We need to reset metadata cache during new IOTLB initialization,
otherwise the stale pointers to previous IOTLB may be still accessed
which will lead a use after free.
Reported-by: syzbot+c51e6736a1bf614b3272@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache")
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/vhost/vhost.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a502f1a..ed31145 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1560,9 +1560,12 @@ int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled)
d->iotlb = niotlb;
for (i = 0; i < d->nvqs; ++i) {
- mutex_lock(&d->vqs[i]->mutex);
- d->vqs[i]->iotlb = niotlb;
- mutex_unlock(&d->vqs[i]->mutex);
+ struct vhost_virtqueue *vq = d->vqs[i];
+
+ mutex_lock(&vq->mutex);
+ vq->iotlb = niotlb;
+ __vhost_vq_meta_reset(vq);
+ mutex_unlock(&vq->mutex);
}
vhost_umem_clean(oiotlb);
--
2.7.4
