Re: [PATCH v2] net/dccp: fix use after free in tw_timer_handler()

[David Miller]

From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Date: Wed, 22 Feb 2017 12:35:27 +0300

> DCCP doesn't purge timewait sockets on network namespace shutdown.
> So, after net namespace destroyed we could still have an active timer
> which will trigger use after free in tw_timer_handler():
 ...
> Add .exit_batch hook to dccp_v4_ops()/dccp_v6_ops() which will purge
> timewait sockets on net namespace destruction and prevent above issue.
> 
> Fixes: f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH")
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Acked-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Applied and queued up for -sable, thanks.