| From 6eb0c9d3b20ba74608db94037e6e15738b3e3a2c Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 6 May 2022 15:22:25 +0200 |
| Subject: fbdev: efifb: Fix a use-after-free due early fb_info cleanup |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Javier Martinez Canillas <javierm@redhat.com> |
| |
| [ Upstream commit 1b5853dfab7fdde450f00f145327342238135c8a ] |
| |
| 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> |
| Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> |
| Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> |
| Reviewed-by: Thomas Zimmermann <tzimemrmann@suse.de> |
| Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> |
| Link: https://patchwork.freedesktop.org/patch/msgid/20220506132225.588379-1-javierm@redhat.com |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 |
| |
