Re: [PATCH v3 1/4] s390/pci: Fix leak of struct pci_dev reference in zpci_report_status()

[Benjamin Block <bblock@linux.ibm.com>]

On Fri, Sep 18, 2026 at 10:17:49AM +0200, Benjamin Block wrote:
> On Wed, Sep 16, 2026 at 05:14:10PM +0200, Niklas Schnelle wrote:
> > In zpci_report_status(), a reference to the pdev associated with the
> > zdev being reported about is acquired using pci_get_slot(). This
> > reference needs to be dropped with pci_dev_put(), but this call is
> > missing, thus leaking the reference. On subsequent hot unplug, this will
> > cause the struct pci_dev to not be released, leaking memory and
> > preventing reattach.
> > 
> > At the same time, the only existing caller already holds a pdev
> > reference. So instead of reacquiring and then dropping another reference,
> > simply pass the existing pdev pointer to zpci_report_status(). This gets
> > rid of the need for pci_get_slot() as well as the zdev->zbus check.
> > 
> > Cc: stable@vger.kernel.org
> > Fixes: 4ec6054e7321 ("s390/pci: Report PCI error recovery results via SCLP")
> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > ---
> >  arch/s390/pci/pci_event.c  |  2 +-
> >  arch/s390/pci/pci_report.c | 11 +++++------
> >  arch/s390/pci/pci_report.h |  4 +++-
> >  3 files changed, 9 insertions(+), 8 deletions(-)
> > 
> > diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
> > index f317a1465dad..3b4941b65840 100644
> > --- a/arch/s390/pci/pci_event.c
> > +++ b/arch/s390/pci/pci_event.c
> > @@ -298,7 +298,7 @@ static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev,
> >  	pci_uevent_ers(pdev, PCI_ERS_RESULT_RECOVERED);
> >  out_unlock:
> >  	device_unlock(&pdev->dev);
> > -	zpci_report_status(zdev, "recovery", status_str);
> > +	zpci_report_status(zdev, pdev, "recovery", status_str);
> 
> Hmm. Wasn't one of the previous fixes to move the lock below the status
> report?
> 
> Why is that missing here again?

Ah, nevermind, it's in the next patch. Bit confusing. Anyway, since it doesn't
make things worse, and it's fixed one patch later this should be fine.


Reviewed-by: Benjamin Block <bblock@linux.ibm.com>

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