From e07ecd76d4db7bda1e9495395b2110a3fe28845a Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 5 Jan 2016 18:37:23 -0800 Subject: 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: [] memcmp+0xc/0x40 [..] Call Trace: [] is_uuid_busy+0xc1/0x2a0 [libnvdimm] [] ? to_nd_blk_region+0x50/0x50 [libnvdimm] [] device_for_each_child+0x50/0x90 Cc: Signed-off-by: Dan Williams --- drivers/nvdimm/namespace_devs.c | 53 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'drivers/nvdimm/namespace_devs.c') diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index ee6dee41155a..8ebfcaae3f5a 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -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); -- cgit v1.2.3