Re: [PATCH net] net: au1000: move free_irq out of the close-time spinlocked section

[Simon Horman <horms@kernel.org>]

On Fri, Jun 19, 2026 at 11:18:16PM +0800, Runyu Xiao wrote:
> 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.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Cc: stable@vger.kernel.org
> Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>

Reviewed-by: Simon Horman <horms@kernel.org>

FTR, I notice that there is an AI-generated review of this patch on
sashiko.dev. However, I don't think that the issues raised there should
block progress of this patch.