Fix Coverity issue OVERRUN

lib/pkg_editor/src/pkg_editor.c:1641:5:
  Type: Out-of-bounds read (OVERRUN)

lib/pkg_editor/src/pkg_editor.c:1584:3:
  1. path: Condition "buffer != NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  2. path: Condition "input == NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  3. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1588:3:
  4. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1594:3:
  5. path: Condition "ret != 0", taking false branch. lib/pkg_editor/src/pkg_editor.c:1610:3:
  6. path: Condition "z_info.strm.avail_in > 0", taking true branch. lib/pkg_editor/src/pkg_editor.c:1612:5:
  7. path: Condition "!read_data(&info, 20UL /* sizeof (info) */, &z_info, input)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1617:5:
  8. path: Condition "info.magic != 3203399403U", taking false branch. lib/pkg_editor/src/pkg_editor.c:1625:5:
  9. path: Condition "info.kind == PACK_END", taking false branch. lib/pkg_editor/src/pkg_editor.c:1630:5:
  10. path: Condition "!read_data(name, info.name_length, &z_info, input)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1638:5:
  11. path: Condition "12288UL /* 3 * 4096 */ < out_dir_length", taking true branch. lib/pkg_editor/src/pkg_editor.c:1638:5:
  12. cond_at_least: Checking "12288UL < out_dir_length" implies that "out_dir_length" is at least 12289 on the true branch. lib/pkg_editor/src/pkg_editor.c:1641:5:
  13. overrun-local: Overrunning array of 12288 bytes at byte offset 12290 by dereferencing pointer "full_name + out_dir_length + 1". [Note: The source code implementation of the function has been overridden by a builtin model.]

Author: IlanTruanovsky

lib/pkg_editor/src/pkg_editor.c

@@ -1642,11 +1642,12 @@ static int acl_pkg_unpack_buffer_or_file(const char *buffer, size_t buffer_size,
     }
 
     // Generate the full name, truncate or zero pad to avoid buffer overflow
-    if (FULL_NAME_LEN < out_dir_length) {
+    if (FULL_NAME_LEN <= out_dir_length + 1) {
       fprintf(stderr, "%s: Directory name too long\n", routine_name);
+    } else {
+      strncpy(full_name + out_dir_length + 1, name,
+              FULL_NAME_LEN - out_dir_length - 1);
     }
-    strncpy(full_name + out_dir_length + 1, name,
-            FULL_NAME_LEN - out_dir_length - 1);
     if (full_name[FULL_NAME_LEN - 1] != '\0') {
       full_name[FULL_NAME_LEN - 1] = '\0';
     }