From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] net: fix a race in gro_cell_poll()
Date: Tue, 11 Dec 2012 12:50:53 -0500 (EST)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 10 Dec 2012 14:32:03 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> Dmitry Kravkov reported packet drops for GRE packets since GRO support
> was added.
> 
> There is a race in gro_cell_poll() because we call napi_complete()
> without any synchronization with a concurrent gro_cells_receive()
> 
> Once bug was triggered, we queued packets but did not schedule NAPI
> poll.
> 
> We can fix this issue using the spinlock protected the napi_skbs queue,
> as we have to hold it to perform skb dequeue anyway.
> 
> As we open-code skb_dequeue(), we no longer need to mask IRQS, as both
> producer and consumer run under BH context.
> 
> Bug added in commit c9e6bc644e (net: add gro_cells infrastructure)
> 
> Reported-by: Dmitry Kravkov <dmitry@broadcom.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied and queued up for -stable, thanks.