From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1A80C65BB3 for ; Mon, 10 Dec 2018 15:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EDBD2146D for ; Mon, 10 Dec 2018 15:37:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7EDBD2146D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728191AbeLJPhV (ORCPT ); Mon, 10 Dec 2018 10:37:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727313AbeLJPhU (ORCPT ); Mon, 10 Dec 2018 10:37:20 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9D6A24E938; Mon, 10 Dec 2018 15:37:20 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.131]) by smtp.corp.redhat.com (Postfix) with SMTP id 38FB51001914; Mon, 10 Dec 2018 15:37:19 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 10 Dec 2018 16:37:20 +0100 (CET) Date: Mon, 10 Dec 2018 16:37:18 +0100 From: Oleg Nesterov To: "Eric W. Biederman" Cc: Tycho Andersen , Linus Torvalds , Kees Cook , Thomas Gleixner , Linux List Kernel Mailing Subject: Re: siginfo pid not populated from ptrace? Message-ID: <20181210153717.GA7581@redhat.com> References: <87zhtthkuy.fsf@xmission.com> <87k1ktqoe5.fsf@xmission.com> <87r2euiuql.fsf@xmission.com> <20181206192059.GD10086@cisco> <87lg528io7.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87lg528io7.fsf@xmission.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 10 Dec 2018 15:37:20 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/06, Eric W. Biederman wrote: > > The challenge is that we could be delivering this to a zombie signal > group leader. ... > Sigh it is probably time that I dig in and figure out how to avoid that > case which we need to fix anyway because we can get the permission > checks wrong for multi-threaded processes that call setuid and friends. this is another issue... I am sure we have already discussed this, but I failed to find any link to the previous discussion. > Once that is sorted your small change will at least be safe. I don't think so, any sub-thread can dequeue SIGSTOP unless type == PIDTYPE_PID, this has nothing to do with the problems connected to zombie leader, or I misunderstood you. Oleg.