From: Gustavo A. R. Silva Date: Mon, 20 Nov 2017 14:28:14 +0000 (-0600) Subject: dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved X-Git-Tag: v4.9.84~73 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3250df9fa82bb8c25af7acfd5875d684b9995119;p=platform%2Fkernel%2Flinux-amlogic.git dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved [ 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 Acked-by: Ludovic Desroches Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index a4c8f80..e2cec5b 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -709,7 +709,7 @@ 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; @@ -721,6 +721,8 @@ 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,