From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [FIX NETLINK] properly check arguments to netlink_bind()
Date: Tue, 18 Sep 2007 14:53:31 -0700 (PDT)
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From: Holger Eitzenberger <holger@my-eitzenberger.de>
Date: Tue, 18 Sep 2007 23:05:52 +0200

> Holger Eitzenberger <holger@my-eitzenberger.de> writes:
> 
> > while going through going netlink code I found out that netlink_bind()
> > does not properly check bind parameters.  I checked both 2.6.23-rc1 as
> > well as 2.6.16.53, both are affected.
> >
> > With a small test prog I wasn't able to crash my maschine though, but
> > data was accessed out of bounds.
> 
> See my attached patch, thanks.

Your patch is incorrect and also unnecessary.

Firstly, you patch compares the address _pointer_ against
the minimum length.  That's obviously wrong.

And if you check the call sites of the protocol ->bind() methods, they
all use on-stack buffer for the address object which is at least
MAX_SOCK_ADDR bytes in length so that the bind methods don't have to
check the size if they don't want to.