2014-10-14 18:49 GMT+08:00 Florian Westphal <fw@xxxxxxxxx>:
> Houcheng Lin <houcheng@xxxxxxxxx> wrote:
>> When system is under heavy loading, the __nfulnl_send() may may failed
>> to put nlmsg into skbuf of nfulnl_instance. If not clear the skbuff on failed,
>> the __nfulnl_send() will still try to put next nlmsg onto this half-full skbuf
>> and cause the user program can never receive packet.
>>
>> This patch fix this issue by releasing skbuf immediately after nlmst put
>> failed.
>
> Could you please try this patch on top of this one and see if the
> WARN_ON goes away?
>
> Thanks
>
> diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
> --- a/net/netfilter/nfnetlink_log.c
> +++ b/net/netfilter/nfnetlink_log.c
> @@ -649,7 +649,8 @@ nfulnl_log_packet(struct net *net,
> + nla_total_size(sizeof(u_int32_t)) /* gid */
> + nla_total_size(plen) /* prefix */
> + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
> - + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
> + + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
> + + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
>
> if (in && skb_mac_header_was_set(skb)) {
> size += nla_total_size(skb->dev->hard_header_len)
> @@ -692,8 +693,7 @@ nfulnl_log_packet(struct net *net,
> goto unlock_and_release;
> }
>
> - if (inst->skb &&
> - size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
> + if (inst->skb && size > skb_tailroom(inst->skb)) {
> /* either the queue len is too high or we don't have
> * enough room in the skb left. flush to userspace. */
> __nfulnl_flush(inst);
Hi Florian,
The modified code seems won't affect the program flow: Size is add a
extra value,
sizeof(struct nfgenmsg), during initialization. comparison size with tailroom
space, the right-side value also add the same value. Is there anything
I miss or
not understand ?
--
Best regards,
Houcheng Lin
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