Re: cgroup_release_agent() with call_usermodehelper() withUMH_WAIT_EXEC may crash

From: Heiko Carstens
Date: Sat Feb 04 2012 - 23:13:38 EST

On Sat, Feb 04, 2012 at 07:16:51AM -0800, Linus Torvalds wrote:
> On Sat, Feb 4, 2012 at 2:03 AM, Heiko Carstens
> <heiko.carstens@xxxxxxxxxx> wrote:
> >
> > Something like the patch below? Still boots...
> Yes, except that if we touch the comm copying code, let's do what Oleg
> suggested and make it a helper function to create the "comm[]" data
> array instead of open-coding it and adding new random local variables
> to prepare_binprm().
> But looks good otherwise. I'm a *bit* nervous that some
> prepare_binprm() caller hasn't set up bprm->filename that early yet,
> though. It seems like we expect that to be set up by the caller, which
> seems a bit odd, actually.

Ok, I moved it to flush_old_exec() instead like Oleg initially suggested.