bool creds_are_invalid(const struct cred *cred)
{
	if (cred->magic != CRED_MAGIC)
		return true;
#ifdef CONFIG_SECURITY_SELINUX
	/*
	 * cred->security == NULL if security_cred_alloc_blank() or
	 * security_prepare_creds() returned an error.
	 */
	if (selinux_is_enabled() && cred->security) {
		if ((unsigned long) cred->security < PAGE_SIZE)
			return true;
		if ((*(u32 *)cred->security & 0xffffff00) ==
		    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
			return true;
	}
#endif
	return false;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.