summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJason Wang <jasowang@redhat.com>2018-03-29 16:00:04 +0800
committerDavid S. Miller <davem@davemloft.net>2018-03-29 16:22:47 -0400
commitd65026c6c62e7d9616c8ceb5a53b68bcdc050525 (patch)
treedccd59dd04aef986186afb3bb4ff279bebe245b7
parent58f101bf87e32753342a6924772c6ebb0fbde24a (diff)
downloadlinux-sh-d65026c6c62e7d9616c8ceb5a53b68bcdc050525.tar.gz
vhost: validate log when IOTLB is enabled
Vq log_base is the userspace address of bitmap which has nothing to do with IOTLB. So it needs to be validated unconditionally otherwise we may try use 0 as log_base which may lead to pin pages that will lead unexpected result (e.g trigger BUG_ON() in set_bit_to_user()). Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/vhost/vhost.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 5d5a9d9e66d3..5320039671b7 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1244,14 +1244,12 @@ static int vq_log_access_ok(struct vhost_virtqueue *vq,
/* Caller should have vq mutex and device mutex */
int vhost_vq_access_ok(struct vhost_virtqueue *vq)
{
- if (vq->iotlb) {
- /* When device IOTLB was used, the access validation
- * will be validated during prefetching.
- */
- return 1;
- }
- return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) &&
- vq_log_access_ok(vq, vq->log_base);
+ int ret = vq_log_access_ok(vq, vq->log_base);
+
+ if (ret || vq->iotlb)
+ return ret;
+
+ return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used);
}
EXPORT_SYMBOL_GPL(vhost_vq_access_ok);