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D-Bus: Fix P2P NULL dereference after interface removal

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When the P2P management interface is deleted, P2P is then disabled and
global->p2p_init_wpa_s is set to NULL. After that, other interfaces can
still trigger P2P functions (like wpas_p2p_find()) using D-Bus. This
makes wpa_supplicant terminate with SIGSEGV, because it dereferences a
NULL pointer. Fix this by adding proper checks, like it's done with
wpa_cli.

CC: Beniamino Galvani <bgalvani@redhat.com>
CC: Benjamin Berg <benjamin@sipsolutions.net>
Reported-by: Vladimir Benes <vbenes@redhat.com>
Signed-off-by: Davide Caratti <davide.caratti@gmail.com>
This commit is contained in:
Davide Caratti 2019-10-02 14:08:41 +02:00 committed by Jouni Malinen
parent 937644aa2c
commit b2ad4e6b24
1 changed files with 67 additions and 2 deletions
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69
wpa_supplicant/dbus/dbus_new_handlers_p2p.c
View file

@ -40,6 +40,14 @@ static int wpas_dbus_validate_dbus_ipaddr(struct wpa_dbus_dict_entry entry)
}
static dbus_bool_t no_p2p_mgmt_interface(DBusError *error)
{
dbus_set_error_const(error, WPAS_DBUS_ERROR_IFACE_UNKNOWN,
"Could not find P2P mgmt interface");
return FALSE;
}
/**
* Parses out the mac address from the peer object path.
* @peer_path - object path of the form
@ -78,6 +86,22 @@ wpas_dbus_error_persistent_group_unknown(DBusMessage *message)
}
/**
* wpas_dbus_error_no_p2p_mgmt_iface - Return a new InterfaceUnknown error
* message
* @message: Pointer to incoming dbus message this error refers to
* Returns: a dbus error message
*
* Convenience function to create and return an unknown interface error.
*/
static DBusMessage * wpas_dbus_error_no_p2p_mgmt_iface(DBusMessage *message)
{
wpa_printf(MSG_DEBUG, "dbus: Could not find P2P mgmt interface");
return dbus_message_new_error(message, WPAS_DBUS_ERROR_IFACE_UNKNOWN,
"Could not find P2P mgmt interface");
}
DBusMessage * wpas_dbus_handler_p2p_find(DBusMessage *message,
struct wpa_supplicant *wpa_s)
{
@ -145,6 +169,10 @@ DBusMessage * wpas_dbus_handler_p2p_find(DBusMessage *message,
}
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s) {
reply = wpas_dbus_error_no_p2p_mgmt_iface(message);
goto error_nop2p;
}
if (wpas_p2p_find(wpa_s, timeout, type, num_req_dev_types,
req_dev_types, NULL, 0, 0, NULL, freq))
@ -157,8 +185,9 @@ DBusMessage * wpas_dbus_handler_p2p_find(DBusMessage *message,
error_clear:
wpa_dbus_dict_entry_clear(&entry);
error:
os_free(req_dev_types);
reply = wpas_dbus_error_invalid_args(message, entry.key);
error_nop2p:
os_free(req_dev_types);
return reply;
}
@ -166,7 +195,9 @@ error:
DBusMessage * wpas_dbus_handler_p2p_stop_find(DBusMessage *message,
struct wpa_supplicant *wpa_s)
{
wpas_p2p_stop_find(wpa_s->global->p2p_init_wpa_s);
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (wpa_s)
wpas_p2p_stop_find(wpa_s);
return NULL;
}
@ -185,6 +216,8 @@ DBusMessage * wpas_dbus_handler_p2p_rejectpeer(DBusMessage *message,
return wpas_dbus_error_invalid_args(message, NULL);
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return wpas_dbus_error_no_p2p_mgmt_iface(message);
if (wpas_p2p_reject(wpa_s, peer_addr) < 0)
return wpas_dbus_error_unknown_error(message,
@ -204,6 +237,8 @@ DBusMessage * wpas_dbus_handler_p2p_listen(DBusMessage *message,
return wpas_dbus_error_no_memory(message);
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return wpas_dbus_error_no_p2p_mgmt_iface(message);
if (wpas_p2p_listen(wpa_s, (unsigned int) timeout)) {
return dbus_message_new_error(message,
@ -245,6 +280,8 @@ DBusMessage * wpas_dbus_handler_p2p_extendedlisten(
}
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return wpas_dbus_error_no_p2p_mgmt_iface(message);
if (wpas_p2p_ext_listen(wpa_s, period, interval))
return wpas_dbus_error_unknown_error(
@ -350,6 +387,10 @@ DBusMessage * wpas_dbus_handler_p2p_group_add(DBusMessage *message,
}
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s) {
reply = wpas_dbus_error_no_p2p_mgmt_iface(message);
goto out;
}
if (pg_object_path != NULL) {
char *net_id_str;
@ -433,6 +474,12 @@ static dbus_bool_t wpa_dbus_p2p_check_enabled(struct wpa_supplicant *wpa_s,
"P2P is not available for this interface");
return FALSE;
}
if (!wpa_s->global->p2p_init_wpa_s) {
if (out_reply)
*out_reply = wpas_dbus_error_no_p2p_mgmt_iface(
message);
return no_p2p_mgmt_interface(error);
}
return TRUE;
}
@ -822,6 +869,8 @@ DBusMessage * wpas_dbus_handler_p2p_prov_disc_req(DBusMessage *message,
return wpas_dbus_error_invalid_args(message, NULL);
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return wpas_dbus_error_no_p2p_mgmt_iface(message);
if (wpas_p2p_prov_disc(wpa_s, peer_addr, config_method,
WPAS_P2P_PD_FOR_GO_NEG, NULL) < 0)
@ -1882,6 +1931,8 @@ dbus_bool_t wpas_dbus_getter_p2p_peer_groups(
wpa_s = peer_args->wpa_s;
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return no_p2p_mgmt_interface(error);
wpa_s_go = wpas_get_p2p_client_iface(wpa_s, info->p2p_device_addr);
if (wpa_s_go) {
@ -1963,6 +2014,9 @@ dbus_bool_t wpas_dbus_getter_persistent_groups(
dbus_bool_t success = FALSE;
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return no_p2p_mgmt_interface(error);
if (!wpa_s->parent->dbus_new_path)
return FALSE;
@ -2077,6 +2131,11 @@ DBusMessage * wpas_dbus_handler_add_persistent_group(
dbus_message_iter_init(message, &iter);
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s) {
reply = wpas_dbus_error_no_p2p_mgmt_iface(message);
goto err;
}
if (wpa_s->parent->dbus_new_path)
ssid = wpa_config_add_network(wpa_s->conf);
if (ssid == NULL) {
@ -2159,6 +2218,10 @@ DBusMessage * wpas_dbus_handler_remove_persistent_group(
DBUS_TYPE_INVALID);
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s) {
reply = wpas_dbus_error_no_p2p_mgmt_iface(message);
goto out;
}
/*
* Extract the network ID and ensure the network is actually a child of
@ -2235,6 +2298,8 @@ DBusMessage * wpas_dbus_handler_remove_all_persistent_groups(
struct wpa_config *config;
wpa_s = wpa_s->global->p2p_init_wpa_s;
if (!wpa_s)
return wpas_dbus_error_no_p2p_mgmt_iface(message);
config = wpa_s->conf;
ssid = config->ssid;