[PATCH 2/7] vfio-container-base: Introduce vfio_container_get_iova_ranges() helper

[Eric Auger <eric.auger@redhat.com>]

Introduce vfio_container_get_iova_ranges() to retrieve the usable
IOVA regions of the base container and use it in the Host IOMMU
device implementations of get_iova_ranges() callback.

We also fix a UAF bug as the list was shallow copied while
g_list_free_full() was used both on the single call site, in
virtio_iommu_set_iommu_device() but also in
vfio_container_instance_finalize(). Instead use g_list_copy_deep.

Fixes: cf2647a76e ("virtio-iommu: Compute host reserved regions")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Cédric Le Goater <clg@redhat.com>
---
 include/hw/vfio/vfio-container-base.h |  2 ++
 hw/vfio/container-base.c              | 15 +++++++++++++++
 hw/vfio/container.c                   |  8 +-------
 hw/vfio/iommufd.c                     |  8 +-------
 4 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index 419e45ee7a..45d7c40fce 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -86,6 +86,8 @@ int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
 int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                    VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp);
 
+GList *vfio_container_get_iova_ranges(const VFIOContainerBase *bcontainer);
+
 #define TYPE_VFIO_IOMMU "vfio-iommu"
 #define TYPE_VFIO_IOMMU_LEGACY TYPE_VFIO_IOMMU "-legacy"
 #define TYPE_VFIO_IOMMU_SPAPR TYPE_VFIO_IOMMU "-spapr"
diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
index 50b1664f89..809b157674 100644
--- a/hw/vfio/container-base.c
+++ b/hw/vfio/container-base.c
@@ -83,6 +83,21 @@ int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                                                errp);
 }
 
+static gpointer copy_iova_range(gconstpointer src, gpointer data)
+{
+     Range *source = (Range *)src;
+     Range *dest = g_new(Range, 1);
+
+     range_set_bounds(dest, range_lob(source), range_upb(source));
+     return dest;
+}
+
+GList *vfio_container_get_iova_ranges(const VFIOContainerBase *bcontainer)
+{
+    assert(bcontainer);
+    return g_list_copy_deep(bcontainer->iova_ranges, copy_iova_range, NULL);
+}
+
 static void vfio_container_instance_finalize(Object *obj)
 {
     VFIOContainerBase *bcontainer = VFIO_IOMMU(obj);
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 2e7ecdf10e..2ad57cd845 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -1169,15 +1169,9 @@ static GList *
 hiod_legacy_vfio_get_iova_ranges(HostIOMMUDevice *hiod, Error **errp)
 {
     VFIODevice *vdev = hiod->agent;
-    GList *l = NULL;
 
     g_assert(vdev);
-
-    if (vdev->bcontainer) {
-        l = g_list_copy(vdev->bcontainer->iova_ranges);
-    }
-
-    return l;
+    return vfio_container_get_iova_ranges(vdev->bcontainer);
 }
 
 static void vfio_iommu_legacy_instance_init(Object *obj)
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index c2f158e603..890d8d6a38 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -647,15 +647,9 @@ static GList *
 hiod_iommufd_vfio_get_iova_ranges(HostIOMMUDevice *hiod, Error **errp)
 {
     VFIODevice *vdev = hiod->agent;
-    GList *l = NULL;
 
     g_assert(vdev);
-
-    if (vdev->bcontainer) {
-        l = g_list_copy(vdev->bcontainer->iova_ranges);
-    }
-
-    return l;
+    return vfio_container_get_iova_ranges(vdev->bcontainer);
 }
 
 static void hiod_iommufd_vfio_class_init(ObjectClass *oc, void *data)
-- 
2.41.0