# Re: \[PATCH 0/4\] fbdev: defio: Protect against device/module removal

- From: Thomas Zimmermann \<tzimmermann@suse.de\>
- Date: 2026-02-23 12:50:56 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2026/02/9270862
- Thread: https://ratatoskr.run/linux-fbdev/2026/01/9269806/t.md

```text
ping for review

Am 22.01.26 um 14:08 schrieb Thomas Zimmermann:
> There's a long-standing bug in defio where the framebuffer device or
> module gets removed while mmap'ed areas of the framebuffer memory
> persists in userspace. Page faults in the area then operate on defined
> state.
>
> Patches 1 and 2 fix these problems. Patches 3 and 4 build upon the fix
> and put defio state into the correct places.
>
> Thomas Zimmermann (4):
>    fbdev: defio: Disconnect deferred I/O from the lifetime of struct
>      fb_info
>    fbdev: defio: Keep module reference from VMAs
>    fbdev: defio: Move variable state into struct fb_deferred_io_state
>    fbdev: defio: Move pageref array to struct fb_deferred_io_state
>
>   drivers/video/fbdev/core/fb_defio.c | 266 ++++++++++++++++++++--------
>   include/linux/fb.h                  |   9 +-
>   2 files changed, 195 insertions(+), 80 deletions(-)
>
>
> base-commit: a3ecd278f9a05323fab7471760a7ea10081251d6

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)


```