dmaengine: fsl-edma: use struct_size() helper

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.

Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Link: https://lore.kernel.org/r/20230821073600.4078584-1-liaoyu15@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
index e407696..8c9ee9f 100644 (file)
--- a/drivers/dma/fsl-edma.c
+++ b/drivers/dma/fsl-edma.c
@@ -270,9 +270,8 @@ static int fsl_edma_probe(struct platform_device *pdev)
        struct device_node *np = pdev->dev.of_node;
        struct fsl_edma_engine *fsl_edma;
        const struct fsl_edma_drvdata *drvdata = NULL;
-       struct fsl_edma_chan *fsl_chan;
        struct edma_regs *regs;
-       int len, chans;
+       int chans;
        int ret, i;
 
        if (of_id)
@@ -288,8 +287,8 @@ static int fsl_edma_probe(struct platform_device *pdev)
                return ret;
        }
 
-       len = sizeof(*fsl_edma) + sizeof(*fsl_chan) * chans;
-       fsl_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
+       fsl_edma = devm_kzalloc(&pdev->dev, struct_size(fsl_edma, chans, chans),
+                               GFP_KERNEL);
        if (!fsl_edma)
                return -ENOMEM;