From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: ip6_rt_gc_elasticity and ip6_rt_gc_min_interval race in
 rt6_alloc_cow() ?
Date: Fri, 30 Nov 2012 13:50:14 -0500 (EST)
Message-ID: <20121130.135014.1380924721756973206.davem@davemloft.net>
References: <20121130184336.GB7113@midget.suse.cz>
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From: Jiri Bohac <jbohac@suse.cz>
Date: Fri, 30 Nov 2012 19:43:36 +0100

> I believe there is a race condition in the setting of
> ip6_rt_gc_elasticity and ip6_rt_gc_min_interval. I have not seen
> happen, though:
> 
> 1) a setting made by the user via sysctl while ip6_dst_gc() is
>    running will get lost
> 
> 2) another instance of rt6_alloc_cow() may save the temporary
>    values in the saved_* variables, making those permanent.
> 
> Am I overlooking some synchronization or should I send a
> patch to fix this?

The ipv4 routing cache had the same issue, I really and sincerely
doubt this race matters in practice.