[Qemu-devel] [PATCH RFC for-2.2] virtio-blk: force 1st s/g to match header

["Michael S. Tsirkin" <mst@redhat.com>]

We leak cpu mappings when 1st s/g is not exactly the
header. As we don't set ANY_LAYOUT, we can at this point
simply assert the correct length.

This will have to be fixed once ANY_LAYOUT is set.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

Untested: posting for early feedback.

 hw/block/virtio-blk.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index b19b102..1404b3f 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -381,6 +381,12 @@ void virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
         exit(1);
     }
 
+    /* We don't advertize ANY_LAYOUT, so first s/g is exactly the header. */
+    if (iov[0].iov_len != sizeof(req->out)) {
+        error_report("virtio-blk request outhdr too long");
+        exit(1);
+    }
+
     iov_discard_front(&iov, &out_num, sizeof(req->out));
 
     if (in_num < 1 ||
-- 
MST