Messages in this thread Patch in this message | | | From | Javier Martinez Canillas <> | Subject | [PATCH] fbdev: efifb: Fix a use-after-free due early fb_info cleanup | Date | Fri, 6 May 2022 15:22:25 +0200 |
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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@linux.intel.com> 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
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