Commit b13f9c63 authored Aug 08, 2018 by Jason Wang Committed by David S. Miller Aug 08, 2018

vhost: reset metadata cache when initializing new IOTLB



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@syzkaller.appspotmail.com>
Fixes: f8894913 ("vhost: introduce O(1) vq metadata cache")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0dcb8225

drivers/vhost/vhost.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -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);