From: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx> [ Upstream commit 0e86d981f9b7252e9716c5137cd8e4d9ad8ef32f ] 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 trigger a NULL pointer dereference because dma_chan is not set. Avoid calling dma_release_channel() if epf_test->dma_supported is false. Link: https://lore.kernel.org/r/1587540287-10458-1-git-send-email-hayashi.kunihiko@xxxxxxxxxxxxx Fixes: 5ebf3fc59bd2 ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data") Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx> [lorenzo.pieralisi@xxxxxxx: commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 60330f3e3751..c89a9561439f 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; } -- 2.25.1
