Re: [PATCH] wait_for_helper: SIGCHLD from user-space can lead touse-after-free
From: Roland McGrath
Date: Wed Mar 10 2010 - 16:28:26 EST
> Yes. kthreads run with all signal ignored, this is inherited from
> kthreadd() which does ignore_signal().
Ok.
> I don't think this can work. SIG_DFL for SIGCHLD is OK because it is
> sig_kernel_ignore(). But, say, SIGHUP and other signals still should
> be ignored, otherwise we have the same problems with the unwanted
> signal_pending() this patch tries to avoid.
Yes, I see.
> But even if we could do this,
>
> > That should make it redundant in ____call_usermodehelper,
> > so it could be removed from there.
>
> Please note that __call_usermodehelper() forks ____call_usermodehelper() too.
Ok.
Thanks,
Roland
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/