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)

diff --git a/ospfd/ospf_te.c b/ospfd/ospf_te.c
index 23a1b181ecd11a4b162c9612f4a102070325e586..d1f114e30a6331d6e1128a78d5b4a12fdfaf41e1 100644 (file)
--- 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",