CVE-2024-46870

/// Technical description

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

drm/amd/display: Disable DMCUB timeout for DCN35

[Why]

DMCUB can intermittently take longer than expected to process commands.

Old ASIC policy was to continue while logging a diagnostic error - which

works fine for ASIC without IPS, but with IPS this could lead to a race

condition where we attempt to access DCN state while it's inaccessible,

leading to a system hang when the NIU port is not disabled or register

accesses that timeout and the display configuration in an undefined

state.

[How]

We need to investigate why these accesses take longer than expected, but

for now we should disable the timeout on DCN35 to avoid this race

condition. Since the waits happen only at lower interrupt levels the

risk of taking too long at higher IRQ and causing a system watchdog

timeout are minimal.

/// 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