4.20-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams dan.j.williams@intel.com
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: stable@vger.kernel.org Cc: stuart hayes stuart.w.hayes@gmail.com Fixes: e02fb7264d8a ("nfit: add Microsoft NVDIMM DSM command set...") Reported-by: Jeff Moyer jmoyer@redhat.com Reviewed-by: Jeff Moyer jmoyer@redhat.com Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/acpi/nfit/core.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1844,6 +1844,13 @@ static int acpi_nfit_add_dimm(struct acp 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; + guid = to_nfit_uuid(nfit_mem->family); for_each_set_bit(i, &dsm_mask, BITS_PER_LONG) if (acpi_check_dsm(adev_dimm->handle, guid,