run_in_fork should never propagate exceptions from the child

Otherwise an exception handler in the caller may be invoked in
unexpected ways. If an exception occurs, exit non-zero and reraise in
the parent with less detail.

1 files changed, 12 insertions, 6 deletions

diff --git a/linuxnamespaces/__init__.py b/linuxnamespaces/__init__.py
index a39f43a..8adf45b 100644
--- a/linuxnamespaces/__init__.py
+++ b/linuxnamespaces/__init__.py
@@ -33,9 +33,12 @@ class run_in_fork:
         self.efd = EventFD()
         self.pid = os.fork()
         if self.pid == 0:
-            self.efd.read()
-            self.efd.close()
-            function()
+            try:
+                self.efd.read()
+                self.efd.close()
+                function()
+            except:
+                os._exit(1)
             os._exit(0)
 
     def start(self) -> None:
@@ -80,9 +83,12 @@ class async_run_in_fork:
             self.efd = EventFD()
             self.pid = os.fork()
             if self.pid == 0:
-                self.efd.read()
-                self.efd.close()
-                function()
+                try:
+                    self.efd.read()
+                    self.efd.close()
+                    function()
+                except:
+                    os._exit(1)
                 os._exit(0)
             watcher.add_child_handler(self.pid, self._child_callback)