On Tue, 2015-06-30 at 20:42 +0300, Dan Carpenter wrote: Thanks Dan! 8<----- nfit: fix smatch "use after null check" report From: Dan Williams <dan.j.williams(a)intel.com&gt; drivers/acpi/nfit.c:1224 acpi_nfit_blk_region_enable() error: we previously assumed 'nfit_mem' could be null (see line 1223) drivers/acpi/nfit.c 1222 nfit_mem = nvdimm_provider_data(nvdimm); 1223 if (!nfit_mem || !nfit_mem->dcr || !nfit_mem->bdw) { ^^^^^^^^ Check. 1224 dev_dbg(dev, "%s: missing%s%s%s\n", __func__, 1225 nfit_mem ? "" : " nfit_mem", 1226 nfit_mem->dcr ? "" : " dcr", ^^^^^^^^^^^^^ Unchecked dereference. Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; Acked-by: Ross Zwisler <ross.zwisler(a)linux.intel.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt; --- drivers/acpi/nfit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index 2161fa178c8d..a20b7c883ca0 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -1223,8 +1223,8 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, if (!nfit_mem || !nfit_mem->dcr || !nfit_mem->bdw) { dev_dbg(dev, "%s: missing%s%s%s\n", __func__, nfit_mem ? "" : " nfit_mem", - nfit_mem->dcr ? "" : " dcr", - nfit_mem->bdw ? "" : " bdw"); + (nfit_mem && nfit_mem->dcr) ? "" : " dcr", + (nfit_mem && nfit_mem->bdw) ? "" : " bdw"); return -ENXIO; }