podman-container-tools/podman · error

internal error: path too long

Error message

internal error: path too long

What it means

For each entry in a preexec-hooks dir, do_preexec_hooks_dir() composes '<dir>/<filename>' into a char path[PATH_MAX] with snprintf and treats a return of PATH_MAX as overflow (pkg/rootless/rootless_linux.c:461-465). Because filenames are capped at NAME_MAX (255), in practice the hooks directory path itself must be near PATH_MAX (4096) to trigger this. It is an internal sanity assertion, not an expected runtime error.

Source

Thrown at pkg/rootless/rootless_linux.c:464

        continue;

      strncpy (buffer + nfiles * (NAME_MAX + 1), de->d_name, NAME_MAX + 1);
      nfiles++;
    }

  qsort (buffer, nfiles, NAME_MAX + 1, (int (*)(const void *, const void *)) strcmp);

  for (i = 0; i < nfiles; i++)
    {
      const char *fname = buffer + i * (NAME_MAX + 1);
      char path[PATH_MAX];
      struct stat st;
      int ret;

      ret = snprintf (path, PATH_MAX, "%s/%s", dir, fname);
      if (ret == PATH_MAX)
        {
          fprintf (stderr, "internal error: path too long\n");
          exit (EXIT_FAILURE);
        }

      ret = stat (path, &st);
      if (ret < 0)
        {
          /* Ignore the failure if the file was deleted.  */
          if (errno == ENOENT)
            continue;

          fprintf (stderr, "stat %s: %m\n", path);
          exit (EXIT_FAILURE);
        }

      /* Not an executable.  */
      if ((st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
        continue;

View on GitHub (pinned to a2409076ef)

Solutions

1. Shorten the hooks dir path: keep hooks in the default locations (/etc/containers/pre-exec-hooks, LIBEXECPODMAN/pre-exec-hooks)
2. Print ${#PODMAN_PREEXEC_HOOKS_DIR} and ensure it is well under 4096 - 256 characters
3. Unset PODMAN_PREEXEC_HOOKS_DIR or remove /etc/containers/podman_preexec_hooks.txt to bypass hooks entirely
4. If triggered without an obviously long path, report upstream - it indicates memory corruption or a patched build

# Reject absurd hook dir paths before podman scans them
d="${PODMAN_PREEXEC_HOOKS_DIR:-}"
if [ -n "$d" ] && [ "${#d}" -ge 3800 ]; then
  echo "preexec hooks dir path too long: ${#d} chars" >&2
  exit 1
fi

When it happens

Trigger: A hooks directory (e.g. via PODMAN_PREEXEC_HOOKS_DIR) deployed at a path roughly 4090+ characters long, or a symlink-resolved dir path of that length; deliberate path fuzzing of the env var.

Common situations: Never seen in normal packaging; only with scripted generation of absurdly deep directory trees or hostile environment fuzzing. Note the upstream check is 'ret == PATH_MAX' where 'ret >= PATH_MAX' would be stricter, so it is marked 'internal error'.

Related errors

• internal error: namespace path too long
• invalid value for XDG_RUNTIME_DIR: %m
• malloc: %m
• waitpid: %m
• opendir %s: %m

AI-assisted analysis of podman-container-tools/podman@a2409076ef (2026-08-15). Data as JSON: /api/errors/5aed79859061dc67. Report an issue: GitHub.