From: Oleg Nesterov <oleg@redhat.com>
To: Stijn Volckaert <Stijn.Volckaert@elis.ugent.be>
Cc: Roland McGrath <roland@hack.frob.com>,
Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] Allow introspection to already attached ptracer in __ptrace_may_access
Date: Wed, 24 Dec 2014 19:06:54 +0100 [thread overview]
Message-ID: <20141224180654.GA11973@redhat.com> (raw)
In-Reply-To: <549ABF87.8060905@elis.ugent.be>
On 12/24, Stijn Volckaert wrote:
>
> The question now is whether or not it's the security module's
> responsibility to check whether a tracee relationship is already in
> place or if ptrace itself should do it.
Honestly, I have no idea
> --- a/kernel/ptrace.c 2014-12-24 13:53:23.055346526 +0100
> +++ b/kernel/ptrace.c 2014-12-24 14:17:20.617824840 +0100
> @@ -232,6 +232,9 @@ static int __ptrace_may_access(struct ta
> /* Don't let security modules deny introspection */
> if (same_thread_group(task, current))
> return 0;
> + /* Don't deny introspection to already attached ptracer */
> + if (!ptrace_check_attach(task, true))
> + return 0;
Perhaps this makes sense, probably security checks do not make sense
if the target is traced.
But in this case I'd suggest to simply
if (ptrace_parent(task) == current)
return 0;
Oleg.
next prev parent reply other threads:[~2014-12-24 18:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-24 13:28 [PATCH RFC] Allow introspection to already attached ptracer in __ptrace_may_access Stijn Volckaert
2014-12-24 18:06 ` Oleg Nesterov [this message]
2015-01-05 23:47 ` Kees Cook
2015-01-06 0:17 ` Casey Schaufler
2015-01-06 9:07 ` Stijn Volckaert
2015-01-06 18:44 ` Oleg Nesterov
2015-01-08 10:40 ` Stijn Volckaert
2015-01-08 19:18 ` 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=20141224180654.GA11973@redhat.com \
--to=oleg@redhat.com \
--cc=Stijn.Volckaert@elis.ugent.be \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=roland@hack.frob.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox