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

[Yao Yiqi <yyaqia@gmail.com>]

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@gmail.com/
v1: https://lore.kernel.org/all/20261014085102.497789-1-yaoyiqi3@huawei.com/

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(-)

-- 
2.56.0