From: Oleg Nesterov <oleg@redhat.com>
To: Christian Brauner <brauner@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Tycho Andersen <tycho@tycho.pizza>,
linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] pidfd: change pidfd_send_signal() to respect PIDFD_THREAD
Date: Fri, 16 Feb 2024 14:06:25 +0100 [thread overview]
Message-ID: <20240216130625.GA8723@redhat.com> (raw)
In-Reply-To: <20240216-albern-aufwiegen-1de327c7dafd@brauner>
On 02/16, Christian Brauner wrote:
>
> On Wed, Feb 14, 2024 at 01:36:56PM +0100, Oleg Nesterov wrote:
> >
> > and I am not sure that task_pid(current) == pid should allow
> > the "arbitrary signals" if PIDFD_SIGNAL_PROCESS_GROUP.
> >
> > Perhaps
> >
> > /* Only allow sending arbitrary signals to yourself. */
> > ret = -EPERM;
> > if ((task_pid(current) != pid || type == PIDTYPE_PGID) &&
> > (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL)
> > goto err;
>
> Honestly, we should probably just do:
>
> if (kinfo->si_code != SI_USER)
> goto err
Hmm. This doesn't look right. The purpose of the current check is to
forbid SI_TKILL and si_code >= 0, and SI_USER == 0.
SI_USER means that the target can trust the values of si_pid/si_uid
in siginfo.
> + if (kinfo.si_code != SI_USER)
> goto err;
See above...
Oleg.
next prev parent reply other threads:[~2024-02-16 13:07 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-09 13:06 [PATCH v2 1/2] signal: add the "int si_code" arg to prepare_kill_siginfo() Oleg Nesterov
2024-02-09 13:06 ` [PATCH v2 2/2] pidfd: change pidfd_send_signal() to respect PIDFD_THREAD Oleg Nesterov
2024-02-09 15:11 ` Christian Brauner
2024-02-09 15:15 ` Christian Brauner
2024-02-09 15:43 ` Oleg Nesterov
2024-02-09 15:49 ` Christian Brauner
2024-02-09 15:56 ` Oleg Nesterov
2024-02-10 10:23 ` Christian Brauner
2024-02-10 12:30 ` Oleg Nesterov
2024-02-10 12:47 ` Oleg Nesterov
2024-02-10 12:54 ` Christian Brauner
2024-02-10 13:15 ` Oleg Nesterov
2024-02-10 14:26 ` Christian Brauner
2024-02-10 16:51 ` Oleg Nesterov
2024-02-10 17:22 ` Christian Brauner
2024-02-14 12:36 ` Oleg Nesterov
2024-02-16 12:28 ` Christian Brauner
2024-02-16 13:06 ` Oleg Nesterov [this message]
2024-02-16 14:46 ` Christian Brauner
2024-02-16 18:12 ` Oleg Nesterov
2024-02-20 8:34 ` Christian Brauner
2024-02-20 9:02 ` Oleg Nesterov
2024-02-20 9:22 ` Christian Brauner
2024-02-20 11:00 ` Oleg Nesterov
2024-02-20 12:59 ` Christian Brauner
2024-02-20 16:22 ` Oleg Nesterov
2024-02-21 7:42 ` Christian Brauner
2024-02-21 12:55 ` Oleg Nesterov
2024-02-21 13:35 ` Christian Brauner
2024-02-09 19:08 ` Tycho Andersen
2024-02-09 15:10 ` [PATCH v2 1/2] signal: add the "int si_code" arg to prepare_kill_siginfo() Christian Brauner
2024-02-09 16:13 ` Christian Brauner
2024-02-09 16:22 ` Eric W. Biederman
2024-02-09 16:39 ` Oleg Nesterov
2024-02-09 19:36 ` Christian Brauner
2024-02-09 19:53 ` Oleg Nesterov
2024-02-09 20:01 ` Tycho Andersen
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