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

[Myeonghun Pak]

Hi Ioana,

Thanks for the suggestion. I've moved devm_free_irq() into
unregister_dpio_irq_handlers() to keep registration and unregistration
in sync.

I'll resend both fixes as a two-patch v2 series, with the probe
error-path cleanup first. That removes the unnecessary unregister call
before the second patch adds the managed IRQ release.

Thanks,
Myeonghun


2026년 10월 2일 (금) 오전 6:44, Ioana Ciornei <ioana.ciornei@xxxxxxx>님이 작성:
>
> 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