From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Graf <tgraf-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH v3] core, nfqueue,
 openvswitch: Orphan frags in skb_zerocopy and handle errors
Date: Thu, 20 Mar 2014 23:22:53 +0100
Message-ID: <532B6A3D.1060600@redhat.com>
References: <1395331354-23659-1-git-send-email-zoltan.kiss@citrix.com>
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Cc: netfilter-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Miklos Szeredi <mszeredi-AlSwsSmVLrQ@public.gmane.org>,
 kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Michael S. Tsirkin" <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
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To: Zoltan Kiss <zoltan.kiss-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>, Jesse Gross <jesse-l0M0P4e3n4LQT0dZR+AlfA@public.gmane.org>,
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On 03/20/2014 05:02 PM, Zoltan Kiss wrote:
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -464,7 +464,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>   	}
>   	nla->nla_len = nla_attr_size(skb->len);
>
> -	skb_zerocopy(user_skb, skb, skb->len, hlen);
> +	err = skb_zerocopy(user_skb, skb, skb->len, hlen);
> +	if (err)
> +		goto out;
>
>   	/* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
>   	if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
> @@ -478,6 +480,7 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>
>   	err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);
>   out:
> +	skb_tx_error(skb);

Really sorry to bug you again. We'll get this right ;-)

Patch looks great except for this call to skb_tx_error() which is now
done in the error *and* success path. Make the call conditional on
if (err) and we're good.