From 829445382c196301309b7f12630c1e04a4986eba Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@linaro.org>
Date: Wed, 26 Jul 2023 09:54:52 +0300
Subject: [PATCH] efi_loader: Fix memory corruption on 32bit systems
It's pretty unlikely that anyone is going to be using EFI authentication
on a 32bit system. However, if you did, the efi_prepare_aligned_image()
function would write 8 bytes of data to the &efi_size variable and it
can only hold 4 bytes so that corrupts memory.
Fixes: 163a0d7e2cbd ("efi_loader: add PE/COFF image measurement")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
lib/efi_loader/efi_image_loader.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
index 26df0da16c..97547571ce 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -592,6 +592,7 @@ static bool efi_image_authenticate(void *efi, size_t efi_size)
struct efi_signature_store *db = NULL, *dbx = NULL;
void *new_efi = NULL;
u8 *auth, *wincerts_end;
+ u64 new_efi_size = efi_size;
size_t auth_size;
bool ret = false;
@@ -600,11 +601,11 @@ static bool efi_image_authenticate(void *efi, size_t efi_size)
if (!efi_secure_boot_enabled())
return true;
- new_efi = efi_prepare_aligned_image(efi, (u64 *)&efi_size);
+ new_efi = efi_prepare_aligned_image(efi, &new_efi_size);
if (!new_efi)
return false;
- if (!efi_image_parse(new_efi, efi_size, ®s, &wincerts,
+ if (!efi_image_parse(new_efi, new_efi_size, ®s, &wincerts,
&wincerts_len)) {
log_err("Parsing PE executable image failed\n");
goto out;
--
2.39.5