CVE-2024-26593

What it actually does

Missing second reset of the I2C block buffer index before reading causes the driver to read from the wrong offset in the block buffer during process call transactions, resulting in incorrect data access and potential memory corruption.

Why it matters to the business

Linux systems using affected I2C hardware may experience data corruption, crashes, or information disclosure, increasing operational risk for servers and embedded devices until patched; the high CVSS and kernel impact warrant prompt attention despite low EPSS.

How an attack unfolds

An attacker with local access crafts or triggers I2C block process call transactions on vulnerable hardware; the missing reset leads to reading stale or incorrect buffer contents, enabling memory corruption or information leaks that can be chained for further impact.

How to fix it

Update the Linux kernel to the fixed commit d074d5ff5ae77b18300e5079c6bda6342a4d44b7 or later stable versions containing the double-reset logic for block process calls; rebuild and reboot with the patched kernel.

How to confirm the fix worked

Confirm the running kernel includes commit d074d5ff5ae77b18300e5079c6bda6342a4d44b7 by checking git log or kernel version; test I2C block process call transactions to verify correct buffer indexing and data handling.

Typical attack path

1. Obtain local access to a vulnerable Linux system with i801 I2C controller
2. Trigger or manipulate SMBus block process call transactions via user-space tools or drivers
3. Exploit the incorrect buffer read to corrupt memory or leak kernel data
4. Escalate privileges or cause denial of service using the corrupted state

How to detect it

Inspect kernel logs for I2C transaction errors or unexpected buffer behavior around i801 driver calls; review dmesg and audit logs for anomalous SMBus activity post-transaction.

What your security team should do

• Prioritize kernel updates on all affected systems within standard patching windows given the local attack vector and memory corruption impact
• Monitor for new stable kernel releases containing the fix and schedule testing in non-production environments first
• Review I2C/SMBus usage in custom drivers or hardware configurations for additional hardening opportunities