Commit e07ecd76 authored by Dan Williams's avatar Dan Williams
Browse files

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: default avatarDan Williams <dan.j.williams@intel.com>
parent 0731de0d

drivers/nvdimm/namespace_devs.c

+53 −0
Original line number Diff line number Diff line
@@ -77,6 +77,59 @@ static bool is_namespace_io(struct device *dev) 
	return dev ? dev->type == &namespace_io_device_type : false;

}



static int is_uuid_busy(struct device *dev, void *data)

{

	u8 *uuid1 = data, *uuid2 = NULL;



	if (is_namespace_pmem(dev)) {

		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);



		uuid2 = nspm->uuid;

	} else if (is_namespace_blk(dev)) {

		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);



		uuid2 = nsblk->uuid;

	} else if (is_nd_btt(dev)) {

		struct nd_btt *nd_btt = to_nd_btt(dev);



		uuid2 = nd_btt->uuid;

	} else if (is_nd_pfn(dev)) {

		struct nd_pfn *nd_pfn = to_nd_pfn(dev);



		uuid2 = nd_pfn->uuid;

	}



	if (uuid2 && memcmp(uuid1, uuid2, NSLABEL_UUID_LEN) == 0)

		return -EBUSY;



	return 0;

}



static int is_namespace_uuid_busy(struct device *dev, void *data)

{

	if (is_nd_pmem(dev) || is_nd_blk(dev))

		return device_for_each_child(dev, data, is_uuid_busy);

	return 0;

}



/**

 * nd_is_uuid_unique - verify that no other namespace has @uuid

 * @dev: any device on a nvdimm_bus

 * @uuid: uuid to check

 */

bool nd_is_uuid_unique(struct device *dev, u8 *uuid)

{

	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);



	if (!nvdimm_bus)

		return false;

	WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm_bus->dev));

	if (device_for_each_child(&nvdimm_bus->dev, uuid,

				is_namespace_uuid_busy) != 0)

		return false;

	return true;

}



bool pmem_should_map_pages(struct device *dev)

{

	struct nd_region *nd_region = to_nd_region(dev->parent);

drivers/nvdimm/region_devs.c

+0 −56
Original line number Diff line number Diff line
@@ -134,62 +134,6 @@ int nd_region_to_nstype(struct nd_region *nd_region) 
}

EXPORT_SYMBOL(nd_region_to_nstype);



static int is_uuid_busy(struct device *dev, void *data)

{

	struct nd_region *nd_region = to_nd_region(dev->parent);

	u8 *uuid = data;



	switch (nd_region_to_nstype(nd_region)) {

	case ND_DEVICE_NAMESPACE_PMEM: {

		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);



		if (!nspm->uuid)

			break;

		if (memcmp(uuid, nspm->uuid, NSLABEL_UUID_LEN) == 0)

			return -EBUSY;

		break;

	}

	case ND_DEVICE_NAMESPACE_BLK: {

		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);



		if (!nsblk->uuid)

			break;

		if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) == 0)

			return -EBUSY;

		break;

	}

	default:

		break;

	}



	return 0;

}



static int is_namespace_uuid_busy(struct device *dev, void *data)

{

	if (is_nd_pmem(dev) || is_nd_blk(dev))

		return device_for_each_child(dev, data, is_uuid_busy);

	return 0;

}



/**

 * nd_is_uuid_unique - verify that no other namespace has @uuid

 * @dev: any device on a nvdimm_bus

 * @uuid: uuid to check

 */

bool nd_is_uuid_unique(struct device *dev, u8 *uuid)

{

	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);



	if (!nvdimm_bus)

		return false;

	WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm_bus->dev));

	if (device_for_each_child(&nvdimm_bus->dev, uuid,

				is_namespace_uuid_busy) != 0)

		return false;

	return true;

}



static ssize_t size_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

CRA Git | Maintained and supported by SUSTech CRA and CCSE