2019-08-16 04:34:24

by Wenwen Wang

Subject: [PATCH] ACPI / PCI: fix a memory leak bug

In acpi_pci_irq_enable(), 'entry' is allocated by invoking
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.

Signed-off-by: Wenwen Wang <[email protected]>
---
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

2019-08-19 21:25:09

by Bjorn Helgaas

Subject: Re: [PATCH] ACPI / PCI: fix a memory leak bug

The subject line should give a clue about where the leak is, e.g.,

ACPI / PCI: fix acpi_pci_irq_enable() memory leak

On Thu, Aug 15, 2019 at 11:33:22PM -0500, Wenwen Wang wrote:
> In acpi_pci_irq_enable(), 'entry' is allocated by invoking
> 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.

I think the corresponding kzalloc() is the one in
acpi_pci_irq_check_entry().

> Signed-off-by: Wenwen Wang <[email protected]>
> ---
> 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;
> + }

Looks like we missed this when e237a5518425 ("x86/ACPI/PCI: Recognize
that Interrupt Line 255 means "not connected"") was merged.

You could add:

Fixes: e237a5518425 ("x86/ACPI/PCI: Recognize that Interrupt Line 255 means "not connected"")

> if (acpi_isa_register_gsi(dev))
> dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
> --
> 2.7.4
>

2019-08-21 03:48:23

by Wenwen Wang

Subject: Re: [PATCH] ACPI / PCI: fix a memory leak bug

On Mon, Aug 19, 2019 at 5:23 PM Bjorn Helgaas <[email protected]> wrote:
>
> The subject line should give a clue about where the leak is, e.g.,
>
> ACPI / PCI: fix acpi_pci_irq_enable() memory leak
>
> On Thu, Aug 15, 2019 at 11:33:22PM -0500, Wenwen Wang wrote:
> > In acpi_pci_irq_enable(), 'entry' is allocated by invoking
> > 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.
>
> I think the corresponding kzalloc() is the one in
> acpi_pci_irq_check_entry().
>
> > Signed-off-by: Wenwen Wang <[email protected]>
> > ---
> > 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;
> > + }
>
> Looks like we missed this when e237a5518425 ("x86/ACPI/PCI: Recognize
> that Interrupt Line 255 means "not connected"") was merged.
>
> You could add:
>
> Fixes: e237a5518425 ("x86/ACPI/PCI: Recognize that Interrupt Line 255 means "not connected"")
>
> > if (acpi_isa_register_gsi(dev))
> > dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
> > --
> > 2.7.4
> >

Thanks for your comments and suggestions! I will rework the patch.

Wenwen