CVE-2026-89977: accel/ethosu: check MMIO mapping errors in probe
In the Linux kernel, the following vulnerability has been resolved:
accel/ethosu: check MMIO mapping errors in probe
devmplatformioremapresource() returns an error pointer when the register resource cannot be mapped. ethosuprobe() stores it and continues until initialization dereferences it through MMIO accessors.
Return the mapping error before initializing the device.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Update the Linux kernel to the version that includes the fix "accel/ethosu: check MMIO mapping errors in probe" (i.e., ensure the driver returns the mapping error before initializing the device, so MMIO accessors are not dereferenced when devm_platform_ioremap_resource() cannot map the resource).
Event History
Frequently Asked Questions
Under what condition can this issue be triggered?
It is triggered when the Ethos-U driver's register resource cannot be mapped and devm_platform_ioremap_resource() returns an error pointer. The probe path continues initialization and later dereferences that pointer through MMIO accessors.
What is the immediate mitigation if an updated kernel is not available?
Prevent the affected Ethos-U device driver from probing on systems where its register resource cannot be mapped. The provided data does not identify a configuration-only workaround beyond avoiding that failed probe condition.
How can I tell whether a system is affected at runtime?
Look for an Ethos-U driver probe in which MMIO/register-resource mapping fails, followed by continued device initialization or MMIO access. The fixed behavior returns the mapping error before device initialization proceeds.