Re: [PATCH] soc: fsl: dpio: Free the IRQ before releasing the I/O object

[Ioana Ciornei]

On Thu, Sep 17, 2026 at 04:01:36PM -0400, Myeonghun Pak wrote:
> The DPIO interrupt handler accesses priv->io, but dpaa2_dpio_remove()
> releases that object before tearing down the interrupts. The IRQ was
> requested with devm_request_irq(), and unregister_dpio_irq_handlers()
> only clears its affinity hint. fsl_mc_free_irqs() returns IRQ resources
> to the MC resource pool without freeing the handler. An interrupt can
> therefore access the freed I/O object before devres releases the IRQ.
> 
> Explicitly free the managed IRQ before returning its resource to the
> pool, and perform IRQ teardown before releasing the I/O object. This
> also waits for an in-flight handler while the object is still valid.
> 
> This issue was identified during our ongoing static-analysis research
> while reviewing kernel code.
> 
> Fixes: 993fec7e11ca ("bus: fsl-mc: dpio: add the DPAA2 DPIO object driver")
> Assisted-by: LLM
> Co-developed-by: Ijae Kim <ae878000@xxxxxxxxx>
> Signed-off-by: Ijae Kim <ae878000@xxxxxxxxx>
> Signed-off-by: Myeonghun Pak <mhun512@xxxxxxxxx>
> ---
>  drivers/soc/fsl/dpio/dpio-driver.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/soc/fsl/dpio/dpio-driver.c b/drivers/soc/fsl/dpio/dpio-driver.c
> index d5198ffc4455..fa82cdcc4922 100644
> --- a/drivers/soc/fsl/dpio/dpio-driver.c
> +++ b/drivers/soc/fsl/dpio/dpio-driver.c
> @@ -263,6 +263,8 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
>  static void dpio_teardown_irqs(struct fsl_mc_device *dpio_dev)
>  {
>  	unregister_dpio_irq_handlers(dpio_dev);
> +	devm_free_irq(&dpio_dev->dev, dpio_dev->irqs[0]->virq,
> +		      &dpio_dev->dev);


I would suggest moving the devm_free_irq() call inside
unregister_dpio_irq_handlers() so that we keep the register_ and
unregister_ in sync.

Thanks,
Ioana