[PATCH AUTOSEL 4.19 15/27] dmaengine: stm32-mdma: Fix a possible null-pointer dereference in stm32_mdma_irq_handler()

Sasha Levin
2019-08-20T13:42:35Z

From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 39c71a5b8212f4b502d9a630c6706ac723abd422 ]

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 <baijiaju1990@gmail.com>
Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
Link: https://lore.kernel.org/r/20190729020849.17971-1-baijiaju1990@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 06dd1725375e5..8c3c3e5b812a8 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1376,7 +1376,7 @@ 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;
}

--
2.20.1