Re: [patch] tehuti: using uninitialized data in bdx_ioctl_priv()

[Ben Hutchings <bhutchings@solarflare.com>]

On Mon, 2013-06-24 at 13:01 -0700, David Miller wrote:
> From: Dan Carpenter <dan.carpenter@oracle.com>
> Date: Mon, 24 Jun 2013 19:05:03 +0300
> 
> > If we "cmd == SIOCDEVPRIVATE" then we use data[] without initializing
> > it.  The most common case is that we would return -EOPNOTSUPP.  The
> > other case is that we'd end up reading and writing to randomish places.
> > This requires CAP_SYS_RAWIO so it's not very bad.
> > 
> > The fix is to not allow SIOCDEVPRIVATE because it doesn't work.  I
> > returned -EOPNOTSUPP instead of -ENOTTY because that's what is used in
> > the rest of the file.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> I think the intention is to only allow SIOCDEVPRIVATE, rather than
> accept any and all values other than it which are inside of the
> private ioctl range.
> 
> The 'cmd' validation is one step, and it determines the interpretation
> of data[0].

But data is only initialised on the error path.  So this whole function
is useless.  It might as well be removed entirely.

(Also, drivers generally should not assign SIOCDEVPRIVATE+{0,1,2}, as
those numbers used to be conventionally used for MII operations.)

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
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