Commit 6c11df58 authored by Helge Deller's avatar Helge Deller
Browse files

fbmem: Check virtual screen sizes in fb_set_var() 



Verify that the fbdev or drm driver correctly adjusted the virtual
screen sizes. On failure report the failing driver and reject the screen
size change.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Reviewed-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v5.4+
parent e64242ca

drivers/video/fbdev/core/fbmem.c

+10 −0
Original line number Diff line number Diff line
@@ -1017,6 +1017,16 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) 
	if (ret)

		return ret;



	/* verify that virtual resolution >= physical resolution */

	if (var->xres_virtual < var->xres ||

	    var->yres_virtual < var->yres) {

		pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",

			info->fix.id,

			var->xres_virtual, var->yres_virtual,

			var->xres, var->yres);

		return -EINVAL;

	}



	if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)

		return 0;