netdev - Re: [PATCHv2 net] netfilter: check duplicate config when initializing in ipt

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] [day] [month] [year] [list]

Message-ID: <20161223141837.GA21441@salvia>
Date:   Fri, 23 Dec 2016 15:18:37 +0100
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     Xin Long <lucien.xin@...il.com>
Cc:     network dev <netdev@...r.kernel.org>,
        netfilter-devel@...r.kernel.org, davem@...emloft.net,
        Marcelo Ricardo Leitner <marcelo.leitner@...il.com>
Subject: Re: [PATCHv2 net] netfilter: check duplicate config when
 initializing in ipt_CLUSTERIP

On Tue, Dec 20, 2016 at 07:14:34PM +0800, Xin Long wrote:
> Now when adding an ipt_CLUSTERIP rule, it only checks duplicate config in
> clusterip_config_find_get(). But after that, there may be still another
> thread to insert a config with the same ip, then it leaves proc_create_data
> to do duplicate check.
> 
> It's more reasonable to check duplicate config by ipt_CLUSTERIP itself,
> instead of checking it by proc fs duplicate file check. Before, when proc
> fs allowed duplicate name files in a directory, It could even crash kernel
> because of use-after-free.
> 
> This patch is to check duplicate config under the protection of clusterip
> net lock when initializing a new config and correct the return err.
> 
> Note that it also moves proc file node creation after adding new config, as
> proc_create_data may sleep, it couldn't be called under the clusterip_net
> lock. clusterip_config_find_get returns NULL if c->pde is null to make sure
> it can't be used until the proc file node creation is done.

Applied, thanks.