diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2018-04-11 04:35:40 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-04-11 16:54:06 +0200 |
| commit | d14d2b78090c7de0557362b26a4ca591aa6a9faa (patch) | |
| tree | 94e3974bf7a5a5ea27d3cbc4c117792213ac6a3e | |
| parent | vhost: Fix vhost_copy_to_user() (diff) | |
| download | linux-d14d2b78090c7de0557362b26a4ca591aa6a9faa.tar.xz linux-d14d2b78090c7de0557362b26a4ca591aa6a9faa.zip | |
vhost: fix vhost_vq_access_ok() log check
Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log
when IOTLB is enabled") introduced a regression. The logic was
originally:
if (vq->iotlb)
return 1;
return A && B;
After the patch the short-circuit logic for A was inverted:
if (A || vq->iotlb)
return A;
return B;
This patch fixes the regression by rewriting the checks in the obvious
way, no longer returning A when vq->iotlb is non-NULL (which is hard to
understand).
Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@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.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index f44aead98d60..9a18535fafba 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1244,10 +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) { - int ret = vq_log_access_ok(vq, vq->log_base); + if (!vq_log_access_ok(vq, vq->log_base)) + return 0; - if (ret || vq->iotlb) - return ret; + /* Access validation occurs at prefetch time with IOTLB */ + if (vq->iotlb) + return 1; return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); } |