commit e07ecd76d4 upstream.
When btt devices were re-worked to be child devices of regions this
routine was overlooked. It mistakenly attempts to_nd_namespace_pmem()
or to_nd_namespace_blk() conversions on btt and pfn devices. By luck to
date we have happened to be hitting valid memory leading to a uuid
miscompare, but a recent change to struct nd_namespace_common causes:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
IP: [<ffffffff814610dc>] memcmp+0xc/0x40
[..]
Call Trace:
[<ffffffffa0028631>] is_uuid_busy+0xc1/0x2a0 [libnvdimm]
[<ffffffffa0028570>] ? to_nd_blk_region+0x50/0x50 [libnvdimm]
[<ffffffff8158c9c0>] device_for_each_child+0x50/0x90
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6e8ea2f225