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From: Florian Westphal <fw@strlen•de>
To: Houcheng Lin <houcheng@gmail•com>
Cc: pablo@netfilter•org, Patrick McHardy <kaber@trash•net>,
	kadlec@blackhole•kfki.hu, davem@davemloft•net,
	netfilter-devel@vger•kernel.org, Florian Westphal <fw@strlen•de>,
	coreteam@netfilter•org, netdev@vger•kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger•kernel.org>
Subject: Re: [PATCH v2] netfilter: release skbuf when nlmsg put fail
Date: Tue, 14 Oct 2014 12:49:23 +0200	[thread overview]
Message-ID: <20141014104923.GA30916@breakpoint.cc> (raw)
In-Reply-To: <CAL8JtxD=Vopo7fvKEnfKgOa3T=WyVH=mb_YqX9mES+n-6dJbrQ@mail.gmail.com>

Houcheng Lin <houcheng@gmail•com> 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);

next prev parent reply	other threads:[~2014-10-14 10:49 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-14  9:42 [PATCH v2] netfilter: release skbuf when nlmsg put fail Houcheng Lin
2014-10-14 10:49 ` Florian Westphal [this message]
2014-10-14 14:51   ` Houcheng Lin
2014-10-14 17:27     ` Florian Westphal

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