From: Jiang Liu <jiang.liu@xxxxxxxxxx>
On error recovery path in function vfio_create_group(), it should
unregister the IOMMU notifier for the new VFIO group. Otherwise it may
cause invalid memory access later when handling bus notifications.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
drivers/vfio/vfio.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 17830c9..3359ec2 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -191,6 +191,17 @@ static void vfio_container_put(struct vfio_container *container)
kref_put(&container->kref, vfio_container_release);
}
+static void vfio_group_unlock_and_free(struct vfio_group *group)
+{
+ mutex_unlock(&vfio.group_lock);
+ /*
+ * Unregister outside of lock. A spurious callback is harmless now
+ * that the group is no longer in vfio.group_list.
+ */
+ iommu_group_unregister_notifier(group->iommu_group, &group->nb);
+ kfree(group);
+}
+
/**
* Group objects - create, release, get, put, search
*/
@@ -229,8 +240,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
minor = vfio_alloc_group_minor(group);
if (minor < 0) {
- mutex_unlock(&vfio.group_lock);
- kfree(group);
+ vfio_group_unlock_and_free(group);
return ERR_PTR(minor);
}
@@ -239,8 +249,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
if (tmp->iommu_group == iommu_group) {
vfio_group_get(tmp);
vfio_free_group_minor(minor);
- mutex_unlock(&vfio.group_lock);
- kfree(group);
+ vfio_group_unlock_and_free(group);
return tmp;
}
}
@@ -249,8 +258,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
group, "%d", iommu_group_id(iommu_group));
if (IS_ERR(dev)) {
vfio_free_group_minor(minor);
- mutex_unlock(&vfio.group_lock);
- kfree(group);
+ vfio_group_unlock_and_free(group);
return (struct vfio_group *)dev; /* ERR_PTR */
}
@@ -274,16 +282,7 @@ static void vfio_group_release(struct kref *kref)
device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor));
list_del(&group->vfio_next);
vfio_free_group_minor(group->minor);
-
- mutex_unlock(&vfio.group_lock);
-
- /*
- * Unregister outside of lock. A spurious callback is harmless now
- * that the group is no longer in vfio.group_list.
- */
- iommu_group_unregister_notifier(group->iommu_group, &group->nb);
-
- kfree(group);
+ vfio_group_unlock_and_free(group);
}
static void vfio_group_put(struct vfio_group *group)
--
1.7.9.5
--
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