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From: David Miller <davem@davemloft.net>
To: simon@fire.lp0.eu
Cc: netdev@vger.kernel.org, paulus@samba.org, linux-ppp@vger.kernel.org
Subject: Re: [PATCH 2/2] ppp_generic: linearise skbs before passing them to pppd
Date: Sun, 02 May 2010 23:27:11 -0700 (PDT)	[thread overview]
Message-ID: <20100502.232711.256856995.davem@davemloft.net> (raw)
In-Reply-To: <4BDB2469.6020105@simon.arlott.org.uk>

From: Simon Arlott <simon@fire.lp0.eu>
Date: Fri, 30 Apr 2010 19:41:45 +0100

> Frequently when using PPPoE with an interface MTU greater than 1500,
> the skb is likely to be non-linear. If the skb needs to be passed to
> pppd then the skb must be linearised first.
> 
> The previous commit fixes an issue with accidentally sending skbs
> to pppd based on an invalid read of the protocol type. When that
> error occurred pppd was reading invalid skb data too.
> 
> Signed-off-by: Simon Arlott <simon@fire.lp0.eu>

Don't propagate stupidity.

The real problem is that ppp_read() can't handle non-linear SKBs, so
fix that instead.  The easiest way to do that is to put a "struct
iovec iov;" on ppp_read()'s stack, fill it in with ther user buffer
pointer and length, then use that to call
skb_copy_datagram_const_iovec().

  reply	other threads:[~2010-05-03  6:27 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-30 18:41 [PATCH 1/2] ppp_generic: pull 2 bytes so that PPP_PROTO(skb) is valid Simon Arlott
2010-04-30 18:41 ` [PATCH 2/2] ppp_generic: linearise skbs before passing them to pppd Simon Arlott
2010-05-03  6:27   ` David Miller [this message]
2010-05-03 16:51     ` [PATCH 2/2] ppp_generic: handle non-linear skbs when " Simon Arlott
2010-05-03  6:25 ` [PATCH 1/2] ppp_generic: pull 2 bytes so that PPP_PROTO(skb) is valid David Miller
2010-05-03 11:50   ` Simon Arlott
2010-05-03 19:49     ` David Miller

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