| Message ID | 1449486028-29344-1-git-send-email-cedric.madianga@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Dec 07, 2015 at 12:00:28PM +0100, M'boumba Cedric Madianga wrote: > 'commit d8b468394fb7 ("dmaengine: Add STM32 DMA driver")' leads to the > following Smatch complaint: > > drivers/dma/stm32-dma.c:562 stm32_dma_issue_pending() > error: we previously assumed 'chan->desc' could be null (see line 560) > > So, this patch fixes the unchecked dereference of chan->desc by returning > operation not permitted error when stm32_dma_start_transfer() does not > succeed to allocate a virtual channel descriptor. Applied, thanks
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index 12f3a3e..047476a 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -437,7 +437,7 @@ static int stm32_dma_start_transfer(struct stm32_dma_chan *chan) if (!chan->desc) { vdesc = vchan_next_desc(&chan->vchan); if (!vdesc) - return 0; + return -EPERM; chan->desc = to_stm32_dma_desc(vdesc); chan->next_sg = 0; @@ -559,7 +559,7 @@ static void stm32_dma_issue_pending(struct dma_chan *c) if (!chan->busy) { if (vchan_issue_pending(&chan->vchan) && !chan->desc) { ret = stm32_dma_start_transfer(chan); - if ((chan->desc->cyclic) && (!ret)) + if ((!ret) && (chan->desc->cyclic)) stm32_dma_configure_next_sg(chan); } }
'commit d8b468394fb7 ("dmaengine: Add STM32 DMA driver")' leads to the following Smatch complaint: drivers/dma/stm32-dma.c:562 stm32_dma_issue_pending() error: we previously assumed 'chan->desc' could be null (see line 560) So, this patch fixes the unchecked dereference of chan->desc by returning operation not permitted error when stm32_dma_start_transfer() does not succeed to allocate a virtual channel descriptor. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com> --- Changes since v1: Explain what the patch fixes in the title (Vinod) Add Dan as reporter using Reported-by tag (Vinod) --- --- drivers/dma/stm32-dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)