ACPICA: Resource Mgr: Prevent infinite loops in resource walks

Add checks for zero-length resource descriptors in all code that
loops through a resource descriptor list. This prevents possible
infinite loops because the length is used to increment the traveral
pointer and detect the end-of-descriptor.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/rslist.c b/drivers/acpi/acpica/rslist.c
index ee2e206fc6c8..6053aa182093 100644
--- a/drivers/acpi/acpica/rslist.c
+++ b/drivers/acpi/acpica/rslist.c
@@ -178,6 +178,14 @@ acpi_rs_convert_resources_to_aml(struct acpi_resource *resource,
                         return_ACPI_STATUS(AE_BAD_DATA);
                 }
 
+                /* Sanity check the length. It must not be zero, or we loop forever */
+
+                if (!resource->length) {
+                        ACPI_ERROR((AE_INFO,
+                                    "Invalid zero length descriptor in resource list\n"));
+                        return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
+                }
+
                 /* Perform the conversion */
 
                 if (resource->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {