From 59f9f2c76fe16026f293d87ae6001f80ccab420b 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 [ 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- 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 244e5256c526..3cf74f54c7a1 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1578,9 +1578,12 @@ 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); -- 2.20.1