netdev - Re: [Patch net 2/2] ipmr,ip6mr: call list_del_rcu() when deleting mr table from list

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1427314022.3581245.245236665.477D7858@webmail.messagingengine.com>
Date:	Wed, 25 Mar 2015 21:07:02 +0100
From:	Hannes Frederic Sowa <hannes@...essinduktion.org>
To:	Cong Wang <xiyou.wangcong@...il.com>, netdev@...r.kernel.org
Subject: Re: [Patch net 2/2] ipmr,ip6mr: call list_del_rcu() when deleting mr
 table from list



On Wed, Mar 25, 2015, at 20:05, Cong Wang wrote:
> Probably not a big deal, just for corretness.
> 
> Signed-off-by: Cong Wang <xiyou.wangcong@...il.com>
> ---
>  net/ipv4/ipmr.c  | 2 +-
>  net/ipv6/ip6mr.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
> index d6fede8..68f67b8 100644
> --- a/net/ipv4/ipmr.c
> +++ b/net/ipv4/ipmr.c
> @@ -280,7 +280,7 @@ static void __net_exit ipmr_rules_exit(struct net
> *net)
>  
>  	rtnl_lock();
>  	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
> -               list_del(&mrt->list);
> +               list_del_rcu(&mrt->list);
>  		ipmr_free_table(mrt);
>  	}
>  	rtnl_unlock();

I really do wonder if we have the rcu locking correct in there:

Looking into getsockopt/setsockopt operations, we might have socket
lock, but I cannot see where we lock rcu, so the ipmr_get_table call is
safe. Do you also see the problem?

Thanks,
Hannes
--
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