The mm parameter in iommu_sva_bind_device() is intended for privileged
process perform bind() on behalf of other processes. This use case has
yet to be materialized, let alone potential security implications of
adding kernel hooks without explicit user consent.
In addition, with the agreement that IOASID allocation shall be subject
cgroup limit. It will be inline with misc cgroup proposal if IOASID
allocation as part of the SVA bind is limited to the current task.
Link: https://lore.kernel.org/linux-iommu/20210303160205.151d114e@jacob-builder/
Link: https://lore.kernel.org/linux-iommu/YFhiMLR35WWMW%2FHu@myrica/
Signed-off-by: Jacob Pan
---
drivers/dma/idxd/cdev.c | 2 +-
drivers/dma/idxd/init.c | 2 +-
drivers/iommu/iommu-sva-lib.c | 11 +++
drivers/iommu/iommu.c | 20 +---
drivers/misc/uacce/uacce.c| 2 +-
include/linux/iommu.h | 3 +--
6 files changed, 24 insertions(+), 16 deletions(-)
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index 21ec82bc47b6..8c3347c8930c 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -103,7 +103,7 @@ static int idxd_cdev_open(struct inode *inode, struct file
*filp)
filp->private_data = ctx;
if (device_pasid_enabled(idxd)) {
- sva = iommu_sva_bind_device(dev, current->mm, 0);
+ sva = iommu_sva_bind_device(dev, 0);
if (IS_ERR(sva)) {
rc = PTR_ERR(sva);
dev_err(dev, "pasid allocation failed: %d\n", rc);
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 82a0985ad6dc..a92fa625f3b5 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -305,7 +305,7 @@ static int idxd_enable_system_pasid(struct idxd_device
*idxd)
flags = IOMMU_SVA_BIND_SUPERVISOR;
- sva = iommu_sva_bind_device(>pdev->dev, NULL, flags);
+ sva = iommu_sva_bind_device(>pdev->dev, flags);
if (IS_ERR(sva)) {
dev_warn(>pdev->dev,
"iommu sva bind failed: %ld\n", PTR_ERR(sva));
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index bd41405d34e9..6e3d1a010d47 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -12,13 +12,13 @@ static DECLARE_IOASID_SET(iommu_sva_pasid);
/**
* iommu_sva_alloc_pasid - Allocate a PASID for the mm
- * @mm: the mm
* @min: minimum PASID value (inclusive)
* @max: maximum PASID value (inclusive)
*
- * Try to allocate a PASID for this mm, or take a reference to the existing one
- * provided it fits within the [@min, @max] range. On success the PASID is
- * available in mm->pasid, and must be released with iommu_sva_free_pasid().
+ * Try to allocate a PASID for the current mm, or take a reference to the
+ * existing one provided it fits within the [@min, @max] range. On success
+ * the PASID is available in the current mm->pasid, and must be released with
+ * iommu_sva_free_pasid().
* @min must be greater than 0, because 0 indicates an unused mm->pasid.
*
* Returns 0 on success and < 0 on error.
@@ -28,6 +28,9 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min,
ioasid_t max)
int ret = 0;
ioasid_t pasid;
+ if (mm != current->mm)
+ return -EINVAL;
+
if (min == INVALID_IOASID || max == INVALID_IOASID ||
min == 0 || max < min)
return -EINVAL;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index eefa541d8674..5bbc35c395a6 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -23,6 +23,7 @@
#include
#include
#include
+#include
#include
static struct kset *iommu_group_kset;
@@ -2959,15 +2960,14 @@ int iommu_aux_get_pasid(struct iommu_domain *domain,
struct device *dev)
EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
/**
- * iommu_sva_bind_device() - Bind a process address space to a device
+ * iommu_sva_bind_device() - Bind the current process address space to a device
* @dev: the device
- * @mm: the mm to bind, caller must hold a reference to it
* @flags: options for the bind operation defined as IOMMU_SVA_BIND_*
*
* Create a bond between device and address space, allowing the device to
access
* the mm using the returned PASID. If a bond already exists between @device
and
- * @mm, it is returned and an additional reference is taken. Caller must call
- * iommu_sva_unbind_device() to release each reference.
+ * the current mm, it is returned and an additional reference is taken. Caller
+ * must call iommu_sva_unbind_device() to release each reference.
*
* iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
* initialize the required SVA features.
@@ -2975,9 +2975,10 @@ EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
* On error, returns an ERR_PTR value.
*/
struct iommu_sva *
-iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, unsigned int
flags)
