Patchwork [12/12] netfilter: nfnetlink_queue: only add CAP_LEN attr when needed

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Submitter Pablo Neira
Date June 5, 2013, 8:40 p.m.
Message ID <1370464832-4216-12-git-send-email-pablo@netfilter.org>
Download mbox | patch
Permalink /patch/249201/
State Accepted
Headers show

Comments

Pablo Neira - June 5, 2013, 8:40 p.m.
From: Florian Westphal <fw@strlen.de>

CAP_LEN contains the size of the network packet we're queueing to
userspace, i.e. normally it is the same as the NFQA_PAYLOAD attribute len.

Include it only in the unlikely case when NFQA_PAYLOAD is truncated due
to copy_range limitations.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nfnetlink_queue_core.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c
index 3c42181..eb2cde8 100644
--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/net/netfilter/nfnetlink_queue_core.c
@@ -472,7 +472,8 @@  nfqnl_build_packet_message(struct nfqnl_instance *queue,
 	if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0)
 		goto nla_put_failure;
 
-	if (cap_len > 0 && nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
+	if (cap_len > data_len &&
+	    nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
 		goto nla_put_failure;
 
 	if (nfqnl_put_packet_info(skb, entskb))