From 077614c9f2b9f9d062fed66e3ae7669937ea6b85 Mon Sep 17 00:00:00 2001
From: Xiaojun Sang <xsang@codeaurora.org>
Date: Fri, 04 Nov 2016 14:35:58 +0800
Subject: [PATCH] ASoC: soc: qdsp6: prevent risk of buffer overflow

In case of large value for bufcnt,
cmd_size may overflow. Buffer size allocated by cmd_size might
be not as expected.
Possible buffer overflow could happen.

Backport reference:
 * Change-Id: I9556f18dd6a9fdf3f76c133ae75c04ecce171f08
 * CRs-Fixed: 1084210

Change-Id: I93f820e0344bfa05dee6a3e83d84ef688e23f761
Signed-off-by: Xiaojun Sang <xsang@codeaurora.org>
Signed-off-by: Adrian DC <radian.dc@gmail.com>
---

diff --git a/sound/soc/msm/qdsp6/q6asm.c b/sound/soc/msm/qdsp6/q6asm.c
index 2cde92a..c3bcdcd 100644
--- a/sound/soc/msm/qdsp6/q6asm.c
+++ b/sound/soc/msm/qdsp6/q6asm.c
@@ -2893,7 +2893,7 @@
 	void	*payload = NULL;
 	int	rc = 0;
 	int	i = 0;
-	int	cmd_size = 0;
+	uint32_t cmd_size = 0;
 
 	if (!ac || ac->apr == NULL || this_mmap.apr == NULL) {
 		pr_err("APR handle NULL\n");
@@ -2901,6 +2901,14 @@
 	}
 	pr_debug("%s: Session[%d]\n", __func__, ac->session);
 
+	if (bufcnt > (UINT_MAX
+			- sizeof(struct asm_stream_cmd_memory_map_regions))
+			/ sizeof(struct asm_memory_map_regions)) {
+		pr_err("%s: Unsigned Integer Overflow. bufcnt = %u\n",
+				__func__, bufcnt);
+		return -EINVAL;
+	}
+
 	cmd_size = sizeof(struct asm_stream_cmd_memory_map_regions)
 			+ sizeof(struct asm_memory_map_regions) * bufcnt;