In the unlikely case that the screen is tiny, and smaller than the
font width, it leads to a divide by 0:

draw_line_with_wrap()
chars_per_row = sb->width / font->width = 0
line_wrap.len = line->len % chars_per_row;

This will trigger a divide by 0

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---
 drivers/gpu/drm/drm_panic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 69be9d835ccf..bc5158683b2b 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -523,7 +523,7 @@ static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
 	struct drm_panic_line line;
 	int yoffset;
 
-	if (!font)
+	if (!font || font->width > sb->width)
 		return;
 
 	yoffset = sb->height - font->height - (sb->height % font->height) / 2;
-- 
2.51.0

Jocelyn Falempe <jfalempe@redhat.com> writes:

> In the unlikely case that the screen is tiny, and smaller than the
> font width, it leads to a divide by 0:
>
> draw_line_with_wrap()
> chars_per_row = sb->width / font->width = 0
> line_wrap.len = line->len % chars_per_row;
>
> This will trigger a divide by 0
>
> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
> ---

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat