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* [PATCH v2] nf_conntrack_sip: extend request line validation
@ 2016-10-24 16:07 Ulrich Weber
  2016-10-25  7:07 ` Marco Angaroni
  0 siblings, 1 reply; 3+ messages in thread
From: Ulrich Weber @ 2016-10-24 16:07 UTC (permalink / raw)
  To: netfilter-devel; +Cc: kaber, marcoangaroni, pablo

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

Signed-off-by: Ulrich Weber <ulrich.weber@riverbed.com>
---
 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 7700556..df773d6 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) {
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] nf_conntrack_sip: extend request line validation
  2016-10-24 16:07 [PATCH v2] nf_conntrack_sip: extend request line validation Ulrich Weber
@ 2016-10-25  7:07 ` Marco Angaroni
  2016-10-27 16:29   ` Pablo Neira Ayuso
  0 siblings, 1 reply; 3+ messages in thread
From: Marco Angaroni @ 2016-10-25  7:07 UTC (permalink / raw)
  To: Ulrich Weber; +Cc: netfilter-devel, kaber, Pablo Neira Ayuso

Hello,

2016-10-24 18:07 GMT+02:00 Ulrich Weber <ulrich.weber@riverbed.com>:
> 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
>
> Signed-off-by: Ulrich Weber <ulrich.weber@riverbed.com>

Looks ok to me.

Acked-by: Marco Angaroni <marcoangaroni@gmail.com>

> ---
>  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 7700556..df773d6 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) {
> --
> 2.7.4
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] nf_conntrack_sip: extend request line validation
  2016-10-25  7:07 ` Marco Angaroni
@ 2016-10-27 16:29   ` Pablo Neira Ayuso
  0 siblings, 0 replies; 3+ messages in thread
From: Pablo Neira Ayuso @ 2016-10-27 16:29 UTC (permalink / raw)
  To: Marco Angaroni; +Cc: Ulrich Weber, netfilter-devel, kaber

On Tue, Oct 25, 2016 at 09:07:23AM +0200, Marco Angaroni wrote:
> Hello,
> 
> 2016-10-24 18:07 GMT+02:00 Ulrich Weber <ulrich.weber@riverbed.com>:
> > 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
> >
> > Signed-off-by: Ulrich Weber <ulrich.weber@riverbed.com>
> 
> Looks ok to me.
> 
> Acked-by: Marco Angaroni <marcoangaroni@gmail.com>

Applied, thanks!

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2016-10-27 16:29 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2016-10-24 16:07 [PATCH v2] nf_conntrack_sip: extend request line validation Ulrich Weber
2016-10-25  7:07 ` Marco Angaroni
2016-10-27 16:29   ` Pablo Neira Ayuso

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