diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2017-04-24 15:43:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-20 14:28:42 +0200 |
| commit | 5b6e7f353290ca9b042090e0913caa71c2180d35 (patch) | |
| tree | 70a40fd6556eb1eb5f696a6e48211e80a2fdb538 | |
| parent | 46ba11b007c1988cd12ac5f40224b4393689a86b (diff) | |
libnvdimm, region: fix flush hint detection crash
commit bc042fdfbb92b5b13421316b4548e2d6e98eed37 upstream.
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
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/nvdimm/region_devs.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index 9cf6f1a88fce..f62306246ca4 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -968,17 +968,20 @@ EXPORT_SYMBOL_GPL(nvdimm_flush); */ int nvdimm_has_flush(struct nd_region *nd_region) { - struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev); int i; /* no nvdimm == flushing capability unknown */ if (nd_region->ndr_mappings == 0) return -ENXIO; - for (i = 0; i < nd_region->ndr_mappings; i++) - /* flush hints present, flushing required */ - if (ndrd_get_flush_wpq(ndrd, i, 0)) + for (i = 0; i < nd_region->ndr_mappings; i++) { + struct nd_mapping *nd_mapping = &nd_region->mapping[i]; + struct nvdimm *nvdimm = nd_mapping->nvdimm; + + /* flush hints present / available */ + if (nvdimm->num_flush) return 1; + } /* * The platform defines dimm devices without hints, assume |