dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved

[ Upstream commit 62a277d43d ]

_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: 4483320e24 ("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>
This commit is contained in:
Gustavo A. R. Silva 2017-11-20 08:28:14 -06:00 committed by Greg Kroah-Hartman
parent 27e2830b31
commit 05fc2b8ba0

View File

@ -708,7 +708,7 @@ atc_prep_dma_interleaved(struct dma_chan *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 *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,