copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
{
	switch(version) {
	case IPC_64:
		if (copy_from_user(out, buf, sizeof(*out)))
			return -EFAULT;
		return 0;
	case IPC_OLD:
	{
		struct msqid_ds tbuf_old;

		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
			return -EFAULT;

		out->msg_perm.uid      	= tbuf_old.msg_perm.uid;
		out->msg_perm.gid      	= tbuf_old.msg_perm.gid;
		out->msg_perm.mode     	= tbuf_old.msg_perm.mode;

		if (tbuf_old.msg_qbytes == 0)
			out->msg_qbytes	= tbuf_old.msg_lqbytes;
		else
			out->msg_qbytes	= tbuf_old.msg_qbytes;

		return 0;
	}
	default:
		return -EINVAL;
	}
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.