From e17df688f7064dae1417ce425dd1e4b71d24d63b Mon Sep 17 00:00:00 2001
From: Patrick McHardy <kaber@trash.net>
Date: Tue, 2 May 2006 23:23:07 +0200
Subject: [PATCH] [NETFILTER] SCTP conntrack: fix infinite loop
fix infinite loop in the SCTP-netfilter code: check SCTP chunk size to
guarantee progress of for_each_sctp_chunk(). (all other uses of
for_each_sctp_chunk() are preceded by do_basic_checks(), so this fix
should be complete.)
Based on patch from Ingo Molnar <mingo@elte.hu>
CVE-2006-1527
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
net/ipv4/netfilter/ip_conntrack_proto_sctp.c | 11 +++++++----
net/netfilter/nf_conntrack_proto_sctp.c | 11 +++++++----
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
index 5259abd0fb42..0416073c5600 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
@@ -235,12 +235,15 @@ static int do_basic_checks(struct ip_conntrack *conntrack,
flag = 1;
}
- /* Cookie Ack/Echo chunks not the first OR
- Init / Init Ack / Shutdown compl chunks not the only chunks */
- if ((sch->type == SCTP_CID_COOKIE_ACK
+ /*
+ * Cookie Ack/Echo chunks not the first OR
+ * Init / Init Ack / Shutdown compl chunks not the only chunks
+ * OR zero-length.
+ */
+ if (((sch->type == SCTP_CID_COOKIE_ACK
|| sch->type == SCTP_CID_COOKIE_ECHO
|| flag)
- && count !=0 ) {
+ && count !=0) || !sch->length) {
DEBUGP("Basic checks failed\n");
return 1;
}
diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index 9cccc325b687..0c6da496cfa9 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -240,12 +240,15 @@ static int do_basic_checks(struct nf_conn *conntrack,
flag = 1;
}
- /* Cookie Ack/Echo chunks not the first OR
- Init / Init Ack / Shutdown compl chunks not the only chunks */
- if ((sch->type == SCTP_CID_COOKIE_ACK
+ /*
+ * Cookie Ack/Echo chunks not the first OR
+ * Init / Init Ack / Shutdown compl chunks not the only chunks
+ * OR zero-length.
+ */
+ if (((sch->type == SCTP_CID_COOKIE_ACK
|| sch->type == SCTP_CID_COOKIE_ECHO
|| flag)
- && count !=0 ) {
+ && count !=0) || !sch->length) {
DEBUGP("Basic checks failed\n");
return 1;
}