qemu/authz/pamacct.c
Kevin Wolf 3428455df9 authz-pam: Check that 'service' property is set
If the 'service' property is not set, we'll call pam_start() with a NULL
pointer for the service name. This fails and leaves a message like this
in the syslog:

qemu-storage-daemon[294015]: PAM pam_start: invalid argument: service == NULL

Make specifying the property mandatory and catch the error already
during the creation of the object.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-11-18 10:51:35 +00:00

154 lines
3.8 KiB
C

/*
* QEMU PAM authorization driver
*
* Copyright (c) 2018 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "authz/pamacct.h"
#include "trace.h"
#include "qemu/module.h"
#include "qom/object_interfaces.h"
#include <security/pam_appl.h>
static bool qauthz_pam_is_allowed(QAuthZ *authz,
const char *identity,
Error **errp)
{
QAuthZPAM *pauthz = QAUTHZ_PAM(authz);
const struct pam_conv pam_conversation = { 0 };
pam_handle_t *pamh = NULL;
int ret;
trace_qauthz_pam_check(authz, identity, pauthz->service);
ret = pam_start(pauthz->service,
identity,
&pam_conversation,
&pamh);
if (ret != PAM_SUCCESS) {
error_setg(errp, "Unable to start PAM transaction: %s",
pam_strerror(NULL, ret));
return false;
}
ret = pam_acct_mgmt(pamh, PAM_SILENT);
pam_end(pamh, ret);
if (ret != PAM_SUCCESS) {
error_setg(errp, "Unable to authorize user '%s': %s",
identity, pam_strerror(pamh, ret));
return false;
}
return true;
}
static void
qauthz_pam_prop_set_service(Object *obj,
const char *service,
Error **errp G_GNUC_UNUSED)
{
QAuthZPAM *pauthz = QAUTHZ_PAM(obj);
g_free(pauthz->service);
pauthz->service = g_strdup(service);
}
static char *
qauthz_pam_prop_get_service(Object *obj,
Error **errp G_GNUC_UNUSED)
{
QAuthZPAM *pauthz = QAUTHZ_PAM(obj);
return g_strdup(pauthz->service);
}
static void
qauthz_pam_complete(UserCreatable *uc, Error **errp)
{
QAuthZPAM *pauthz = QAUTHZ_PAM(uc);
if (!pauthz->service) {
error_setg(errp, "The 'service' property must be set");
return;
}
}
static void
qauthz_pam_finalize(Object *obj)
{
QAuthZPAM *pauthz = QAUTHZ_PAM(obj);
g_free(pauthz->service);
}
static void
qauthz_pam_class_init(ObjectClass *oc, void *data)
{
UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
QAuthZClass *authz = QAUTHZ_CLASS(oc);
ucc->complete = qauthz_pam_complete;
authz->is_allowed = qauthz_pam_is_allowed;
object_class_property_add_str(oc, "service",
qauthz_pam_prop_get_service,
qauthz_pam_prop_set_service);
}
QAuthZPAM *qauthz_pam_new(const char *id,
const char *service,
Error **errp)
{
return QAUTHZ_PAM(
object_new_with_props(TYPE_QAUTHZ_PAM,
object_get_objects_root(),
id, errp,
"service", service,
NULL));
}
static const TypeInfo qauthz_pam_info = {
.parent = TYPE_QAUTHZ,
.name = TYPE_QAUTHZ_PAM,
.instance_size = sizeof(QAuthZPAM),
.instance_finalize = qauthz_pam_finalize,
.class_init = qauthz_pam_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_USER_CREATABLE },
{ }
}
};
static void
qauthz_pam_register_types(void)
{
type_register_static(&qauthz_pam_info);
}
type_init(qauthz_pam_register_types);