[PATCH 5.10.y] fbcon: Retry rotated font allocation after failure

[Sasha Levin <sashal@kernel.org>]

From: Yao Yiqi <yaoyiqi3@huawei.com>

[ Upstream commit 7935db1a4a0f83a63590a222500e5016e2f6c85e ]

fbcon_rotate_font() records the font, its geometry and the rotation in
par->rotated before calling font_data_rotate(). If the allocation
fails, the error path clears par->rotated.buf, but the recorded key
already looks up to date, so the next call takes the early-out and
never retries. The rotated putcs/cursor ops keep returning early on
the NULL buffer, and the console stays blank even after memory is
available again.

Also test par->rotated.buf in the early-out, so a failed allocation
is retried on the next call: at the next fbcon_switch(),
fbcon_modechanged() or font change.

Fixes: e4ef723d8975 ("fbcon: Avoid OOB font access if console rotation fails")
Cc: stable@vger.kernel.org
Signed-off-by: Yao Yiqi <yaoyiqi3@huawei.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
[ sashal: Adapted the par->rotated.buf check to use ops->fontbuffer. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/core/fbcon_rotate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/core/fbcon_rotate.c b/drivers/video/fbdev/core/fbcon_rotate.c
index c1beb4a837081..d5ef2babc2bc8 100644
--- a/drivers/video/fbdev/core/fbcon_rotate.c
+++ b/drivers/video/fbdev/core/fbcon_rotate.c
@@ -27,7 +27,8 @@ static int fbcon_rotate_font(struct fb_info *info, struct vc_data *vc)
 	u8 *dst;
 
 	if (vc->vc_font.data == ops->fontdata &&
-	    ops->p->con_rotate == ops->cur_rotate)
+	    ops->p->con_rotate == ops->cur_rotate &&
+	    ops->fontbuffer)
 		goto finished;
 
 	src = ops->fontdata = vc->vc_font.data;
-- 
2.53.0