qcacld-3.0: Prevent overread of UP to AC mapping table

Currently the User Priority (UP) returned by hdd_wmm_classify_pkt() is
used without any checks by hdd_get_queue_index() to lookup the Access
Category (AC) in the mapping table hdd_linux_up_to_ac_map[].  Although
the UP returned by hdd_wmm_classify_pkt() should be within the valid
range, for safety add an explicit check to prevent an overread of the
table.

Change-Id: Iacd8d97bcc7a3939cdb2469f6830adc2ffc24765
CRs-Fixed: 1041989

core/hdd/src/wlan_hdd_wmm.c

@@ -1643,6 +1643,19 @@ void hdd_wmm_classify_pkt(hdd_adapter_t *adapter,
 	return;
 }
 
+/**
+ * __hdd_get_queue_index() - get queue index
+ * @up: user priority
+ *
+ * Return: queue_index
+ */
+static uint16_t __hdd_get_queue_index(uint16_t up)
+{
+	if (qdf_unlikely(up >= ARRAY_SIZE(hdd_linux_up_to_ac_map)))
+		return HDD_LINUX_AC_BE;
+	return hdd_linux_up_to_ac_map[up];
+}
+
 #ifdef QCA_LL_TX_FLOW_CONTROL_V2
 /**
  * hdd_get_queue_index() - get queue index
@@ -1656,14 +1669,13 @@ uint16_t hdd_get_queue_index(uint16_t up, bool is_eapol)
 {
 	if (qdf_unlikely(is_eapol == true))
 		return HDD_LINUX_AC_HI_PRIO;
-	else
-		return hdd_linux_up_to_ac_map[up];
+	return __hdd_get_queue_index(up);
 }
 #else
 static
 uint16_t hdd_get_queue_index(uint16_t up, bool is_eapol)
 {
-	return hdd_linux_up_to_ac_map[up];
+	return __hdd_get_queue_index(up);
 }
 #endif