pci_ioremap_bar may return null. This is eventually de-referenced at drivers/dma/dw/core.c:1154 and drivers/dma/dw/core.c:1168. A null check is needed to prevent null de-reference. I am adding the check and in case of failure. Thanks to Andy Shevchenko for the hint on the necessity of pci_iounmap when exiting. Update: also covered the dw_dma_probe() failure.
Signed-off-by: Navid Emamdoost <[email protected]> --- drivers/tty/serial/8250/8250_lpss.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 53ca9ba6ab4b..19b356119ef6 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -169,15 +169,20 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) struct pci_dev *pdev = to_pci_dev(port->dev); int ret; + chip->pdata = &qrk_serial_dma_pdata; chip->dev = &pdev->dev; chip->irq = pci_irq_vector(pdev, 0); chip->regs = pci_ioremap_bar(pdev, 1); - chip->pdata = &qrk_serial_dma_pdata; + if (!chip->regs) + return; /* Falling back to PIO mode if DMA probing fails */ ret = dw_dma_probe(chip); - if (ret) + if (ret) { + dw_dma_remove(chip); + pci_iounmap(to_pci_dev(chip->dev), chip->regs); return; + } pci_try_set_mwi(pdev); @@ -195,11 +200,15 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) static void qrk_serial_exit_dma(struct lpss8250 *lpss) { + struct dw_dma_chip *chip = &lpss->dma_chip; struct dw_dma_slave *param = &lpss->dma_param; if (!param->dma_dev) return; - dw_dma_remove(&lpss->dma_chip); + + dw_dma_remove(chip); + + pci_iounmap(to_pci_dev(chip->dev), chip->regs); } #else /* CONFIG_SERIAL_8250_DMA */ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {} -- 2.17.1
