[PATCH 4.14 15/65] dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate()

From: Yu Kuai yukuai3@huawei.com

[ Upstream commit 0cef8e2c5a07d482ec907249dbd6687e8697677f ]

The reurn value of of_find_device_by_node() is not checked, thus null pointer dereference will be triggered if of_find_device_by_node() failed.

Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Signed-off-by: Yu Kuai yukuai3@huawei.com Link: https://lore.kernel.org/r/20200817115728.1706719-2-yukuai3@huawei.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/at_hdmac.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 21ed0e20c5d91..cf3225a229890 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1677,6 +1677,8 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, return NULL;

dmac_pdev = of_find_device_by_node(dma_spec->np); + if (!dmac_pdev) + return NULL;

dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask);