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CVE Record

CVE-2022-49427: iommu/mediatek: Remove clk_disable in mtk_iommu_remove

In the Linux kernel, the following vulnerability has been resolved: iommu/mediatek: Remove clk_disable in mtk_iommu_remove After the commit b34ea31fe013 ("iommu/mediatek: Always enable the clk on resume"), the iommu clock is controlled by the runtime callback. thus remove the clk control in the mtk_iommu_remove. Otherwise, it will warning like: echo 14018000.iommu > /sys/bus/platform/drivers/mtk-iommu/unbind [ 51.413044] ------------[ cut here ]------------ [ 51.413648] vpp0_smi_iommu already disabled [ 51.414233] WARNING: CPU: 2 PID: 157 at */v5.15-rc1/kernel/mediatek/ drivers/clk/clk.c:952 clk_core_disable+0xb0/0xb8 [ 51.417174] Hardware name: MT8195V/C(ENG) (DT) [ 51.418635] pc : clk_core_disable+0xb0/0xb8 [ 51.419177] lr : clk_core_disable+0xb0/0xb8 ... [ 51.429375] Call trace: [ 51.429694] clk_core_disable+0xb0/0xb8 [ 51.430193] clk_core_disable_lock+0x24/0x40 [ 51.430745] clk_disable+0x20/0x30 [ 51.431189] mtk_iommu_remove+0x58/0x118 [ 51.431705] platform_remove+0x28/0x60 [ 51.432197] device_release_driver_internal+0x110/0x1f0 [ 51.432873] device_driver_detach+0x18/0x28 [ 51.433418] unbind_store+0xd4/0x108 [ 51.433886] drv_attr_store+0x24/0x38 [ 51.434363] sysfs_kf_write+0x40/0x58 [ 51.434843] kernfs_fop_write_iter+0x164/0x1e0

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

CVE-2022-49427 is a Linux kernel issue in the MediaTek IOMMU driver. It can cause a kernel warning when the driver is removed because a clock is disabled twice. The public record does not show data theft, privilege escalation, remote access, or active exploitation.

Executive priority

Treat as routine patch management unless you operate MediaTek-based Linux devices at scale. No public source provided indicates active exploitation or a high-impact security outcome.

Technical view

The issue is in iommu/mediatek mtk_iommu_remove after commit b34ea31fe013 changed clock handling to runtime callbacks. The remove path still called clk_disable, producing an “already disabled” warning during platform driver unbind. Stable kernel commits remove that redundant clock control.

Likely exposure

Exposure appears limited to Linux systems using the MediaTek IOMMU driver, especially MediaTek SoC platforms such as the MT8195 example in the disclosure. Generic servers and non-MediaTek devices are unlikely to be exposed based on the provided sources.

Exploitation context

The source describes a local driver unbind/remove scenario that triggers a kernel warning. There is no KEV listing and no cited evidence of active exploitation. The security impact is not clearly characterized in the public CVE data.

Researcher notes

The CVE record is sparse and severity is unknown. The observable failure is a WARN path from redundant clk_disable in mtk_iommu_remove. Assess impact in downstream kernels because vendor backports may differ from upstream stable commit history.

Mitigation direction

  • Apply a vendor kernel update containing the referenced stable Linux fixes.
  • Prioritize MediaTek-based devices running affected Linux kernel builds.
  • If updates are unavailable, check vendor guidance for supported workarounds.
  • Avoid unnecessary driver unbind/remove operations on exposed MediaTek IOMMU systems.

Validation and detection

  • Inventory Linux devices using MediaTek SoCs or the mtk-iommu driver.
  • Compare running kernel builds against vendor advisories and the referenced stable commits.
  • Review kernel logs for MediaTek IOMMU clock disable warnings.
  • Confirm updated kernels include the mtk_iommu_remove clock-control fix.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxb34ea31fe013569d42b7e8681ef3f717f77c5b72, b34ea31fe013569d42b7e8681ef3f717f77c5b72, b34ea31fe013569d42b7e8681ef3f717f77c5b72, b34ea31fe013569d42b7e8681ef3f717f77c5b72, 5cad9e2caa9613fdcd246bd4ebf0ffbec1cba2caunaffected
LinuxLinux5.13, 0, 5.15.46, 5.17.14, 5.18.3, 5.19affected
Weakness

CWE details

No CWE listed

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