From: Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Aleksa Sarai <asarai-IBi9RG/b67k@public.gmane.org>,
Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>,
Attila Fazekas <afazekas-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Jann Horn <jann-XZ1E9jl8jIdeoWH0uzbU5w@public.gmane.org>,
Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Ulrich Obergfell
<uobergfe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct
Date: Wed, 5 Apr 2017 18:24:59 +0200 [thread overview]
Message-ID: <20170405162458.GF14536@redhat.com> (raw)
In-Reply-To: <87k2728lrp.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
On 04/02, Eric W. Biederman wrote:
>
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1515,6 +1515,13 @@ static __latent_entropy struct task_struct *copy_process(
> if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
> return ERR_PTR(-EINVAL);
>
> + /* Disallow CLONE_THREAD with a shared SIGHAND structure. No
> + * one cares
Well, can't resists... I won't argue, but we can't know if no one cares
or not. I agree that most probably this won't break something, but who
knows... I am always scared when we add the incompatible changes.
> and supporting it leads to unnecessarily complex
> + * code.
> + */
> + if ((clone_flags & CLONE_THREAD) && (atomic_read(¤t->sighand->count) > 1))
> + return ERR_PTR(-EINVAL);
Perhaps the comment should explain why we do this and say that
sighand-unsharing in de_thread() depends on this.
Oleg.
WARNING: multiple messages have this Message-ID (diff)
From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Aleksa Sarai <asarai@suse.com>,
Andy Lutomirski <luto@amacapital.net>,
Attila Fazekas <afazekas@redhat.com>, Jann Horn <jann@thejh.net>,
Kees Cook <keescook@chromium.org>,
Michal Hocko <mhocko@kernel.org>,
Ulrich Obergfell <uobergfe@redhat.com>,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org
Subject: Re: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct
Date: Wed, 5 Apr 2017 18:24:59 +0200 [thread overview]
Message-ID: <20170405162458.GF14536@redhat.com> (raw)
In-Reply-To: <87k2728lrp.fsf_-_@xmission.com>
On 04/02, Eric W. Biederman wrote:
>
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1515,6 +1515,13 @@ static __latent_entropy struct task_struct *copy_process(
> if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
> return ERR_PTR(-EINVAL);
>
> + /* Disallow CLONE_THREAD with a shared SIGHAND structure. No
> + * one cares
Well, can't resists... I won't argue, but we can't know if no one cares
or not. I agree that most probably this won't break something, but who
knows... I am always scared when we add the incompatible changes.
> and supporting it leads to unnecessarily complex
> + * code.
> + */
> + if ((clone_flags & CLONE_THREAD) && (atomic_read(¤t->sighand->count) > 1))
> + return ERR_PTR(-EINVAL);
Perhaps the comment should explain why we do this and say that
sighand-unsharing in de_thread() depends on this.
Oleg.
next prev parent reply other threads:[~2017-04-05 16:24 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-13 14:14 [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
2017-02-13 14:15 ` [PATCH 1/2] exec: don't wait for zombie threads with cred_guard_mutex held Oleg Nesterov
2017-02-13 16:12 ` kbuild test robot
2017-02-13 16:47 ` Oleg Nesterov
2017-02-13 16:39 ` kbuild test robot
2017-02-13 17:27 ` Mika Penttilä
2017-02-13 18:01 ` Oleg Nesterov
2017-02-13 18:04 ` [PATCH V2 " Oleg Nesterov
2017-02-16 11:42 ` Eric W. Biederman
2017-02-20 15:22 ` Oleg Nesterov
2017-02-20 15:36 ` Oleg Nesterov
2017-02-20 22:30 ` Eric W. Biederman
2017-02-21 17:53 ` Oleg Nesterov
2017-02-21 20:20 ` Eric W. Biederman
2017-02-22 17:41 ` Oleg Nesterov
2017-02-17 4:42 ` Eric W. Biederman
2017-02-20 15:50 ` Oleg Nesterov
2017-02-13 14:15 ` [PATCH 2/2] ptrace: ensure PTRACE_EVENT_EXIT won't stop if the tracee is killed by exec Oleg Nesterov
2017-02-24 16:03 ` [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
2017-03-03 1:05 ` Eric W. Biederman
2017-03-03 17:33 ` Oleg Nesterov
[not found] ` <20170303173326.GA17899-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-03-03 18:23 ` Eric W. Biederman
2017-03-03 18:23 ` Eric W. Biederman
2017-03-03 18:59 ` Eric W. Biederman
2017-03-03 18:59 ` Eric W. Biederman
[not found] ` <87d1dyw5iw.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-03-03 20:06 ` Eric W. Biederman
2017-03-03 20:06 ` Eric W. Biederman
[not found] ` <87tw7aunuh.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-03-03 20:11 ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Eric W. Biederman
2017-03-03 20:11 ` Eric W. Biederman
2017-03-04 17:03 ` Oleg Nesterov
2017-03-30 8:07 ` Eric W. Biederman
[not found] ` <8760ir192p.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-01 5:11 ` [RFC][PATCH 0/2] exec: Fixing ptrace'd mulit-threaded hang Eric W. Biederman
2017-04-01 5:11 ` Eric W. Biederman
[not found] ` <878tnkpv8h.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-01 5:14 ` [RFC][PATCH 1/2] sighand: Count each thread group once in sighand_struct Eric W. Biederman
2017-04-01 5:14 ` Eric W. Biederman
2017-04-01 5:16 ` [RFC][PATCH 2/2] exec: If possible don't wait for ptraced threads to be reaped Eric W. Biederman
2017-04-01 5:16 ` Eric W. Biederman
[not found] ` <87vaqooggs.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-02 15:35 ` Oleg Nesterov
2017-04-02 15:35 ` Oleg Nesterov
[not found] ` <20170402153517.GA12637-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-04-02 18:53 ` Eric W. Biederman
2017-04-02 18:53 ` Eric W. Biederman
[not found] ` <877f32k5ew.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-03 18:12 ` Oleg Nesterov
2017-04-03 18:12 ` Oleg Nesterov
2017-04-03 21:04 ` Eric W. Biederman
2017-04-05 16:44 ` Oleg Nesterov
2017-04-02 15:38 ` [RFC][PATCH 0/2] exec: Fixing ptrace'd mulit-threaded hang Oleg Nesterov
2017-04-02 15:38 ` Oleg Nesterov
2017-04-02 22:50 ` [RFC][PATCH v2 0/5] " Eric W. Biederman
2017-04-02 22:50 ` Eric W. Biederman
[not found] ` <874ly6a0h1.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-02 22:51 ` [RFC][PATCH v2 1/5] ptrace: Don't wait in PTRACE_O_TRACEEXIT for exec or coredump Eric W. Biederman
2017-04-02 22:51 ` Eric W. Biederman
2017-04-05 16:19 ` Oleg Nesterov
2017-04-02 22:51 ` [RFC][PATCH v2 2/5] sighand: Count each thread group once in sighand_struct Eric W. Biederman
2017-04-02 22:51 ` Eric W. Biederman
2017-04-02 22:52 ` [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct Eric W. Biederman
2017-04-02 22:52 ` Eric W. Biederman
[not found] ` <87k2728lrp.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-05 16:24 ` Oleg Nesterov [this message]
2017-04-05 16:24 ` Oleg Nesterov
2017-04-05 17:34 ` Eric W. Biederman
2017-04-05 18:11 ` Oleg Nesterov
2017-04-02 22:53 ` [RFC][PATCH v2 4/5] exec: If possible don't wait for ptraced threads to be reaped Eric W. Biederman
2017-04-02 22:53 ` Eric W. Biederman
2017-04-05 16:15 ` Oleg Nesterov
2017-04-02 22:57 ` [RFC][PATCH v2 5/5] signal: Don't allow accessing signal_struct by old threads after exec Eric W. Biederman
2017-04-02 22:57 ` Eric W. Biederman
[not found] ` <87zify76z9.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-05 16:18 ` Oleg Nesterov
2017-04-05 16:18 ` Oleg Nesterov
[not found] ` <20170405161812.GD14536-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-04-05 18:16 ` Eric W. Biederman
2017-04-05 18:16 ` Eric W. Biederman
[not found] ` <87zifu90to.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-06 15:48 ` Oleg Nesterov
2017-04-06 15:48 ` Oleg Nesterov
2017-04-02 16:15 ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Oleg Nesterov
2017-04-02 16:15 ` Oleg Nesterov
[not found] ` <20170402161518.GC12637-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-04-02 21:07 ` Eric W. Biederman
2017-04-02 21:07 ` Eric W. Biederman
[not found] ` <87inmmbjsq.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-03 18:37 ` Oleg Nesterov
2017-04-03 18:37 ` Oleg Nesterov
[not found] ` <20170403183728.GB31390-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-04-03 22:49 ` Eric W. Biederman
2017-04-03 22:49 ` Eric W. Biederman
2017-04-03 22:49 ` scope of cred_guard_mutex Eric W. Biederman
2017-04-03 22:49 ` Eric W. Biederman
2017-04-05 16:08 ` Oleg Nesterov
2017-04-05 16:11 ` Kees Cook
2017-04-05 17:53 ` Eric W. Biederman
2017-04-05 18:15 ` Oleg Nesterov
[not found] ` <87fuhpjeco.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-04-06 15:55 ` Oleg Nesterov
2017-04-06 15:55 ` Oleg Nesterov
[not found] ` <20170406155540.GC7444-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-04-07 22:07 ` Kees Cook
2017-04-07 22:07 ` Kees Cook
2017-09-04 3:19 ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Robert O'Callahan
2017-09-04 3:19 ` Robert O'Callahan
[not found] ` <87tw7axlr0.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-03-04 16:54 ` [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
2017-03-04 16:54 ` Oleg Nesterov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170405162458.GF14536@redhat.com \
--to=oleg-h+wxahxf7alqt0dzr+alfa@public.gmane.org \
--cc=afazekas-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
--cc=akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org \
--cc=asarai-IBi9RG/b67k@public.gmane.org \
--cc=ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org \
--cc=jann-XZ1E9jl8jIdeoWH0uzbU5w@public.gmane.org \
--cc=keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org \
--cc=linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org \
--cc=mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
--cc=uobergfe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.