This is a note to let you know that I've just added the patch titled dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate() to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dmaengine-at_hdmac-check-return-value-of-of_find_dev.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 05a98bad9f17c0c27bb1d188821d706ace841425 Author: Yu Kuai <yukuai3@xxxxxxxxxx> Date: Mon Aug 17 19:57:26 2020 +0800 dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate() [ 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@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200817115728.1706719-2-yukuai3@xxxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 73a20780744bf..22c1c507055a3 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1650,6 +1650,8 @@ 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);