diff --git a/grub-core/fs/jfs.c b/grub-core/fs/jfs.c
index e5bbda61c..804c42d31 100644
--- a/grub-core/fs/jfs.c
+++ b/grub-core/fs/jfs.c
@@ -261,13 +261,15 @@ static grub_err_t grub_jfs_lookup_symlink (struct grub_jfs_data *data, grub_uint
 static grub_int64_t
 getblk (struct grub_jfs_treehead *treehead,
 	struct grub_jfs_tree_extent *extents,
+	int max_extents,
 	struct grub_jfs_data *data,
 	grub_uint64_t blk)
 {
   int found = -1;
   int i;
 
-  for (i = 0; i < grub_le_to_cpu16 (treehead->count) - 2; i++)
+  for (i = 0; i < grub_le_to_cpu16 (treehead->count) - 2 &&
+	      i < max_extents; i++)
     {
       if (treehead->flags & GRUB_JFS_TREE_LEAF)
 	{
@@ -302,7 +304,7 @@ getblk (struct grub_jfs_treehead *treehead,
 			   << (grub_le_to_cpu16 (data->sblock.log2_blksz)
 			       - GRUB_DISK_SECTOR_BITS), 0,
 			   sizeof (*tree), (char *) tree))
-	ret = getblk (&tree->treehead, &tree->extents[0], data, blk);
+	ret = getblk (&tree->treehead, &tree->extents[0], 254, data, blk);
       grub_free (tree);
       return ret;
     }
@@ -316,7 +318,7 @@ static grub_int64_t
 grub_jfs_blkno (struct grub_jfs_data *data, struct grub_jfs_inode *inode,
 		grub_uint64_t blk)
 {
-  return getblk (&inode->file.tree, &inode->file.extents[0], data, blk);
+  return getblk (&inode->file.tree, &inode->file.extents[0], 16, data, blk);
 }