CVE-2026-74468

/// Technical description

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

gpio: pch: use raw_spinlock_t for the register lock

pch_irq_type() is registered as the irq_chip .irq_set_type callback and

takes chip->spinlock with spin_lock_irqsave(). This callback is reached

from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while

the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled.

That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is

an rtmutex-backed sleeping lock, so acquiring it there is invalid.

This was confirmed on a PREEMPT_RT kernel with lockdep

(PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP). A grounded PoC mirrored

pch_irq_type()'s locking and drove it through the real genirq carrier

irq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e.

the same __irq_set_trigger() edge that __setup_irq() takes for a

requested IRQ. With the original spin_lock_irqsave() edge lockdep

reported an invalid wait context, immediately

/// 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