CVE-2024-27009

/// Technical description

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

s390/cio: fix race condition during online processing

A race condition exists in ccw_device_set_online() that can cause the

online process to fail, leaving the affected device in an inconsistent

state. As a result, subsequent attempts to set that device online fail

with return code ENODEV.

The problem occurs when a path verification request arrives after

a wait for final device state completed, but before the result state

is evaluated.

Fix this by ensuring that the CCW-device lock is held between

determining final state and checking result state.

Note that since:

commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")

path verification requests are much more likely to occur during boot,

resulting in an increased chance of this race condition occurring.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. 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.

/// References