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