From: Yang Yingliang <yangyingliang@xxxxxxxxxx> [ Upstream commit d9ed8af1dee37f181096631fb03729ece98ba816 ] It will cause null-ptr-deref when using 'res', if platform_get_resource() returns NULL, so move using 'res' after devm_ioremap_resource() that will check it to avoid null-ptr-deref. And use devm_platform_get_and_ioremap_resource() to simplify code. Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220425114136.2649310-1-yangyingliang@xxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index df24bbe3ea4f..6b41fe229a05 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -2123,11 +2123,10 @@ static int arm_smmu_device_probe(struct platform_device *pdev) if (err) return err; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - ioaddr = res->start; - smmu->base = devm_ioremap_resource(dev, res); + smmu->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(smmu->base)) return PTR_ERR(smmu->base); + ioaddr = res->start; /* * The resource size should effectively match the value of SMMU_TOP; * stash that temporarily until we know PAGESIZE to validate it with. -- 2.35.1