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> --- 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