agent: don't attempt to read from the device if it was released

if vdi_port_read_buf_process failes, we detach the agent and also release
the read buffer. We shouldn't try reading from the device afterwards.

1 files changed, 3 insertions, 1 deletions

diff --git a/server/reds.c b/server/reds.c
index 8d6dbfb7..53f0a396 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -831,7 +831,9 @@ static void vdi_port_read_buf_unref(VDIReadBuf *buf)
         ring was empty. So we call it again so it can complete its work if
         necessary. Note that since we can be called from spice_char_device_wakeup
         this can cause recursion, but we have protection for that */
-        spice_char_device_wakeup(reds->agent_state.base);
+        if (reds->agent_state.base) {
+            spice_char_device_wakeup(reds->agent_state.base);
+        }
     }
 }