {
if (ostate->ruid != ROOT_UID || ostate->suid != ROOT_UID) {
if (setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_SUDOERS: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
ROOT_UID);
goto bad;
}
}
if (setuidx(ID_EFFECTIVE, state->euid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_SUDOERS: setuidx(ID_EFFECTIVE, %d)", (int)sudoers_uid);
goto bad;
}
}
break;
}
case PERM_TIMESTAMP:
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
state->rgid = ostate->rgid;
state->egid = ostate->egid;
state->sgid = ostate->sgid;
state->ruid = ROOT_UID;
state->euid = timestamp_get_uid();
state->suid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_TIMESTAMP: uid: "
"[%d, %d, %d] -> [%d, %d, %d]", __func__,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid,
(int)state->ruid, (int)state->euid, (int)state->suid);
if (UID_CHANGED) {
if (ostate->ruid != ROOT_UID || ostate->suid != ROOT_UID) {
if (setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_TIMESTAMP: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
ROOT_UID);
goto bad;
}
}
if (setuidx(ID_EFFECTIVE, state->euid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_TIMESTAMP: setuidx(ID_EFFECTIVE, %d)",
(int)state->euid);
goto bad;
}
}
break;
}
perm_stack_depth++;
debug_return_bool(true);
bad:
if (errno == EAGAIN)
sudo_warnx(U_("%s: %s"), U_(errstr), U_("too many processes"));
else
sudo_warn("%s", U_(errstr));
debug_return_bool(false);
}
bool
restore_perms(void)
{
struct perm_state *state, *ostate;
debug_decl(restore_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth < 2) {
sudo_warnx("%s", U_("perm stack underflow"));
debug_return_bool(true);
}
state = &perm_stack[perm_stack_depth - 1];
ostate = &perm_stack[perm_stack_depth - 2];
perm_stack_depth--;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: uid: [%d, %d, %d] -> [%d, %d, %d]",
__func__, (int)state->ruid, (int)state->euid, (int)state->suid,
(int)ostate->ruid, (int)ostate->euid, (int)ostate->suid);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: gid: [%d, %d, %d] -> [%d, %d, %d]",
__func__, (int)state->rgid, (int)state->egid, (int)state->sgid,
(int)ostate->rgid, (int)ostate->egid, (int)ostate->sgid);
if (OID(ruid) != NO_UID || OID(euid) != NO_UID || OID(suid) != NO_UID) {
if (OID(euid) == ROOT_UID) {
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: setuidx(ID_EFFECTIVE, %d)",
__func__, ROOT_UID);
if (setuidx(ID_EFFECTIVE, ROOT_UID)) {
sudo_warn("setuidx(ID_EFFECTIVE) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->ruid, (int)state->euid, (int)state->suid,
-1, ROOT_UID, -1);
goto bad;
}
}
if (OID(ruid) == OID(euid) && OID(euid) == OID(suid)) {
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
__func__, (int)OID(ruid));
if (setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, OID(ruid))) {
sudo_warn("setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->ruid, (int)state->euid, (int)state->suid,
(int)OID(ruid), (int)OID(euid), (int)OID(suid));
goto bad;
}
} else if (OID(ruid) == NO_UID && OID(suid) == NO_UID) {
/* May have already changed euid to ROOT_UID above. */
if (OID(euid) != ROOT_UID) {
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s: setuidx(ID_EFFECTIVE, %d)", __func__, OID(euid));
if (setuidx(ID_EFFECTIVE, OID(euid))) {
sudo_warn("setuidx(ID_EFFECTIVE) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->ruid, (int)state->euid, (int)state->suid,
(int)OID(ruid), (int)OID(euid), (int)OID(suid));
goto bad;
}
}
} else if (OID(suid) == NO_UID) {
/* Cannot set the real uid alone. */
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s: setuidx(ID_REAL|ID_EFFECTIVE, %d)", __func__, OID(ruid));
if (setuidx(ID_REAL|ID_EFFECTIVE, OID(ruid))) {
sudo_warn("setuidx(ID_REAL|ID_EFFECTIVE) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->ruid, (int)state->euid, (int)state->suid,
(int)OID(ruid), (int)OID(euid), (int)OID(suid));
goto bad;
}
/* Restore the effective euid if it doesn't match the ruid. */
if (OID(euid) != OID(ruid)) {
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s: setuidx(ID_EFFECTIVE, %d)", __func__, ostate->euid);
if (setuidx(ID_EFFECTIVE, ostate->euid)) {
sudo_warn("setuidx(ID_EFFECTIVE, %d)", (int)ostate->euid);
goto bad;
}
}
}
}
if (OID(rgid) != NO_GID || OID(egid) != NO_GID || OID(sgid) != NO_GID) {
if (OID(rgid) == OID(egid) && OID(egid) == OID(sgid)) {
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s: setgidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)",
__func__, (int)OID(rgid));
if (setgidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, OID(rgid))) {
sudo_warn("setgidx(ID_EFFECTIVE|ID_REAL|ID_SAVED) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->rgid, (int)state->egid, (int)state->sgid,
(int)OID(rgid), (int)OID(egid), (int)OID(sgid));
goto bad;
}
} else if (OID(rgid) == NO_GID && OID(sgid) == NO_GID) {
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: setgidx(ID_EFFECTIVE, %d)",
__func__, (int)OID(egid));
if (setgidx(ID_EFFECTIVE, OID(egid))) {
sudo_warn("setgidx(ID_EFFECTIVE) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->rgid, (int)state->egid, (int)state->sgid,
(int)OID(rgid), (int)OID(egid), (int)OID(sgid));
goto bad;
}
} else if (OID(sgid) == NO_GID) {
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s: setgidx(ID_EFFECTIVE|ID_REAL, %d)", __func__, OID(rgid));
if (setgidx(ID_REAL|ID_EFFECTIVE, OID(rgid))) {
sudo_warn("setgidx(ID_REAL|ID_EFFECTIVE) [%d, %d, %d] -> [%d, %d, %d]",
(int)state->rgid, (int)state->egid, (int)state->sgid,
(int)OID(rgid), (int)OID(egid), (int)OID(sgid));
goto bad;
}
}
}
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(ostate->gidlist->ngids, ostate->gidlist->gids)) {
sudo_warn("setgroups()");
goto bad;
}
}
sudo_gidlist_delref(state->gidlist);
debug_return_bool(true);
bad:
debug_return_bool(false);
}
#elif defined(HAVE_SETREUID)
#define UID_CHANGED (state->ruid != ostate->ruid || state->euid != ostate->euid)
#define GID_CHANGED (state->rgid != ostate->rgid || state->egid != ostate->egid)
/*
* Set real and effective and saved uids and gids based on perm.
* We always retain a saved uid of 0 unless we are headed for an exec().
* We only flip the effective gid since it only changes for PERM_SUDOERS.
* The ctx argument may be NULL for PERM_ROOT, PERM_SUDOERS and PERM_TIMESTAMP.
* This version of set_perms() works fine with the "stay_setuid" option.
*/
bool
set_perms(const struct sudoers_context *ctx, int perm)
{
struct perm_state *state, *ostate = NULL;
char errbuf[1024];
const char *errstr = errbuf;
debug_decl(set_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth == PERM_STACK_MAX) {
errstr = N_("perm stack overflow");
errno = EINVAL;
goto bad;
}
if (perm == PERM_INITIAL) {
if (perm_stack_depth > 1)
rewind_perms();
perm_stack_depth = 0;
} else {
if (perm_stack_depth == 0) {
errstr = N_("perm stack underflow");
errno = EINVAL;
goto bad;
}
ostate = &perm_stack[perm_stack_depth - 1];
}
state = &perm_stack[perm_stack_depth];
switch (perm) {
case PERM_INITIAL:
/* Stash initial state */
state->ruid = getuid();
state->euid = geteuid();
state->rgid = getgid();
state->egid = getegid();
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_INITIAL: "
"ruid: %d, euid: %d, rgid: %d, egid: %d", __func__,
(int)state->ruid, (int)state->euid,
(int)state->rgid, (int)state->egid);
break;
case PERM_ROOT:
state->ruid = ROOT_UID;
state->euid = ROOT_UID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
/*
* setreuid(0, 0) may fail on some systems if euid is not already 0.
*/
if (ostate->euid != ROOT_UID) {
if (setreuid(NO_UID, ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_ROOT: setreuid(-1, %d)", ROOT_UID);
goto bad;
}
}
if (ostate->ruid != ROOT_UID) {
if (setreuid(ROOT_UID, NO_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_ROOT: setreuid(%d, -1)", ROOT_UID);
goto bad;
}
}
state->rgid = ostate->rgid;
state->egid = ROOT_GID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setregid(ID(rgid), ID(egid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_ROOT: setregid(%d, %d)", (int)ID(rgid), (int)ID(egid));
goto bad;
}
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
break;
case PERM_USER:
state->rgid = ostate->rgid;
state->egid = ctx->user.gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setregid(ID(rgid), ID(egid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setregid(%d, %d)", (int)ID(rgid), (int)ID(egid));
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_USER: setgroups";
goto bad;
}
}
state->ruid = ROOT_UID;
state->euid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (UID_CHANGED && setreuid(ID(ruid), ID(euid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setreuid(%d, %d)", (int)ID(ruid), (int)ID(euid));
goto bad;
}
break;
case PERM_FULL_USER:
/* headed for exec() */
state->rgid = ctx->user.gid;
state->egid = ctx->user.gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setregid(ID(rgid), ID(egid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setregid(%d, %d)",
(int)ID(rgid), (int)ID(egid));
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_FULL_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
state->euid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (UID_CHANGED && setreuid(ID(ruid), ID(euid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setreuid(%d, %d)",
(int)ID(ruid), (int)ID(euid));
goto bad;
}
break;
case PERM_RUNAS:
state->rgid = ostate->rgid;
state->egid = ctx->runas.gr ? ctx->runas.gr->gr_gid : ctx->runas.pw->pw_gid; // -V595
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setregid(ID(rgid), ID(egid))) {
errstr = N_("unable to change to runas gid");
goto bad;
}
state->gidlist = runas_setgroups(ctx);
if (state->gidlist == NULL) {
errstr = N_("unable to set runas group vector");
goto bad;
}
state->ruid = ROOT_UID;
state->euid = ctx->runas.pw ? ctx->runas.pw->pw_uid : ctx->user.uid; // -V595
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (UID_CHANGED && setreuid(ID(ruid), ID(euid))) {
errstr = N_("unable to change to runas uid");
goto bad;
}
break;
case PERM_SUDOERS: {
const uid_t sudoers_uid = sudoers_file_uid();
const gid_t sudoers_gid = sudoers_file_gid();
const mode_t sudoers_mode = sudoers_file_mode();
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
/* assume euid == ROOT_UID, ruid == user */
state->rgid = ostate->rgid;
state->egid = sudoers_gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setregid(ID(rgid), ID(egid))) {
errstr = N_("unable to change to sudoers gid");
goto bad;
}
state->ruid = ROOT_UID;
/*
* If sudoers_uid == ROOT_UID and sudoers_mode is group readable
* we use a non-zero uid in order to avoid NFS lossage.
* Using uid 1 is a bit bogus but should work on all OS's.
*/
if (sudoers_uid == ROOT_UID && (sudoers_mode & S_IRGRP))
state->euid = 1;
else
state->euid = sudoers_uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (UID_CHANGED && setreuid(ID(ruid), ID(euid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_SUDOERS: setreuid(%d, %d)",
(int)ID(ruid), (int)ID(euid));
goto bad;
}
break;
}
case PERM_TIMESTAMP:
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
state->rgid = ostate->rgid;
state->egid = ostate->egid;
state->ruid = ROOT_UID;
state->euid = timestamp_get_uid();
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_TIMESTAMP: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (UID_CHANGED && setreuid(ID(ruid), ID(euid))) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_TIMESTAMP: setreuid(%d, %d)",
(int)ID(ruid), (int)ID(euid));
goto bad;
}
break;
}
perm_stack_depth++;
debug_return_bool(true);
bad:
if (errno == EAGAIN)
sudo_warnx(U_("%s: %s"), U_(errstr), U_("too many processes"));
else
sudo_warn("%s", U_(errstr));
debug_return_bool(false);
}
bool
restore_perms(void)
{
struct perm_state *state, *ostate;
debug_decl(restore_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth < 2) {
sudo_warnx("%s", U_("perm stack underflow"));
debug_return_bool(true);
}
state = &perm_stack[perm_stack_depth - 1];
ostate = &perm_stack[perm_stack_depth - 2];
perm_stack_depth--;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: uid: [%d, %d] -> [%d, %d]",
__func__, (int)state->ruid, (int)state->euid,
(int)ostate->ruid, (int)ostate->euid);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: gid: [%d, %d] -> [%d, %d]",
__func__, (int)state->rgid, (int)state->egid,
(int)ostate->rgid, (int)ostate->egid);
/*
* When changing euid to ROOT_UID, setreuid() may fail even if
* the ruid is ROOT_UID so call setuid() first.
*/
if (OID(euid) == ROOT_UID) {
/* setuid() may not set the saved ID unless the euid is ROOT_UID */
if (ID(euid) != ROOT_UID) {
if (setreuid(NO_UID, ROOT_UID) != 0) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
"setreuid() [%d, %d] -> [-1, %d)", (int)state->ruid,
(int)state->euid, ROOT_UID);
}
}
if (setuid(ROOT_UID)) {
sudo_warn("setuid() [%d, %d] -> %d)", (int)state->ruid,
(int)state->euid, ROOT_UID);
goto bad;
}
}
if (setreuid(OID(ruid), OID(euid))) {
sudo_warn("setreuid() [%d, %d] -> [%d, %d]", (int)state->ruid,
(int)state->euid, (int)OID(ruid), (int)OID(euid));
goto bad;
}
if (setregid(OID(rgid), OID(egid))) {
sudo_warn("setregid() [%d, %d] -> [%d, %d]", (int)state->rgid,
(int)state->egid, (int)OID(rgid), (int)OID(egid));
goto bad;
}
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(ostate->gidlist->ngids, ostate->gidlist->gids)) {
sudo_warn("setgroups()");
goto bad;
}
}
sudo_gidlist_delref(state->gidlist);
debug_return_bool(true);
bad:
debug_return_bool(false);
}
#elif defined(HAVE_SETEUID)
#define GID_CHANGED (state->rgid != ostate->rgid || state->egid != ostate->egid)
/*
* Set real and effective uids and gids based on perm.
* We always retain a real or effective uid of ROOT_UID unless
* we are headed for an exec().
* The ctx argument may be NULL for PERM_ROOT, PERM_SUDOERS and PERM_TIMESTAMP.
* This version of set_perms() works fine with the "stay_setuid" option.
*/
bool
set_perms(const struct sudoers_context *ctx, int perm)
{
struct perm_state *state, *ostate = NULL;
char errbuf[1024];
const char *errstr = errbuf;
debug_decl(set_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth == PERM_STACK_MAX) {
errstr = N_("perm stack overflow");
errno = EINVAL;
goto bad;
}
if (perm == PERM_INITIAL) {
if (perm_stack_depth > 1)
rewind_perms();
perm_stack_depth = 0;
} else {
if (perm_stack_depth == 0) {
errstr = N_("perm stack underflow");
errno = EINVAL;
goto bad;
}
ostate = &perm_stack[perm_stack_depth - 1];
}
state = &perm_stack[perm_stack_depth];
/*
* Since we only have setuid() and seteuid() and semantics
* for these calls differ on various systems, we set
* real and effective uids to ROOT_UID initially to be safe.
*/
if (perm != PERM_INITIAL) {
if (ostate->euid != ROOT_UID && seteuid(ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"set_perms: seteuid(%d)", ROOT_UID);
goto bad;
}
if (ostate->ruid != ROOT_UID && setuid(ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"set_perms: setuid(%d)", ROOT_UID);
goto bad;
}
}
switch (perm) {
case PERM_INITIAL:
/* Stash initial state */
state->ruid = getuid();
state->euid = geteuid();
state->rgid = getgid();
state->egid = getegid();
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_INITIAL: "
"ruid: %d, euid: %d, rgid: %d, egid: %d", __func__,
(int)state->ruid, (int)state->euid,
(int)state->rgid, (int)state->egid);
break;
case PERM_ROOT:
/* We already set ruid/euid above. */
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, ROOT_UID, ROOT_UID);
state->ruid = ROOT_UID;
state->euid = ROOT_UID;
state->rgid = ostate->rgid;
state->egid = ROOT_GID;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, ROOT_GID, ROOT_GID);
if (GID_CHANGED && setegid(ROOT_GID)) {
errstr = N_("unable to change to root gid");
goto bad;
}
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
break;
case PERM_USER:
state->egid = ctx->user.gid;
state->rgid = ostate->rgid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setegid(ctx->user.gid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: setegid(%d)", (int)ctx->user.gid);
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_USER: setgroups";
goto bad;
}
}
state->ruid = ROOT_UID;
state->euid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_USER: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (seteuid(ctx->user.uid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_USER: seteuid(%d)", (int)ctx->user.uid);
goto bad;
}
break;
case PERM_FULL_USER:
/* headed for exec() */
state->rgid = ctx->user.gid;
state->egid = ctx->user.gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setgid(ctx->user.gid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setgid(%d)", (int)ctx->user.gid);
goto bad;
}
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_FULL_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
state->euid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (setuid(ctx->user.uid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setuid(%d)", (int)ctx->user.uid);
goto bad;
}
break;
case PERM_RUNAS:
state->rgid = ostate->rgid;
state->egid = ctx->runas.gr ? ctx->runas.gr->gr_gid : ctx->runas.pw->pw_gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setegid(state->egid)) {
errstr = N_("unable to change to runas gid");
goto bad;
}
state->gidlist = runas_setgroups(ctx);
if (state->gidlist == NULL) {
errstr = N_("unable to set runas group vector");
goto bad;
}
state->ruid = ostate->ruid;
state->euid = ctx->runas.pw ? ctx->runas.pw->pw_uid : ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_RUNAS: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (seteuid(state->euid)) {
errstr = N_("unable to change to runas uid");
goto bad;
}
break;
case PERM_SUDOERS: {
const uid_t sudoers_uid = sudoers_file_uid();
const gid_t sudoers_gid = sudoers_file_gid();
const mode_t sudoers_mode = sudoers_file_mode();
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
/* assume euid == ROOT_UID, ruid == user */
state->rgid = ostate->rgid;
state->egid = sudoers_gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: gid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->rgid,
(int)ostate->egid, (int)state->rgid, (int)state->egid);
if (GID_CHANGED && setegid(sudoers_gid)) {
errstr = N_("unable to change to sudoers gid");
goto bad;
}
state->ruid = ROOT_UID;
/*
* If sudoers_uid == ROOT_UID and sudoers_mode is group readable
* we use a non-zero uid in order to avoid NFS lossage.
* Using uid 1 is a bit bogus but should work on all OS's.
*/
if (sudoers_uid == ROOT_UID && (sudoers_mode & S_IRGRP))
state->euid = 1;
else
state->euid = sudoers_uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_SUDOERS: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (seteuid(state->euid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_SUDOERS: seteuid(%d)", (int)state->euid);
goto bad;
}
break;
}
case PERM_TIMESTAMP:
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
state->rgid = ostate->rgid;
state->egid = ostate->egid;
state->ruid = ROOT_UID;
state->euid = timestamp_get_uid();
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_TIMESTAMP: uid: "
"[%d, %d] -> [%d, %d]", __func__, (int)ostate->ruid,
(int)ostate->euid, (int)state->ruid, (int)state->euid);
if (seteuid(state->euid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_TIMESTAMP: seteuid(%d)", (int)state->euid);
goto bad;
}
break;
}
perm_stack_depth++;
debug_return_bool(true);
bad:
if (errno == EAGAIN)
sudo_warnx(U_("%s: %s"), U_(errstr), U_("too many processes"));
else
sudo_warn("%s", U_(errstr));
debug_return_bool(false);
}
bool
restore_perms(void)
{
struct perm_state *state, *ostate;
debug_decl(restore_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth < 2) {
sudo_warnx("%s", U_("perm stack underflow"));
debug_return_bool(true);
}
state = &perm_stack[perm_stack_depth - 1];
ostate = &perm_stack[perm_stack_depth - 2];
perm_stack_depth--;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: uid: [%d, %d] -> [%d, %d]",
__func__, (int)state->ruid, (int)state->euid,
(int)ostate->ruid, (int)ostate->euid);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: gid: [%d, %d] -> [%d, %d]",
__func__, (int)state->rgid, (int)state->egid,
(int)ostate->rgid, (int)ostate->egid);
/*
* Since we only have setuid() and seteuid() and semantics
* for these calls differ on various systems, we set
* real and effective uids to ROOT_UID initially to be safe.
*/
if (seteuid(ROOT_UID)) {
sudo_warn("seteuid() [%d] -> [%d]", (int)state->euid, ROOT_UID);
goto bad;
}
if (setuid(ROOT_UID)) {
sudo_warn("setuid() [%d, %d] -> [%d, %d]", (int)state->ruid, ROOT_UID,
ROOT_UID, ROOT_UID);
goto bad;
}
if (OID(egid) != NO_GID && setegid(ostate->egid)) {
sudo_warn("setegid(%d)", (int)ostate->egid);
goto bad;
}
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(ostate->gidlist->ngids, ostate->gidlist->gids)) {
sudo_warn("setgroups()");
goto bad;
}
}
if (OID(euid) != NO_UID && seteuid(ostate->euid)) {
sudo_warn("seteuid(%d)", (int)ostate->euid);
goto bad;
}
sudo_gidlist_delref(state->gidlist);
debug_return_bool(true);
bad:
debug_return_bool(false);
}
#else /* !HAVE_SETRESUID && !HAVE_SETREUID && !HAVE_SETEUID */
/*
* Set uids and gids based on perm via setuid() and setgid().
* The ctx argument may be NULL for PERM_ROOT, PERM_SUDOERS and PERM_TIMESTAMP.
* NOTE: does not support the "stay_setuid" or timestampowner options.
* Also, sudoers_uid and sudoers_gid are not used.
*/
bool
set_perms(const struct sudoers_context *ctx, int perm)
{
struct perm_state *state, *ostate = NULL;
char errbuf[1024];
const char *errstr = errbuf;
debug_decl(set_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth == PERM_STACK_MAX) {
errstr = N_("perm stack overflow");
errno = EINVAL;
goto bad;
}
if (perm == PERM_INITIAL) {
if (perm_stack_depth > 1)
rewind_perms();
perm_stack_depth = 0;
} else {
if (perm_stack_depth == 0) {
errstr = N_("perm stack underflow");
errno = EINVAL;
goto bad;
}
ostate = &perm_stack[perm_stack_depth - 1];
}
state = &perm_stack[perm_stack_depth];
switch (perm) {
case PERM_INITIAL:
/* Stash initial state */
state->ruid = geteuid() == ROOT_UID ? ROOT_UID : getuid();
state->rgid = getgid();
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_INITIAL: "
"ruid: %d, rgid: %d", __func__, (int)state->ruid, (int)state->rgid);
break;
case PERM_ROOT:
state->ruid = ROOT_UID;
state->rgid = ROOT_GID;
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: uid: "
"[%d] -> [%d]", __func__, (int)ostate->ruid, (int)state->ruid);
if (setuid(ROOT_UID)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_ROOT: setuid(%d)", ROOT_UID);
goto bad;
}
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_ROOT: gid: "
"[%d] -> [%d]", __func__, (int)ostate->rgid, (int)state->rgid);
if (setgid(ROOT_GID)) {
errstr = N_("unable to change to root gid");
goto bad;
}
break;
case PERM_FULL_USER:
state->rgid = ctx->user.gid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: gid: "
"[%d] -> [%d]", __func__, (int)ostate->rgid, (int)state->rgid);
(void) setgid(ctx->user.gid);
state->gidlist = ctx->user.gid_list;
sudo_gidlist_addref(state->gidlist);
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(state->gidlist->ngids, state->gidlist->gids)) {
errstr = "PERM_FULL_USER: setgroups";
goto bad;
}
}
state->ruid = ctx->user.uid;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: uid: "
"[%d] -> [%d]", __func__, (int)ostate->ruid, (int)state->ruid);
if (setuid(ctx->user.uid)) {
(void)snprintf(errbuf, sizeof(errbuf),
"PERM_FULL_USER: setuid(%d)", (int)ctx->user.uid);
goto bad;
}
break;
case PERM_USER:
case PERM_SUDOERS:
case PERM_RUNAS:
case PERM_TIMESTAMP:
/* Unsupported since we can't set euid. */
state->ruid = ostate->ruid;
state->rgid = ostate->rgid;
state->gidlist = ostate->gidlist;
sudo_gidlist_addref(state->gidlist);
break;
}
perm_stack_depth++;
debug_return_bool(true);
bad:
if (errno == EAGAIN)
sudo_warnx(U_("%s: %s"), U_(errstr), U_("too many processes"));
else
sudo_warn("%s", U_(errstr));
debug_return_bool(false);
}
bool
restore_perms(void)
{
struct perm_state *state, *ostate;
debug_decl(restore_perms, SUDOERS_DEBUG_PERMS);
if (perm_stack_depth < 2) {
sudo_warnx("%s", U_("perm stack underflow"));
debug_return_bool(true);
}
state = &perm_stack[perm_stack_depth - 1];
ostate = &perm_stack[perm_stack_depth - 2];
perm_stack_depth--;
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: uid: [%d] -> [%d]",
__func__, (int)state->ruid, (int)ostate->ruid);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s: gid: [%d] -> [%d]",
__func__, (int)state->rgid, (int)ostate->rgid);
if (OID(rgid) != NO_GID && setgid(ostate->rgid)) {
sudo_warn("setgid(%d)", (int)ostate->rgid);
goto bad;
}
if (state->gidlist != ostate->gidlist) {
if (sudo_setgroups(ostate->gidlist->ngids, ostate->gidlist->gids)) {
sudo_warn("setgroups()");
goto bad;
}
}
sudo_gidlist_delref(state->gidlist);
if (OID(ruid) != NO_UID && setuid(ostate->ruid)) {
sudo_warn("setuid(%d)", (int)ostate->ruid);
goto bad;
}
debug_return_bool(true);
bad:
debug_return_bool(false);
}
#endif /* HAVE_SETRESUID || HAVE_SETREUID || HAVE_SETEUID */
#if defined(HAVE_SETRESUID) || defined(HAVE_SETREUID) || defined(HAVE_SETEUID)
static struct gid_list *
runas_setgroups(const struct sudoers_context *ctx)
{
struct gid_list *gidlist;
debug_decl(runas_setgroups, SUDOERS_DEBUG_PERMS);
gidlist = runas_getgroups(ctx);
if (gidlist != NULL && !def_preserve_groups) {
if (sudo_setgroups(gidlist->ngids, gidlist->gids) < 0) {
sudo_gidlist_delref(gidlist);
gidlist = NULL;
}
}
debug_return_ptr(gidlist);
}
#endif /* HAVE_SETRESUID || HAVE_SETREUID || HAVE_SETEUID */
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