diff mbox series

[12/42] PCI: aardvark: Check for virq mapping when processing INTx IRQ

Message ID 20210506153153.30454-13-pali@kernel.org (mailing list archive)
State New, archived
Headers show
Series PCI: aardvark: Various driver fixes | expand

Commit Message

Pali Rohár May 6, 2021, 3:31 p.m. UTC
It is possible that we receive spurious INTx interrupt. So add needed check
before calling generic_handle_irq() function.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org
---
 drivers/pci/controller/pci-aardvark.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Marc Zyngier May 7, 2021, 9:15 a.m. UTC | #1
On Thu, 06 May 2021 16:31:23 +0100,
Pali Rohár <pali@kernel.org> wrote:
> 
> It is possible that we receive spurious INTx interrupt. So add needed check
> before calling generic_handle_irq() function.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Reviewed-by: Marek Behún <kabel@kernel.org>
> Cc: stable@vger.kernel.org
> ---
>  drivers/pci/controller/pci-aardvark.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> index 362faddae935..e7089db11f79 100644
> --- a/drivers/pci/controller/pci-aardvark.c
> +++ b/drivers/pci/controller/pci-aardvark.c
> @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie)
>  			    PCIE_ISR1_REG);
>  
>  		virq = irq_find_mapping(pcie->irq_domain, i);
> -		generic_handle_irq(virq);
> +		if (virq)
> +			generic_handle_irq(virq);
> +		else
> +			dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A');

Please don't scream like this. This is the best way to get into a DoS
situation if you interrupt rate is high enough. At least rate-limit
it.

	M.
Pali Rohár June 4, 2021, 4:24 p.m. UTC | #2
On Friday 07 May 2021 10:15:39 Marc Zyngier wrote:
> On Thu, 06 May 2021 16:31:23 +0100,
> Pali Rohár <pali@kernel.org> wrote:
> > 
> > It is possible that we receive spurious INTx interrupt. So add needed check
> > before calling generic_handle_irq() function.
> > 
> > Signed-off-by: Pali Rohár <pali@kernel.org>
> > Reviewed-by: Marek Behún <kabel@kernel.org>
> > Cc: stable@vger.kernel.org
> > ---
> >  drivers/pci/controller/pci-aardvark.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> > index 362faddae935..e7089db11f79 100644
> > --- a/drivers/pci/controller/pci-aardvark.c
> > +++ b/drivers/pci/controller/pci-aardvark.c
> > @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie)
> >  			    PCIE_ISR1_REG);
> >  
> >  		virq = irq_find_mapping(pcie->irq_domain, i);
> > -		generic_handle_irq(virq);
> > +		if (virq)
> > +			generic_handle_irq(virq);
> > +		else
> > +			dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A');
> 
> Please don't scream like this. This is the best way to get into a DoS
> situation if you interrupt rate is high enough. At least rate-limit
> it.

Ok, I will fix it!

Just to note that this code pattern is used also in other drivers.
So other drivers should fixed too...
Marc Zyngier June 4, 2021, 4:29 p.m. UTC | #3
On Fri, 04 Jun 2021 17:24:51 +0100,
Pali Rohár <pali@kernel.org> wrote:
> 
> On Friday 07 May 2021 10:15:39 Marc Zyngier wrote:
> > On Thu, 06 May 2021 16:31:23 +0100,
> > Pali Rohár <pali@kernel.org> wrote:
> > > 
> > > It is possible that we receive spurious INTx interrupt. So add needed check
> > > before calling generic_handle_irq() function.
> > > 
> > > Signed-off-by: Pali Rohár <pali@kernel.org>
> > > Reviewed-by: Marek Behún <kabel@kernel.org>
> > > Cc: stable@vger.kernel.org
> > > ---
> > >  drivers/pci/controller/pci-aardvark.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> > > index 362faddae935..e7089db11f79 100644
> > > --- a/drivers/pci/controller/pci-aardvark.c
> > > +++ b/drivers/pci/controller/pci-aardvark.c
> > > @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie)
> > >  			    PCIE_ISR1_REG);
> > >  
> > >  		virq = irq_find_mapping(pcie->irq_domain, i);
> > > -		generic_handle_irq(virq);
> > > +		if (virq)
> > > +			generic_handle_irq(virq);
> > > +		else
> > > +			dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A');
> > 
> > Please don't scream like this. This is the best way to get into a DoS
> > situation if you interrupt rate is high enough. At least rate-limit
> > it.
> 
> Ok, I will fix it!
> 
> Just to note that this code pattern is used also in other drivers.
> So other drivers should fixed too...

"We should fix the kernel" is a common theme. Please go ahead.

	M.
diff mbox series

Patch

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 362faddae935..e7089db11f79 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1106,7 +1106,10 @@  static void advk_pcie_handle_int(struct advk_pcie *pcie)
 			    PCIE_ISR1_REG);
 
 		virq = irq_find_mapping(pcie->irq_domain, i);
-		generic_handle_irq(virq);
+		if (virq)
+			generic_handle_irq(virq);
+		else
+			dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A');
 	}
 }