diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2020-11-23 17:43:53 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2020-11-23 17:43:53 -0800 |
| commit | 9a7e3d7f056831a6193d6d737fb7a26dfdceb04b (patch) | |
| tree | 2ac4133f657744f067dbbbdffb5419723b2e8207 | |
| parent | 2dd2a1740ee19cd2636d247276cf27bfa434b0e2 (diff) | |
ACPI: NFIT: Fix input validation of bus-family
Dan reports that smatch thinks userspace can craft an out-of-bound bus
family number. However, nd_cmd_clear_to_send() blocks all non-zero
values of bus-family since only the kernel can initiate these commands.
However, in the speculation path, family is a user controlled array
index value so mask it for speculation safety. Also, since the
nd_cmd_clear_to_send() safety is non-obvious and possibly may change in
the future include input validation as if userspace could get past the
nd_cmd_clear_to_send() gatekeeper.
Link: http://lore.kernel.org/r/20201111113000.GA1237157@mwanda
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 6450ddbd5d8e ("ACPI: NFIT: Define runtime firmware activation commands")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | drivers/acpi/nfit/core.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index cda7b6c52504..b11b08a60684 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -5,6 +5,7 @@ #include <linux/list_sort.h> #include <linux/libnvdimm.h> #include <linux/module.h> +#include <linux/nospec.h> #include <linux/mutex.h> #include <linux/ndctl.h> #include <linux/sysfs.h> @@ -479,8 +480,11 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, cmd_mask = nd_desc->cmd_mask; if (cmd == ND_CMD_CALL && call_pkg->nd_family) { family = call_pkg->nd_family; - if (!test_bit(family, &nd_desc->bus_family_mask)) + if (family > NVDIMM_BUS_FAMILY_MAX || + !test_bit(family, &nd_desc->bus_family_mask)) return -EINVAL; + family = array_index_nospec(family, + NVDIMM_BUS_FAMILY_MAX + 1); dsm_mask = acpi_desc->family_dsm_mask[family]; guid = to_nfit_bus_uuid(family); } else { |