[PATCH] dma: stm32-mdma: Fix a possible null-pointer dereference in stm32_mdma_irq_handler()

[Jia-Ju Bai]

In stm32_mdma_irq_handler(), chan is checked on line 1368.
When chan is NULL, it is still used on line 1369:
    dev_err(chan2dev(chan), "MDMA channel not initialized\n");

Thus, a possible null-pointer dereference may occur.

To fix this bug, "dev_dbg(mdma2dev(dmadev), ...)" is used instead.

Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com>
---
 drivers/dma/stm32-mdma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index d6e919d3936a..1311de74bfdd 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1366,7 +1366,7 @@ static irqreturn_t stm32_mdma_irq_handler(int irq, void 
*devid)
 
        chan = &dmadev->chan[id];
        if (!chan) {
-               dev_err(chan2dev(chan), "MDMA channel not initialized\n");
+               dev_dbg(mdma2dev(dmadev), "MDMA channel not initialized\n");
                goto exit;
        }
 
-- 
2.17.0