qcacld-3.0: Fix OOB write in wma_unified_debug_print_event_handler

The routine wma_unified_debug_print_event_handler logs the data from debug
print event handler. The param event data from firmware is copied to a
destination buffer .If the maximum size of the data exceeds or equals
BIG_ENDIAN_MAX_DEBUG_BUF for big endian hosts then possible OOB write will
occur in wma_unified_debug_print_event_handler. For other hosts, OOB read
could occur if datalen exceeds maximum firmware message size
WMI_SVC_MAX_SIZE.

Add check to validate datalen doesnot exceed the maximum firmware msg size
WMI_SVC_MAX_SIZE. Return failure if it exceeds.
Add check to ensure datalen doesnot exceed or equal the maximum buffer
length value for big endian hosts BIG_ENDIAN_MAX_DEBUG_BUF.
Invoke strlcpy instead of memcpy to ensure the string is null terminated
before printed.

Change-Id: I45943ae76d8fcf7b53e1f064c462d01cd6d00dcf
CRs-Fixed: 2211133

core/wma/src/wma_utils.c

@@ -3525,31 +3525,43 @@ int wma_unified_debug_print_event_handler(void *handle, uint8_t *datap,
 	WMI_DEBUG_PRINT_EVENTID_param_tlvs *param_buf;
 	uint8_t *data;
 	uint32_t datalen;
+	char dbgbuf[WMI_SVC_MSG_MAX_SIZE] = { 0 };
 
 	param_buf = (WMI_DEBUG_PRINT_EVENTID_param_tlvs *) datap;
-	if (!param_buf) {
+	if (!param_buf || !param_buf->data) {
 		WMA_LOGE("Get NULL point message from FW");
 		return -ENOMEM;
 	}
 	data = param_buf->data;
 	datalen = param_buf->num_data;
+	if (datalen > WMI_SVC_MSG_MAX_SIZE) {
+		WMA_LOGE("Received data len %d exceeds max value %d",
+				datalen, WMI_SVC_MSG_MAX_SIZE);
+		return QDF_STATUS_E_FAILURE;
+	}
 
 #ifdef BIG_ENDIAN_HOST
 	{
-		if (datalen > BIG_ENDIAN_MAX_DEBUG_BUF) {
+		if (datalen >= BIG_ENDIAN_MAX_DEBUG_BUF) {
 			WMA_LOGE("%s Invalid data len %d, limiting to max",
 				 __func__, datalen);
-			datalen = BIG_ENDIAN_MAX_DEBUG_BUF;
+			datalen = BIG_ENDIAN_MAX_DEBUG_BUF-1;
 		}
-		char dbgbuf[BIG_ENDIAN_MAX_DEBUG_BUF] = { 0 };
 
-		memcpy(dbgbuf, data, datalen);
+		strlcpy(dbgbuf, data, datalen);
 		SWAPME(dbgbuf, datalen);
 		WMA_LOGD("FIRMWARE:%s", dbgbuf);
 		return 0;
 	}
 #else
-	WMA_LOGD("FIRMWARE:%s", data);
+	if (datalen == WMI_SVC_MSG_MAX_SIZE) {
+		WMA_LOGE("%s Invalid data len %d, limiting to max",
+				__func__, datalen);
+		datalen = WMI_SVC_MSG_MAX_SIZE -1 ;
+	}
+
+	strlcpy(dbgbuf, data, datalen);
+	WMA_LOGD("FIRMWARE:%s", dbgbuf);
 	return 0;
 #endif /* BIG_ENDIAN_HOST */
 }