From: Jocelyn Falempe Date: Thu, 9 Oct 2025 12:24:52 +0000 (+0200) Subject: drm/panic: Fix divide by 0 if the screen width < font width X-Git-Tag: v6.18-rc3~16^2~2^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2e337dd278c6c38982b520c309f36e0f88696e6e;p=thirdparty%2Flinux.git drm/panic: Fix divide by 0 if the screen width < font width 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 Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20251009122955.562888-6-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe --- 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;