CVE-2026-45968

/// Technical description

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

cpuidle: Skip governor when only one idle state is available

On certain platforms (PowerNV systems without a power-mgt DT node),

cpuidle may register only a single idle state. In cases where that

single state is a polling state (state 0), the ladder governor may

incorrectly treat state 1 as the first usable state and pass an

out-of-bounds index. This can lead to a NULL enter callback being

invoked, ultimately resulting in a system crash.

[ 13.342636] cpuidle-powernv : Only Snooze is available

[ 13.351854] Faulting instruction address: 0x00000000

[ 13.376489] NIP [0000000000000000] 0x0

[ 13.378351] LR [c000000001e01974] cpuidle_enter_state+0x2c4/0x668

Fix this by adding a bail-out in cpuidle_select() that returns state 0

directly when state_count <= 1, bypassing the governor and keeping the

tick running.

/// 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