From 6fd737031eb6869430d0f3cf6bf1440adf7aedf5 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 3 May 2006 23:16:29 -0700 Subject: [PATCH] [NETFILTER]: H.323 helper: fix endless loop caused by invalid TPKT len When the TPKT len included in the packet is below the lowest valid value of 4 an underflow occurs which results in an endless loop. Found by testcase 0000058 from the PROTOS c07-h2250v4 testsuite. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ip_conntrack_helper_h323.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/netfilter/ip_conntrack_helper_h323.c b/net/ipv4/netfilter/ip_conntrack_helper_h323.c index 2c2fb700d83..518f581d39e 100644 --- a/net/ipv4/netfilter/ip_conntrack_helper_h323.c +++ b/net/ipv4/netfilter/ip_conntrack_helper_h323.c @@ -162,6 +162,8 @@ static int get_tpkt_data(struct sk_buff **pskb, struct ip_conntrack *ct, /* Validate TPKT length */ tpktlen = tpkt[2] * 256 + tpkt[3]; + if (tpktlen < 4) + goto clear_out; if (tpktlen > tcpdatalen) { if (tcpdatalen == 4) { /* Separate TPKT header */ /* Netmeeting sends TPKT header and data separately */ -- 2.20.1