From: David Schwartz <davids@webmaster.com>
To: <daw@mozart.cs.berkeley.edu>, <linux-kernel@vger.kernel.org>
Subject: Re: capable open_port() check wrong for kmem
Date: Mon, 9 Dec 2002 22:27:23 -0800 [thread overview]
Message-ID: <20021210062724.AAA6047@shell.webmaster.com@whenever> (raw)
In-Reply-To: <at3v15$mur$1@abraham.cs.berkeley.edu>
On 10 Dec 2002 05:45:09 GMT, David Wagner wrote:
>carbonated beverage wrote:
>> I found that I can't open /dev/kmem O_RDONLY. The open_mem
>>and open_kmem calls (open_port()) in drivers/char/mem.c checks for
>>CAP_SYS_RAWIO.
>> Is there a possibility of splitting that off into a read and
>>write pair, i.e. CAP_SYS_RAWIO_WRITE, CAP_SYS_RAWIO_READ?
>Read-only access to /dev/kmem is probably enough to get root access
>(maybe you can snoop root's password, for instance). This would make
>the power of the two capabilities roughly equivalent, so if this is true,
>I'm not sure I understand the point of splitting them in two this way.
Many capabilities can be leveraged into root access with sufficient
cleverness. If this were considered a sufficient argument for merging
capabilities, we'd have far fewer of them.
DS
next prev parent reply other threads:[~2002-12-10 6:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-10 3:22 capable open_port() check wrong for kmem carbonated beverage
2002-12-10 5:45 ` David Wagner
2002-12-10 6:27 ` David Schwartz [this message]
[not found] ` <20021210064134.GA17928@net-ronin.org>
2002-12-10 6:51 ` carbonated beverage
2002-12-12 0:43 ` Chris Wright
2002-12-12 1:38 ` carbonated beverage
2002-12-12 2:11 ` Chris Wright
2002-12-10 11:33 ` Olaf Dietsche
2002-12-11 22:38 ` carbonated beverage
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