int readlinkat_malloc(int fd, const char *p, char **ret) {
        size_t l = 100;
        int r;

        assert(p);
        assert(ret);

        for (;;) {
                char *c;
                ssize_t n;

                c = new(char, l);
                if (!c)
                        return -ENOMEM;

                n = readlinkat(fd, p, c, l-1);
                if (n < 0) {
                        r = -errno;
                        free(c);
                        return r;
                }

                if ((size_t) n < l-1) {
                        c[n] = 0;
                        *ret = c;
                        return 0;
                }

                free(c);
                l *= 2;
        }
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.