[PATCH] fs: Fix block lists not being able to address to end of disk sometimes

[PATCH] fs: Fix block lists not being able to address to end of disk sometimes

[Glenn Washburn]

When checking if a block list goes past the end of the disk, make sure
the total size of the disk is in grub native sector sizes, otherwise there
will be blocks at the end of the disk unaccessible by block lists.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/kern/fs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/grub-core/kern/fs.c b/grub-core/kern/fs.c
index fb30da9f4..c698295bc 100644
--- a/grub-core/kern/fs.c
+++ b/grub-core/kern/fs.c
@@ -139,6 +139,7 @@ grub_fs_blocklist_open (grub_file_t file, const char *name)
   unsigned i;
   grub_disk_t disk = file->device->disk;
   struct grub_fs_block *blocks;
+  grub_size_t max_sectors;
 
   /* First, count the number of blocks.  */
   do
@@ -156,6 +157,7 @@ grub_fs_blocklist_open (grub_file_t file, const char *name)
     return 0;
 
   file->size = 0;
+  max_sectors = grub_disk_from_native_sector (disk, disk->total_sectors);
   p = (char *) name;
   for (i = 0; i < num; i++)
     {
@@ -181,7 +183,7 @@ grub_fs_blocklist_open (grub_file_t file, const char *name)
 	  goto fail;
 	}
 
-      if (disk->total_sectors < blocks[i].offset + blocks[i].length)
+      if (max_sectors < blocks[i].offset + blocks[i].length)
 	{
 	  grub_error (GRUB_ERR_BAD_FILENAME, "beyond the total sectors");
 	  goto fail;
-- 
2.27.0

Re: [PATCH] fs: Fix block lists not being able to address to end of disk sometimes

[Daniel Kiper]

On Mon, Nov 23, 2020 at 03:27:42AM -0600, Glenn Washburn wrote:
> When checking if a block list goes past the end of the disk, make sure
> the total size of the disk is in grub native sector sizes, otherwise there
> will be blocks at the end of the disk unaccessible by block lists.
>
> Signed-off-by: Glenn Washburn <development@efficientek.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

Daniel