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dmaengine: at_xdmac: Use struct_size() in devm_kzalloc()

PATCH Applied Gustavo A. R. Silva 3 participants 3 messages Dec 8, 2021 – Dec 13, 2021

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dmaengine Microchip AT91 DMA drivers
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Gustavo A. R. Silva

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#0 lore raw

PATCH 1/1 dmaengine: at_xdmac: Use struct_size() 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 worst 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/at_xdmac.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
drivers/dma/at_xdmac.c +4 -4
index 275a76f188ae..e42dede5b243 100644
@@ -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;
Signature · 1 line
2.27.0
maintainer Applied
#2 lore raw
In reply to Gustavo A. R. Silva
Quoted 3 lines · Gustavo A. R. Silva

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.

Applied, thanks

Signature · 1 line
~Vinod