diff --git a/sound/soc/sof/ipc3-dtrace.c b/sound/soc/sof/ipc3-dtrace.c
index 1d3bca2d28dd..35da85a45a9a 100644
--- a/sound/soc/sof/ipc3-dtrace.c
+++ b/sound/soc/sof/ipc3-dtrace.c
@@ -186,7 +186,6 @@ static ssize_t dfsentry_trace_filter_write(struct file *file, const char __user
 	struct snd_sof_dfsentry *dfse = file->private_data;
 	struct sof_ipc_trace_filter_elem *elems = NULL;
 	struct snd_sof_dev *sdev = dfse->sdev;
-	loff_t pos = 0;
 	int num_elems;
 	char *string;
 	int ret;
@@ -201,11 +200,11 @@ static ssize_t dfsentry_trace_filter_write(struct file *file, const char __user
 	if (!string)
 		return -ENOMEM;
 
-	/* assert null termination */
-	string[count] = 0;
-	ret = simple_write_to_buffer(string, count, &pos, from, count);
-	if (ret < 0)
+	if (copy_from_user(string, from, count)) {
+		ret = -EFAULT;
 		goto error;
+	}
+	string[count] = '\0';
 
 	ret = trace_filter_parse(sdev, string, &num_elems, &elems);
 	if (ret < 0)