CVE-2024-42146

What it actually does

Missing outer runtime_pm reference in xe_dma_buf kunit test allowing unprotected inner memory access and triggering warnings in xe_pm_runtime_get_noresume within the Xe graphics driver.

Why it matters to the business

Low operational risk limited to kernel development and testing environments; may produce warnings or minor instability during graphics driver validation on affected Linux systems, with no known active exploitation or ransomware use.

How an attack unfolds

The issue surfaces only when running specific kunit tests that perform DMA buffer operations without standard driver entry points; an attacker would need local access to trigger the test harness in a vulnerable build, but the flaw is primarily a development-time power management protection gap rather than a remote attack vector.

How to fix it

Update the Linux kernel to a version containing commit 0888d15ea45ba8ef4508edd1123ea5ad95b58994 or later; rebuild and deploy the fixed drm/xe module.

How to confirm the fix worked

Confirm the fix commit is present in the running kernel source; re-run the affected kunit test and verify absence of the 'Missing outer runtime PM protection' warning.

Typical attack path

1. Compile or load a vulnerable Xe driver build containing the kunit test
2. Execute xe_test_dmabuf_import_same_driver test case
3. Observe missing outer runtime PM protection warning in kernel log

How to detect it

Search kernel logs and dmesg for the warning string produced by xe_pm_runtime_get_noresume during kunit execution of dma_buf tests; inspect test output for xe_dma_buf_kunit runs.

• Missing outer runtime PM protection
• xe_test_dmabuf_import_same_driver
• xe_dma_buf_kunit

What your security team should do

• Apply the referenced kernel commit to all development and test systems using the Xe driver
• Monitor kernel logs for runtime PM warnings during graphics driver testing
• Prioritize kernel updates on systems building or validating drm/xe code