Tyson Smith [:tsmith] Reporter
	Description • 7 years ago

When launching Firefox via Python using subprocess.Popen() we see Firefox process hanging around. We call terminate() (and also tried kill()) and when calling wait() on the process it returns a return code as if the process has terminated. Checking the running processes there is still a process hanging around. This happens intermittently and we cannot consistently reproduce. It seems to happen often on our fuzzing machines.

truber was able to get a back trace from one of the hanging processes. So far we have seen this on ASan opts builds with e10s disabled. It seem similar to bug 1341621

	Andrew McCreight [:mccr8]
	Comment 1 • 7 years ago

Just based on the stack, it looks more like an ASan bug, but I figured we should have a bugzilla bug for this issue.

	Eric Rahm [:erahm]
	Comment 2 • 7 years ago

(In reply to Andrew McCreight [:mccr8] from comment #1)
> Just based on the stack, it looks more like an ASan bug, but I figured we
> should have a bugzilla bug for this issue.

Arguably this is a bug in both ASAN and in glib when fork/execing processes. They could just change their file descriptor closing code to brute force rather than enumerating the proc directory (and allocating).

	Eric Rahm [:erahm]
	Comment 3 • 7 years ago

(In reply to Eric Rahm [:erahm] from comment #2)
> (In reply to Andrew McCreight [:mccr8] from comment #1)
> > Just based on the stack, it looks more like an ASan bug, but I figured we
> > should have a bugzilla bug for this issue.
> 
> Arguably this is a bug in both ASAN and in glib when fork/execing processes.
> They could just change their file descriptor closing code to brute force
> rather than enumerating the proc directory (and allocating).

glib already has a bug for this [1], I'll add links to our Fx bugs.

[1] https://bugzilla.gnome.org/show_bug.cgi?id=738620

	Eric Rahm [:erahm]
	Comment 4 • 7 years ago

Bug filed for ASAN [1] as well.

[1] https://github.com/google/sanitizers/issues/774

	Nathan Froyd [:froydnj]
	Comment 5 • 7 years ago

The upstream asan bug is fixed, I'm going to call this fixed as well.