2021-09-29 22:50:15

by Gustavo A. R. Silva

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

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 <[email protected]>
---
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

2021-09-30 21:54:34

by Kees Cook

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

On Wed, Sep 29, 2021 at 05:29:22PM -0500, Gustavo A. R. Silva wrote:
> 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 <[email protected]>

Looks right to me.

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2021-10-01 08:16:03

by Amelie Delaunay

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

On 9/30/21 12:29 AM, Gustavo A. R. Silva wrote:
> 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 <[email protected]>

Reviewed-by: Amelie Delaunay <[email protected]>

> ---
> 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;
>

2021-10-01 13:02:20

by Vinod Koul

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

On 29-09-21, 17:29, Gustavo A. R. Silva wrote:
> 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.

Applied, thanks

--
~Vinod