[PATCH][next] dmaengine: stm32-mdma: Use struct_size() helper in devm_kzalloc()

From: Gustavo A. R. Silva
Date: Wed Sep 29 2021 - 18:25:20 EST


Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worse scenario, could lead to heap overflows.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
drivers/dma/stm32-mdma.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 18cbd1e43c2e..d30a4a28d3bf 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1566,7 +1566,8 @@ static int stm32_mdma_probe(struct platform_device *pdev)
if (count < 0)
count = 0;

- dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev) + sizeof(u32) * count,
+ dmadev = devm_kzalloc(&pdev->dev,
+ struct_size(dmadev, ahb_addr_masks, count),
GFP_KERNEL);
if (!dmadev)
return -ENOMEM;
--
2.27.0