CVE-2026-98893

What it actually does

The kernel fails to validate that a received SENSOR_UPDATE notification payload contains the expected number of variable-length sensor readings before parsing, enabling out-of-bounds memory access during deserialization.

Why it matters to the business

ARM-based Linux systems using SCMI sensor notifications risk kernel crashes, denial of service, or limited information disclosure in embedded or server environments.

How an attack unfolds

An attacker with the ability to inject or intercept SCMI notifications supplies a truncated SENSOR_UPDATE payload whose declared sensor count exceeds the actual data present; the unvalidated parser then reads beyond the received buffer.

How to fix it

Apply the upstream kernel commit that adds explicit payload-size validation before iterating over sensor readings in the arm_scmi SENSOR_UPDATE handler; rebuild and deploy the patched kernel on all affected systems.

How to confirm the fix worked

Confirm the presence of the size check that rejects truncated SENSOR_UPDATE notifications by inspecting the arm_scmi sensor parsing code path in the running kernel source or binary.

Typical attack path

1. Obtain or emulate an SCMI transport capable of delivering notifications
2. Craft a SENSOR_UPDATE message with a sensor count larger than the supplied payload bytes
3. Deliver the message to trigger arm_scmi parsing
4. Induce out-of-bounds read leading to crash or data leak

How to detect it

Search kernel logs and crash dumps for arm_scmi sensor parsing faults or out-of-bounds accesses occurring after receipt of SCMI notifications; correlate with process or driver activity involving sensor updates.

What your security team should do

• Prioritize kernel updates for all ARM SCMI-enabled devices within standard patch windows given low EPSS and absence from KEV
• Enable kernel panic and oops logging to central collection for rapid anomaly detection
• Review downstream distributions for backported fixes once released