From 77cdb40423e29a5f9d1318cd0ada874ee1916450 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Tue, 12 Aug 2014 15:33:19 +0200
Subject: [PATCH 46/74] unhook_system_services: bail on systab == NULL
Prevent unhook_system_services() from dereferencing a NULL systab, which
may occur if hook_system_services() has never been called.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
replacements.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/replacements.c b/replacements.c
index 48dc437..5dfa355 100644
--- a/replacements.c
+++ b/replacements.c
@@ -70,6 +70,9 @@ static EFI_HANDLE last_loaded_image;
void
unhook_system_services(void)
{
+ if (!systab)
+ return;
+
systab->BootServices->Exit = system_exit;
systab->BootServices->LoadImage = system_load_image;
systab->BootServices->StartImage = system_start_image;
--
1.9.3