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authorDan Williams <dan.j.williams@intel.com>2017-09-19 00:48:58 +0300
committerDan Williams <dan.j.williams@intel.com>2017-09-19 03:29:01 +0300
commit33a56086712561b8b9cdc881e0317f4c36861f72 (patch)
tree34cc2c124accee1b2b38b803925e2ce5c832d41d /drivers/nvdimm/namespace_devs.c
parent5e75fe3927559505682b0053b5745e3f42d66e8c (diff)
downloadlinux-33a56086712561b8b9cdc881e0317f4c36861f72.tar.xz
libnvdimm, namespace: fix btt claim class crash
Maurice reports: BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: holder_class_store+0x253/0x2b0 [libnvdimm] ...while trying to reconfigure an NVDIMM-N namespace into 'sector' / 'btt' mode. The crash points to this line: (gdb) li *(holder_class_store+0x253) 0x7773 is in holder_class_store (drivers/nvdimm/namespace_devs.c:1420). 1415 for (i = 0; i < nd_region->ndr_mappings; i++) { 1416 struct nd_mapping *nd_mapping = &nd_region->mapping[i]; 1417 struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); 1418 struct nd_namespace_index *nsindex; 1419 1420 nsindex = to_namespace_index(ndd, ndd->ns_current); ...where we are failing because ndd is NULL due to NVDIMM-N dimms not supporting labels. Long story short, default to the BTTv1 format in the label-less / NVDIMM-N case. Fixes: 14e494542636 ("libnvdimm, btt: BTT updates for UEFI 2.7 format") Cc: <stable@vger.kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Reported-by: Maurice A. Saldivar <maurice.a.saldivar@hpe.com> Tested-by: Maurice A. Saldivar <maurice.a.saldivar@hpe.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/namespace_devs.c')
-rw-r--r--drivers/nvdimm/namespace_devs.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 1427a386a033..3e4d1e7998da 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1417,6 +1417,15 @@ static int btt_claim_class(struct device *dev)
struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
struct nd_namespace_index *nsindex;
+ /*
+ * If any of the DIMMs do not support labels the only
+ * possible BTT format is v1.
+ */
+ if (!ndd) {
+ loop_bitmask = 0;
+ break;
+ }
+
nsindex = to_namespace_index(ndd, ndd->ns_current);
if (nsindex == NULL)
loop_bitmask |= 1;