pcu: Fix memory corruption bugs (ASAN)

ASAN has found improper deletion of objects. These only occur
on shutdown but makes it impossible to run the test cases with
full ASAN support.

This commit fixes some of them and deactivates the freeing of the_pcu.bctx
which may cause a corruption in BTS::~BTS() later on.

Note that the latter is only a work-aound and should be fixed
properly. It will leak bctx objects, but this is currently not
critical, since gprs_bssgp_destroy is only called once, immediately
before a call to exit().

Ticket: OW#1572
Sponsored-by: On-Waves ehf

src/bts.cpp

@@ -150,7 +150,12 @@ BTS::BTS()
 
 BTS::~BTS()
 {
+	/* this can cause counter updates and must not be left to the
+	 * m_ms_store's destructor */
+	m_ms_store.cleanup();
+
 	rate_ctr_group_free(m_ratectrs);
+	osmo_stat_item_group_free(m_statg);
 }
 
 

src/gprs_bssgp_pcu.cpp

@@ -872,28 +872,33 @@ struct gprs_bssgp_pcu *gprs_bssgp_create_and_connect(struct gprs_rlcmac_bts *bts
 
 void gprs_bssgp_destroy(void)
 {
-	if (!bssgp_nsi)
+	struct gprs_ns_inst *nsi = bssgp_nsi;
+	if (!nsi)
 		return;
 
+	bssgp_nsi = NULL;
+
 	osmo_timer_del(&the_pcu.bvc_timer);
 
 	osmo_signal_unregister_handler(SS_L_NS, nsvc_signal_cb, NULL);
 
 	the_pcu.nsvc = NULL;
 
-	/* FIXME: move this to libgb: btsctx_free() */
-	llist_del(&the_pcu.bctx->list);
-	talloc_free(the_pcu.bctx);
-	the_pcu.bctx = NULL;
-
 	/* FIXME: blocking... */
 	the_pcu.nsvc_unblocked = 0;
 	the_pcu.bvc_sig_reset = 0;
 	the_pcu.bvc_reset = 0;
 	the_pcu.bvc_unblocked = 0;	
 
-	gprs_ns_destroy(bssgp_nsi);
-	bssgp_nsi = NULL;
+	gprs_ns_destroy(nsi);
+
+	/* FIXME: move this to libgb: btsctx_free() */
+	llist_del(&the_pcu.bctx->list);
+#warning "This causes ASAN to complain. It is not critical for normal operation but should be fixed nevertheless"
+#if 0
+	talloc_free(the_pcu.bctx);
+#endif
+	the_pcu.bctx = NULL;
 }
 
 struct bssgp_bvc_ctx *gprs_bssgp_pcu_current_bctx(void)

src/gprs_ms_storage.cpp

@@ -33,6 +33,11 @@ GprsMsStorage::GprsMsStorage(BTS *bts) :
 }
 
 GprsMsStorage::~GprsMsStorage()
+{
+	cleanup();
+}
+
+void GprsMsStorage::cleanup()
 {
 	LListHead<GprsMs> *pos, *tmp;
 

src/gprs_ms_storage.h

@@ -33,6 +33,8 @@ public:
 	GprsMsStorage(BTS *bts);
 	~GprsMsStorage();
 
+	void cleanup();
+
 	virtual void ms_idle(class GprsMs *);
 	virtual void ms_active(class GprsMs *);