RE: [PATCH 1/1] iommu: Return right value in iommu_sva_bind_device()

[Tian, Kevin]

> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Tuesday, May 28, 2024 12:25 PM
> 
> iommu_sva_bind_device() should return either a sva bond handle or an
> ERR_PTR value in error cases. Existing drivers (idxd and uacce) only
> check the return value with IS_ERR(). This could potentially lead to
> a kernel NULL pointer dereference issue if the function returns NULL
> instead of an error pointer.
> 
> In reality, this doesn't cause any problems because iommu_sva_bind_device()
> only returns NULL when the kernel is not configured with
> CONFIG_IOMMU_SVA.
> In this case, iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) will
> return an error, and the device drivers won't call iommu_sva_bind_device()
> at all.
> 
> Fixes: 26b25a2b98e4 ("iommu: Bind process address spaces to devices")
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>