From: Rafael J. Wysocki rafael.j.wysocki@intel.com
commit 40d8abf364bcab23bc715a9221a3c8623956257b upstream.
If the NumEntries field in the _CPC return package is less than 2, do not attempt to access the "Revision" element of that package, because it may not be present then.
Fixes: 337aadff8e45 ("ACPI: Introduce CPU performance controls using CPPC") BugLink: https://lore.kernel.org/lkml/20220322143534.GC32582@xsang-OptiPlex-9020/ Reported-by: kernel test robot oliver.sang@intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Huang Rui ray.huang@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/cppc_acpi.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -690,6 +690,11 @@ int acpi_cppc_processor_probe(struct acp cpc_obj = &out_obj->package.elements[0]; if (cpc_obj->type == ACPI_TYPE_INTEGER) { num_ent = cpc_obj->integer.value; + if (num_ent <= 1) { + pr_debug("Unexpected _CPC NumEntries value (%d) for CPU:%d\n", + num_ent, pr->id); + goto out_free; + } } else { pr_debug("Unexpected entry type(%d) for NumEntries\n", cpc_obj->type);