From ffb9da65755815611010e07ad1c937858f226cb2 Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Fri, 30 Jan 2015 15:58:23 +0900 Subject: [PATCH] usb: renesas_usbhs: fix NULL pointer dereference in dma_release_channel() This patch fixes an issue that the following commit causes NULL pointer dereference in dma_release_channel(). "usb: renesas_usbhs: add support for requesting DT DMA" (commit id abd2dbf6bb1b5f3a03a8c76b1a8879da1dd30caa) The usbhsf_dma_init_dt() should set fifo->{t,r}x_chan to NULL if dma_request_slave_channel_reason() returns IS_ERR value. Otherwise, usbhsf_dma_quit() will call dma_release_channel(), and then NULL pointer dereference happens. Acked-by: Geert Uytterhoeven Tested-by: Simon Horman Reported-by: Simon Horman Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi --- drivers/usb/renesas_usbhs/fifo.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c index 4c086b1cda04..d891bff39d66 100644 --- a/drivers/usb/renesas_usbhs/fifo.c +++ b/drivers/usb/renesas_usbhs/fifo.c @@ -1072,7 +1072,11 @@ static void usbhsf_dma_init_pdev(struct usbhs_fifo *fifo) static void usbhsf_dma_init_dt(struct device *dev, struct usbhs_fifo *fifo) { fifo->tx_chan = dma_request_slave_channel_reason(dev, "tx"); + if (IS_ERR(fifo->tx_chan)) + fifo->tx_chan = NULL; fifo->rx_chan = dma_request_slave_channel_reason(dev, "rx"); + if (IS_ERR(fifo->rx_chan)) + fifo->rx_chan = NULL; } static void usbhsf_dma_init(struct usbhs_priv *priv,