Re: [PATCH] The sun50i_iommu_of_xlate() function didn't properly handle the case where of_find_device_by_node() returns NULL. This could lead to a NULL pointer dereference when accessing platform_get_drvdata(iommu_pdev) if the device node couldn't be found.
From: Robin Murphy <robin.murphy@arm.com>
Date: 2025-06-25 10:42:14
Also in:
linux-iommu, linux-sunxi, lkml
On 2025-06-24 9:35 am, Zhang Shurong wrote:
Add a WARN_ON() check to detect this condition and return -ENODEV when it occurs. This ensures proper error handling and helps diagnose incorrect device tree configurations at runtime.
Please look at how this op is called in of_iommu_xlate(), then at how the ops are registered by sun50i_iommu_probe(), and then clarify how you think the driver could ever be bound to a device which does not exist. Thanks, Robin.
quoted hunk ↗ jump to hunk
Fixes: 4100b8c229b3 ("iommu: Add Allwinner H6 IOMMU driver") Signed-off-by: Zhang Shurong <redacted> --- drivers/iommu/sun50i-iommu.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c index 76c9620af4bb..0f85850269ae 100644 --- a/drivers/iommu/sun50i-iommu.c +++ b/drivers/iommu/sun50i-iommu.c@@ -833,6 +833,9 @@ static int sun50i_iommu_of_xlate(struct device *dev, const struct of_phandle_args *args) { struct platform_device *iommu_pdev = of_find_device_by_node(args->np); + if (WARN_ON(!iommu_pdev)) + return -ENODEV; + unsigned id = args->args[0]; dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev));