Re: [Intel-gfx] [PATCH] fbdev: efifb: Fix a use-after-free due early fb_info cleanup

From: Andi Shyti
Date: Fri May 06 2022 - 11:44:57 EST


Hi Javier,

On Fri, May 06, 2022 at 03:22:25PM +0200, Javier Martinez Canillas wrote:
> Commit d258d00fb9c7 ("fbdev: efifb: Cleanup fb_info in .fb_destroy rather
> than .remove") attempted to fix a use-after-free error due driver freeing
> the fb_info in the .remove handler instead of doing it in .fb_destroy.
>
> But ironically that change introduced yet another use-after-free since the
> fb_info was still used after the free.
>
> This should fix for good by freeing the fb_info at the end of the handler.
>
> Fixes: d258d00fb9c7 ("fbdev: efifb: Cleanup fb_info in .fb_destroy rather than .remove")
> Reported-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Reported-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
> Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>

Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>

Andi