File 0023-ospfd-protect-call-to-get_edge-in-ospf_te.c.patch of Package frr.35334

From cef38442420aeac8e163f8aa55f1b985908f993c Mon Sep 17 00:00:00 2001
From: Olivier Dugeon <olivier.dugeon@orange.com>
Date: Tue, 16 Apr 2024 16:42:06 +0200
Upstream: yes
References: CVE-2024-34088,bsc#1223786,gh#FRRouting/frr#16088
Subject: [PATCH 3/3] ospfd: protect call to get_edge() in ospf_te.c

During fuzzing, Iggy Frankovic discovered that get_edge() function in ospf_te.c
could return null pointer, in particular when the link_id or advertised router
IP addresses are fuzzed. As the null pointer returned by get_edge() function is
not handlei by calling functions, this could cause ospfd crash.

This patch introduces new verification of returned pointer by get_edge()
function and stop the processing in case of null pointer. In addition, link ID
and advertiser router ID are validated before calling ls_find_edge_by_key() to
avoid the creation of a new edge with an invalid key.

CVE-2024-34088

Co-authored-by: Iggy Frankovic <iggyfran@amazon.com>
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
(cherry picked from commit 8c177d69e32b91b45bda5fc5da6511fa03dc11ca)
---
 ospfd/ospf_te.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/ospfd/ospf_te.c b/ospfd/ospf_te.c
index 23a1b181ec..d1f114e30a 100644
--- a/ospfd/ospf_te.c
+++ b/ospfd/ospf_te.c
@@ -1686,6 +1686,11 @@ static struct ls_edge *get_edge(struct ls_ted *ted, struct ls_node_id adv,
 	struct ls_edge *edge;
 	struct ls_attributes *attr;
 
+	/* Check that Link ID and Node ID are valid */
+	if (IPV4_NET0(link_id.s_addr) || IPV4_NET0(adv.id.ip.addr.s_addr) ||
+	    adv.origin != OSPFv2)
+		return NULL;
+
 	/* Search Edge that corresponds to the Link ID */
 	key = ((uint64_t)ntohl(link_id.s_addr)) & 0xffffffff;
 	edge = ls_find_edge_by_key(ted, key);
@@ -1758,6 +1763,10 @@ static void ospf_te_update_link(struct ls_ted *ted, struct ls_vertex *vertex,
 
 	/* Get Corresponding Edge from Link State Data Base */
 	edge = get_edge(ted, vertex->node->adv, link_data);
+	if (!edge) {
+		ote_debug("  |- Found no edge from Link Data. Abort!");
+		return;
+	}
 	attr = edge->attributes;
 
 	/* re-attached edge to vertex if needed */
@@ -2276,11 +2285,11 @@ static int ospf_te_parse_te(struct ls_ted *ted, struct ospf_lsa *lsa)
 	}
 
 	/* Get corresponding Edge from Link State Data Base */
-	if (IPV4_NET0(attr.standard.local.s_addr) && !attr.standard.local_id) {
-		ote_debug("  |- Found no TE Link local address/ID. Abort!");
+	edge = get_edge(ted, attr.adv, attr.standard.local);
+	if (!edge) {
+		ote_debug("  |- Found no edge from Link local add./ID. Abort!");
 		return -1;
 	}
-	edge = get_edge(ted, attr.adv, attr.standard.local);
 	old = edge->attributes;
 
 	ote_debug("  |- Process Traffic Engineering LSA %pI4 for Edge %pI4",
@@ -2786,6 +2795,10 @@ static int ospf_te_parse_ext_link(struct ls_ted *ted, struct ospf_lsa *lsa)
 	lnid.id.ip.area_id = lsa->area->area_id;
 	ext = (struct ext_tlv_link *)TLV_HDR_TOP(lsa->data);
 	edge = get_edge(ted, lnid, ext->link_data);
+	if (!edge) {
+		ote_debug("  |- Found no edge from Extended Link Data. Abort!");
+		return -1;
+	}
 	atr = edge->attributes;
 
 	ote_debug("  |- Process Extended Link LSA %pI4 for edge %pI4",
-- 
2.35.3