!4 isulad: fix code bug

Merge pull request !4 from Grooooot/12.29.1

docs/build_guide.md

+## Install Dependencies
+
+```sh
+$ sudo yum install -y cmake gcc-c++ systemd-devel yajl-devel libcurl libcurl-devel clibcni clibcni-devel protobuf-devel grpc-devel grpc-plugins http-parser-devel libwebsockets-devel libevhtp-devel libevent-devel lcr lxc-devel
+```
+
+
+
+## Build steps:
+
+Run the cmds under the iSulad source directory
+```sh
+$ sudo mkdir build
+$ sudo cd build
+$ sudo cmake ..
+$ sudo make
+$ sudo make install
+```
+

src/cutils/utils.c

@@ -514,9 +514,13 @@ static void set_stderr_buf(char **stderr_buf, const char *format, ...)
     va_list argp;
     va_start(argp, format);
 
-    (void)vsprintf(errbuf, format, argp);
+    int nret = vsnprintf(errbuf, BUFSIZ, format, argp);
     va_end(argp);
 
+    if (nret < 0 || nret >= BUFSIZ) {
+        return;
+    }
+
     *stderr_buf = json_marshal_string(errbuf, strlen(errbuf), NULL, &jerr);
     if (*stderr_buf == NULL) {
         *stderr_buf = util_strdup_s(errbuf);

src/services/execution/execute/execution_stream.c

@@ -1190,6 +1190,10 @@ static ssize_t extract_stream_to_io_read(void *content, void *buf, size_t buf_le
         DEBUG("Client may exited");
         return -1;
     }
+    if (copy.data_len > buf_len) {
+        free(copy.data);
+        return -1;
+    }
     (void)memcpy(buf, copy.data, copy.data_len);
     free(copy.data);
     return (ssize_t)(copy.data_len);