From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: TongZhang <ztong@vt.edu>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>,
adobriyan@gmail.com, akpm@linux-foundation.org,
viro@zeniv.linux.org.uk, LKML <linux-kernel@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org,
Wenbo Shen <shenwenbosmile@gmail.com>
Subject: Re: Leaking path for set_task_comm
Date: Tue, 25 Sep 2018 23:16:45 -0400 [thread overview]
Message-ID: <20180926031645.GB3321@thunk.org> (raw)
In-Reply-To: <0CD63E6E-7512-4DD6-8858-4408416DC730@vt.edu>
On Tue, Sep 25, 2018 at 08:44:39PM -0400, TongZhang wrote:
> Yes, this is exactly what I am saying.
> A process can change its own name using prctl or /proc/self/comm.
> prctl is protected by security_task_prctl, whereas /proc/self/comm is not protected by this LSM hook.
>
> A system admin may expect to use security_task_prctl to block all attempt to change process name, however, it can still change name using /proc/self/comm.
None of the in-tree LSM's try to affect PR_SET_NAME. Looking at
security/commoncap.c, it's clear what is of interest is to checking
things relating to security sensitive things relating to capabilities, such as:
PR_SET_SECUREBITS
PR_CAPBSET_*
PR_*_SECUREBITS
PR_*_KEEPCAPS
PR_CAP_AMBIENT
Trying to depend on task name for anything security sensitive is at
_really_ bad idea, so it seems unlikely that a LSM would want to
protect the process name. (And if they did, the first thing I would
ask is "Why? What are you trying to do? Do you realize how many
*other* ways the process name can be spoofed or otherwise controlled
by a potentially malicious user?")
- Ted
next prev parent reply other threads:[~2018-09-26 3:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 17:27 Leaking path for set_task_comm Tong Zhang
2018-09-25 18:39 ` Cyrill Gorcunov
2018-09-26 0:44 ` TongZhang
2018-09-26 3:16 ` Theodore Y. Ts'o [this message]
2018-09-26 22:39 ` Alan Cox
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