From b13f9c6364373a1b9f71e9846dc4fb199296f926 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 8 Aug 2018 11:43:04 +0800 Subject: [PATCH] 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: f88949138058 ("vhost: introduce O(1) vq metadata cache") Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- 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 a502f1af4a21..ed3114556fda 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);