4.17-stable review patch. If anyone has any objections, please let me know.
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From: Jason Wang jasowang@redhat.com
[ Upstream commit b13f9c6364373a1b9f71e9846dc4fb199296f926 ]
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: f88949138058 ("vhost: introduce O(1) vq metadata cache") Signed-off-by: Jason Wang jasowang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/vhost/vhost.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1556,9 +1556,12 @@ int vhost_init_device_iotlb(struct vhost 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);