lssubsys: Fix strncpy() truncation warning

Fix the following strncpy() string truncation warning:

In function ‘strncat’,
    inlined from ‘print_all_controllers_in_hierarchy’ at lssubsys.c:134:4,
    inlined from ‘cgroup_list_all_controllers’ at lssubsys.c:222:9,
    inlined from ‘main’ at lssubsys.c:290:8:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:136:10: warning: ‘__builtin___strncat_chk’ output may be truncated copying 4095 bytes from a string of length 4095 [-Wstringop-truncation]
  136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>

diff --git a/src/tools/lssubsys.c b/src/tools/lssubsys.c
index d0a88b62468e0c8e05dc7d0cbbabca0a187e6dac..e77859b40e331c45f1c8f6b13352aa52eacf1253 100644 (file)
--- a/src/tools/lssubsys.c
+++ b/src/tools/lssubsys.c
@@ -132,6 +132,7 @@ static int print_all_controllers_in_hierarchy(const char *tname,
                        /* the next controller in the hierarchy */
                        strncat(cont_names, ",", FILENAME_MAX-1);
                        strncat(cont_names, info.name, FILENAME_MAX-1);
+                       cont_names[sizeof(cont_names) - 1] = '\0';
                }
 next:
                ret = cgroup_get_all_controller_next(&handle, &info);