diff options
Diffstat (limited to '')
| -rw-r--r-- | plugins/sudoers/set_perms.c | 1613 |
1 files changed, 1613 insertions, 0 deletions
diff --git a/plugins/sudoers/set_perms.c b/plugins/sudoers/set_perms.c new file mode 100644 index 0000000..77ce395 --- /dev/null +++ b/plugins/sudoers/set_perms.c @@ -0,0 +1,1613 @@ +/* + * 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" + +/* + * Prototypes + */ +#if defined(HAVE_SETRESUID) || defined(HAVE_SETREUID) || defined(HAVE_SETEUID) +static struct gid_list *runas_setgroups(void); +#endif + +/* + * We keep track of the current permisstions 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 ? (uid_t)-1 : state->x) +#undef OID +#define OID(x) (ostate->x == state->x ? (uid_t)-1 : 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. + * This version of set_perms() works fine with the "stay_setuid" option. + */ +bool +set_perms(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 = 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 = 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 = 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 = user_uid; + state->euid = 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 = user_gid; + state->egid = user_gid; + state->sgid = 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 = 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 = user_uid; + state->euid = user_uid; + state->suid = 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 = runas_gr ? runas_gr->gr_gid : 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 && setresgid(ID(rgid), ID(egid), ID(sgid))) { + errstr = N_("unable to change to runas gid"); + goto bad; + } + state->gidlist = runas_setgroups(); + if (state->gidlist == NULL) { + errstr = N_("unable to set runas group vector"); + goto bad; + } + state->ruid = ostate->ruid; + state->euid = runas_pw ? runas_pw->pw_uid : 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: + 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_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(-1, ROOT_UID, -1)) { + 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. + * This version of set_perms() works fine with the "stay_setuid" option. + */ +bool +set_perms(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 = 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 = 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, user_gid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_USER: setgidx(ID_EFFECTIVE, %d)", (int)user_gid); + goto bad; + } + state->gidlist = 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 = user_uid; + state->euid = 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, user_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_USER: setuidx(ID_EFFECTIVE|ID_REAL, %d)", (int)user_uid); + goto bad; + } + break; + + case PERM_FULL_USER: + /* headed for exec() */ + state->rgid = user_gid; + state->egid = user_gid; + state->sgid = 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, user_gid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_FULL_USER: setgidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)", + (int)user_gid); + goto bad; + } + state->gidlist = 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 = user_uid; + state->euid = user_uid; + state->suid = 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, user_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_FULL_USER: setuidx(ID_EFFECTIVE|ID_REAL|ID_SAVED, %d)", + (int)user_uid); + goto bad; + } + break; + + case PERM_RUNAS: + state->rgid = ostate->rgid; + state->egid = runas_gr ? runas_gr->gr_gid : 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(); + if (state->gidlist == NULL) { + errstr = N_("unable to set runas group vector"); + goto bad; + } + state->ruid = ostate->ruid; + state->euid = runas_pw ? runas_pw->pw_uid : 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: + 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_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, timestamp_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_TIMESTAMP: setuidx(ID_EFFECTIVE, %d)", + (int)timestamp_uid); + 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) != (uid_t)-1 || OID(euid) != (uid_t)-1 || OID(suid) != (uid_t)-1) { + 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) == (uid_t)-1 && OID(suid) == (uid_t)-1) { + /* 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) == (uid_t)-1) { + /* 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) != (gid_t)-1 || OID(egid) != (gid_t)-1 || OID(sgid) != (gid_t)-1) { + 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) == (gid_t)-1 && OID(sgid) == (gid_t)-1) { + 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) == (gid_t)-1) { + 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. + * This version of set_perms() works fine with the "stay_setuid" option. + */ +bool +set_perms(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 = 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(-1, 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, -1)) { + (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 = 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 = 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 = 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 = user_gid; + state->egid = 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 = 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 = user_uid; + state->euid = 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 = runas_gr ? runas_gr->gr_gid : 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 && setregid(ID(rgid), ID(egid))) { + errstr = N_("unable to change to runas gid"); + goto bad; + } + state->gidlist = runas_setgroups(); + if (state->gidlist == NULL) { + errstr = N_("unable to set runas group vector"); + goto bad; + } + state->ruid = ROOT_UID; + state->euid = runas_pw ? runas_pw->pw_uid : 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 (UID_CHANGED && setreuid(ID(ruid), ID(euid))) { + errstr = N_("unable to change to runas uid"); + goto bad; + } + break; + + case PERM_SUDOERS: + 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_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(-1, 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(). + * This version of set_perms() works fine with the "stay_setuid" option. + */ +bool +set_perms(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 = 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 = 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(user_gid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_USER: setegid(%d)", (int)user_gid); + goto bad; + } + state->gidlist = 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 = 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(user_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_USER: seteuid(%d)", (int)user_uid); + goto bad; + } + break; + + case PERM_FULL_USER: + /* headed for exec() */ + state->rgid = user_gid; + state->egid = 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(user_gid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_FULL_USER: setgid(%d)", (int)user_gid); + goto bad; + } + state->gidlist = 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 = user_uid; + state->euid = 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(user_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_FULL_USER: setuid(%d)", (int)user_uid); + goto bad; + } + break; + + case PERM_RUNAS: + state->rgid = ostate->rgid; + state->egid = runas_gr ? runas_gr->gr_gid : 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(); + if (state->gidlist == NULL) { + errstr = N_("unable to set runas group vector"); + goto bad; + } + state->ruid = ostate->ruid; + state->euid = runas_pw ? runas_pw->pw_uid : 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: + 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_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(timestamp_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_TIMESTAMP: seteuid(%d)", (int)timestamp_uid); + 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) != (gid_t)-1 && 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) != (uid_t)-1 && 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(). + * NOTE: does not support the "stay_setuid" or timestampowner options. + * Also, sudoers_uid and sudoers_gid are not used. + */ +bool +set_perms(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 = 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 = user_gid; + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: gid: " + "[%d] -> [%d]", __func__, (int)ostate->rgid, (int)state->rgid); + (void) setgid(user_gid); + state->gidlist = 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 = user_uid; + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: PERM_FULL_USER: uid: " + "[%d] -> [%d]", __func__, (int)ostate->ruid, (int)state->ruid); + if (setuid(user_uid)) { + (void)snprintf(errbuf, sizeof(errbuf), + "PERM_FULL_USER: setuid(%d)", (int)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) != (gid_t)-1 && 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) != (uid_t)-1 && 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(void) +{ + struct gid_list *gidlist; + debug_decl(runas_setgroups, SUDOERS_DEBUG_PERMS); + + gidlist = runas_getgroups(); + 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 */ |