netdev - Re: [PATCH net-next 7/8] openvswitch: Drop user features if old user space attempted to create datapath

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

Message-ID: <1385058197.1586.15.camel@bwh-desktop.uk.level5networks.com>
Date:	Thu, 21 Nov 2013 18:23:17 +0000
From:	Ben Hutchings <bhutchings@...arflare.com>
To:	Thomas Graf <tgraf@...g.ch>
CC:	<jesse@...ira.com>, <davem@...emloft.net>, <dev@...nvswitch.org>,
	<netdev@...r.kernel.org>, <dborkman@...hat.com>,
	<ffusco@...hat.com>, <fleitner@...hat.com>,
	<eric.dumazet@...il.com>
Subject: Re: [PATCH net-next 7/8] openvswitch: Drop user features if old
 user space attempted to create datapath

On Thu, 2013-11-21 at 19:13 +0100, Thomas Graf wrote:
> Drop user features if an outdated user space instance that does not
> understand the concept of user_features attempted to create a new
> datapath.
> 
> Signed-off-by: Thomas Graf <tgraf@...g.ch>
> Reviewed-by: Daniel Borkmann <dborkman@...hat.com>
> ---
>  include/uapi/linux/openvswitch.h | 11 ++++++++++-
>  net/openvswitch/datapath.c       | 10 ++++++++++
>  2 files changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
> index 07ef2c3..4f74c2c 100644
> --- a/include/uapi/linux/openvswitch.h
> +++ b/include/uapi/linux/openvswitch.h
> @@ -40,7 +40,16 @@ struct ovs_header {
>  
>  #define OVS_DATAPATH_FAMILY  "ovs_datapath"
>  #define OVS_DATAPATH_MCGROUP "ovs_datapath"
> -#define OVS_DATAPATH_VERSION 0x1
> +
> +/**
> + * V2:

This is not kernel-doc format so don't use '/**'.

> + *   - API users are expected to provide OVS_DP_ATTR_USER_FEATURES
> + *     with NLM_F_REPLACE when creating the datapath.
> + */
> +#define OVS_DATAPATH_VERSION 2
> +
> +/* First OVS datapath version to support features */
> +#define OVS_DP_VER_FEATURES 2
>  
>  enum ovs_datapath_cmd {
>  	OVS_DP_CMD_UNSPEC,
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 3f1fb87..72cdffb 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -1198,6 +1198,16 @@ static int ovs_dp_create_or_update(struct sk_buff *skb, struct genl_info *info,
>  		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
>  			goto update;
>  
> +		/* An outdated user space instance that does not understand
> +		 * the concept of user_features has attempted to create a new
> +		 * datapath. Drop all user features.
> +		 */
> +		if (info->genlhdr->version < OVS_DP_VER_FEATURES) {
> +			WARN_ONCE(dp->user_features, "Dropping previously "
> +				  "announced user features");

Log messages shouldn't be split like this as it makes them harder to
find.  There should also be a newline at the end of the message.

Ben.

> +			dp->user_features = 0;
> +		}
> +
>  		err = -EEXIST;
>  		goto err_unlock_ovs;
>  	}

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

--
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