From: Andy Lutomirski <luto@kernel.org>
To: Sargun Dhillon <sargun@sargun.me>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux Containers <containers@lists.linux-foundation.org>,
Linux API <linux-api@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
Tycho Andersen <tycho@tycho.ws>, Jann Horn <jannh@google.com>,
Aleksa Sarai <cyphar@cyphar.com>,
Christian Brauner <christian.brauner@ubuntu.com>,
Oleg Nesterov <oleg@redhat.com>,
Al Viro <viro@zeniv.linux.org.uk>,
gpascutto@mozilla.com, ealvarez@mozilla.com,
Florian Weimer <fweimer@redhat.com>,
jld@mozilla.com, Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v4 2/5] pid: Add PIDFD_IOCTL_GETFD to fetch file descriptors from processes
Date: Thu, 19 Dec 2019 17:43:17 -0800 [thread overview]
Message-ID: <CALCETrUK-SHA=sOUrBscpf+Bpxxff2L3RpXEaAfRHNnHGxa-LQ@mail.gmail.com> (raw)
In-Reply-To: <20191218235459.GA17271@ircssh-2.c.rugged-nimbus-611.internal>
On Wed, Dec 18, 2019 at 3:55 PM Sargun Dhillon <sargun@sargun.me> wrote:
>
> +
> + if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) {
> + file = ERR_PTR(-EPERM);
> + goto out;
> + }
I don't think this is MODE_READ. By copying an fd from the task, you
can easily change its state.
IMO it would be really nice if pidfd could act more like a capability
here and carry a ptrace mode, for example. But I guess it doesn't
right now.
--Andy
next prev parent reply other threads:[~2019-12-20 1:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-18 23:55 [PATCH v4 2/5] pid: Add PIDFD_IOCTL_GETFD to fetch file descriptors from processes Sargun Dhillon
2019-12-19 8:03 ` Arnd Bergmann
2019-12-19 10:35 ` Christian Brauner
2019-12-19 11:31 ` Arnd Bergmann
2019-12-19 16:15 ` Sargun Dhillon
2019-12-20 4:35 ` Aleksa Sarai
2019-12-21 13:53 ` Arnd Bergmann
2019-12-19 10:23 ` Christian Brauner
2019-12-20 1:43 ` Andy Lutomirski [this message]
2019-12-20 5:21 ` Sargun Dhillon
2019-12-20 9:20 ` Christian Brauner
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