[PATCH v2] Fix possible integer overflow in i386-pc mode with large partitions

[Maxim Fomin]

>From f9e2970e5731f13fdc506dbf5c722fd24b20a1aa Mon Sep 17 00:00:00 2001
From: Maxim Fomin <maxim@fomin.one>
Date: Wed, 28 Dec 2022 20:25:05 +0000
Subject: [PATCH v2] Fix possible integer overflow in i386-pc mode with large
 partitions

The i386-pc mode supports MBR partition scheme
where maximum partition size is 2 TiB. In case
of large partitions left shift expression with
unsigned long int 'length' object may cause
integer overflow making calculated partition
size less than true value. This issue is fixed
by increasing the size of 'length' integer type.
---
 grub-core/kern/fs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/grub-core/kern/fs.c b/grub-core/kern/fs.c
index b9508296d..7ad0aaf4e 100644
--- a/grub-core/kern/fs.c
+++ b/grub-core/kern/fs.c
@@ -130,7 +130,7 @@ grub_fs_probe (grub_device_t device)
 struct grub_fs_block
 {
   grub_disk_addr_t offset;
-  unsigned long length;
+  grub_disk_addr_t length;
 };
 
 static grub_err_t
-- 
2.39.0