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Commit b2518c78 authored by Toshi Kani's avatar Toshi Kani Committed by Dan Williams
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libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify 



The following BUG was observed when nd_pmem_notify() was called
for a BTT device.  The use of a pmem_device pointer is not valid
with BTT.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
 IP: nd_pmem_notify+0x30/0xf0 [nd_pmem]
 Call Trace:
  nd_device_notify+0x40/0x50
  child_notify+0x10/0x20
  device_for_each_child+0x50/0x90
  nd_region_notify+0x20/0x30
  nd_device_notify+0x40/0x50
  nvdimm_region_notify+0x27/0x30
  acpi_nfit_scrub+0x341/0x590 [nfit]
  process_one_work+0x197/0x450
  worker_thread+0x4e/0x4a0
  kthread+0x109/0x140

Fix nd_pmem_notify() by setting nd_region and badblocks pointers
properly for BTT.

Cc: <stable@vger.kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Fixes: 71999466 ("libnvdimm: async notification support")
Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent ab630891

drivers/nvdimm/pmem.c

+25 −12
Original line number Diff line number Diff line
@@ -388,12 +388,12 @@ static void nd_pmem_shutdown(struct device *dev) 


static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)

{

	struct pmem_device *pmem = dev_get_drvdata(dev);

	struct nd_region *nd_region = to_region(pmem);

	struct nd_region *nd_region;

	resource_size_t offset = 0, end_trunc = 0;

	struct nd_namespace_common *ndns;

	struct nd_namespace_io *nsio;

	struct resource res;

	struct badblocks *bb;



	if (event != NVDIMM_REVALIDATE_POISON)

		return;
@@ -402,20 +402,33 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) 
		struct nd_btt *nd_btt = to_nd_btt(dev);



		ndns = nd_btt->ndns;

	} else if (is_nd_pfn(dev)) {

		nd_region = to_nd_region(ndns->dev.parent);

		nsio = to_nd_namespace_io(&ndns->dev);

		bb = &nsio->bb;

	} else {

		struct pmem_device *pmem = dev_get_drvdata(dev);



		nd_region = to_region(pmem);

		bb = &pmem->bb;



		if (is_nd_pfn(dev)) {

			struct nd_pfn *nd_pfn = to_nd_pfn(dev);

			struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;



			ndns = nd_pfn->ndns;

		offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad);

			offset = pmem->data_offset +

					__le32_to_cpu(pfn_sb->start_pad);

			end_trunc = __le32_to_cpu(pfn_sb->end_trunc);

	} else

		} else {

			ndns = to_ndns(dev);

		}



		nsio = to_nd_namespace_io(&ndns->dev);

	}



	res.start = nsio->res.start + offset;

	res.end = nsio->res.end - end_trunc;

	nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);

	nvdimm_badblocks_populate(nd_region, bb, &res);

}



MODULE_ALIAS("pmem");