Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH v1 1/2] ACPI: CPPC: Avoid out of bounds access when parsing _CPC data | Date | Tue, 22 Mar 2022 17:02:05 +0100 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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> --- drivers/acpi/cppc_acpi.c | 5 +++++ 1 file changed, 5 insertions(+)
Index: linux-pm/drivers/acpi/cppc_acpi.c =================================================================== --- linux-pm.orig/drivers/acpi/cppc_acpi.c +++ linux-pm/drivers/acpi/cppc_acpi.c @@ -679,6 +679,11 @@ 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);
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