From: Cong Wang <[email protected]>
Date: Wed, 12 Apr 2017 12:32:13 -0700
> Similar to commit 87e9f0315952
> ("ipv4: fix a potential deadlock in mcast getsockopt() path"),
> there is a deadlock scenario for IP_ROUTER_ALERT too:
>
> CPU0 CPU1
> ---- ----
> lock(rtnl_mutex);
> lock(sk_lock-AF_INET);
> lock(rtnl_mutex);
> lock(sk_lock-AF_INET);
>
> Fix this by always locking RTNL first on all setsockopt() paths.
>
> Note, after this patch ip_ra_lock is no longer needed either.
>
> Reported-by: Dmitry Vyukov <[email protected]>
> Tested-by: Andrey Konovalov <[email protected]>
> Signed-off-by: Cong Wang <[email protected]>
Applied.
