drivers: soc: Add buffer overflow check for svc send request

Add buffer overflow check in voice_svc_send_req.

CRs-fixed: 1010081
Change-Id: I4ae703334b0cf04f327b392bc9cd6febd4ad32f2
Signed-off-by: Josh Kirsch <jkirsch@codeaurora.org>
Reviewed-on: http://mcrd1-22-pc.corpnet.asus/code-review/master/256473
Reviewed-by: jay_chuang <jay_chuang@asus.com>
Tested-by: jay_chuang <jay_chuang@asus.com>
Reviewed-by: Eric1 Lin <Eric1_Lin@asus.com>
diff --git a/drivers/soc/qcom/qdsp6v2/voice_svc.c b/drivers/soc/qcom/qdsp6v2/voice_svc.c
index 3e51f97..d1ad102 100644
--- a/drivers/soc/qcom/qdsp6v2/voice_svc.c
+++ b/drivers/soc/qcom/qdsp6v2/voice_svc.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2014-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -181,7 +181,8 @@
 	int ret = 0;
 	void *apr_handle = NULL;
 	struct apr_data *aprdata = NULL;
-	uint32_t user_payload_size = 0;
+	uint32_t user_payload_size;
+	uint32_t payload_size;
 
 	pr_debug("%s\n", __func__);
 
@@ -193,15 +194,19 @@
 	}
 
 	user_payload_size = apr_request->payload_size;
+	payload_size = sizeof(struct apr_data) + user_payload_size;
 
-	aprdata = kmalloc(sizeof(struct apr_data) + user_payload_size,
-			  GFP_KERNEL);
-
-	if (aprdata == NULL) {
-		pr_err("%s: aprdata kmalloc failed.\n", __func__);
-
-		ret = -ENOMEM;
+	if (payload_size <= user_payload_size) {
+		pr_err("%s: invalid payload size ( 0x%x ).\n",
+			__func__, user_payload_size);
+		ret = -EINVAL;
 		goto done;
+	} else {
+		aprdata = kmalloc(payload_size, GFP_KERNEL);
+		if (aprdata == NULL) {
+			ret = -ENOMEM;
+			goto done;
+		}
 	}
 
 	voice_svc_update_hdr(apr_request, aprdata);
@@ -381,18 +386,31 @@
 
 	switch (cmd) {
 	case MSG_REGISTER:
-		ret = process_reg_cmd(
+		if (count  >=
+				(sizeof(struct voice_svc_register) +
+				sizeof(*data))) {
+			ret = process_reg_cmd(
 			(struct voice_svc_register *)data->payload, prtd);
-		if (!ret)
-			ret = count;
-
+			if (!ret)
+				ret = count;
+		} else {
+			pr_err("%s: invalid payload size\n", __func__);
+			ret = -EINVAL;
+			goto done;
+		}
 		break;
 	case MSG_REQUEST:
+	if (count >= (sizeof(struct voice_svc_cmd_request) +
+					sizeof(*data))) {
 		ret = voice_svc_send_req(
 			(struct voice_svc_cmd_request *)data->payload, prtd);
 		if (!ret)
 			ret = count;
-
+	} else {
+		pr_err("%s: invalid payload size\n", __func__);
+		ret = -EINVAL;
+		goto done;
+	}
 		break;
 	default:
 		pr_debug("%s: Invalid command: %u\n", __func__, cmd);