The provided code snippet does not actually contain a CWE-401  vulnerability at line 31. The line:

```c
31 	args.ignore_crossmnt = (ignore_crossmnt != 0);
```

is simply assigning a boolean value to the `ignore_crossmnt` field of the `args` structure. This operation does not involve any memory deallocation or use of freed memory, which are the hallmarks of a  vulnerability.

A CWE-401 vulnerability occurs when a program continues to use a pointer after it has been freed, which can lead to various security issues such as crashes, arbitrary code execution, or data corruption. In this case, there's no evidence of such behavior.

The given line is performing a simple boolean conversion and assignment, which is a safe operation. The expression `(ignore_crossmnt != 0)` converts the integer `ignore_crossmnt` to a boolean value (true if non-zero, false if zero), and this boolean value is then assigned to `args.ignore_crossmnt`.

Without more context about how `args` or `ignore_crossmnt` are used elsewhere in the program, it's not possible to identify a  vulnerability in this code snippet. If there is indeed a CWE-401 vulnerability associated with this code, it would likely be in how these variables are used in other parts of the program not shown here.