leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fbcon: Disallow setting font bigger than screen size

Browse Source 
Prevent that users set a font size which is bigger than the physical screen.
It's unlikely this may happen (because screens are usually much larger than the
fonts and each font char is limited to 32x32 pixels), but it may happen on
smaller screens/LCD displays.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v4.14+
This commit is contained in:
Helge Deller 2022-06-25 12:56:49 +02:00
parent 3663a2fb32
commit 65a01e601d
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/video/fbdev/core/fbcon.c
View File

@ -2469,6 +2469,11 @@ static int fbcon_set_font(struct vc_data *vc, struct console_font *font,
if (charcount != 256 && charcount != 512)
return -EINVAL;
/* font bigger than screen resolution ? */
if (w > FBCON_SWAP(info->var.rotate, info->var.xres, info->var.yres) ||
h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres))
return -EINVAL;
/* Make sure drawing engine can handle the font */
if (!(info->pixmap.blit_x & (1 << (font->width - 1))) ||
!(info->pixmap.blit_y & (1 << (font->height - 1))))