]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
libnvdimm, region: fix flush hint detection crash
authorDan Williams <dan.j.williams@intel.com>
Mon, 24 Apr 2017 22:43:05 +0000 (15:43 -0700)
committerDan Williams <dan.j.williams@intel.com>
Mon, 24 Apr 2017 23:01:56 +0000 (16:01 -0700)
commitbc042fdfbb92b5b13421316b4548e2d6e98eed37
treed560c809c43acb727daed3f90d9eb3849e5fd19a
parentfbabd829fe76a72a6444f64361cf8b2a9848639d
libnvdimm, region: fix flush hint detection crash

In the case where a dimm does not have any associated flush hints the
ndrd->flush_wpq array may be uninitialized leading to crashes with the
following signature:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
 IP: region_visible+0x10f/0x160 [libnvdimm]

 Call Trace:
  internal_create_group+0xbe/0x2f0
  sysfs_create_groups+0x40/0x80
  device_add+0x2d8/0x650
  nd_async_device_register+0x12/0x40 [libnvdimm]
  async_run_entry_fn+0x39/0x170
  process_one_work+0x212/0x6c0
  ? process_one_work+0x197/0x6c0
  worker_thread+0x4e/0x4a0
  kthread+0x10c/0x140
  ? process_one_work+0x6c0/0x6c0
  ? kthread_create_on_node+0x60/0x60
  ret_from_fork+0x31/0x40

Cc: <stable@vger.kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Fixes: f284a4f23752 ("libnvdimm: introduce nvdimm_flush() and nvdimm_has_flush()")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/nvdimm/region_devs.c