[PATCH][next] dmaengine: at_xdmac: Use struct_size() in devm_kzalloc()

Gustavo A. R. Silva
2021-12-08T00:04:50Z

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 worst scenario, could lead to heap overflows.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/dma/at_xdmac.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 275a76f188ae..e42dede5b243 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -2031,7 +2031,7 @@ static int __maybe_unused atmel_xdmac_resume(struct device *dev)
static int at_xdmac_probe(struct platform_device *pdev)
{
struct at_xdmac *atxdmac;
- int irq, size, nr_channels, i, ret;
+ int irq, nr_channels, i, ret;
void __iomem *base;
u32 reg;

@@ -2056,9 +2056,9 @@ static int at_xdmac_probe(struct platform_device *pdev)
return -EINVAL;
}

- size = sizeof(*atxdmac);
- size += nr_channels * sizeof(struct at_xdmac_chan);
- atxdmac = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+ atxdmac = devm_kzalloc(&pdev->dev,
+ struct_size(atxdmac, chan, nr_channels),
+ GFP_KERNEL);
if (!atxdmac) {
dev_err(&pdev->dev, "can't allocate at_xdmac structure\n");
return -ENOMEM;
--
2.27.0