[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20150803.222057.510107185355144530.davem@davemloft.net>
Date: Mon, 03 Aug 2015 22:20:57 -0700 (PDT)
From: David Miller <davem@...emloft.net>
To: eric.dumazet@...il.com
Cc: Gregory.Hoggarth@...iedtelesis.co.nz, sbohrer@...advisors.com,
netdev@...r.kernel.org, alexgartrell@...il.com, mkubecek@...e.cz
Subject: Re: [PATCH net] udp: fix dst races with multicast early demux
From: Eric Dumazet <eric.dumazet@...il.com>
Date: Sat, 01 Aug 2015 12:14:33 +0200
> From: Eric Dumazet <edumazet@...gle.com>
>
> Multicast dst are not cached. They carry DST_NOCACHE.
>
> As mentioned in commit f8864972126899 ("ipv4: fix dst race in
> sk_dst_get()"), these dst need special care before caching them
> into a socket.
>
> Caching them is allowed only if their refcnt was not 0, ie we
> must use atomic_inc_not_zero()
>
> Also, we must use READ_ONCE() to fetch sk->sk_rx_dst, as mentioned
> in commit d0c294c53a771 ("tcp: prevent fetching dst twice in early demux
> code")
>
> Fixes: 421b3885bf6d ("udp: ipv4: Add udp early demux")
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Reported-by: Gregory Hoggarth <Gregory.Hoggarth@...iedtelesis.co.nz>
> Reported-by: Alex Gartrell <agartrell@...com>
> Cc: Michal Kubeček <mkubecek@...e.cz>
> ---
> David : I will be on vacation for following 7 days, no internet access.
> Please wait for tests done by Gregory & Alex before merging this ?
> Thanks !
Now that this has been tested by Gregory, applied and queued up for
-stable thanks!
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists