mrrl

commit 4286a49ad4df0c4d1fb5263ba6e90c7f7648f376
parent c5396f3a84e5fb7d998073b11f93317e735d76b4
Author: Jan Pobříslo <ccx@te2000.cz>
Date:   Thu, 22 Feb 2024 08:42:53 +0100

Set up uid/gid mapping

Diffstat:
M
userns_sandbox.py
 | 
15
++++++++++++++-

1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/userns_sandbox.py b/userns_sandbox.py
@@ -200,14 +200,27 @@ def exec_command(argv):
     raise SystemExit(127)
 
 
+def map_uid_gid(orig_uid, orig_gid):
+    with open('/proc/self/uid_map', 'wt') as f:
+        f.write(f'{orig_uid} {orig_uid} 1\n')
+
+    with open('/proc/self/gid_map', 'wt') as f:
+        f.write(f'{orig_gid} {orig_gid} 1\n')
+
+    os.setuid(orig_uid)
+    os.setgid(orig_gid)
+
+
 def pidns_run(unshare_flags, continuation, *args, **kwargs):
     (parent_rfd, parent_wfd) = os.pipe()
     nonblock_cloexec(parent_rfd)
     nonblock_cloexec(parent_wfd)
+    orig_uid = os.getuid()
+    orig_gid = os.getgid()
     if libc.unshare(CLONE_NEWPID | unshare_flags) != 0:
         raise c_error()
     if unshare_flags & CLONE_NEWUSER:
-        os.setuid(0)
+        map_uid_gid(orig_uid, orig_gid)
     fork_pid = os.fork()
     if fork_pid == 0:
         # child