4.14-stable review patch. If anyone has any objections, please let me know.
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From: "Gustavo A. R. Silva" garsilva@embeddedor.com
[ 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@embeddedor.com Acked-by: Ludovic Desroches ludovic.desroches@microchip.com Signed-off-by: Vinod Koul vinod.koul@intel.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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,