CVE-2026-90035 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel maintenance, deployment, and security should assess exposure and prioritize patching or mitigation efforts. This includes verifying Linux kernel versions, applying patches or mitigations, and monitoring for device-reported estimated-bandwidth changes to prevent potential system crashes or denial-of-service conditions.

Why it matters

CVE-2026-90035 is a division by zero vulnerability in the Linux kernel's drm/amd/display component. Defenders should verify Linux kernel versions for potential exposure, prioritize patching or mitigation efforts, and monitor for device-reported estimated-bandwidth changes to prevent potential system crashes or denial-of-service conditions.

• Division by zero in IRQ path can cause system crashes
• Potential for denial-of-service (DoS) conditions
• Need for verification of Linux kernel versions and exposure
• Prioritization of patching or mitigation efforts

Technical summary

The get_estimated_bw() function in the Linux kernel's drm/amd/display component performs a division by link->dpia_bw_alloc_config.bw_granularity, which can be zero if DP_TUNELLING_BW_ALLOC_CAP_CHANGED has not been handled for that link. A connected USB4/DPIA tunneling device reporting an estimated-bandwidth change before a capability change can trigger this division by zero in the IRQ path. The vulnerability can cause system crashes or denial-of-service conditions. Defenders should prioritize verifying if their Linux kernel versions are affected and apply patches or mitigations as available.

Defensive priority

Defenders should prioritize verifying if their Linux kernel versions are affected and apply patches or mitigations as available.

Recommended defensive actions

• Verify Linux kernel versions for potential exposure
• Apply patches or mitigations as available
• Monitor for device-reported estimated-bandwidth changes
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and references to source code changes. The Linux kernel's drm/amd/display component is affected, and defenders should verify kernel versions and apply patches or mitigations as available. The source code changes are provided in the references.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.