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authorM'boumba Cedric Madianga <cedric.madianga@gmail.com>2016-12-13 14:40:46 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-02 09:28:52 +0530
commit57b5a32135c813f2ab669039fb4ec16b30cb3305 (patch)
tree5db51a28628595e87a6c8f9df879cc84140a3666 /drivers/dma
parent7e96304d99477de1f70db42035071e56439da817 (diff)
downloadlinux-57b5a32135c813f2ab669039fb4ec16b30cb3305.tar.bz2
dmaengine: stm32-dma: Fix null pointer dereference in stm32_dma_tx_status
chan->desc is always set to NULL when a DMA transfer is complete. As a DMA transfer could be complete during the call of stm32_dma_tx_status, we need to be sure that chan->desc is not NULL before using this variable to avoid a null pointer deference issue. Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com> Reviewed-by: Ludovic BARRE <ludovic.barre@st.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/stm32-dma.c10
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index a884b857cba4..3056ce7f8c69 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -880,7 +880,7 @@ static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
struct virt_dma_desc *vdesc;
enum dma_status status;
unsigned long flags;
- u32 residue;
+ u32 residue = 0;
status = dma_cookie_status(c, cookie, state);
if ((status == DMA_COMPLETE) || (!state))
@@ -888,16 +888,12 @@ static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
spin_lock_irqsave(&chan->vchan.lock, flags);
vdesc = vchan_find_desc(&chan->vchan, cookie);
- if (cookie == chan->desc->vdesc.tx.cookie) {
+ if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
residue = stm32_dma_desc_residue(chan, chan->desc,
chan->next_sg);
- } else if (vdesc) {
+ else if (vdesc)
residue = stm32_dma_desc_residue(chan,
to_stm32_dma_desc(vdesc), 0);
- } else {
- residue = 0;
- }
-
dma_set_residue(state, residue);
spin_unlock_irqrestore(&chan->vchan.lock, flags);