netdev - Re: [PATCH ipsec,v2] net: xfrm_policy: fix device unregistration hang

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Tue, 13 Feb 2018 07:55:05 +0100
From:   Steffen Klassert <steffen.klassert@...unet.com>
To:     Eyal Birger <eyal.birger@...il.com>
CC:     <herbert@...dor.apana.org.au>, <davem@...emloft.net>,
        <netdev@...r.kernel.org>, <fw@...len.de>,
        <shmulik@...anetworks.com>, <shannon.nelson@...cle.com>
Subject: Re: [PATCH ipsec,v2] net: xfrm_policy: fix device unregistration hang

On Mon, Feb 12, 2018 at 08:58:28PM +0200, Eyal Birger wrote:
> In setups like the following:
> 
>        Host A          --        Host B
> tun0 -- ipsec -- eth0  --  eth0 -- ipsec -- tun0
> 
> where tun0 are tunnel devices using dst_cache (ipip, ipip6, etc...).
> 
> Unregistration of an underlying eth0 device leads to the following log
> messages:
> 
> unregister_netdevice: waiting for eth0 to become free. Usage count = 2
> 
> This is since xfrm dsts device references are not released upon device
> unregistration when the xfrm dst is cached in a dst_cache.
> 
> Several approaches for fixing this were discussed in [1]; this commit keeps
> track of allocated xdsts and releases their device references on a netdev
> unregister event.
> 
> Signed-off-by: Eyal Birger <eyal.birger@...il.com>

Please add a 'Fixes' tag, it is not so clear what introduced this bug.