Messages in this thread Patch in this message | | | Date | Mon, 20 Nov 2017 08:28:14 -0600 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH] dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved |
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_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> --- drivers/dma/at_hdmac.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index fbab271..a861b5b 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -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, -- 2.7.4
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