Hi Helge, On Thu, Jun 30, 2022 at 9:17 PM Helge Deller <del...@gmx.de> wrote: > On 6/30/22 21:11, Geert Uytterhoeven wrote: > > On Wed, Jun 29, 2022 at 10:00 PM Helge Deller <del...@gmx.de> wrote: > >> Prevent that drivers configure a virtual screen resolution smaller than > >> the physical screen resolution. This is important, because otherwise we > >> may access memory outside of the graphics memory area. > >> > >> Signed-off-by: Helge Deller <del...@gmx.de> > >> Cc: sta...@vger.kernel.org # v5.4+ > > > > Thanks for your patch! > > > >> --- a/drivers/video/fbdev/core/fbmem.c > >> +++ b/drivers/video/fbdev/core/fbmem.c > >> @@ -1006,6 +1006,12 @@ fb_set_var(struct fb_info *info, struct > >> fb_var_screeninfo *var) > >> if (var->xres < 8 || var->yres < 8) > >> return -EINVAL; > >> > >> + /* make sure virtual resolution >= physical resolution */ > >> + if (WARN_ON(var->xres_virtual < var->xres)) > >> + var->xres_virtual = var->xres; > >> + if (WARN_ON(var->yres_virtual < var->yres)) > >> + var->yres_virtual = var->yres; > > > > This should be moved below the call to info->fbops->fb_check_var(), > > so the WARN_ON() catches buggy fbdev drivers, not userspace fuzzers. > > Yes, makes sense.
And print the name of the frame buffer device driver, so people know who to blame. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds