From 3c65959673e24fc803071d131018eedaacc42ac8 Mon Sep 17 00:00:00 2001
From: Eric Snowberg <eric.snowberg@oracle.com>
Date: Thu, 28 Mar 2019 14:32:31 -0600
Subject: [PATCH] efidisk: Write to NULL pointer ldp

Function grub_efi_find_last_device_path() may return constant NULL when
called from find_parent_device().

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/disk/efi/efidisk.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/grub-core/disk/efi/efidisk.c b/grub-core/disk/efi/efidisk.c
index 0f132f559..961c1552b 100644
--- a/grub-core/disk/efi/efidisk.c
+++ b/grub-core/disk/efi/efidisk.c
@@ -129,6 +129,9 @@ find_parent_device (struct grub_efidisk_data *devices,
     return 0;
 
   ldp = grub_efi_find_last_device_path (dp);
+  if (! ldp)
+    return 0;
+
   ldp->type = GRUB_EFI_END_DEVICE_PATH_TYPE;
   ldp->subtype = GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE;
   ldp->length = sizeof (*ldp);