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From: Alan Cox <alan@linux.intel.com>
To: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: David Miller <davem@davemloft.net>,
	Heikki Hannikainen <hessu@hes.iki.fi>,
	Network Development <netdev@vger.kernel.org>,
	Willem de Bruijn <willemb@google.com>
Subject: Re: Sending short raw packets using sendmsg() broke
Date: Fri, 04 Mar 2016 15:54:09 +0000	[thread overview]
Message-ID: <1457106849.7064.55.camel@linux.intel.com> (raw)
In-Reply-To: <CAF=yD-+-QFp=g8BSsxjwwMmMwuHzkEiubZHNuyoLccF7qTs0ow@mail.gmail.com>

> > A quick search for ethhdr in drivers/net/ethernet shows, for
> > instance,
> > bnx2x_select_queue casting skb->data to an ethernet header. Reading
> > nonsense in that particular function is quite safe and given the
> > skbuff layout (skb_shared_info) code will never read beyond an
> > allocated region. But that was just the first occurrence I found.
> > efx_tso_check_protocol is another example.

So would always allocating that much space be a good mitigation in
general, and perhaps then making the logic check validate() IFF
CAP_SYS_RAWIO is not set.

A user with CAP_SYS_RAWIO already has the power to control the device
by banging registers so the check is not a security loss.

Alan

  reply	other threads:[~2016-03-04 15:54 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-25 19:36 Sending short raw packets using sendmsg() broke Heikki Hannikainen
2016-02-25 20:26 ` David Miller
2016-02-26 14:44   ` Alan Cox
2016-02-26 17:33     ` Willem de Bruijn
2016-02-26 17:46       ` David Miller
2016-02-27 23:02         ` Willem de Bruijn
2016-03-02  0:00           ` Alan Cox
2016-03-03 16:40             ` Willem de Bruijn
2016-03-03 16:43               ` Willem de Bruijn
2016-03-04 15:54                 ` Alan Cox [this message]
2016-03-04 16:33                   ` Willem de Bruijn
2016-03-04 20:52                     ` Willem de Bruijn
2016-03-01 23:34       ` Alan Cox
2016-02-26 17:34     ` David Miller
2016-02-25 20:49 ` Willem de Bruijn

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