CVE-2026-64205

Technical Description

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

i2c: i801: fix hardware state machine corruption in error path

A severe livelock and subsequent Hung Task panic were observed in the

i2c-i801 driver during concurrent Fuzzing. The crash is caused by an

unconditional hardware register cleanup in the error handling path of

i801_access().

When i801_check_pre() fails (e.g., returning -EBUSY because the SMBus

controller is actively used by BIOS/ACPI), the kernel does not actually

acquire the hardware ownership. However, the code jumps to the 'out'

label and executes:

iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv));

This forcefully clears the INUSE_STS lock and resets the hardware status

flags without owning the controller. Doing so interrupts ongoing BIOS/ACPI

transactions and totally corrupts the SMBus hardware state machine.

Consequently, all subsequent i801_access() calls fail at the pre-check

stage, triggering an endless stream of "SMBus is busy,

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References