vyos.utils: T8977: do not fail when a listening process vanishes mid-check

The list of listening sockets is a snapshot, and the owning process was
looked up afterwards. A process exiting in between, or one belonging to
another user when we do not run privileged, raised an exception that
escaped and aborted the conf-mode script asking whether a port is taken.
Neither case can be the service being looked for, so such a socket is
skipped now.

1 files changed, 9 insertions, 1 deletions

diff --git a/python/vyos/utils/network.py b/python/vyos/utils/network.py
index e4d98777b..e5fa398cf 100644
--- a/python/vyos/utils/network.py
+++ b/python/vyos/utils/network.py
@@ -450,6 +450,8 @@ def is_listen_port_bind_service(port: int, service: str, address: str = None) ->
     """
     from psutil import net_connections as connections
     from psutil import Process as process
+    from psutil import AccessDenied
+    from psutil import NoSuchProcess
     from ipaddress import ip_address
 
     has_address = bool(address)
@@ -470,7 +472,13 @@ def is_listen_port_bind_service(port: int, service: str, address: str = None) ->
         if pid is None:
             continue
 
-        pid_name = process(pid).name()
+        # The socket table is a snapshot - the process behind it may be gone
+        # by now, or belong to another user. Neither can be our service.
+        try:
+            pid_name = process(pid).name()
+        except (NoSuchProcess, AccessDenied):
+            continue
+
         pid_port = addr.port
 
         # Ignore address check when service listening on "any address",