Your periodic test works fine:
Corrupted low memory at ffff88000000be9c (be9c phys) = b02a0004
<IRQ> [<ffffffff8020fc9b>] check_for_bios_corruption+0x93/0x9f
[<ffffffff8020fca7>] ? periodic_check_for_corruption+0x0/0x25
[<ffffffff8020fcb0>] periodic_check_for_corruption+0x9/0x25
By the way I confirmed this bug on Sony Vaio FW11M (my one is FW11S).
Probably more machines from FW11* are affected.
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Rafał Miłecki