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References: <20110131214515.GC6368@thinkpad-t410>
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Date: Sun, 6 Feb 2011 20:37:21 +0100
Message-ID: <AANLkTi=mRO99U5t3Z_gscuwix0X+brFhWtC=9nkytE+M@mail.gmail.com>
Subject: Re: Missing skb_pad() return value checks in rt2x00 driver
From: Wolfgang Kufner <wolfgang.kufner@gmail.com>
To: Ivo Van Doorn <ivdoorn@gmail.com>
Cc: Seth Forshee <seth.forshee@canonical.com>,
	Gertjan van Wingerde <gwingerde@gmail.com>,
	"John W. Linville" <linville@tuxdriver.com>,
	linux-wireless@vger.kernel.org, users@rt2x00.serialmonkey.com
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Sender: linux-wireless-owner@vger.kernel.org

Hi Ivo,

On Sun, Feb 6, 2011 at 5:17 PM, Ivo Van Doorn <ivdoorn@gmail.com> wrote:
> Between here and where you added the padding are a couple of function
> calls which use the skb->len field. So this patch would change the value what
> they expect. Have you checked the possible impact?

I don't think skb_pad() touches skb->len. It writes zeros into the tailroom:
/**
*      skb_pad                 -       zero pad the tail of an skb
*      @skb: buffer to pad
*      @pad: space to pad
*
*      Ensure that a buffer is followed by a padding area that is zero
*      filled. Used by network drivers which may DMA or transfer data
*      beyond the buffer end onto the wire.
*
*      May return error in out of memory cases. The skb is freed on error.
*/

Thanks,
Wolfgang