xi-keyring

commit

c486ff3137e3b2f71806c3deb2d5f17c7af668a7

parent

b8204a6d85e93d71fa3806bdd3e6fe7f58b720f5

Author

Tobias Bengfort <tobias.bengfort@posteo.de>

Date

2026-03-05 11:13

app_id: use pidfd to protect against data races

see https://github.com/swaywm/sway/pull/3088#issuecomment-456078987 for
examples of possible attacks

Diffstat

2 files changed, 16 insertions, 7 deletions

diff --git a/xikeyring/app_id.py b/xikeyring/app_id.py

@@ -1,13 +1,21 @@
    1     1 import configparser
   -1     2 import selectors
    2     3 from pathlib import Path
    3     4 
    4     5 
    5    -1 def get_app_id(pid: int) -> str:
   -1     6 def get_app_id(pid: int, pidfd: int) -> str:
    6     7     path = Path('/proc') / str(pid) / 'root' / '.flatpak-info'
    7     8     config = configparser.ConfigParser()
    8     9     try:
    9    10         with path.open() as fh:
   10    11             config.read_file(fh)
   11    -1         return config['Application']['name']
   -1    12         app_id = config['Application']['name']
   12    13     except Exception:
   13    14         return ''
   -1    15 
   -1    16     with selectors.DefaultSelector() as sel:
   -1    17         sel.register(pidfd, selectors.EVENT_READ)
   -1    18         if sel.select(0) != []:
   -1    19             raise ValueError('Calling process has quit')
   -1    20 
   -1    21     return app_id

diff --git a/xikeyring/dbus.py b/xikeyring/dbus.py

@@ -116,18 +116,19 @@ class BaseDBusService:
  116   116         return True
  117   117 
  118   118     def get_app_id(self, conn, sender) -> str:
  119    -1         pid = conn.call_sync(
   -1   119         (cred,), fds = conn.call_with_unix_fd_list_sync(
  120   120             'org.freedesktop.DBus',
  121   121             '/org/freedesktop/DBus',
  122   122             'org.freedesktop.DBus',
  123    -1             'GetConnectionUnixProcessID',
   -1   123             'GetConnectionCredentials',
  124   124             GLib.Variant('(s)', [sender]),
  125    -1             GLib.VariantType('(u)'),
   -1   125             GLib.VariantType('(a{sv})'),
  126   126             Gio.DBusCallFlags.NONE,
  127   127             -1,
   -1   128             Gio.UnixFDList(),
  128   129             None,
  129    -1         )[0]
  130    -1         return get_app_id(pid)
   -1   130         )
   -1   131         return get_app_id(cred['ProcessID'], fds.get(cred['ProcessFD']))
  131   132 
  132   133 
  133   134 class DBusService(BaseDBusService):