From: gorcunov@gmail.com (Cyrill Gorcunov)
To: linux-security-module@vger.kernel.org
Subject: Leaking path for set_task_comm
Date: Tue, 25 Sep 2018 21:39:53 +0300 [thread overview]
Message-ID: <20180925183953.GI15710@uranus> (raw)
In-Reply-To: <F7DFF547-5267-4EF3-8BF3-70DAF6C2A53A@vt.edu>
On Tue, Sep 25, 2018 at 01:27:08PM -0400, Tong Zhang wrote:
> Kernel Version: 4.18.5
>
> Problem Description:
>
> When using prctl(PR_SET_NAME) to set the thread name, it is checked by security_task_prctl.
>
> We discovered a leaking path that can also use method implemented in
> fs/proc/base.c:1526 comm_write(), to do similar thing without asking LSM?s decision.
I don't understand how it is a problem. Could you please explain?
procfs/comm is created with S_IRUGO|S_IWUSR permissions. So
prctl and procfs are simply different interfaces.
WARNING: multiple messages have this Message-ID (diff)
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Tong Zhang <ztong@vt.edu>
Cc: adobriyan@gmail.com, akpm@linux-foundation.org,
viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org, wenbo.s@samsung.com
Subject: Re: Leaking path for set_task_comm
Date: Tue, 25 Sep 2018 21:39:53 +0300 [thread overview]
Message-ID: <20180925183953.GI15710@uranus> (raw)
In-Reply-To: <F7DFF547-5267-4EF3-8BF3-70DAF6C2A53A@vt.edu>
On Tue, Sep 25, 2018 at 01:27:08PM -0400, Tong Zhang wrote:
> Kernel Version: 4.18.5
>
> Problem Description:
>
> When using prctl(PR_SET_NAME) to set the thread name, it is checked by security_task_prctl.
>
> We discovered a leaking path that can also use method implemented in
> fs/proc/base.c:1526 comm_write(), to do similar thing without asking LSM’s decision.
I don't understand how it is a problem. Could you please explain?
procfs/comm is created with S_IRUGO|S_IWUSR permissions. So
prctl and procfs are simply different interfaces.
next prev parent reply other threads:[~2018-09-25 18:39 UTC|newest]
Thread overview: 10+ 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 17:27 ` Tong Zhang
2018-09-25 18:39 ` Cyrill Gorcunov [this message]
2018-09-25 18:39 ` Cyrill Gorcunov
2018-09-26 0:44 ` TongZhang
2018-09-26 0:44 ` TongZhang
2018-09-26 3:16 ` Theodore Y. Ts'o
2018-09-26 3:16 ` Theodore Y. Ts'o
2018-09-26 22:39 ` Alan Cox
2018-09-26 22:39 ` Alan Cox
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