Re: [PATCH v5 0/3] fbcon: fix rotated font buffer handling on font change

[Thomas Zimmermann]

Hi,

for the series:

Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

although I cannot claim to understand fbcon code in its entirety.

Best regards
Thomas


Am 19.10.26 um 11:43 schrieb Yao Yiqi:
> Fix out-of-bounds reads of the rotated font buffer when the console
> font changes on a rotated console (fbcon=rotate:N). KDFONTOP installs
> the new geometry and vc_resize() redraws before par->rotated.buf is
> updated, so the old buffer is indexed with the new cell size.
>
> Patch 1 keys the rotated font cache on the font geometry. Patch 2
> rebuilds it on font changes, saving and restoring the whole cache if
> the change fails. Patch 3 retries a failed allocation.
>
> Changes since v4: save, clear and restore the entire par->rotated
> state instead of only the buffer; restoring just the buffer left the
> cache key describing the rejected font, which could make a later
> switch skip the rebuild and index the smaller buffer with the larger
> font's geometry (found by the Sashiko review).
>
> v4: https://lore.kernel.org/all/20261019090206.1094958-1-yyaqia@xxxxxxxxx/
> v1: https://lore.kernel.org/all/20261014085102.497789-1-yaoyiqi3@xxxxxxxxxx/
>
> Yao Yiqi (3):
>    fbcon: Include font geometry in the rotated font cache
>    fbcon: Rebuild rotated font buffer on font change
>    fbcon: Retry rotated font allocation after failure
>
>   drivers/video/fbdev/core/fbcon.c        | 46 ++++++++++++++++++++++++++
>   drivers/video/fbdev/core/fbcon.h        | 19 ++++++----
>   drivers/video/fbdev/core/fbcon_rotate.c | 10 ++++++-
>   3 files changed, 68 insertions(+), 7 deletions(-)

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)