CVE-2021-47025

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

iommu/mediatek: Always enable the clk on resume

In mtk_iommu_runtime_resume always enable the clk, even

if m4u_dom is null. Otherwise the 'suspend' cb might

disable the clk which is already disabled causing the warning:

[ 1.586104] infra_m4u already disabled

[ 1.586133] WARNING: CPU: 0 PID: 121 at drivers/clk/clk.c:952 clk_core_disable+0xb0/0xb8

[ 1.594391] mtk-iommu 10205000.iommu: bound 18001000.larb (ops mtk_smi_larb_component_ops)

[ 1.598108] Modules linked in:

[ 1.598114] CPU: 0 PID: 121 Comm: kworker/0:2 Not tainted 5.12.0-rc5 #69

[ 1.609246] mtk-iommu 10205000.iommu: bound 14027000.larb (ops mtk_smi_larb_component_ops)

[ 1.617487] Hardware name: Google Elm (DT)

[ 1.617491] Workqueue: pm pm_runtime_work

[ 1.620545] mtk-iommu 10205000.iommu: bound 19001000.larb (ops mtk_smi_larb_component_ops)

[ 1.627229] pstate: 60000085 (nZCv daIf -PAN -UAO -TCO BTYPE=--)

[ 1.659297] pc : clk

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References