In the Linux kernel, the following vulnerability has been resolved: net: au1000: move free_irq out of the close-time spinlocked section au1000_close() calls free_irq() while aup->lock is still held with spin_lock_irqsave()

Overview

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

net: au1000: move free_irq out of the close-time spinlocked section

au1000_close() calls free_irq() while aup->lock is still held with spin_lock_irqsave(). free_irq() can sleep because it takes the IRQ descriptor request mutex, so it does not belong inside the close-time spinlocked section.

This was found by our static analysis tool and then confirmed by manual review of the in-tree au1000_close() .ndo_stop path. The reviewed path keeps aup->lock held across the MAC reset, queue stop and free_irq(dev->irq, dev).

A directed runtime validation kept that ndo_stop carrier and the same free_irq(dev->irq, dev) operation under the driver lock. Lockdep reported "BUG: sleeping function called from invalid context" and "Invalid wait context" while free_irq() was taking desc->request_mutex, with au1000_close() and free_irq() on the stack.

Drop aup->lock before freeing the IRQ. The protected close-time work still stops the device and queue before IRQ teardown, but the sleepable IRQ core path now runs outside the spinlocked section.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.