Test code demonstrating getspnam_r problem

test.c (text/x-csrc), 555 bytes, created by Marcin Deranek on 2021-07-21 08:22:16 UTC

#include <stdio.h>
#include <stdlib.h>
#include <shadow.h>
#include <errno.h>

#define PWD_INITIAL_LENGTH     0x400

int main() {
	int status;
	void *buffer = NULL;
	size_t length = PWD_INITIAL_LENGTH;
	void *new_buffer;
	struct spwd *result = NULL;

	new_buffer = realloc(buffer, sizeof(struct spwd) + length);
	buffer = new_buffer;
	errno = 0;
	status = getspnam_r(getenv("USER"), buffer,
             sizeof(struct spwd) + (char *) buffer,
             length, &result);
	printf("Errno: %d Status: %d Result: %d\n", errno, status, result == buffer);
}