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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>
hifive-unleashed-5.1
Dan Williams 2016-01-05 18:37:23 -08:00
parent 0731de0dd9
commit e07ecd76d4
2 changed files with 53 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
drivers/nvdimm/namespace_devs.c
View File

@ -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);

56
drivers/nvdimm/region_devs.c
View File

@ -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)
{