From: Richard Weinberger <richard@nod.at>
To: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Cc: LKML <linux-kernel@vger.kernel.org>,
Andreas Schwab <schwab@linux-m68k.org>
Subject: Re: ls -l /proc/1/exe -> Permission denied
Date: Sun, 20 Jul 2014 22:00:02 +0200 [thread overview]
Message-ID: <53CC1FC2.5000806@nod.at> (raw)
In-Reply-To: <OF2729CE69.3EF22126-ONC1257D1B.0069427B-C1257D1B.0069CA17@transmode.se>
Am 20.07.2014 21:15, schrieb Joakim Tjernlund:
> Richard Weinberger <richard@nod.at> wrote on 2014/07/20 14:05:41:
>>
>> Am 20.07.2014 13:51, schrieb Andreas Schwab:
>>> Richard Weinberger <richard.weinberger@gmail.com> writes:
>>>> Do you have an example?
>>>
>>> proc symlinks are special because they actually resolve to the inode.
>>
>> Ah. If an attacker manages the kernel to follow the symlink he could
>> indirectly access that file.
>> Thanks for pointing this out!
>
> That is a big if, I read this as you don't trust the kernels impl.
> of proc sym links so paper over this with denying all other to read
> trivial
> data such as the exe sym link.
Feel free to propose a solution for that. :-)
Thanks,
//richard
next prev parent reply other threads:[~2014-07-20 20:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-17 11:18 ls -l /proc/1/exe -> Permission denied Joakim Tjernlund
2014-07-18 12:58 ` Richard Weinberger
2014-07-18 13:49 ` Joakim Tjernlund
[not found] ` <OF542E7A59.842197B0-ONC1257D19.004B7FF4-C1257D19.004BEC7C@LocalDomain>
2014-07-18 15:05 ` Joakim Tjernlund
2014-07-19 20:06 ` Richard Weinberger
2014-07-19 20:21 ` Andreas Schwab
2014-07-20 9:02 ` Joakim Tjernlund
2014-07-20 10:55 ` Andreas Schwab
2014-07-20 11:06 ` Richard Weinberger
2014-07-20 11:19 ` Joakim Tjernlund
2014-07-20 11:51 ` Andreas Schwab
2014-07-20 12:05 ` Richard Weinberger
2014-07-20 12:05 ` Richard Weinberger
2014-07-20 19:15 ` Joakim Tjernlund
2014-07-20 20:00 ` Richard Weinberger [this message]
2014-07-20 22:05 ` Joakim Tjernlund
2014-07-20 12:08 ` Richard Weinberger
2014-07-21 17:48 ` Eric W. Biederman
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