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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Mon, 2 Sep 2019 23:19:58 +0200
Message-ID: <CAJZ5v0gm3Mv0-6fVe+7v4Kd49xG6W=TXcxfTJthpe9o46n4EEQ@mail.gmail.com>
Subject: Re: [PATCH v2] ACPI / PCI: fix acpi_pci_irq_enable() memory leak
To:     Wenwen Wang <wenwen@cs.uga.edu>,
        Bjorn Helgaas <bhelgaas@google.com>
Cc:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <lenb@kernel.org>,
        "open list:PCI SUBSYSTEM" <linux-pci@vger.kernel.org>,
        "open list:ACPI" <linux-acpi@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Wed, Aug 21, 2019 at 5:44 AM Wenwen Wang <wenwen@cs.uga.edu> wrote:
>
> In acpi_pci_irq_enable(), 'entry' is allocated by kzalloc() in
> acpi_pci_irq_check_entry() (invoked from acpi_pci_irq_lookup()). However,
> it is not deallocated if acpi_pci_irq_valid() returns false, leading to a
> memory leak. To fix this issue, free 'entry' before returning 0.
>
> Fixes: e237a5518425 ("x86/ACPI/PCI: Recognize that Interrupt Line 255 means
> "not connected"")
>
> Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>

Bjorn, any more comments?

> ---
>  drivers/acpi/pci_irq.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
> index d2549ae..dea8a60 100644
> --- a/drivers/acpi/pci_irq.c
> +++ b/drivers/acpi/pci_irq.c
> @@ -449,8 +449,10 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
>                  * No IRQ known to the ACPI subsystem - maybe the BIOS /
>                  * driver reported one, then use it. Exit in any case.
>                  */
> -               if (!acpi_pci_irq_valid(dev, pin))
> +               if (!acpi_pci_irq_valid(dev, pin)) {
> +                       kfree(entry);
>                         return 0;
> +               }
>
>                 if (acpi_isa_register_gsi(dev))
>                         dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
> --
> 2.7.4
>