linux-kernel - Re: ls -l /proc/1/exe -> Permission denied

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Date:	Sun, 20 Jul 2014 22:00:02 +0200
From:	Richard Weinberger <richard@....at>
To:	Joakim Tjernlund <joakim.tjernlund@...nsmode.se>
CC:	LKML <linux-kernel@...r.kernel.org>,
	Andreas Schwab <schwab@...ux-m68k.org>
Subject: Re: ls -l /proc/1/exe -> Permission denied

Am 20.07.2014 21:15, schrieb Joakim Tjernlund:
> Richard Weinberger <richard@....at> wrote on 2014/07/20 14:05:41:
>>
>> Am 20.07.2014 13:51, schrieb Andreas Schwab:
>>> Richard Weinberger <richard.weinberger@...il.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
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