From: Rusty Russell <rusty@rustcorp.com.au>
To: J Troy Piper <jtp@dok.org>
Cc: linux-kernel@vger.kernel.org, Alan Cox <laughing@shared-source.org>
Subject: Re: [Problem] Linux 2.4.5-ac17 ipt_unclean 'fixes'
Date: Mon, 16 Jul 2001 20:28:45 +1000 [thread overview]
Message-ID: <m15M5cN-000CK9C@localhost> (raw)
In-Reply-To: Your message of "Sat, 14 Jul 2001 17:00:21 EST." <20010714170021.B1391@dok.org>
In message <20010714170021.B1391@dok.org> you write:
> today) but there seems to be a problem with the ipt_unclean fixes by Rusty
> Russell. ANY incoming packets from any interface (ppp0 and eth0) are
> marked as 'unclean' with some variation on the following syslog entry:
>
> Jul 8 23:16:04 paranoia kernel: ipt_unclean: TCP option 3 at 37 too long
Please try this patch which fixes this as well, which is in Linus'
pre-patches.
Rusty.
--
Premature optmztion is rt of all evl. --DK
diff -urN linux-2.4.6/net/ipv4/netfilter/ipt_unclean.c linux-2.4.6-f1/net/ipv4/netfilter/ipt_unclean.c
--- linux-2.4.6/net/ipv4/netfilter/ipt_unclean.c Wed Jul 4 21:27:32 2001
+++ linux-2.4.6-f1/net/ipv4/netfilter/ipt_unclean.c Thu Jul 5 19:16:00 2001
@@ -268,6 +268,7 @@
int embedded)
{
u_int8_t *opt = (u_int8_t *)tcph;
+ u_int8_t *endhdr = (u_int8_t *)tcph + tcph->doff * 4;
u_int8_t tcpflags;
int end_of_options = 0;
size_t i;
@@ -373,7 +374,7 @@
return 0;
}
/* CHECK: oversize options. */
- else if (opt[i+1] + i >= tcph->doff * 4) {
+ else if (&opt[i] + opt[i+1] > endhdr) {
limpk("TCP option %u at %Zu too long\n",
(unsigned int) opt[i], i);
return 0;
@@ -392,6 +393,7 @@
check_ip(struct iphdr *iph, size_t length, int embedded)
{
u_int8_t *opt = (u_int8_t *)iph;
+ u_int8_t *endhdr = (u_int8_t *)iph + iph->ihl * 4;
int end_of_options = 0;
void *protoh;
size_t datalen;
@@ -444,7 +446,7 @@
return 0;
}
/* CHECK: oversize options. */
- else if (opt[i+1] + i > iph->ihl * 4) {
+ else if (&opt[i] + opt[i+1] > endhdr) {
limpk("IP option %u at %u too long\n",
opt[i], i);
return 0;
next prev parent reply other threads:[~2001-07-16 12:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-07-14 22:00 [Problem] Linux 2.4.5-ac17 ipt_unclean 'fixes' J Troy Piper
2001-07-14 22:50 ` Josh McKinney
2001-07-16 10:28 ` Rusty Russell [this message]
2001-07-16 22:09 ` J Troy Piper
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