[PATCH] dmaengine: fsl-edma: fix potential NULL pointer dereference in fsl_edma_tx_status()

[Andrew Chernyakov]

fsl_edma_desc_residue() dereferences fsl_chan->edesc, but it is checked
for NULL only in one of two places where fsl_edma_desc_residue() is
called from fsl_edma_tx_status().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrew Chernyakov <acherniakov@xxxxxxxxxxxxx>
---
 drivers/dma/fsl-edma-common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index a06a1575a2a5..fb712d85d556 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -330,7 +330,7 @@ enum dma_status fsl_edma_tx_status(struct dma_chan *chan,
 	if (fsl_chan->edesc && cookie == fsl_chan->edesc->vdesc.tx.cookie)
 		txstate->residue =
 			fsl_edma_desc_residue(fsl_chan, vdesc, true);
-	else if (vdesc)
+	else if (fsl_chan->edesc && vdesc)
 		txstate->residue =
 			fsl_edma_desc_residue(fsl_chan, vdesc, false);
 	else
-- 
2.35.1