This is a note to let you know that I've just added the patch titled dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved to the 4.14-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-fix-potential-null-pointer-dereference-in-atc_prep_dma_interleaved.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Feb 23 11:45:09 CET 2018 From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> Date: Mon, 20 Nov 2017 08:28:14 -0600 Subject: dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> [ Upstream commit 62a277d43d47e74972de44d33bd3763e31992414 ] _xt_ is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after _xt_ has been null checked. This issue was detected with the help of Coccinelle. Fixes: 4483320e241c ("dmaengine: Use Pointer xt after NULL check.") Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx> Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx> Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/dma/at_hdmac.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -708,7 +708,7 @@ atc_prep_dma_interleaved(struct dma_chan unsigned long flags) { struct at_dma_chan *atchan = to_at_dma_chan(chan); - struct data_chunk *first = xt->sgl; + struct data_chunk *first; struct at_desc *desc = NULL; size_t xfer_count; unsigned int dwidth; @@ -720,6 +720,8 @@ atc_prep_dma_interleaved(struct dma_chan if (unlikely(!xt || xt->numf != 1 || !xt->frame_size)) return NULL; + first = xt->sgl; + dev_info(chan2dev(chan), "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n", __func__, &xt->src_start, &xt->dst_start, xt->numf, Patches currently in stable-queue which might be from garsilva@xxxxxxxxxxxxxx are queue-4.14/dmaengine-at_hdmac-fix-potential-null-pointer-dereference-in-atc_prep_dma_interleaved.patch