Re: [PATCH 09/17] fs: 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.

[Patrick Steinhardt]

On Wed, Jul 29, 2020 at 04:50:14PM -0500, development@efficientek.com wrote:
> From: Glenn Washburn <development@efficientek.com>

The commit message header is quite long. Could you please shorten it to
at most 80 characters and maybe put remaining info into the message
body?

> 
> 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..14c17df74 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 total_native_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;
> +  total_native_sectors = disk->total_sectors << (disk->log_sector_size - 
> GRUB_DISK_SECTOR_BITS);
>    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 (total_native_sectors < blocks[i].offset + blocks[i].length)
>       {
>         grub_error (GRUB_ERR_BAD_FILENAME, "beyond the total sectors");
>         goto fail;
> -- 
> 2.25.1
>

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