From fa995d0d9471b630d2d1942000d5a4f065c5cdd5 Mon Sep 17 00:00:00 2001
From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Mon, 6 Aug 2018 22:28:18 +0200
Subject: [PATCH] efi_loader: avoid NULL dereference in efi_get_memory_map()
We should only dereference parameter memory_map_size after checking that
it is valid.
Fixes: 8e835554b36b ("efi_loader: check parameters of GetMemoryMap")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
lib/efi_loader/efi_memory.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index 4b6269f35e..3ee1079e75 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -457,11 +457,13 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
efi_uintn_t map_size = 0;
int map_entries = 0;
struct list_head *lhandle;
- efi_uintn_t provided_map_size = *memory_map_size;
+ efi_uintn_t provided_map_size;
if (!memory_map_size)
return EFI_INVALID_PARAMETER;
+ provided_map_size = *memory_map_size;
+
list_for_each(lhandle, &efi_mem)
map_entries++;
--
2.39.5