diff options
| author | M'boumba Cedric Madianga <cedric.madianga@gmail.com> | 2016-12-13 14:40:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-09 22:01:50 +0100 |
| commit | 7468e767d8f2115427f2066203e5262f5dee8c5c (patch) | |
| tree | c58cc4bc56a8f5e195df643c494ffb74fc9ddb07 /drivers/dma | |
| parent | 000e7180633f254aef401a8cbca7f470ead41fed (diff) | |
dmaengine: stm32-dma: Fix null pointer dereference in stm32_dma_tx_status
[ Upstream commit 57b5a32135c813f2ab669039fb4ec16b30cb3305 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/stm32-dma.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index bd758e67843c..ae3f60be7759 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -884,7 +884,7 @@ 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)) @@ -892,16 +892,12 @@ 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); |