CVE-2026-53180

/// Technical description

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

timers/migration: Fix livelock in tmigr_handle_remote_up()

tmigr_handle_remote_cpu() skips timer_expire_remote() when cpu ==

smp_processor_id(), assuming the local softirq path already handled this

CPU's timers.

This assumption is wrong because jiffies can advance after the handling of

the CPU's global timers in run_timer_base(BASE_GLOBAL) and before

tmigr_handle_remote() evaluates the expiry times.

As a consequence a timer which expires after the CPU local timer wheel

advanced and becomes expired in the remote handling is ignored and the

callback is never invoked and removed from the timer wheel.

What's worse is that fetch_next_timer_interrupt_remote() keeps reporting it

as expired, and the event is re-queued with expires == now on each

iteration. The goto-again loop spins indefinitely.

Fix this by calling timer_expire_remote() unconditionally. That's minimal

overhead for the common case as __run_timer_base() r

/// 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