From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] netlink: rx mmap: fix POLLIN condition
Date: Sun, 30 Aug 2015 21:56:03 -0700 (PDT)
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From: Ken-ichirou MATSUZAWA <chamaken@gmail.com>
Date: Mon, 31 Aug 2015 07:54:49 +0900

> Poll() returns immediately after setting the kernel current frame
> (ring->head) to SKIP from user space even though there is no new
> frame. And in a case of all frames is VALID, user space program
> unintensionally sets (only) kernel current frame to UNUSED, then
> calls poll(), it will not return immediately even though there are
> VALID frames.
> 
> To avoid situations like above, I think we need to scan all frames
> to find VALID frames at poll() like netlink_alloc_skb(),
> netlink_forward_ring() finding an UNUSED frame at skb allocation.
> 
> Signed-off-by: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>

Applied, thanks.