From: Jason Gunthorpe <jgg@nvidia.com>
Date: Wed, 27 Mar 2024 10:41:39 -0300
Subject: iommu: Validate the PASID in iommu_attach_device_pasid()
Git-commit: c404f55c26fc23c70a9f2262f3f36a69fc46289b
Patch-mainline: v6.9-rc2
References: jsc#PED-10968 bsc#1244100

The SVA code checks that the PASID is valid for the device when assigning
the PASID to the MM, but the normal PAGING related path does not check it.

Devices that don't support PASID or PASID values too large for the device
should not invoke the driver callback. The drivers should rely on the
core code for this enforcement.

Fixes: 16603704559c7a68 ("iommu: Add attach/detach_dev_pasid iommu interfaces")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/0-v1-460705442b30+659-iommu_check_pasid_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/iommu.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 098869007c69..a95a483def2d 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3354,6 +3354,7 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 {
 	/* Caller must be a probed driver on dev */
 	struct iommu_group *group = dev->iommu_group;
+	struct group_device *device;
 	void *curr;
 	int ret;
 
@@ -3363,10 +3364,18 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 	if (!group)
 		return -ENODEV;
 
-	if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner)
+	if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner ||
+	    pasid == IOMMU_NO_PASID)
 		return -EINVAL;
 
 	mutex_lock(&group->mutex);
+	for_each_group_device(group, device) {
+		if (pasid >= device->dev->iommu->max_pasids) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+	}
+
 	curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
 	if (curr) {
 		ret = xa_err(curr) ? : -EBUSY;

