Messages in this thread Patch in this message | | | From | Jerry Snitselaar <> | Subject | [RFC PATCH v2] iommu: Add sanity check to iommu_sva_bind_device() | Date | Thu, 13 Oct 2022 10:13:57 -0700 |
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iommu_sva_bind_device() should only be called if iommu_dev_enable_feature() succeeded. There has been one case already where that hasn't been the case, which resulted in a null pointer deref in dev_iommu_ops(). To avoid that happening in the future if another driver makes that mistake, sanity check dev->iommu and dev->iommu->iommu_dev prior to calling dev_iommu_ops().
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com> --- v2: Fix summary, and typo in dev_warn()
drivers/iommu/iommu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 4893c2429ca5..c745e935f26a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2746,7 +2746,15 @@ iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) { struct iommu_group *group; struct iommu_sva *handle = ERR_PTR(-EINVAL); - const struct iommu_ops *ops = dev_iommu_ops(dev); + const struct iommu_ops *ops; + + if (!dev->iommu || !dev->iommu->iommu_dev) { + dev_warn(dev, "%s called without checking success of iommu_dev_enable_feature?\n", + __func__); + return ERR_PTR(-ENODEV); + } + + ops = dev_iommu_ops(dev); if (!ops->sva_bind) return ERR_PTR(-ENODEV); -- 2.37.2
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