iommu: Return right value in iommu_sva_bind_device()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: iommu: Return right value in iommu_sva_bind_device() 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.

References

• https://git.kernel.org/stable/c/700f564758882db7c039dfba9443fe762561a3f8
• https://git.kernel.org/stable/c/cf34f8f66982a36e5cba0d05781b21ec9606b91e
• https://git.kernel.org/stable/c/2973b8e7d127754de9013177c41c0b5547406998
• https://git.kernel.org/stable/c/6325eab6c108fed27f60ff51852e3eac0ba23f3f
• https://git.kernel.org/stable/c/7388ae6f26c0ba95f70cc96bf9c5d5cb06c908b6
• https://git.kernel.org/stable/c/61a96da9649a6b6a1a5d5bde9374b045fdb5c12e
• https://git.kernel.org/stable/c/89e8a2366e3bce584b6c01549d5019c5cda1205e