The test corpus for version-1 RAID generated an infinite recursion
in grub_partition_iterate() while attempting to read the superblock.
The reason for the issue was that the data region overlapped with
the superblock.
The infinite call loop looks like this:
grub_partition_iterate() -> partmap->iterate() ->
-> grub_disk_read() -> grub_disk_read_small() ->
-> grub_disk_read_small_real() -> grub_diskfilter_read() ->
-> read_lv() -> read_segment() -> grub_diskfilter_read_node() ->
-> grub_disk_read() -> grub_disk_read_small() -> ...
The fix adds checks for both the superblock region and the data
region when parsing the superblock metadata in grub_mdraid_detect().
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>