linux-kernel - Re: [PATCH] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 28 Nov 2018 15:42:31 +0100
From:   Oleg Nesterov <oleg@...hat.com>
To:     Jürg Billeter <j@...ron.ch>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Eric Biederman <ebiederm@...ssion.com>,
        Kees Cook <keescook@...omium.org>,
        Andy Lutomirski <luto@...nel.org>, linux-api@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON_EXIT

On 11/27, Jürg Billeter wrote:
>
> @@ -704,6 +713,9 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
>  	struct task_struct *p, *n;
>  	LIST_HEAD(dead);
>  
> +	if (group_dead && tsk->signal->kill_descendants_on_exit)
> +		walk_process_tree(tsk, kill_descendant_visitor, NULL);

Well, this is not exactly right, at least this is suboptimal in that
other sub-threads can too call walk_process_tree(kill_descendant_visitor)
later for no reason.