From d208ea44e25b31db5a4d5e8c31df51787a3e9303 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 22 Mar 2022 17:02:05 +0100 Subject: [PATCH] ACPI: CPPC: Avoid out of bounds access when parsing _CPC data 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 Signed-off-by: Rafael J. Wysocki Reviewed-by: Huang Rui Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/cppc_acpi.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 5b2e58cbeb35..54ec4e191a8e 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -678,6 +678,11 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) 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); -- 2.20.1