From: Alexey Makhalov <amakhalov@vmware.com>
Date: Wed, 8 Jul 2020 20:41:56 +0000 (+0000)
Subject: gfxmenu: Fix double free in load_image()
X-Git-Tag: grub-2.06-rc1~239
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26a8c19307f998f67dbfb784068e394c8e9c8478;p=thirdparty%2Fgrub.git

gfxmenu: Fix double free in load_image()

self->bitmap should be zeroed after free. Otherwise, there is a chance
to double free (USE_AFTER_FREE) it later in rescale_image().

Fixes: CID 292472

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/gfxmenu/gui_image.c b/grub-core/gfxmenu/gui_image.c
index 29784ed2d..6b2e976f1 100644
--- a/grub-core/gfxmenu/gui_image.c
+++ b/grub-core/gfxmenu/gui_image.c
@@ -195,7 +195,10 @@ load_image (grub_gui_image_t self, const char *path)
     return grub_errno;
 
   if (self->bitmap && (self->bitmap != self->raw_bitmap))
-    grub_video_bitmap_destroy (self->bitmap);
+    {
+      grub_video_bitmap_destroy (self->bitmap);
+      self->bitmap = 0;
+    }
   if (self->raw_bitmap)
     grub_video_bitmap_destroy (self->raw_bitmap);