diff options
| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-01-29 18:17:40 +0300 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2023-02-04 16:29:19 +0300 |
| commit | 2b09d5d364986f724f17001ccfe4126b9b43a0be (patch) | |
| tree | 929f404819c632e4b120d2ee2ab91fce1260e9e1 /drivers/video | |
| parent | ee9fffdc3887a46eab3209bc46b228b543c75fa6 (diff) | |
| download | linux-2b09d5d364986f724f17001ccfe4126b9b43a0be.tar.xz | |
fbcon: Check font dimension limits
blit_x and blit_y are u32, so fbcon currently cannot support fonts
larger than 32x32.
The 32x32 case also needs shifting an unsigned int, to properly set bit
31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font",
as reported on:
http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com
Kernel Branch: 6.2.0-rc5-next-20230124
Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing
Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing
Reported-by: Sanan Hasanov <sanan.hasanov@Knights.ucf.edu>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver")
Cc: stable@vger.kernel.org
Tested-by: Miko Larsson <mikoxyzzz@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/core/fbcon.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 14a7d404062c..1b14c21af2b7 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2495,9 +2495,12 @@ static int fbcon_set_font(struct vc_data *vc, struct console_font *font, h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres)) return -EINVAL; + if (font->width > 32 || font->height > 32) + 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)))) + if (!(info->pixmap.blit_x & BIT(font->width - 1)) || + !(info->pixmap.blit_y & BIT(font->height - 1))) return -EINVAL; /* Make sure driver can handle the font length */ |