pthbs

commit 0703677ef8750f39eb8007de9f7031ebec11ee14
parent d3f9e2c7fb637a3a5fda06a09f4d00c409e87a0a
Author: Jan Pobříslo <ccx@te2000.cz>
Date:   Thu, 22 Feb 2024 08:13:07 +0100

Mount /dev conditionally

Diffstat:
M
userns_sandbox.py
 | 
16
++++++++++++----

1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/userns_sandbox.py b/userns_sandbox.py
@@ -93,6 +93,8 @@ _umount.argtypes = (ctypes.c_char_p,)
 
 
 def c_path(path):
+    if path is None:
+        return path
     if isinstance(path, pathlib.PosixPath):
         path = path.as_posix()
     if isinstance(path, str):
@@ -141,7 +143,7 @@ def bind_mount(
     return mount(
         source,
         target,
-        "",
+        None,
         (
             MountFlag.BIND
             | (0 if write else MountFlag.RDONLY)
@@ -252,7 +254,7 @@ class MountTMPFS:
 class MountBind:
     src: pathlib.PosixPath
     dst: pathlib.PosixPath
-    write: bool
+    write: bool = False
 
     def __post_init__(self):
         assert isinstance(self.src, pathlib.PosixPath)
@@ -338,11 +340,17 @@ class Settings:
 
 def sandbox_run(settings, command):
     mount('proc', settings.root / 'proc', 'proc', MountFlag.NOSUID | MountFlag.NODEV)
-    mount('/dev', settings.root / 'dev', "", MountFlag.BIND | MountFlag.NOSUID)
-    mountpoints = list(command.extra_mount)
+    if not (settings.root / 'dev/null').is_char_device():
+        mount('/dev', settings.root / 'dev', None, (MountFlag.BIND | MountFlag.NOSUID))
+
+    mountpoints = [
+        MountTMPFS(relpath('/dev/shm')),
+    ]
+    mountpoints.extend(settings.extra_mount)
     mountpoints.append(MountBind(settings.versions, settings.versions.relative_to('/')))
     for m in mountpoints:
         m.mount(settings.root)
+
     os.chroot(str(settings.root))
     os.chdir('/')
     exec_command(command)