Date: Thu, 6 Nov 2003 01:52:24 +0100
From: Tomas Szepe <szepe@pinerecords.com>
To: Larry McVoy <lm@work.bitmover.com>,
       Chad Kitching <CKitching@powerlandcomputers.com>,
       linux-kernel@vger.kernel.org
Subject: Re: BK2CVS problem
Message-ID: <20031106005224.GA7105@louise.pinerecords.com>
References: <18DFD6B776308241A200853F3F83D507169CBC@pl6w2kex.lan.powerlandcomputers.com> <20031105230350.GB12992@work.bitmover.com>
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On Nov-05 2003, Wed, 15:03 -0800
Larry McVoy <lm@bitmover.com> wrote:

> > > > +       if ((options == (__WCLONE|__WALL)) && (current->uid = 0))
> > > > +                       retval = -EINVAL;
> > > 
> > > That looks odd
> > 
> > Setting current->uid to zero when options __WCLONE and __WALL are set?  The 
> > retval is dead code because of the next line, but it looks like an attempt
> > to backdoor the kernel, does it not?
> 
> It sure does.  Note "current->uid = 0", not "current->uid == 0". 
> Good eyes, I missed that.  This function is sys_wait4() so by passing in
> __WCLONE|__WALL you are root.  How nice.

Also note the extra parentheses to avoid a gcc warning.

-- 
Tomas Szepe <szepe@pinerecords.com>
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