[PATCH v3 3/4] fbmem: Check screen resolution change against font size

[Daniel Vetter]

On Sun, Jun 26, 2022 at 12:06:29AM +0200, Helge Deller wrote:
> Enhance the check in the FBIOPUT_VSCREENINFO ioctl handler to verify if the
> user-provided new screen size is bigger than the current font size.
> 
> Signed-off-by: Helge Deller <deller at gmx.de>
> Cc: stable at vger.kernel.org # v5.4+

Please squash with previous patch. You might also want to add a note there
that on older kernels backporters need to open-code
fbcon_info_from_console instead, since it only exists since 
409d6c95f9c6 ("fbcon: Introduce wrapper for console->fb_info lookup")

With these two nits: Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/video/fbdev/core/fbmem.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
> index afa2863670f3..160389365a36 100644
> --- a/drivers/video/fbdev/core/fbmem.c
> +++ b/drivers/video/fbdev/core/fbmem.c
> @@ -1106,7 +1106,9 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
>  			return -EFAULT;
>  		console_lock();
>  		lock_fb_info(info);
> -		ret = fb_set_var(info, &var);
> +		ret = fbcon_modechange_possible(info, &var);
> +		if (!ret)
> +			ret = fb_set_var(info, &var);
>  		if (!ret)
>  			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
>  		unlock_fb_info(info);
> --
> 2.35.3
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch