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 <hayashi.kunihiko@xxxxxxxxxxxxx> Thank you for fixing this. Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx> 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; > } >