From 17f69298472cb0682e7247dc265d6b4f4e4cd9ac Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 14 Jan 2019 14:07:19 -0800 Subject: acpi/nfit: Block function zero DSMs commit 5e9e38d0db1d29efed1dd4cf9a70115d33521be7 upstream. In preparation for using function number 0 as an error value, prevent it from being considered a valid function value by acpi_nfit_ctl(). Cc: Cc: stuart hayes Fixes: e02fb7264d8a ("nfit: add Microsoft NVDIMM DSM command set...") Reported-by: Jeff Moyer Reviewed-by: Jeff Moyer Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/nfit/core.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index ef32e5766a01..b337c082773b 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1433,6 +1433,13 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, return 0; } + /* + * Function 0 is the command interrogation function, don't + * export it to potential userspace use, and enable it to be + * used as an error value in acpi_nfit_ctl(). + */ + dsm_mask &= ~1UL; + uuid = to_nfit_uuid(nfit_mem->family); for_each_set_bit(i, &dsm_mask, BITS_PER_LONG) if (acpi_check_dsm(adev_dimm->handle, uuid, 1, 1ULL << i)) -- cgit v1.2.3