Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx> ~PYM~ On 12/07/2017 02:18 PM, Ludovic BARRE wrote: > with Pierre Yves mail it's better ;-) > > On 12/07/2017 02:04 PM, Ludovic BARRE wrote: >> add Pierre-yves Mordret >> >> acked-by: Ludovic BARRE <ludovic.barre@xxxxxx> >> >> On 12/07/2017 01:56 PM, Greg Kroah-Hartman wrote: >>> 4.9-stable review patch. If anyone has any objections, please let me >>> know. >>> >>> ------------------ >>> >>> From: M'boumba Cedric Madianga <cedric.madianga@xxxxxxxxx> >>> >>> >>> [ 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@xxxxxxxxx> >>> Reviewed-by: Ludovic BARRE <ludovic.barre@xxxxxx> >>> Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx> >>> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> >>> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> >>> --- >>> drivers/dma/stm32-dma.c | 10 +++------- >>> 1 file changed, 3 insertions(+), 7 deletions(-) >>> >>> --- a/drivers/dma/stm32-dma.c >>> +++ b/drivers/dma/stm32-dma.c >>> @@ -884,7 +884,7 @@ static enum dma_status stm32_dma_tx_stat >>> 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_stat >>> 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); >>> >>>