acpi, nfit: validate ars_status output buffer size
If an ARS Status command returns truncated output, do not process
partial records or otherwise consume non-status fields.
Cc: <stable@vger.kernel.org>
Fixes: 0caeef63e6d2 ("libnvdimm: Add a poison list and export badblocks")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index e58ec32..4b8b4f5 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -146,7 +146,8 @@
* then just continue with the returned results.
*/
if (status == NFIT_ARS_STATUS_INTR) {
- if (ars_status->flags & NFIT_ARS_F_OVERFLOW)
+ if (ars_status->out_length >= 40 && (ars_status->flags
+ & NFIT_ARS_F_OVERFLOW))
return -ENOSPC;
return 0;
}
@@ -2002,19 +2003,32 @@
return cmd_rc;
}
-static int ars_status_process_records(struct nvdimm_bus *nvdimm_bus,
+static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc,
struct nd_cmd_ars_status *ars_status)
{
+ struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus;
int rc;
u32 i;
+ /*
+ * First record starts at 44 byte offset from the start of the
+ * payload.
+ */
+ if (ars_status->out_length < 44)
+ return 0;
for (i = 0; i < ars_status->num_records; i++) {
+ /* only process full records */
+ if (ars_status->out_length
+ < 44 + sizeof(struct nd_ars_record) * (i + 1))
+ break;
rc = nvdimm_bus_add_poison(nvdimm_bus,
ars_status->records[i].err_address,
ars_status->records[i].length);
if (rc)
return rc;
}
+ if (i < ars_status->num_records)
+ dev_warn(acpi_desc->dev, "detected truncated ars results\n");
return 0;
}
@@ -2267,8 +2281,7 @@
if (rc < 0 && rc != -ENOSPC)
return rc;
- if (ars_status_process_records(acpi_desc->nvdimm_bus,
- acpi_desc->ars_status))
+ if (ars_status_process_records(acpi_desc, acpi_desc->ars_status))
return -ENOMEM;
return 0;