Re: [PATCH] fbdev: efifb: Fix a use-after-free due early fb_info cleanup
From: Lucas De Marchi <hidden>
Date: 2022-05-07 16:21:03
Also in:
dri-devel, intel-gfx, lkml
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")are these patches going through any CI before being applied? Maybe would be a good idea to cc intel-gfx mailing list on these fixes to have Intel CI to pick them up for some tests? pushed to drm-misc-fixes where the previous patch was applied. thanks LUcas De Marchi
quoted hunk ↗ jump to hunk
Reported-by: Ville Syrjälä <redacted> Reported-by: Andrzej Hajda <andrzej.hajda@intel.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> --- drivers/video/fbdev/efifb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c index cfa3dc0b4eee..b3d5f884c544 100644 --- a/drivers/video/fbdev/efifb.c +++ b/drivers/video/fbdev/efifb.c@@ -259,12 +259,12 @@ static void efifb_destroy(struct fb_info *info)memunmap(info->screen_base); } - framebuffer_release(info); - if (request_mem_succeeded) release_mem_region(info->apertures->ranges[0].base, info->apertures->ranges[0].size); fb_dealloc_cmap(&info->cmap); + + framebuffer_release(info); } static const struct fb_ops efifb_ops = { -- 2.35.1