2020-04-22 07:26:42

by Kunihiko Hayashi

Subject: [PATCH v2] PCI: endpoint: functions/pci-epf-test: Avoid DMA release when DMA is unsupported

When unbinding pci_epf_test, pci_epf_test_clean_dma_chan() is called in
pci_epf_test_unbind() even though epf_test->dma_supported is false.
As a result, dma_release_channel() will occur null pointer access because
dma_chan isn't set.

This avoids calling dma_release_channel() if epf_test->dma_supported
is false.

Fixes: a1d105d4ab8e ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data")
Signed-off-by: Kunihiko Hayashi <[email protected]>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 60330f3e..c89a956 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -187,6 +187,9 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test)
*/
static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test)
{
+ if (!epf_test->dma_supported)
+ return;
+
dma_release_channel(epf_test->dma_chan);
epf_test->dma_chan = NULL;
}
--
2.7.4

2020-04-22 08:00:30

by Kishon Vijay Abraham I

Subject: Re: [PATCH v2] PCI: endpoint: functions/pci-epf-test: Avoid DMA release when DMA is unsupported

Hi Kunihiko,

On 4/22/2020 12:54 PM, Kunihiko Hayashi wrote:
> When unbinding pci_epf_test, pci_epf_test_clean_dma_chan() is called in
> pci_epf_test_unbind() even though epf_test->dma_supported is false.
> As a result, dma_release_channel() will occur null pointer access because
> dma_chan isn't set.
>
> This avoids calling dma_release_channel() if epf_test->dma_supported
> is false.
>
> Fixes: a1d105d4ab8e ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data")
> Signed-off-by: Kunihiko Hayashi <[email protected]>

Thank you for fixing this.

Acked-by: Kishon Vijay Abraham I <[email protected]>

Regards
Kishon

> ---
> drivers/pci/endpoint/functions/pci-epf-test.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 60330f3e..c89a956 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -187,6 +187,9 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test)
> */
> static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test)
> {
> + if (!epf_test->dma_supported)
> + return;
> +
> dma_release_channel(epf_test->dma_chan);
> epf_test->dma_chan = NULL;
> }
>

2020-05-05 11:31:54

by Lorenzo Pieralisi

Subject: Re: [PATCH v2] PCI: endpoint: functions/pci-epf-test: Avoid DMA release when DMA is unsupported

On Wed, Apr 22, 2020 at 04:24:47PM +0900, Kunihiko Hayashi wrote:
> When unbinding pci_epf_test, pci_epf_test_clean_dma_chan() is called in
> pci_epf_test_unbind() even though epf_test->dma_supported is false.
> As a result, dma_release_channel() will occur null pointer access because
> dma_chan isn't set.
>
> This avoids calling dma_release_channel() if epf_test->dma_supported
> is false.
>
> Fixes: a1d105d4ab8e ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data")
> Signed-off-by: Kunihiko Hayashi <[email protected]>
> ---
> drivers/pci/endpoint/functions/pci-epf-test.c | 3 +++
> 1 file changed, 3 insertions(+)

Applied (with the proper Fixes: SHA-1 ID) to pci/endpoint, thanks.

Lorenzo

> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 60330f3e..c89a956 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -187,6 +187,9 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test)
> */
> static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test)
> {
> + if (!epf_test->dma_supported)
> + return;
> +
> dma_release_channel(epf_test->dma_chan);
> epf_test->dma_chan = NULL;
> }
> --
> 2.7.4
>