The function returns NULL if the ring buffer doesn't contain enough
readable bytes to constitute a packet descriptor. The ring buffer's
write_index is in memory which is shared with the Hyper-V host, an
erroneous or malicious host could thus change its value and overturn
the result of hvs_stream_has_data().
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
---
net/vmw_vsock/hyperv_transport.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index e111e13b66604..943352530936e 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -603,6 +603,8 @@ static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
if (need_refill) {
hvs->recv_desc = hv_pkt_iter_first_raw(hvs->chan);
+ if (!hvs->recv_desc)
+ return -ENOBUFS;
ret = hvs_update_recv_data(hvs);
if (ret)
return ret;
--
2.25.1
