This is a note to let you know that I've just added the patch titled iommu: Check dev->iommu in iommu_dev_xxx functions to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iommu-check-dev-iommu-in-iommu_dev_xxx-functions.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d9d21f7665ec656e00ecb9712373d5a9beff6645 Author: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> Date: Wed Mar 3 17:36:11 2021 +0000 iommu: Check dev->iommu in iommu_dev_xxx functions [ Upstream commit b9abb19fa5fd2d8a4be61c6cd4b2a48aa1a17f9c ] The device iommu probe/attach might have failed leaving dev->iommu to NULL and device drivers may still invoke these functions resulting in a crash in iommu vendor driver code. Hence make sure we check that. Fixes: a3a195929d40 ("iommu: Add APIs for multiple domains per device") Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx> Link: https://lore.kernel.org/r/20210303173611.520-1-shameerali.kolothum.thodi@xxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0d9adce6d812..9b8664d388af 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2872,10 +2872,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_has_feature); int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; - if (ops && ops->dev_enable_feat) - return ops->dev_enable_feat(dev, feat); + if (ops->dev_enable_feat) + return ops->dev_enable_feat(dev, feat); + } return -ENODEV; } @@ -2888,10 +2890,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); */ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; - if (ops && ops->dev_disable_feat) - return ops->dev_disable_feat(dev, feat); + if (ops->dev_disable_feat) + return ops->dev_disable_feat(dev, feat); + } return -EBUSY; } @@ -2899,10 +2903,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; - if (ops && ops->dev_feat_enabled) - return ops->dev_feat_enabled(dev, feat); + if (ops->dev_feat_enabled) + return ops->dev_feat_enabled(dev, feat); + } return false; }