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From: lantw44@gmail.com
To: netfilter-devel@vger.kernel.org
Cc: Ting-Wei Lan <lantw44@gmail.com>
Subject: [PATCH 2/3] extra: fix wrong implementation in nfq_udp_get_payload
Date: Fri, 20 Jun 2014 18:27:00 +0800	[thread overview]
Message-ID: <1403260021-8732-2-git-send-email-lantw44@gmail.com> (raw)
In-Reply-To: <1403260021-8732-1-git-send-email-lantw44@gmail.com>

From: Ting-Wei Lan <lantw44@gmail.com>

---
 src/extra/udp.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/extra/udp.c b/src/extra/udp.c
index eee732e..2a17a2f 100644
--- a/src/extra/udp.c
+++ b/src/extra/udp.c
@@ -56,13 +56,17 @@ EXPORT_SYMBOL(nfq_udp_get_hdr);
  */
 void *nfq_udp_get_payload(struct udphdr *udph, struct pkt_buff *pktb)
 {
-	unsigned int doff = udph->len;
+	uint16_t len = ntohs (udph->len);
 
-	/* malformed UDP data offset. */
-	if (pktb->transport_header + doff > pktb->tail)
+	/* the UDP packet is too short. */
+	if (len < sizeof(struct udphdr))
 		return NULL;
 
-	return pktb->transport_header + doff;
+	/* malformed UDP packet. */
+	if (pktb->transport_header + len > pktb->tail)
+		return NULL;
+
+	return pktb->transport_header + sizeof(struct udphdr);
 }
 EXPORT_SYMBOL(nfq_udp_get_payload);
 
-- 
1.9.3


  reply	other threads:[~2014-06-20 10:27 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-20 10:26 [PATCH 1/3] extra: use inet_ntop instead of inet_ntoa lantw44
2014-06-20 10:27 ` lantw44 [this message]
2014-06-30 10:02   ` [PATCH 2/3] extra: fix wrong implementation in nfq_udp_get_payload Pablo Neira Ayuso
2014-06-30 17:00     ` 藍挺瑋
2014-06-20 10:27 ` [PATCH 3/3] extra: fix wrong implementation in nfq_udp_get_payload_len lantw44
2014-06-30 10:11   ` Pablo Neira Ayuso
2014-06-30  9:48 ` [PATCH 1/3] extra: use inet_ntop instead of inet_ntoa Pablo Neira Ayuso

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