podman-container-tools/podman · error

save socket listen environments error: %m

Error message

save socket listen environments error: %m

What it means

When podman is socket-activated (LISTEN_PID equals getpid() and LISTEN_FDS is set), the C preamble strdups LISTEN_PID, LISTEN_FDS and LISTEN_FDNAMES into saved globals so the socket environment survives the later re-exec into the user namespace (pkg/rootless/rootless_linux.c:799-808). This message means one of the strdup calls returned NULL (ENOMEM) and the process _exits immediately.

Source

Thrown at pkg/rootless/rootless_linux.c:806

  if (geteuid () != 0 || getenv ("_CONTAINERS_USERNS_CONFIGURED") == NULL)
    do_preexec_hooks(argv, argc);

  listen_pid = getenv("LISTEN_PID");
  listen_fds = getenv("LISTEN_FDS");
  listen_fdnames = getenv("LISTEN_FDNAMES");

  if (listen_pid != NULL && listen_fds != NULL && strtol(listen_pid, NULL, 10) == getpid())
    {
      // save systemd socket environment for rootless child
      do_socket_activation = true;
      saved_systemd_listen_pid = strdup(listen_pid);
      saved_systemd_listen_fds = strdup(listen_fds);
      if (listen_fdnames != NULL)
        saved_systemd_listen_fdnames = strdup(listen_fdnames);
      if (saved_systemd_listen_pid == NULL
          || saved_systemd_listen_fds == NULL)
        {
          fprintf (stderr, "save socket listen environments error: %m\n");
          _exit (EXIT_FAILURE);
        }
    }

  /* Shortcut.  If we are able to join the existing namespace, do it now so we
     don't need to re-exec.  First try using namespace file handles, then fall back
     to the pause.pid approach for older kernels.  */
  xdg_runtime_dir = getenv ("XDG_RUNTIME_DIR");
  if (geteuid () != 0 && xdg_runtime_dir && xdg_runtime_dir[0] && can_use_shortcut (argv))
    {
      cleanup_free char *cwd = NULL;
      cleanup_close int userns_fd = -1;
      cleanup_close int mntns_fd = -1;
      cleanup_close int fd = -1;
      long pid;
      char buf[12];
      uid_t uid;
      gid_t gid;

View on GitHub (pinned to a2409076ef)

Solutions

1. Raise or remove the memory limit on the socket-activated units: 'systemctl edit podman.service' and set/increase MemoryMax
2. Check for OOM events around the failure: 'journalctl -u podman.socket -u podman.service -k'
3. Retry after relieving memory pressure - the condition is transient
4. If limits are generous and it persists, report upstream with systemd unit overrides attached

Example fix

# before
# podman.service has MemoryMax=32M; API connections die with
# 'save socket listen environments error: Cannot allocate memory'

# after
$ sudo systemctl edit podman.service
[Service]
MemoryMax=infinity
$ sudo systemctl daemon-reload && sudo systemctl restart podman.socket

# For socket-activated API usage, sanity-check limits in the unit
systemctl show podman.service -p MemoryMax -p LimitAS
# ensure they are unlimited or generous before enabling the socket

When it happens

Trigger: systemd socket activation of podman.socket/podman.service combined with memory exhaustion: MemoryMax on the service, RLIMIT_AS, or host OOM at connection time.

Common situations: A tight MemoryMax= or memory cgroup limit on the podman systemd units; memory pressure on hosts running the podman API socket for many concurrent connections; virtually nothing else triggers strdup failure for these short strings.

Related errors

• malloc: %m
• unable to print to string
• realloc buffer: %m
• cannot retrieve cmd line
• cannot read argv: %m

AI-assisted analysis of podman-container-tools/podman@a2409076ef (2026-08-15). Data as JSON: /api/errors/42600d951782927c. Report an issue: GitHub.