[PATCH] Fix incorrect address reference in btrfs

[Michael Chang]

We encountered a weird random kernel initrd unpacking error on btrfs
and finally found it was caused by incorrect address reference in range
check for type GRUB_BTRFS_EXTENT_REGULAR and the entire result is
unpredictable.

This is a quick fix to make the address reference to the
grub_btrfs_entent_data structure correctly, not the pointer variable
to it.

Any suggestions to this patch is welcome.
---
 grub-core/fs/btrfs.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
index f7b6c15..95a8fa6 100644
--- a/grub-core/fs/btrfs.c
+++ b/grub-core/fs/btrfs.c
@@ -1051,7 +1051,7 @@ grub_btrfs_extent_read (struct grub_btrfs_data *data,
 
          data->extend = data->extstart + grub_le_to_cpu64 (data->extent->size);
          if (data->extent->type == GRUB_BTRFS_EXTENT_REGULAR
-             && (char *) &data->extent + elemsize
+             && (char *) data->extent + elemsize
              >= (char *) &data->extent->filled + sizeof (data->extent->filled))
            data->extend =
              data->extstart + grub_le_to_cpu64 (data->extent->filled);
-- 
1.7.3.4