static int uvesafb_blank(int blank, struct fb_info *info)
{
	struct uvesafb_ktask *task;
	int err = 1;
#ifdef CONFIG_X86
	struct uvesafb_par *par = info->par;

	if (par->vbe_ib.capabilities & VBE_CAP_VGACOMPAT) {
		int loop = 10000;
		u8 seq = 0, crtc17 = 0;

		if (blank == FB_BLANK_POWERDOWN) {
			seq = 0x20;
			crtc17 = 0x00;
			err = 0;
		} else {
			seq = 0x00;
			crtc17 = 0x80;
			err = (blank == FB_BLANK_UNBLANK) ? 0 : -EINVAL;
		}

		vga_wseq(NULL, 0x00, 0x01);
		seq |= vga_rseq(NULL, 0x01) & ~0x20;
		vga_wseq(NULL, 0x00, seq);

		crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
		while (loop--);
		vga_wcrt(NULL, 0x17, crtc17);
		vga_wseq(NULL, 0x00, 0x03);
	} else
#endif /* CONFIG_X86 */
	{
		task = uvesafb_prep();
		if (!task)
			return -ENOMEM;

		task->t.regs.eax = 0x4f10;
		switch (blank) {
		case FB_BLANK_UNBLANK:
			task->t.regs.ebx = 0x0001;
			break;
		case FB_BLANK_NORMAL:
			task->t.regs.ebx = 0x0101;	/* standby */
			break;
		case FB_BLANK_POWERDOWN:
			task->t.regs.ebx = 0x0401;	/* powerdown */
			break;
		default:
			goto out;
		}

		err = uvesafb_exec(task);
		if (err || (task->t.regs.eax & 0xffff) != 0x004f)
			err = 1;
out:		uvesafb_free(task);
	}
	return err;
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.