CVE-2026-74463 Linux CVE debrief

Who should care

Linux kernel developers and users, I2C adapter users, CCF users, and security teams responsible for vulnerability management and patching. They should review and apply patches or updates to prevent CCF prepare_lock deadlock. Additionally, they should monitor systems for potential deadlocks and review compensating controls for exposed systems while remediation is scheduled and verified. Affected product deployments should be identified in managed environments, and owners should be assigned for follow-up. Relevant monitoring, detection, and logs for exposed assets should be checked for extra review. Exceptions should be tracked, and remediated assets should be retested, with the item only closed after evidence is documented. This affects operators and platforms using the Linux kernel and I2C adapter, requiring a coordinated effort to ensure system security and stability. The static nature of the jz4780 host controller clock means that changes are not expected, but vigilance is still necessary to prevent potential deadlocks in other parts of the system. Security teams should prioritize patching and verifying the effectiveness of compensating controls to minimize exposure. By taking these steps, they can help prevent similar deadlocks and ensure the security and stability of their systems. Linux distributions and maintainers should also review and update their packages to include the necessary patches, ensuring that users have access to secure and stable versions of the Linux kernel. Furthermore, users of I2C adapters and CCF should be aware of the potential risks and take proactive measures to mitigate them, such as implementing monitoring and detection mechanisms to identify potential issues before they become incidents. Overall, a comprehensive approach to vulnerability management and patching is essential to preventing CCF prepare_lock deadlocks and ensuring the security and stability of systems that rely on the Linux kernel and I2C adapter. By working together, developers, users, and security teams can minimize the risks associated with this vulnerability and ensure the continued security and stability of their systems. The importance of this issue cannot be 63

Technical summary

The Linux kernel vulnerability causes a severe AB/BA deadlock between the Common Clock Framework (CCF) and the I2C adapter lock. The jz4780 host controller clock itself is static and never changes at runtime. However, calling clk_get_rate() inside the active transfer path introduces an unnecessary dependency on the CCF internal locks. Eliminate this synchronous clk_get_rate() call from the active transfer path by caching the static host peripheral clock rate once - inside the private jz4780_i2c structure during jz4780_i2c_probe().

Defensive priority

Apply patch or update Linux kernel to prevent CCF prepare_lock deadlock

Recommended defensive actions

• Apply patch or update Linux kernel to prevent CCF prepare_lock deadlock
• Review and update I2C adapter lock and CCF interactions
• Monitor system for potential deadlocks
• 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 Linux kernel vulnerability causes a severe AB/BA deadlock between the Common Clock Framework (CCF) and the I2C adapter lock. Evidence is based on official CVE and NVD records. The jz4780 host controller clock itself is static and never changes at runtime. However, calling clk_get_rate() inside the active transfer path introduces an unnecessary dependency on the CCF internal locks. This synchronous clk_get_rate() call from the active transfer path is eliminated by caching the static host peripheral clock rate once - inside the private jz4780_i2c structure during jz4780_i2c_probe().

Official resources