From: Tycho Andersen <tycho@tycho.ws>
To: Sargun Dhillon <sargun@sargun.me>
Cc: linux-kernel@vger.kernel.org,
containers@lists.linux-foundation.org, linux-api@vger.kernel.org
Subject: Re: [RFC PATCH] ptrace: add PTRACE_GETFD request
Date: Fri, 6 Dec 2019 07:10:45 -0700 [thread overview]
Message-ID: <20191206141045.GA22803@cisco> (raw)
In-Reply-To: <20191205234450.GA26369@ircssh-2.c.rugged-nimbus-611.internal>
On Thu, Dec 05, 2019 at 11:44:53PM +0000, Sargun Dhillon wrote:
> PTRACE_GETFD is a generic ptrace API that allows the tracer to
> get file descriptors from the traceee.
>
> The primary reason to use this syscall is to allow sandboxers to
I might change this to "one motivation to use this ptrace command",
because I'm sure people will invent other crazy uses soon after it's
added :)
> take action on an FD on behalf of the tracee. For example, this
> can be combined with seccomp's user notification feature to extract
> a file descriptor and call privileged syscalls, like binding
> a socket to a privileged port.
This can already be accomplished via injecting parasite code like CRIU
does; adding a ptrace() command like this makes it much nicer to be
sure, but it is redundant.
Tycho
next prev parent reply other threads:[~2019-12-06 14:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-05 23:44 [RFC PATCH] ptrace: add PTRACE_GETFD request Sargun Dhillon
2019-12-06 2:38 ` Jann Horn
2019-12-06 6:16 ` Sargun Dhillon
2019-12-06 6:52 ` Aleksa Sarai
2019-12-06 8:25 ` Christian Brauner
2019-12-06 12:23 ` Oleg Nesterov
2019-12-06 14:10 ` Tycho Andersen [this message]
2019-12-06 19:03 ` Sargun Dhillon
2019-12-06 19:05 ` Jann Horn
2019-12-06 19:05 ` Jann Horn
2019-12-06 20:45 ` Andy Lutomirski
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