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authorM'boumba Cedric Madianga <cedric.madianga@gmail.com>2015-12-07 12:00:28 +0100
committerVinod Koul <vinod.koul@intel.com>2015-12-10 09:45:22 +0530
commitaea08a5dfadf387153cdbbff89f775b0e19d32e4 (patch)
treee131357f4158ae6de8a7ce51b06983ca80c48dc1
parentb341b4a13ca2c6ea8a426a9befb4dec0d7040860 (diff)
dmaengine: stm32-dma: Fix unchecked deference of chan->desc
'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> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
-rw-r--r--drivers/dma/stm32-dma.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 12f3a3eddba9..047476a1383d 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);
}
}