From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 04/14] netfilter: nf_conntrack_sip: extend request line validation Date: Thu, 10 Nov 2016 01:23:37 +0100 Message-ID: <1478737427-1574-5-git-send-email-pablo@netfilter.org> References: <1478737427-1574-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: In-Reply-To: <1478737427-1574-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Ulrich Weber on SIP requests, so a fragmented TCP SIP packet from an allow header starting with INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE,SUBSCRIBE Content-Length: 0 will not bet interpreted as an INVITE request. Also Request-URI must start with an alphabetic character. Confirm with RFC 3261 Request-Line = Method SP Request-URI SP SIP-Version CRLF Fixes: 30f33e6dee80 ("[NETFILTER]: nf_conntrack_sip: support method specific request/response handling") Signed-off-by: Ulrich Weber Acked-by: Marco Angaroni Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_sip.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 621b81c7bddc..c3fc14e021ec 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -1436,9 +1436,12 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff, handler = &sip_handlers[i]; if (handler->request == NULL) continue; - if (*datalen < handler->len || + if (*datalen < handler->len + 2 || strncasecmp(*dptr, handler->method, handler->len)) continue; + if ((*dptr)[handler->len] != ' ' || + !isalpha((*dptr)[handler->len+1])) + continue; if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, &matchoff, &matchlen) <= 0) { -- 2.1.4