In the Linux kernel, the following vulnerability has been resolved:iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get failsarm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases therefcount of the "smmu" even though the return value is less than 0.The reference counting issue happens in some error handling paths ofarm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get()fails, the caller functions forget to decrease the refcount of "smmu"increased by arm_smmu_rpm_get(), causing a refcount leak.Fix this issue by calling pm_runtime_resume_and_get() instead ofpm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcountbalanced in case of failure.
CWE-911 Improper Update of Reference Count