From 9df0a0758af3294997556581120054e49b5f67bd Mon Sep 17 00:00:00 2001
From: SPRESENSE <41312067+SPRESENSE@users.noreply.github.com>
Date: Tue, 7 Mar 2023 14:35:57 +0900
Subject: [PATCH] examples/lte_lwm2mstub: Replace sprintf to snprintf

The sprintf() function has a problem for security.
So, replace it to snprintf().

Detected by CodeSonar 1376927
---
 examples/lte_lwm2mstub/lte_lwm2mstub_main.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/examples/lte_lwm2mstub/lte_lwm2mstub_main.c b/examples/lte_lwm2mstub/lte_lwm2mstub_main.c
index 9f116dc54..a045b4fde 100644
--- a/examples/lte_lwm2mstub/lte_lwm2mstub_main.c
+++ b/examples/lte_lwm2mstub/lte_lwm2mstub_main.c
@@ -64,12 +64,13 @@
 
 #define OBJID_DATACONTAINER  (19)
 #define APP_INIFILE "/mnt/spif/lwm2m.ini"
+#define LWM2M_TMP_BUFF_LEN   (16)
 
 /****************************************************************************
  * Private Data
  ****************************************************************************/
 
-static char tmp_buff[256];
+static char tmp_buff[LWM2M_TMP_BUFF_LEN];
 static uint16_t enableobjs[6] =
 {
   1, 2, 3, 4, 5, OBJID_DATACONTAINER
@@ -154,7 +155,7 @@ static void read_cb(int seq_no, int srv_id,
 
   if (inst->object_id == OBJID_DATACONTAINER && inst->res_id == 0)
     {
-      len = sprintf(tmp_buff, "%08x", periodic_value);
+      len = snprintf(tmp_buff, LWM2M_TMP_BUFF_LEN, "%08x", periodic_value);
       lte_m2m_readresponse(seq_no, inst,
                            LWM2MSTUB_RESP_CONTENT, tmp_buff, len);
     }
@@ -397,7 +398,7 @@ static void notify_value(int value)
   inst.res_id = 0;
   inst.res_inst = -1;
 
-  len = sprintf(tmp_buff, "%08x", value);
+  len = snprintf(tmp_buff, LWM2M_TMP_BUFF_LEN, "%08x", value);
   printf("Update value as : token: %s, /%d/0/0 %s\n",
                                       ov_token, OBJID_DATACONTAINER, tmp_buff);
   printf("observe update : %d\n",