[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>
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
index 5259abd..0416073 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
@@ -235,12 +235,15 @@
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 9cccc32..0c6da49 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -240,12 +240,15 @@
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;
}