libnvdimm: fix namespace object confusion in is_uuid_busy()
authorDan Williams <dan.j.williams@intel.com>
Wed, 6 Jan 2016 02:37:23 +0000 (18:37 -0800)
committerDan Williams <dan.j.williams@intel.com>
Wed, 6 Jan 2016 02:37:23 +0000 (18:37 -0800)
commite07ecd76d4db7bda1e9495395b2110a3fe28845a
tree731c4008d67d1e0ae1267f3f28d38a2abf9281c5
parent0731de0dd95b251ed6cfb5f132486e52357fce53
libnvdimm: fix namespace object confusion in is_uuid_busy()

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

Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/nvdimm/namespace_devs.c
drivers/nvdimm/region_devs.c