[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 <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2006-05-03 23:16:29 -07:00 committed by David S. Miller
parent e17df688f7
commit 6fd737031e

View file

@ -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 */