On Tue, Jan 15, 2019 at 6:16 AM Jeff Moyer <jmoyer@xxxxxxxxxx> wrote: > > Dan Williams <dan.j.williams@xxxxxxxxx> writes: > > > Changes since v1 [1]: > > * Include another patch make sure that function-number zero can be > > safely used as an invalid function number (Jeff) > > * Add a comment clarifying why zero is an invalid function number (Jeff) > > * Pass nfit_mem to cmd_to_func() (Jeff) > > * Collect a Tested-by from Sujith > > [1]: https://lists.01.org/pipermail/linux-nvdimm/2019-January/019435.html > > For the series: > > Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx> > > Thanks, Dan! Thanks, although I just realized one more change. The ND_CMD_CALL case should zero out command after the function translation, otherwise userspace can call functions that the kernel is blocking in the dsm_mask. Holler if this invalidates your "Reviewed-by". diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 87e02f281e51..d7747aceb7ab 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -463,6 +463,12 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, func = cmd_to_func(nfit_mem, cmd, buf); if (func < 0) return func; + /* + * In the ND_CMD_CALL case we're now dependent on 'func' + * being validated by the dimm's dsm_mask + */ + if (cmd == ND_CMD_CALL) + cmd = 0; dimm_name = nvdimm_name(nvdimm); cmd_name = nvdimm_cmd_name(cmd); cmd_mask = nvdimm_cmd_mask(nvdimm); @@ -477,8 +483,10 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, cmd_name = nvdimm_bus_cmd_name(cmd); cmd_mask = nd_desc->cmd_mask; dsm_mask = cmd_mask; - if (cmd == ND_CMD_CALL) + if (cmd == ND_CMD_CALL) { dsm_mask = nd_desc->bus_dsm_mask; + cmd = 0; + } desc = nd_cmd_bus_desc(cmd); guid = to_nfit_uuid(NFIT_DEV_BUS); handle = adev->handle;
