Re: [PATCH] gainfar.c : skb_over_panic (kernel-2.6.32.15)

[David Miller <davem@davemloft.net>]

From: Eran Liberty <liberty@extricom.com>
Date: Thu, 24 Jun 2010 12:53:23 +0300

> Fix possible skb_over_panic event in Freescale's "gianfar" driver. 
> 
> The skb_over_panic occurs due to calling skb_put() within
> gfar_clean_rx_ring(). This happens if (and only if) shortly prior to
> the event and a few lined above the skb_put(), an skb was queued back
> to the priv->rx_recycle queue due to RXBD_LAST or RXBD_ERR status.
> The skb is queued without properly re-setting its state.
> 
> The patch properly reset the skb state.
> 
> I have tested this patch on MPC8548 based product and asserted it
> avoided the skb_over_panic event.
> 
> Signed-off-by: Eran Liberty <liberty@extricom.com>

Eran, this seems to be fixed already.  The code in the current
tree now reads:

				/*
				 * We need to un-reserve() the skb to what it
				 * was before gfar_new_skb() re-aligned
				 * it to an RXBUF_ALIGNMENT boundary
				 * before we put the skb back on the
				 * recycle list.
				 */
				skb_reserve(skb, -GFAR_CB(skb)->alignamount);
				__skb_queue_head(&priv->rx_recycle, skb);