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

[Greg Kroah-Hartman]

From: Yu Kuai <yuku...@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 <yuku...@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-2-yuku...@huawei.com
Signed-off-by: Vinod Koul <vk...@kernel.org>
Signed-off-by: Sasha Levin <sas...@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);
-- 
2.25.1