From 6d7545eabe55dc5001d8b5abfa3587a15c269c66 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: 52f88933c005 ("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 a502f1af4a213..ed3114556fdaf 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); -- 2.39.5